-*- buffer-read-only: t -*- !!!!!!! DO NOT EDIT THIS FILE !!!!!!! This file is built by ..\autodoc.pl extracting documentation from the C source files. Any changes made here will be lost! =head1 NAME perlapi - autogenerated documentation for the perl public API =head1 DESCRIPTION X X X This file contains the documentation of the perl public API generated by F, specifically a listing of functions, macros, flags, and variables that may be used by extension writers. L is a list of functions which have yet to be documented. The interfaces of those are subject to change without notice. Anything not listed here is not part of the public API, and should not be used by extension writers at all. For these reasons, blindly using functions listed in proto.h is to be avoided when writing extensions. In Perl, unlike C, a string of characters may generally contain embedded C characters. Sometimes in the documentation a Perl string is referred to as a "buffer" to distinguish it from a C string, but sometimes they are both just referred to as strings. Note that all Perl API global variables must be referenced with the C prefix. Again, those not listed here are not to be used by extension writers, and can be changed or removed without notice; same with macros. Some macros are provided for compatibility with the older, unadorned names, but this support may be disabled in a future release. Perl was originally written to handle US-ASCII only (that is characters whose ordinal numbers are in the range 0 - 127). And documentation and comments may still use the term ASCII, when sometimes in fact the entire range from 0 - 255 is meant. The non-ASCII characters below 256 can have various meanings, depending on various things. (See, most notably, L.) But usually the whole range can be referred to as ISO-8859-1. Often, the term "Latin-1" (or "Latin1") is used as an equivalent for ISO-8859-1. But some people treat "Latin1" as referring just to the characters in the range 128 through 255, or somethimes from 160 through 255. This documentation uses "Latin1" and "Latin-1" to refer to all 256 characters. Note that Perl can be compiled and run under either ASCII or EBCDIC (See L). Most of the documentation (and even comments in the code) ignore the EBCDIC possibility. For almost all purposes the differences are transparent. As an example, under EBCDIC, instead of UTF-8, UTF-EBCDIC is used to encode Unicode strings, and so whenever this documentation refers to C (and variants of that name, including in function names), it also (essentially transparently) means C. But the ordinals of characters differ between ASCII, EBCDIC, and the UTF- encodings, and a string encoded in UTF-EBCDIC may occupy a different number of bytes than in UTF-8. The listing below is alphabetical, case insensitive. =head1 Array Manipulation Functions =over 8 =item av_clear X Frees the all the elements of an array, leaving it empty. The XS equivalent of C<@array = ()>. See also L. Note that it is possible that the actions of a destructor called directly or indirectly by freeing an element of the array could cause the reference count of the array itself to be reduced (e.g. by deleting an entry in the symbol table). So it is a possibility that the AV could have been freed (or even reallocated) on return from the call unless you hold a reference to it. void av_clear(AV *av) =for hackers Found in file av.c =item av_create_and_push X NOTE: this function is experimental and may change or be removed without notice. Push an SV onto the end of the array, creating the array if necessary. A small internal helper function to remove a commonly duplicated idiom. void av_create_and_push(AV **const avp, SV *const val) =for hackers Found in file av.c =item av_create_and_unshift_one X NOTE: this function is experimental and may change or be removed without notice. Unshifts an SV onto the beginning of the array, creating the array if necessary. A small internal helper function to remove a commonly duplicated idiom. SV** av_create_and_unshift_one(AV **const avp, SV *const val) =for hackers Found in file av.c =item av_delete X Deletes the element indexed by C from the array, makes the element mortal, and returns it. If C equals C, the element is freed and null is returned. Perl equivalent: S> for the non-C version and a void-context S> for the C version. SV* av_delete(AV *av, SSize_t key, I32 flags) =for hackers Found in file av.c =item av_exists X Returns true if the element indexed by C has been initialized. This relies on the fact that uninitialized array elements are set to C. Perl equivalent: C. bool av_exists(AV *av, SSize_t key) =for hackers Found in file av.c =item av_extend X Pre-extend an array. The C is the index to which the array should be extended. void av_extend(AV *av, SSize_t key) =for hackers Found in file av.c =item av_fetch X Returns the SV at the specified index in the array. The C is the index. If lval is true, you are guaranteed to get a real SV back (in case it wasn't real before), which you can then modify. Check that the return value is non-null before dereferencing it to a C. See L for more information on how to use this function on tied arrays. The rough perl equivalent is C<$myarray[$idx]>. SV** av_fetch(AV *av, SSize_t key, I32 lval) =for hackers Found in file av.c =item AvFILL X Same as C. Deprecated, use C instead. int AvFILL(AV* av) =for hackers Found in file av.h =item av_fill X Set the highest index in the array to the given number, equivalent to Perl's S>. The number of elements in the array will be S> after C returns. If the array was previously shorter, then the additional elements appended are set to NULL. If the array was longer, then the excess elements are freed. S> is the same as C. void av_fill(AV *av, SSize_t fill) =for hackers Found in file av.c =item av_len X Same as L. Note that, unlike what the name implies, it returns the highest index in the array, so to get the size of the array you need to use S>. This is unlike L, which returns what you would expect. SSize_t av_len(AV *av) =for hackers Found in file av.c =item av_make X Creates a new AV and populates it with a list of SVs. The SVs are copied into the array, so they may be freed after the call to C. The new AV will have a reference count of 1. Perl equivalent: C AV* av_make(SSize_t size, SV **strp) =for hackers Found in file av.c =item av_pop X Removes one SV from the end of the array, reducing its size by one and returning the SV (transferring control of one reference count) to the caller. Returns C<&PL_sv_undef> if the array is empty. Perl equivalent: C SV* av_pop(AV *av) =for hackers Found in file av.c =item av_push X Pushes an SV (transferring control of one reference count) onto the end of the array. The array will grow automatically to accommodate the addition. Perl equivalent: C. void av_push(AV *av, SV *val) =for hackers Found in file av.c =item av_shift X Removes one SV from the start of the array, reducing its size by one and returning the SV (transferring control of one reference count) to the caller. Returns C<&PL_sv_undef> if the array is empty. Perl equivalent: C SV* av_shift(AV *av) =for hackers Found in file av.c =item av_store X Stores an SV in an array. The array index is specified as C. The return value will be C if the operation failed or if the value did not need to be actually stored within the array (as in the case of tied arrays). Otherwise, it can be dereferenced to get the C that was stored there (= C)). Note that the caller is responsible for suitably incrementing the reference count of C before the call, and decrementing it if the function returned C. Approximate Perl equivalent: C<$myarray[$key] = $val;>. See L for more information on how to use this function on tied arrays. SV** av_store(AV *av, SSize_t key, SV *val) =for hackers Found in file av.c =item av_tindex X Same as C. int av_tindex(AV* av) =for hackers Found in file av.h =item av_top_index X Returns the highest index in the array. The number of elements in the array is S>. Returns -1 if the array is empty. The Perl equivalent for this is C<$#myarray>. (A slightly shorter form is C.) SSize_t av_top_index(AV *av) =for hackers Found in file av.c =item av_undef X Undefines the array. The XS equivalent of C. As well as freeing all the elements of the array (like C), this also frees the memory used by the av to store its list of scalars. See L for a note about the array possibly being invalid on return. void av_undef(AV *av) =for hackers Found in file av.c =item av_unshift X Unshift the given number of C values onto the beginning of the array. The array will grow automatically to accommodate the addition. You must then use C to assign values to these new elements. Perl equivalent: S> void av_unshift(AV *av, SSize_t num) =for hackers Found in file av.c =item get_av X Returns the AV of the specified Perl global or package array with the given name (so it won't work on lexical variables). C are passed to C. If C is set and the Perl variable does not exist then it will be created. If C is zero and the variable does not exist then NULL is returned. Perl equivalent: C<@{"$name"}>. NOTE: the perl_ form of this function is deprecated. AV* get_av(const char *name, I32 flags) =for hackers Found in file perl.c =item newAV X Creates a new AV. The reference count is set to 1. Perl equivalent: C. AV* newAV() =for hackers Found in file av.h =item sortsv X Sort an array. Here is an example: sortsv(AvARRAY(av), av_top_index(av)+1, Perl_sv_cmp_locale); Currently this always uses mergesort. See C> for a more flexible routine. void sortsv(SV** array, size_t num_elts, SVCOMPARE_t cmp) =for hackers Found in file pp_sort.c =item sortsv_flags X Sort an array, with various options. void sortsv_flags(SV** array, size_t num_elts, SVCOMPARE_t cmp, U32 flags) =for hackers Found in file pp_sort.c =back =head1 Callback Functions =over 8 =item call_argv X Performs a callback to the specified named and package-scoped Perl subroutine with C (a C-terminated array of strings) as arguments. See L. Approximate Perl equivalent: C<&{"$sub_name"}(@$argv)>. NOTE: the perl_ form of this function is deprecated. I32 call_argv(const char* sub_name, I32 flags, char** argv) =for hackers Found in file perl.c =item call_method X Performs a callback to the specified Perl method. The blessed object must be on the stack. See L. NOTE: the perl_ form of this function is deprecated. I32 call_method(const char* methname, I32 flags) =for hackers Found in file perl.c =item call_pv X Performs a callback to the specified Perl sub. See L. NOTE: the perl_ form of this function is deprecated. I32 call_pv(const char* sub_name, I32 flags) =for hackers Found in file perl.c =item call_sv X Performs a callback to the Perl sub specified by the SV. If neither the C nor C flag is supplied, the SV may be any of a CV, a GV, a reference to a CV, a reference to a GV or C will be used as the name of the sub to call. If the C flag is supplied, the SV may be a reference to a CV or C will be used as the name of the method to call. If the C flag is supplied, C will be used as the name of the method to call. Some other values are treated specially for internal use and should not be depended on. See L. NOTE: the perl_ form of this function is deprecated. I32 call_sv(SV* sv, VOL I32 flags) =for hackers Found in file perl.c =item ENTER X Opening bracket on a callback. See C> and L. ENTER; =for hackers Found in file scope.h =item eval_pv X Tells Perl to C the given string in scalar context and return an SV* result. NOTE: the perl_ form of this function is deprecated. SV* eval_pv(const char* p, I32 croak_on_error) =for hackers Found in file perl.c =item eval_sv X Tells Perl to C the string in the SV. It supports the same flags as C, with the obvious exception of C. See L. NOTE: the perl_ form of this function is deprecated. I32 eval_sv(SV* sv, I32 flags) =for hackers Found in file perl.c =item FREETMPS X Closing bracket for temporaries on a callback. See C> and L. FREETMPS; =for hackers Found in file scope.h =item LEAVE X Closing bracket on a callback. See C> and L. LEAVE; =for hackers Found in file scope.h =item SAVETMPS X Opening bracket for temporaries on a callback. See C> and L. SAVETMPS; =for hackers Found in file scope.h =back =head1 Character case changing =over 8 =item toFOLD X Converts the specified character to foldcase. If the input is anything but an ASCII uppercase character, that input character itself is returned. Variant C is equivalent. (There is no equivalent C for the full Latin1 range, as the full generality of L is needed there.) U8 toFOLD(U8 ch) =for hackers Found in file handy.h =item toFOLD_utf8 X Converts the UTF-8 encoded character at C

to its foldcase version, and stores that in UTF-8 in C, and its length in bytes in C. Note that the buffer pointed to by C needs to be at least C bytes since the foldcase version may be longer than the original character. The first code point of the foldcased version is returned (but note, as explained just above, that there may be more.) The input character at C

is assumed to be well-formed. UV toFOLD_utf8(U8* p, U8* s, STRLEN* lenp) =for hackers Found in file handy.h =item toFOLD_uvchr X Converts the code point C to its foldcase version, and stores that in UTF-8 in C, and its length in bytes in C. The code point is interpreted as native if less than 256; otherwise as Unicode. Note that the buffer pointed to by C needs to be at least C bytes since the foldcase version may be longer than the original character. The first code point of the foldcased version is returned (but note, as explained just above, that there may be more.) UV toFOLD_uvchr(UV cp, U8* s, STRLEN* lenp) =for hackers Found in file handy.h =item toLOWER X Converts the specified character to lowercase. If the input is anything but an ASCII uppercase character, that input character itself is returned. Variant C is equivalent. U8 toLOWER(U8 ch) =for hackers Found in file handy.h =item toLOWER_L1 X Converts the specified Latin1 character to lowercase. The results are undefined if the input doesn't fit in a byte. U8 toLOWER_L1(U8 ch) =for hackers Found in file handy.h =item toLOWER_LC X Converts the specified character to lowercase using the current locale's rules, if possible; otherwise returns the input character itself. U8 toLOWER_LC(U8 ch) =for hackers Found in file handy.h =item toLOWER_utf8 X Converts the UTF-8 encoded character at C

to its lowercase version, and stores that in UTF-8 in C, and its length in bytes in C. Note that the buffer pointed to by C needs to be at least C bytes since the lowercase version may be longer than the original character. The first code point of the lowercased version is returned (but note, as explained just above, that there may be more.) The input character at C

is assumed to be well-formed. UV toLOWER_utf8(U8* p, U8* s, STRLEN* lenp) =for hackers Found in file handy.h =item toLOWER_uvchr X Converts the code point C to its lowercase version, and stores that in UTF-8 in C, and its length in bytes in C. The code point is interpreted as native if less than 256; otherwise as Unicode. Note that the buffer pointed to by C needs to be at least C bytes since the lowercase version may be longer than the original character. The first code point of the lowercased version is returned (but note, as explained just above, that there may be more.) UV toLOWER_uvchr(UV cp, U8* s, STRLEN* lenp) =for hackers Found in file handy.h =item toTITLE X Converts the specified character to titlecase. If the input is anything but an ASCII lowercase character, that input character itself is returned. Variant C is equivalent. (There is no C for the full Latin1 range, as the full generality of L is needed there. Titlecase is not a concept used in locale handling, so there is no functionality for that.) U8 toTITLE(U8 ch) =for hackers Found in file handy.h =item toTITLE_utf8 X Converts the UTF-8 encoded character at C

to its titlecase version, and stores that in UTF-8 in C, and its length in bytes in C. Note that the buffer pointed to by C needs to be at least C bytes since the titlecase version may be longer than the original character. The first code point of the titlecased version is returned (but note, as explained just above, that there may be more.) The input character at C

is assumed to be well-formed. UV toTITLE_utf8(U8* p, U8* s, STRLEN* lenp) =for hackers Found in file handy.h =item toTITLE_uvchr X Converts the code point C to its titlecase version, and stores that in UTF-8 in C, and its length in bytes in C. The code point is interpreted as native if less than 256; otherwise as Unicode. Note that the buffer pointed to by C needs to be at least C bytes since the titlecase version may be longer than the original character. The first code point of the titlecased version is returned (but note, as explained just above, that there may be more.) UV toTITLE_uvchr(UV cp, U8* s, STRLEN* lenp) =for hackers Found in file handy.h =item toUPPER X Converts the specified character to uppercase. If the input is anything but an ASCII lowercase character, that input character itself is returned. Variant C is equivalent. U8 toUPPER(U8 ch) =for hackers Found in file handy.h =item toUPPER_utf8 X Converts the UTF-8 encoded character at C

to its uppercase version, and stores that in UTF-8 in C, and its length in bytes in C. Note that the buffer pointed to by C needs to be at least C bytes since the uppercase version may be longer than the original character. The first code point of the uppercased version is returned (but note, as explained just above, that there may be more.) The input character at C

is assumed to be well-formed. UV toUPPER_utf8(U8* p, U8* s, STRLEN* lenp) =for hackers Found in file handy.h =item toUPPER_uvchr X Converts the code point C to its uppercase version, and stores that in UTF-8 in C, and its length in bytes in C. The code point is interpreted as native if less than 256; otherwise as Unicode. Note that the buffer pointed to by C needs to be at least C bytes since the uppercase version may be longer than the original character. The first code point of the uppercased version is returned (but note, as explained just above, that there may be more.) UV toUPPER_uvchr(UV cp, U8* s, STRLEN* lenp) =for hackers Found in file handy.h =back =head1 Character classification This section is about functions (really macros) that classify characters into types, such as punctuation versus alphabetic, etc. Most of these are analogous to regular expression character classes. (See L.) There are several variants for each class. (Not all macros have all variants; each item below lists the ones valid for it.) None are affected by C, and only the ones with C in the name are affected by the current locale. The base function, e.g., C, takes an octet (either a C or a C) as input and returns a boolean as to whether or not the character represented by that octet is (or on non-ASCII platforms, corresponds to) an ASCII character in the named class based on platform, Unicode, and Perl rules. If the input is a number that doesn't fit in an octet, FALSE is returned. Variant C (e.g., C) is identical to the base function with no suffix C<"_A">. Variant C imposes the Latin-1 (or EBCDIC equivlalent) character set onto the platform. That is, the code points that are ASCII are unaffected, since ASCII is a subset of Latin-1. But the non-ASCII code points are treated as if they are Latin-1 characters. For example, C will return true when called with the code point 0xDF, which is a word character in both ASCII and EBCDIC (though it represents different characters in each). Variant C is like the C variant, but accepts any UV code point as input. If the code point is larger than 255, Unicode rules are used to determine if it is in the character class. For example, C returns TRUE, since 0x100 is LATIN CAPITAL LETTER A WITH MACRON in Unicode, and is a word character. Variant C is like C, but the input is a pointer to a (known to be well-formed) UTF-8 encoded string (C or C, and possibly containing embedded C characters). The classification of just the first (possibly multi-byte) character in the string is tested. Variant C is like the C and C variants, but the result is based on the current locale, which is what C in the name stands for. If Perl can determine that the current locale is a UTF-8 locale, it uses the published Unicode rules; otherwise, it uses the C library function that gives the named classification. For example, C when not in a UTF-8 locale returns the result of calling C. FALSE is always returned if the input won't fit into an octet. On some platforms where the C library function is known to be defective, Perl changes its result to follow the POSIX standard's rules. Variant C is like C, but is defined on any UV. It returns the same as C for input code points less than 256, and returns the hard-coded, not-affected-by-locale, Unicode results for larger ones. Variant C is like C, but the input is a pointer to a (known to be well-formed) UTF-8 encoded string (C or C, and possibly containing embedded C characters). The classification of just the first (possibly multi-byte) character in the string is tested. =over 8 =item isALPHA X Returns a boolean indicating whether the specified character is an alphabetic character, analogous to C. See the L for an explanation of variants C, C, C, C, C, C, and C. bool isALPHA(char ch) =for hackers Found in file handy.h =item isALPHANUMERIC X Returns a boolean indicating whether the specified character is a either an alphabetic character or decimal digit, analogous to C. See the L for an explanation of variants C, C, C, C, C, C, and C. bool isALPHANUMERIC(char ch) =for hackers Found in file handy.h =item isASCII X Returns a boolean indicating whether the specified character is one of the 128 characters in the ASCII character set, analogous to C. On non-ASCII platforms, it returns TRUE iff this character corresponds to an ASCII character. Variants C and C are identical to C. See the L for an explanation of variants C, C, C, C, and C. Note, however, that some platforms do not have the C library routine C. In these cases, the variants whose names contain C are the same as the corresponding ones without. Also note, that because all ASCII characters are UTF-8 invariant (meaning they have the exact same representation (always a single byte) whether encoded in UTF-8 or not), C will give the correct results when called with any byte in any string encoded or not in UTF-8. And similarly C will work properly on any string encoded or not in UTF-8. bool isASCII(char ch) =for hackers Found in file handy.h =item isBLANK X Returns a boolean indicating whether the specified character is a character considered to be a blank, analogous to C. See the L for an explanation of variants C, C, C, C, C, C, and C. Note, however, that some platforms do not have the C library routine C. In these cases, the variants whose names contain C are the same as the corresponding ones without. bool isBLANK(char ch) =for hackers Found in file handy.h =item isCNTRL X Returns a boolean indicating whether the specified character is a control character, analogous to C. See the L for an explanation of variants C, C, C, C, C, C, and C On EBCDIC platforms, you almost always want to use the C variant. bool isCNTRL(char ch) =for hackers Found in file handy.h =item isDIGIT X Returns a boolean indicating whether the specified character is a digit, analogous to C. Variants C and C are identical to C. See the L for an explanation of variants C, C, C, C, and C. bool isDIGIT(char ch) =for hackers Found in file handy.h =item isGRAPH X Returns a boolean indicating whether the specified character is a graphic character, analogous to C. See the L for an explanation of variants C, C, C, C, C, C, and C. bool isGRAPH(char ch) =for hackers Found in file handy.h =item isIDCONT X Returns a boolean indicating whether the specified character can be the second or succeeding character of an identifier. This is very close to, but not quite the same as the official Unicode property C. The difference is that this returns true only if the input character also matches L. See the L for an explanation of variants C, C, C, C, C, C, and C. bool isIDCONT(char ch) =for hackers Found in file handy.h =item isIDFIRST X Returns a boolean indicating whether the specified character can be the first character of an identifier. This is very close to, but not quite the same as the official Unicode property C. The difference is that this returns true only if the input character also matches L. See the L for an explanation of variants C, C, C, C, C, C, and C. bool isIDFIRST(char ch) =for hackers Found in file handy.h =item isLOWER X Returns a boolean indicating whether the specified character is a lowercase character, analogous to C. See the L for an explanation of variants C, C, C, C, C, C, and C. bool isLOWER(char ch) =for hackers Found in file handy.h =item isOCTAL X Returns a boolean indicating whether the specified character is an octal digit, [0-7]. The only two variants are C and C; each is identical to C. bool isOCTAL(char ch) =for hackers Found in file handy.h =item isPRINT X Returns a boolean indicating whether the specified character is a printable character, analogous to C. See the L for an explanation of variants C, C, C, C, C, C, and C. bool isPRINT(char ch) =for hackers Found in file handy.h =item isPSXSPC X (short for Posix Space) Starting in 5.18, this is identical in all its forms to the corresponding C macros. The locale forms of this macro are identical to their corresponding C forms in all Perl releases. In releases prior to 5.18, the non-locale forms differ from their C forms only in that the C forms don't match a Vertical Tab, and the C forms do. Otherwise they are identical. Thus this macro is analogous to what C matches in a regular expression. See the L for an explanation of variants C, C, C, C, C, C, and C. bool isPSXSPC(char ch) =for hackers Found in file handy.h =item isPUNCT X Returns a boolean indicating whether the specified character is a punctuation character, analogous to C. Note that the definition of what is punctuation isn't as straightforward as one might desire. See L for details. See the L for an explanation of variants C, C, C, C, C, C, and C. bool isPUNCT(char ch) =for hackers Found in file handy.h =item isSPACE X Returns a boolean indicating whether the specified character is a whitespace character. This is analogous to what C matches in a regular expression. Starting in Perl 5.18 this also matches what C does. Prior to 5.18, only the locale forms of this macro (the ones with C in their names) matched precisely what C does. In those releases, the only difference, in the non-locale variants, was that C did not match a vertical tab. (See L for a macro that matches a vertical tab in all releases.) See the L for an explanation of variants C, C, C, C, C, C, and C. bool isSPACE(char ch) =for hackers Found in file handy.h =item isUPPER X Returns a boolean indicating whether the specified character is an uppercase character, analogous to C. See the L for an explanation of variants C, C, C, C, C, C, and C. bool isUPPER(char ch) =for hackers Found in file handy.h =item isWORDCHAR X Returns a boolean indicating whether the specified character is a character that is a word character, analogous to what C and C match in a regular expression. A word character is an alphabetic character, a decimal digit, a connecting punctuation character (such as an underscore), or a "mark" character that attaches to one of those (like some sort of accent). C is a synonym provided for backward compatibility, even though a word character includes more than the standard C language meaning of alphanumeric. See the L for an explanation of variants C, C, C, and C. C, C, and C are also as described there, but additionally include the platform's native underscore. bool isWORDCHAR(char ch) =for hackers Found in file handy.h =item isXDIGIT X Returns a boolean indicating whether the specified character is a hexadecimal digit. In the ASCII range these are C<[0-9A-Fa-f]>. Variants C and C are identical to C. See the L for an explanation of variants C, C, C, C, and C. bool isXDIGIT(char ch) =for hackers Found in file handy.h =back =head1 Cloning an interpreter =over 8 =item perl_clone X Create and return a new interpreter by cloning the current one. C takes these flags as parameters: C - is used to, well, copy the stacks also, without it we only clone the data and zero the stacks, with it we copy the stacks and the new perl interpreter is ready to run at the exact same point as the previous one. The pseudo-fork code uses C while the threads->create doesn't. C - C keeps a ptr_table with the pointer of the old variable as a key and the new variable as a value, this allows it to check if something has been cloned and not clone it again but rather just use the value and increase the refcount. If C is not set then C will kill the ptr_table using the function C, reason to keep it around is if you want to dup some of your own variable who are outside the graph perl scans, an example of this code is in F create. C - This is a win32 thing, it is ignored on unix, it tells perls win32host code (which is c++) to clone itself, this is needed on win32 if you want to run two threads at the same time, if you just want to do some stuff in a separate perl interpreter and then throw it away and return to the original one, you don't need to do anything. PerlInterpreter* perl_clone( PerlInterpreter *proto_perl, UV flags ) =for hackers Found in file sv.c =back =head1 Compile-time scope hooks =over 8 =item BhkDISABLE X NOTE: this function is experimental and may change or be removed without notice. Temporarily disable an entry in this BHK structure, by clearing the appropriate flag. C is a preprocessor token indicating which entry to disable. void BhkDISABLE(BHK *hk, which) =for hackers Found in file op.h =item BhkENABLE X NOTE: this function is experimental and may change or be removed without notice. Re-enable an entry in this BHK structure, by setting the appropriate flag. C is a preprocessor token indicating which entry to enable. This will assert (under -DDEBUGGING) if the entry doesn't contain a valid pointer. void BhkENABLE(BHK *hk, which) =for hackers Found in file op.h =item BhkENTRY_set X NOTE: this function is experimental and may change or be removed without notice. Set an entry in the BHK structure, and set the flags to indicate it is valid. C is a preprocessing token indicating which entry to set. The type of C depends on the entry. void BhkENTRY_set(BHK *hk, which, void *ptr) =for hackers Found in file op.h =item blockhook_register X NOTE: this function is experimental and may change or be removed without notice. Register a set of hooks to be called when the Perl lexical scope changes at compile time. See L. NOTE: this function must be explicitly called as Perl_blockhook_register with an aTHX_ parameter. void Perl_blockhook_register(pTHX_ BHK *hk) =for hackers Found in file op.c =back =head1 COP Hint Hashes =over 8 =item cophh_2hv X NOTE: this function is experimental and may change or be removed without notice. Generates and returns a standard Perl hash representing the full set of key/value pairs in the cop hints hash C. C is currently unused and must be zero. HV * cophh_2hv(const COPHH *cophh, U32 flags) =for hackers Found in file cop.h =item cophh_copy X NOTE: this function is experimental and may change or be removed without notice. Make and return a complete copy of the cop hints hash C. COPHH * cophh_copy(COPHH *cophh) =for hackers Found in file cop.h =item cophh_delete_pv X NOTE: this function is experimental and may change or be removed without notice. Like L, but takes a nul-terminated string instead of a string/length pair. COPHH * cophh_delete_pv(const COPHH *cophh, const char *key, U32 hash, U32 flags) =for hackers Found in file cop.h =item cophh_delete_pvn X NOTE: this function is experimental and may change or be removed without notice. Delete a key and its associated value from the cop hints hash C, and returns the modified hash. The returned hash pointer is in general not the same as the hash pointer that was passed in. The input hash is consumed by the function, and the pointer to it must not be subsequently used. Use L if you need both hashes. The key is specified by C and C. If C has the C bit set, the key octets are interpreted as UTF-8, otherwise they are interpreted as Latin-1. C is a precomputed hash of the key string, or zero if it has not been precomputed. COPHH * cophh_delete_pvn(COPHH *cophh, const char *keypv, STRLEN keylen, U32 hash, U32 flags) =for hackers Found in file cop.h =item cophh_delete_pvs X NOTE: this function is experimental and may change or be removed without notice. Like L, but takes a C-terminated literal string instead of a string/length pair, and no precomputed hash. COPHH * cophh_delete_pvs(const COPHH *cophh, const char *key, U32 flags) =for hackers Found in file cop.h =item cophh_delete_sv X NOTE: this function is experimental and may change or be removed without notice. Like L, but takes a Perl scalar instead of a string/length pair. COPHH * cophh_delete_sv(const COPHH *cophh, SV *key, U32 hash, U32 flags) =for hackers Found in file cop.h =item cophh_fetch_pv X NOTE: this function is experimental and may change or be removed without notice. Like L, but takes a nul-terminated string instead of a string/length pair. SV * cophh_fetch_pv(const COPHH *cophh, const char *key, U32 hash, U32 flags) =for hackers Found in file cop.h =item cophh_fetch_pvn X NOTE: this function is experimental and may change or be removed without notice. Look up the entry in the cop hints hash C with the key specified by C and C. If C has the C bit set, the key octets are interpreted as UTF-8, otherwise they are interpreted as Latin-1. C is a precomputed hash of the key string, or zero if it has not been precomputed. Returns a mortal scalar copy of the value associated with the key, or C<&PL_sv_placeholder> if there is no value associated with the key. SV * cophh_fetch_pvn(const COPHH *cophh, const char *keypv, STRLEN keylen, U32 hash, U32 flags) =for hackers Found in file cop.h =item cophh_fetch_pvs X NOTE: this function is experimental and may change or be removed without notice. Like L, but takes a C-terminated literal string instead of a string/length pair, and no precomputed hash. SV * cophh_fetch_pvs(const COPHH *cophh, const char *key, U32 flags) =for hackers Found in file cop.h =item cophh_fetch_sv X NOTE: this function is experimental and may change or be removed without notice. Like L, but takes a Perl scalar instead of a string/length pair. SV * cophh_fetch_sv(const COPHH *cophh, SV *key, U32 hash, U32 flags) =for hackers Found in file cop.h =item cophh_free X NOTE: this function is experimental and may change or be removed without notice. Discard the cop hints hash C, freeing all resources associated with it. void cophh_free(COPHH *cophh) =for hackers Found in file cop.h =item cophh_new_empty X NOTE: this function is experimental and may change or be removed without notice. Generate and return a fresh cop hints hash containing no entries. COPHH * cophh_new_empty() =for hackers Found in file cop.h =item cophh_store_pv X NOTE: this function is experimental and may change or be removed without notice. Like L, but takes a nul-terminated string instead of a string/length pair. COPHH * cophh_store_pv(const COPHH *cophh, const char *key, U32 hash, SV *value, U32 flags) =for hackers Found in file cop.h =item cophh_store_pvn X NOTE: this function is experimental and may change or be removed without notice. Stores a value, associated with a key, in the cop hints hash C, and returns the modified hash. The returned hash pointer is in general not the same as the hash pointer that was passed in. The input hash is consumed by the function, and the pointer to it must not be subsequently used. Use L if you need both hashes. The key is specified by C and C. If C has the C bit set, the key octets are interpreted as UTF-8, otherwise they are interpreted as Latin-1. C is a precomputed hash of the key string, or zero if it has not been precomputed. C is the scalar value to store for this key. C is copied by this function, which thus does not take ownership of any reference to it, and later changes to the scalar will not be reflected in the value visible in the cop hints hash. Complex types of scalar will not be stored with referential integrity, but will be coerced to strings. COPHH * cophh_store_pvn(COPHH *cophh, const char *keypv, STRLEN keylen, U32 hash, SV *value, U32 flags) =for hackers Found in file cop.h =item cophh_store_pvs X NOTE: this function is experimental and may change or be removed without notice. Like L, but takes a C-terminated literal string instead of a string/length pair, and no precomputed hash. COPHH * cophh_store_pvs(const COPHH *cophh, const char *key, SV *value, U32 flags) =for hackers Found in file cop.h =item cophh_store_sv X NOTE: this function is experimental and may change or be removed without notice. Like L, but takes a Perl scalar instead of a string/length pair. COPHH * cophh_store_sv(const COPHH *cophh, SV *key, U32 hash, SV *value, U32 flags) =for hackers Found in file cop.h =back =head1 COP Hint Reading =over 8 =item cop_hints_2hv X Generates and returns a standard Perl hash representing the full set of hint entries in the cop C. C is currently unused and must be zero. HV * cop_hints_2hv(const COP *cop, U32 flags) =for hackers Found in file cop.h =item cop_hints_fetch_pv X Like L, but takes a nul-terminated string instead of a string/length pair. SV * cop_hints_fetch_pv(const COP *cop, const char *key, U32 hash, U32 flags) =for hackers Found in file cop.h =item cop_hints_fetch_pvn X Look up the hint entry in the cop C with the key specified by C and C. If C has the C bit set, the key octets are interpreted as UTF-8, otherwise they are interpreted as Latin-1. C is a precomputed hash of the key string, or zero if it has not been precomputed. Returns a mortal scalar copy of the value associated with the key, or C<&PL_sv_placeholder> if there is no value associated with the key. SV * cop_hints_fetch_pvn(const COP *cop, const char *keypv, STRLEN keylen, U32 hash, U32 flags) =for hackers Found in file cop.h =item cop_hints_fetch_pvs X Like L, but takes a C-terminated literal string instead of a string/length pair, and no precomputed hash. SV * cop_hints_fetch_pvs(const COP *cop, const char *key, U32 flags) =for hackers Found in file cop.h =item cop_hints_fetch_sv X Like L, but takes a Perl scalar instead of a string/length pair. SV * cop_hints_fetch_sv(const COP *cop, SV *key, U32 hash, U32 flags) =for hackers Found in file cop.h =back =head1 Custom Operators =over 8 =item custom_op_register X Register a custom op. See L. NOTE: this function must be explicitly called as Perl_custom_op_register with an aTHX_ parameter. void Perl_custom_op_register(pTHX_ Perl_ppaddr_t ppaddr, const XOP *xop) =for hackers Found in file op.c =item custom_op_xop X Return the XOP structure for a given custom op. This macro should be considered internal to C and the other access macros: use them instead. This macro does call a function. Prior to 5.19.6, this was implemented as a function. NOTE: this function must be explicitly called as Perl_custom_op_xop with an aTHX_ parameter. const XOP * Perl_custom_op_xop(pTHX_ const OP *o) =for hackers Found in file op.c =item XopDISABLE X Temporarily disable a member of the XOP, by clearing the appropriate flag. void XopDISABLE(XOP *xop, which) =for hackers Found in file op.h =item XopENABLE X Reenable a member of the XOP which has been disabled. void XopENABLE(XOP *xop, which) =for hackers Found in file op.h =item XopENTRY X Return a member of the XOP structure. C is a cpp token indicating which entry to return. If the member is not set this will return a default value. The return type depends on C. This macro evaluates its arguments more than once. If you are using C to retreive a C from a C, use the more efficient L instead. XopENTRY(XOP *xop, which) =for hackers Found in file op.h =item XopENTRYCUSTOM X Exactly like C but more efficient. The C parameter is identical to L. XopENTRYCUSTOM(const OP *o, which) =for hackers Found in file op.h =item XopENTRY_set X Set a member of the XOP structure. C is a cpp token indicating which entry to set. See L for details about the available members and how they are used. This macro evaluates its argument more than once. void XopENTRY_set(XOP *xop, which, value) =for hackers Found in file op.h =item XopFLAGS X Return the XOP's flags. U32 XopFLAGS(XOP *xop) =for hackers Found in file op.h =back =head1 CV Manipulation Functions This section documents functions to manipulate CVs which are code-values, or subroutines. For more information, see L. =over 8 =item caller_cx X The XSUB-writer's equivalent of L. The returned C structure can be interrogated to find all the information returned to Perl by C. Note that XSUBs don't get a stack frame, so C will return information for the immediately-surrounding Perl code. This function skips over the automatic calls to C<&DB::sub> made on the behalf of the debugger. If the stack frame requested was a sub called by C, the return value will be the frame for the call to C, since that has the correct line number/etc. for the call site. If I is non-C, it will be set to a pointer to the frame for the sub call itself. const PERL_CONTEXT * caller_cx( I32 level, const PERL_CONTEXT **dbcxp ) =for hackers Found in file pp_ctl.c =item CvSTASH X Returns the stash of the CV. A stash is the symbol table hash, containing the package-scoped variables in the package where the subroutine was defined. For more information, see L. This also has a special use with XS AUTOLOAD subs. See L. HV* CvSTASH(CV* cv) =for hackers Found in file cv.h =item find_runcv X Locate the CV corresponding to the currently executing sub or eval. If C is non_null, skip CVs that are in the DB package and populate C<*db_seqp> with the cop sequence number at the point that the DB:: code was entered. (This allows debuggers to eval in the scope of the breakpoint rather than in the scope of the debugger itself.) CV* find_runcv(U32 *db_seqp) =for hackers Found in file pp_ctl.c =item get_cv X Uses C to get the length of C, then calls C. NOTE: the perl_ form of this function is deprecated. CV* get_cv(const char* name, I32 flags) =for hackers Found in file perl.c =item get_cvn_flags X Returns the CV of the specified Perl subroutine. C are passed to C. If C is set and the Perl subroutine does not exist then it will be declared (which has the same effect as saying C). If C is not set and the subroutine does not exist then NULL is returned. NOTE: the perl_ form of this function is deprecated. CV* get_cvn_flags(const char* name, STRLEN len, I32 flags) =for hackers Found in file perl.c =back =head1 C variables and internal functions =over 8 =item ax X Variable which is setup by C to indicate the stack base offset, used by the C, C and C macros. The C macro must be called prior to setup the C variable. I32 ax =for hackers Found in file XSUB.h =item CLASS X Variable which is setup by C to indicate the class name for a C++ XS constructor. This is always a C. See C>. char* CLASS =for hackers Found in file XSUB.h =item dAX X Sets up the C variable. This is usually handled automatically by C by calling C. dAX; =for hackers Found in file XSUB.h =item dAXMARK X Sets up the C variable and stack marker variable C. This is usually handled automatically by C by calling C. dAXMARK; =for hackers Found in file XSUB.h =item dITEMS X Sets up the C variable. This is usually handled automatically by C by calling C. dITEMS; =for hackers Found in file XSUB.h =item dUNDERBAR X Sets up any variable needed by the C macro. It used to define C, but it is currently a noop. However, it is strongly advised to still use it for ensuring past and future compatibility. dUNDERBAR; =for hackers Found in file XSUB.h =item dXSARGS X Sets up stack and mark pointers for an XSUB, calling C and C. Sets up the C and C variables by calling C and C. This is usually handled automatically by C. dXSARGS; =for hackers Found in file XSUB.h =item dXSI32 X Sets up the C variable for an XSUB which has aliases. This is usually handled automatically by C. dXSI32; =for hackers Found in file XSUB.h =item items X Variable which is setup by C to indicate the number of items on the stack. See L. I32 items =for hackers Found in file XSUB.h =item ix X Variable which is setup by C to indicate which of an XSUB's aliases was used to invoke it. See L. I32 ix =for hackers Found in file XSUB.h =item RETVAL X Variable which is setup by C to hold the return value for an XSUB. This is always the proper type for the XSUB. See L. (whatever) RETVAL =for hackers Found in file XSUB.h =item ST X Used to access elements on the XSUB's stack. SV* ST(int ix) =for hackers Found in file XSUB.h =item THIS X Variable which is setup by C to designate the object in a C++ XSUB. This is always the proper type for the C++ object. See C> and L. (whatever) THIS =for hackers Found in file XSUB.h =item UNDERBAR X The SV* corresponding to the C<$_> variable. Works even if there is a lexical C<$_> in scope. =for hackers Found in file XSUB.h =item XS X Macro to declare an XSUB and its C parameter list. This is handled by C. It is the same as using the more explicit C macro. =for hackers Found in file XSUB.h =item XS_EXTERNAL X Macro to declare an XSUB and its C parameter list explicitly exporting the symbols. =for hackers Found in file XSUB.h =item XS_INTERNAL X Macro to declare an XSUB and its C parameter list without exporting the symbols. This is handled by C and generally preferable over exporting the XSUB symbols unnecessarily. =for hackers Found in file XSUB.h =back =head1 Debugging Utilities =over 8 =item dump_all X Dumps the entire optree of the current program starting at C to C. Also dumps the optrees for all visible subroutines in C. void dump_all() =for hackers Found in file dump.c =item dump_packsubs X Dumps the optrees for all visible subroutines in C. void dump_packsubs(const HV* stash) =for hackers Found in file dump.c =item op_dump X Dumps the optree starting at OP C to C. void op_dump(const OP *o) =for hackers Found in file dump.c =item sv_dump X Dumps the contents of an SV to the C filehandle. For an example of its output, see L. void sv_dump(SV* sv) =for hackers Found in file dump.c =back =head1 Display and Dump functions =over 8 =item pv_display X Similar to pv_escape(dsv,pv,cur,pvlim,PERL_PV_ESCAPE_QUOTE); except that an additional "\0" will be appended to the string when len > cur and pv[cur] is "\0". Note that the final string may be up to 7 chars longer than pvlim. char* pv_display(SV *dsv, const char *pv, STRLEN cur, STRLEN len, STRLEN pvlim) =for hackers Found in file dump.c =item pv_escape X Escapes at most the first C chars of C and puts the results into C such that the size of the escaped string will not exceed C chars and will not contain any incomplete escape sequences. The number of bytes escaped will be returned in the C parameter if it is not null. When the C parameter is null no escaping actually occurs, but the number of bytes that would be escaped were it not null will be calculated. If flags contains C then any double quotes in the string will also be escaped. Normally the SV will be cleared before the escaped string is prepared, but when C is set this will not occur. If C is set then the input string is treated as UTF-8 if C is set then the input string is scanned using C to determine if it is UTF-8. If C is set then all input chars will be output using C<\x01F1> style escapes, otherwise if C is set, only non-ASCII chars will be escaped using this style; otherwise, only chars above 255 will be so escaped; other non printable chars will use octal or common escaped patterns like C<\n>. Otherwise, if C then all chars below 255 will be treated as printable and will be output as literals. If C is set then only the first char of the string will be escaped, regardless of max. If the output is to be in hex, then it will be returned as a plain hex sequence. Thus the output will either be a single char, an octal escape sequence, a special escape like C<\n> or a hex value. If C is set then the escape char used will be a C<"%"> and not a C<"\\">. This is because regexes very often contain backslashed sequences, whereas C<"%"> is not a particularly common character in patterns. Returns a pointer to the escaped text as held by C. char* pv_escape(SV *dsv, char const * const str, const STRLEN count, const STRLEN max, STRLEN * const escaped, const U32 flags) =for hackers Found in file dump.c =item pv_pretty X Converts a string into something presentable, handling escaping via C and supporting quoting and ellipses. If the C flag is set then the result will be double quoted with any double quotes in the string escaped. Otherwise if the C flag is set then the result be wrapped in angle brackets. If the C flag is set and not all characters in string were output then an ellipsis C<...> will be appended to the string. Note that this happens AFTER it has been quoted. If C is non-null then it will be inserted after the opening quote (if there is one) but before the escaped text. If C is non-null then it will be inserted after the escaped text but before any quotes or ellipses. Returns a pointer to the prettified text as held by C. char* pv_pretty(SV *dsv, char const * const str, const STRLEN count, const STRLEN max, char const * const start_color, char const * const end_color, const U32 flags) =for hackers Found in file dump.c =back =head1 Embedding Functions =over 8 =item cv_clone X Clone a CV, making a lexical closure. C supplies the prototype of the function: its code, pad structure, and other attributes. The prototype is combined with a capture of outer lexicals to which the code refers, which are taken from the currently-executing instance of the immediately surrounding code. CV * cv_clone(CV *proto) =for hackers Found in file pad.c =item cv_name X Returns an SV containing the name of the CV, mainly for use in error reporting. The CV may actually be a GV instead, in which case the returned SV holds the GV's name. Anything other than a GV or CV is treated as a string already holding the sub name, but this could change in the future. An SV may be passed as a second argument. If so, the name will be assigned to it and it will be returned. Otherwise the returned SV will be a new mortal. If C has the C bit set, then the package name will not be included. If the first argument is neither a CV nor a GV, this flag is ignored (subject to change). SV * cv_name(CV *cv, SV *sv, U32 flags) =for hackers Found in file pad.c =item cv_undef X Clear out all the active components of a CV. This can happen either by an explicit C, or by the reference count going to zero. In the former case, we keep the C pointer, so that any anonymous children can still follow the full lexical scope chain. void cv_undef(CV* cv) =for hackers Found in file pad.c =item find_rundefsv X Returns the global variable C<$_>. SV * find_rundefsv() =for hackers Found in file pad.c =item find_rundefsvoffset X DEPRECATED! It is planned to remove this function from a future release of Perl. Do not use it for new code; remove it from existing code. Until the lexical C<$_> feature was removed, this function would find the position of the lexical C<$_> in the pad of the currently-executing function and returns the offset in the current pad, or C. Now it always returns C. NOTE: the perl_ form of this function is deprecated. PADOFFSET find_rundefsvoffset() =for hackers Found in file pad.c =item intro_my X "Introduce" C variables to visible status. This is called during parsing at the end of each statement to make lexical variables visible to subsequent statements. U32 intro_my() =for hackers Found in file pad.c =item load_module X Loads the module whose name is pointed to by the string part of name. Note that the actual module name, not its filename, should be given. Eg, "Foo::Bar" instead of "Foo/Bar.pm". flags can be any of C, C, or C (or 0 for no flags). ver, if specified and not NULL, provides version semantics similar to C. The optional trailing SV* arguments can be used to specify arguments to the module's C method, similar to C. They must be terminated with a final C pointer. Note that this list can only be omitted when the C flag has been used. Otherwise at least a single C pointer to designate the default import list is required. The reference count for each specified C parameter is decremented. void load_module(U32 flags, SV* name, SV* ver, ...) =for hackers Found in file op.c =item newPADNAMELIST X NOTE: this function is experimental and may change or be removed without notice. Creates a new pad name list. C is the highest index for which space is allocated. PADNAMELIST * newPADNAMELIST(size_t max) =for hackers Found in file pad.c =item newPADNAMEouter X NOTE: this function is experimental and may change or be removed without notice. Constructs and returns a new pad name. Only use this function for names that refer to outer lexicals. (See also L.) C is the outer pad name that this one mirrors. The returned pad name has the C flag already set. PADNAME * newPADNAMEouter(PADNAME *outer) =for hackers Found in file pad.c =item newPADNAMEpvn X NOTE: this function is experimental and may change or be removed without notice. Constructs and returns a new pad name. C must be a UTF-8 string. Do not use this for pad names that point to outer lexicals. See C>. PADNAME * newPADNAMEpvn(const char *s, STRLEN len) =for hackers Found in file pad.c =item nothreadhook X Stub that provides thread hook for perl_destruct when there are no threads. int nothreadhook() =for hackers Found in file perl.c =item pad_add_anon X Allocates a place in the currently-compiling pad (via L) for an anonymous function that is lexically scoped inside the currently-compiling function. The function C is linked into the pad, and its C link to the outer scope is weakened to avoid a reference loop. One reference count is stolen, so you may need to do C. C should be an opcode indicating the type of operation that the pad entry is to support. This doesn't affect operational semantics, but is used for debugging. PADOFFSET pad_add_anon(CV *func, I32 optype) =for hackers Found in file pad.c =item pad_add_name_pv X Exactly like L, but takes a nul-terminated string instead of a string/length pair. PADOFFSET pad_add_name_pv(const char *name, U32 flags, HV *typestash, HV *ourstash) =for hackers Found in file pad.c =item pad_add_name_pvn X Allocates a place in the currently-compiling pad for a named lexical variable. Stores the name and other metadata in the name part of the pad, and makes preparations to manage the variable's lexical scoping. Returns the offset of the allocated pad slot. C/C specify the variable's name, including leading sigil. If C is non-null, the name is for a typed lexical, and this identifies the type. If C is non-null, it's a lexical reference to a package variable, and this identifies the package. The following flags can be OR'ed together: padadd_OUR redundantly specifies if it's a package var padadd_STATE variable will retain value persistently padadd_NO_DUP_CHECK skip check for lexical shadowing PADOFFSET pad_add_name_pvn(const char *namepv, STRLEN namelen, U32 flags, HV *typestash, HV *ourstash) =for hackers Found in file pad.c =item pad_add_name_sv X Exactly like L, but takes the name string in the form of an SV instead of a string/length pair. PADOFFSET pad_add_name_sv(SV *name, U32 flags, HV *typestash, HV *ourstash) =for hackers Found in file pad.c =item pad_alloc X NOTE: this function is experimental and may change or be removed without notice. Allocates a place in the currently-compiling pad, returning the offset of the allocated pad slot. No name is initially attached to the pad slot. C is a set of flags indicating the kind of pad entry required, which will be set in the value SV for the allocated pad entry: SVs_PADMY named lexical variable ("my", "our", "state") SVs_PADTMP unnamed temporary store SVf_READONLY constant shared between recursion levels C has been supported here only since perl 5.20. To work with earlier versions as well, use C. C does not cause the SV in the pad slot to be marked read-only, but simply tells C that it I be made read-only (by the caller), or at least should be treated as such. C should be an opcode indicating the type of operation that the pad entry is to support. This doesn't affect operational semantics, but is used for debugging. PADOFFSET pad_alloc(I32 optype, U32 tmptype) =for hackers Found in file pad.c =item pad_findmy_pv X Exactly like L, but takes a nul-terminated string instead of a string/length pair. PADOFFSET pad_findmy_pv(const char *name, U32 flags) =for hackers Found in file pad.c =item pad_findmy_pvn X Given the name of a lexical variable, find its position in the currently-compiling pad. C/C specify the variable's name, including leading sigil. C is reserved and must be zero. If it is not in the current pad but appears in the pad of any lexically enclosing scope, then a pseudo-entry for it is added in the current pad. Returns the offset in the current pad, or C if no such lexical is in scope. PADOFFSET pad_findmy_pvn(const char *namepv, STRLEN namelen, U32 flags) =for hackers Found in file pad.c =item pad_findmy_sv X Exactly like L, but takes the name string in the form of an SV instead of a string/length pair. PADOFFSET pad_findmy_sv(SV *name, U32 flags) =for hackers Found in file pad.c =item padnamelist_fetch X NOTE: this function is experimental and may change or be removed without notice. Fetches the pad name from the given index. PADNAME * padnamelist_fetch(PADNAMELIST *pnl, SSize_t key) =for hackers Found in file pad.c =item padnamelist_store X NOTE: this function is experimental and may change or be removed without notice. Stores the pad name (which may be null) at the given index, freeing any existing pad name in that slot. PADNAME ** padnamelist_store(PADNAMELIST *pnl, SSize_t key, PADNAME *val) =for hackers Found in file pad.c =item pad_setsv X Set the value at offset C in the current (compiling or executing) pad. Use the macro C rather than calling this function directly. void pad_setsv(PADOFFSET po, SV *sv) =for hackers Found in file pad.c =item pad_sv X Get the value at offset C in the current (compiling or executing) pad. Use macro C instead of calling this function directly. SV * pad_sv(PADOFFSET po) =for hackers Found in file pad.c =item pad_tidy X NOTE: this function is experimental and may change or be removed without notice. Tidy up a pad at the end of compilation of the code to which it belongs. Jobs performed here are: remove most stuff from the pads of anonsub prototypes; give it a C<@_>; mark temporaries as such. C indicates the kind of subroutine: padtidy_SUB ordinary subroutine padtidy_SUBCLONE prototype for lexical closure padtidy_FORMAT format void pad_tidy(padtidy_type type) =for hackers Found in file pad.c =item perl_alloc X Allocates a new Perl interpreter. See L. PerlInterpreter* perl_alloc() =for hackers Found in file perl.c =item perl_construct X Initializes a new Perl interpreter. See L. void perl_construct(PerlInterpreter *my_perl) =for hackers Found in file perl.c =item perl_destruct X Shuts down a Perl interpreter. See L. int perl_destruct(PerlInterpreter *my_perl) =for hackers Found in file perl.c =item perl_free X Releases a Perl interpreter. See L. void perl_free(PerlInterpreter *my_perl) =for hackers Found in file perl.c =item perl_parse X Tells a Perl interpreter to parse a Perl script. See L. int perl_parse(PerlInterpreter *my_perl, XSINIT_t xsinit, int argc, char** argv, char** env) =for hackers Found in file perl.c =item perl_run X Tells a Perl interpreter to run. See L. int perl_run(PerlInterpreter *my_perl) =for hackers Found in file perl.c =item require_pv X Tells Perl to C the file named by the string argument. It is analogous to the Perl code C. It's even implemented that way; consider using load_module instead. NOTE: the perl_ form of this function is deprecated. void require_pv(const char* pv) =for hackers Found in file perl.c =back =head1 Exception Handling (simple) Macros =over 8 =item dXCPT X Set up necessary local variables for exception handling. See L. dXCPT; =for hackers Found in file XSUB.h =item XCPT_CATCH X Introduces a catch block. See L. =for hackers Found in file XSUB.h =item XCPT_RETHROW X Rethrows a previously caught exception. See L. XCPT_RETHROW; =for hackers Found in file XSUB.h =item XCPT_TRY_END X Ends a try block. See L. =for hackers Found in file XSUB.h =item XCPT_TRY_START X Starts a try block. See L. =for hackers Found in file XSUB.h =back =head1 Functions in file scope.c =over 8 =item save_gp X Saves the current GP of gv on the save stack to be restored on scope exit. If empty is true, replace the GP with a new GP. If empty is false, mark gv with GVf_INTRO so the next reference assigned is localized, which is how C< local *foo = $someref; > works. void save_gp(GV* gv, I32 empty) =for hackers Found in file scope.c =back =head1 Functions in file vutil.c =over 8 =item new_version X Returns a new version object based on the passed in SV: SV *sv = new_version(SV *ver); Does not alter the passed in ver SV. See "upg_version" if you want to upgrade the SV. SV* new_version(SV *ver) =for hackers Found in file vutil.c =item prescan_version X Validate that a given string can be parsed as a version object, but doesn't actually perform the parsing. Can use either strict or lax validation rules. Can optionally set a number of hint variables to save the parsing code some time when tokenizing. const char* prescan_version(const char *s, bool strict, const char** errstr, bool *sqv, int *ssaw_decimal, int *swidth, bool *salpha) =for hackers Found in file vutil.c =item scan_version X Returns a pointer to the next character after the parsed version string, as well as upgrading the passed in SV to an RV. Function must be called with an already existing SV like sv = newSV(0); s = scan_version(s, SV *sv, bool qv); Performs some preprocessing to the string to ensure that it has the correct characteristics of a version. Flags the object if it contains an underscore (which denotes this is an alpha version). The boolean qv denotes that the version should be interpreted as if it had multiple decimals, even if it doesn't. const char* scan_version(const char *s, SV *rv, bool qv) =for hackers Found in file vutil.c =item upg_version X In-place upgrade of the supplied SV to a version object. SV *sv = upg_version(SV *sv, bool qv); Returns a pointer to the upgraded SV. Set the boolean qv if you want to force this SV to be interpreted as an "extended" version. SV* upg_version(SV *ver, bool qv) =for hackers Found in file vutil.c =item vcmp X Version object aware cmp. Both operands must already have been converted into version objects. int vcmp(SV *lhv, SV *rhv) =for hackers Found in file vutil.c =item vnormal X Accepts a version object and returns the normalized string representation. Call like: sv = vnormal(rv); NOTE: you can pass either the object directly or the SV contained within the RV. The SV returned has a refcount of 1. SV* vnormal(SV *vs) =for hackers Found in file vutil.c =item vnumify X Accepts a version object and returns the normalized floating point representation. Call like: sv = vnumify(rv); NOTE: you can pass either the object directly or the SV contained within the RV. The SV returned has a refcount of 1. SV* vnumify(SV *vs) =for hackers Found in file vutil.c =item vstringify X In order to maintain maximum compatibility with earlier versions of Perl, this function will return either the floating point notation or the multiple dotted notation, depending on whether the original version contained 1 or more dots, respectively. The SV returned has a refcount of 1. SV* vstringify(SV *vs) =for hackers Found in file vutil.c =item vverify X Validates that the SV contains valid internal structure for a version object. It may be passed either the version object (RV) or the hash itself (HV). If the structure is valid, it returns the HV. If the structure is invalid, it returns NULL. SV *hv = vverify(sv); Note that it only confirms the bare minimum structure (so as not to get confused by derived classes which may contain additional hash entries): SV* vverify(SV *vs) =for hackers Found in file vutil.c =back =head1 "Gimme" Values =over 8 =item G_ARRAY X Used to indicate list context. See C>, C> and L. =for hackers Found in file cop.h =item G_DISCARD X Indicates that arguments returned from a callback should be discarded. See L. =for hackers Found in file cop.h =item G_EVAL X Used to force a Perl C wrapper around a callback. See L. =for hackers Found in file cop.h =item GIMME X A backward-compatible version of C which can only return C or C; in a void context, it returns C. Deprecated. Use C instead. U32 GIMME =for hackers Found in file op.h =item GIMME_V X The XSUB-writer's equivalent to Perl's C. Returns C, C or C for void, scalar or list context, respectively. See L for a usage example. U32 GIMME_V =for hackers Found in file op.h =item G_NOARGS X Indicates that no arguments are being sent to a callback. See L. =for hackers Found in file cop.h =item G_SCALAR X Used to indicate scalar context. See C>, C>, and L. =for hackers Found in file cop.h =item G_VOID X Used to indicate void context. See C> and L. =for hackers Found in file cop.h =back =head1 Global Variables These variables are global to an entire process. They are shared between all interpreters and all threads in a process. Any variables not documented here may be changed or removed without notice, so don't use them! If you feel you really do need to use an unlisted variable, first send email to L. It may be that someone there will point out a way to accomplish what you need without using an internal variable. But if not, you should get a go-ahead to document and then use the variable. =over 8 =item PL_check X Array, indexed by opcode, of functions that will be called for the "check" phase of optree building during compilation of Perl code. For most (but not all) types of op, once the op has been initially built and populated with child ops it will be filtered through the check function referenced by the appropriate element of this array. The new op is passed in as the sole argument to the check function, and the check function returns the completed op. The check function may (as the name suggests) check the op for validity and signal errors. It may also initialise or modify parts of the ops, or perform more radical surgery such as adding or removing child ops, or even throw the op away and return a different op in its place. This array of function pointers is a convenient place to hook into the compilation process. An XS module can put its own custom check function in place of any of the standard ones, to influence the compilation of a particular type of op. However, a custom check function must never fully replace a standard check function (or even a custom check function from another module). A module modifying checking must instead B the preexisting check function. A custom check function must be selective about when to apply its custom behaviour. In the usual case where it decides not to do anything special with an op, it must chain the preexisting op function. Check functions are thus linked in a chain, with the core's base checker at the end. For thread safety, modules should not write directly to this array. Instead, use the function L. =for hackers Found in file perlvars.h =item PL_keyword_plugin X NOTE: this function is experimental and may change or be removed without notice. Function pointer, pointing at a function used to handle extended keywords. The function should be declared as int keyword_plugin_function(pTHX_ char *keyword_ptr, STRLEN keyword_len, OP **op_ptr) The function is called from the tokeniser, whenever a possible keyword is seen. C points at the word in the parser's input buffer, and C gives its length; it is not null-terminated. The function is expected to examine the word, and possibly other state such as L<%^H|perlvar/%^H>, to decide whether it wants to handle it as an extended keyword. If it does not, the function should return C, and the normal parser process will continue. If the function wants to handle the keyword, it first must parse anything following the keyword that is part of the syntax introduced by the keyword. See L for details. When a keyword is being handled, the plugin function must build a tree of C structures, representing the code that was parsed. The root of the tree must be stored in C<*op_ptr>. The function then returns a constant indicating the syntactic role of the construct that it has parsed: C if it is a complete statement, or C if it is an expression. Note that a statement construct cannot be used inside an expression (except via C and similar), and an expression is not a complete statement (it requires at least a terminating semicolon). When a keyword is handled, the plugin function may also have (compile-time) side effects. It may modify C<%^H>, define functions, and so on. Typically, if side effects are the main purpose of a handler, it does not wish to generate any ops to be included in the normal compilation. In this case it is still required to supply an op tree, but it suffices to generate a single null op. That's how the C<*PL_keyword_plugin> function needs to behave overall. Conventionally, however, one does not completely replace the existing handler function. Instead, take a copy of C before assigning your own function pointer to it. Your handler function should look for keywords that it is interested in and handle those. Where it is not interested, it should call the saved plugin function, passing on the arguments it received. Thus C actually points at a chain of handler functions, all of which have an opportunity to handle keywords, and only the last function in the chain (built into the Perl core) will normally return C. =for hackers Found in file perlvars.h =back =head1 GV Functions A GV is a structure which corresponds to to a Perl typeglob, ie *foo. It is a structure that holds a pointer to a scalar, an array, a hash etc, corresponding to $foo, @foo, %foo. GVs are usually found as values in stashes (symbol table hashes) where Perl stores its global variables. =over 8 =item GvAV X Return the AV from the GV. AV* GvAV(GV* gv) =for hackers Found in file gv.h =item gv_const_sv X If C is a typeglob whose subroutine entry is a constant sub eligible for inlining, or C is a placeholder reference that would be promoted to such a typeglob, then returns the value returned by the sub. Otherwise, returns C. SV* gv_const_sv(GV* gv) =for hackers Found in file gv.c =item GvCV X Return the CV from the GV. CV* GvCV(GV* gv) =for hackers Found in file gv.h =item gv_fetchmeth X Like L, but lacks a flags parameter. GV* gv_fetchmeth(HV* stash, const char* name, STRLEN len, I32 level) =for hackers Found in file gv.c =item gv_fetchmethod_autoload X Returns the glob which contains the subroutine to call to invoke the method on the C. In fact in the presence of autoloading this may be the glob for "AUTOLOAD". In this case the corresponding variable C<$AUTOLOAD> is already setup. The third parameter of C determines whether AUTOLOAD lookup is performed if the given method is not present: non-zero means yes, look for AUTOLOAD; zero means no, don't look for AUTOLOAD. Calling C is equivalent to calling C with a non-zero C parameter. These functions grant C<"SUPER"> token as a prefix of the method name. Note that if you want to keep the returned glob for a long time, you need to check for it being "AUTOLOAD", since at the later time the call may load a different subroutine due to C<$AUTOLOAD> changing its value. Use the glob created as a side effect to do this. These functions have the same side-effects as C with C. The warning against passing the GV returned by C to C applies equally to these functions. GV* gv_fetchmethod_autoload(HV* stash, const char* name, I32 autoload) =for hackers Found in file gv.c =item gv_fetchmeth_autoload X This is the old form of L, which has no flags parameter. GV* gv_fetchmeth_autoload(HV* stash, const char* name, STRLEN len, I32 level) =for hackers Found in file gv.c =item gv_fetchmeth_pv X Exactly like L, but takes a nul-terminated string instead of a string/length pair. GV* gv_fetchmeth_pv(HV* stash, const char* name, I32 level, U32 flags) =for hackers Found in file gv.c =item gv_fetchmeth_pvn X Returns the glob with the given C and a defined subroutine or C. The glob lives in the given C, or in the stashes accessible via C<@ISA> and C. The argument C should be either 0 or -1. If C, as a side-effect creates a glob with the given C in the given C which in the case of success contains an alias for the subroutine, and sets up caching info for this glob. The only significant values for C are C and C. C indicates that we want to look up the method in the superclasses of the C. The GV returned from C may be a method cache entry, which is not visible to Perl code. So when calling C, you should not use the GV directly; instead, you should use the method's CV, which can be obtained from the GV with the C macro. GV* gv_fetchmeth_pvn(HV* stash, const char* name, STRLEN len, I32 level, U32 flags) =for hackers Found in file gv.c =item gv_fetchmeth_pvn_autoload X Same as C, but looks for autoloaded subroutines too. Returns a glob for the subroutine. For an autoloaded subroutine without a GV, will create a GV even if C. For an autoloaded subroutine without a stub, C of the result may be zero. Currently, the only significant value for C is C. GV* gv_fetchmeth_pvn_autoload(HV* stash, const char* name, STRLEN len, I32 level, U32 flags) =for hackers Found in file gv.c =item gv_fetchmeth_pv_autoload X Exactly like L, but takes a nul-terminated string instead of a string/length pair. GV* gv_fetchmeth_pv_autoload(HV* stash, const char* name, I32 level, U32 flags) =for hackers Found in file gv.c =item gv_fetchmeth_sv X Exactly like L, but takes the name string in the form of an SV instead of a string/length pair. GV* gv_fetchmeth_sv(HV* stash, SV* namesv, I32 level, U32 flags) =for hackers Found in file gv.c =item gv_fetchmeth_sv_autoload X Exactly like L, but takes the name string in the form of an SV instead of a string/length pair. GV* gv_fetchmeth_sv_autoload(HV* stash, SV* namesv, I32 level, U32 flags) =for hackers Found in file gv.c =item GvHV X Return the HV from the GV. HV* GvHV(GV* gv) =for hackers Found in file gv.h =item gv_init X The old form of C. It does not work with UTF-8 strings, as it has no flags parameter. If the C parameter is set, the C flag will be passed to C. void gv_init(GV* gv, HV* stash, const char* name, STRLEN len, int multi) =for hackers Found in file gv.c =item gv_init_pv X Same as C, but takes a nul-terminated string for the name instead of separate char * and length parameters. void gv_init_pv(GV* gv, HV* stash, const char* name, U32 flags) =for hackers Found in file gv.c =item gv_init_pvn X Converts a scalar into a typeglob. This is an incoercible typeglob; assigning a reference to it will assign to one of its slots, instead of overwriting it as happens with typeglobs created by C. Converting any scalar that is C may produce unpredictable results and is reserved for perl's internal use. C is the scalar to be converted. C is the parent stash/package, if any. C and C give the name. The name must be unqualified; that is, it must not include the package name. If C is a stash element, it is the caller's responsibility to ensure that the name passed to this function matches the name of the element. If it does not match, perl's internal bookkeeping will get out of sync. C can be set to C if C is a UTF-8 string, or the return value of SvUTF8(sv). It can also take the C flag, which means to pretend that the GV has been seen before (i.e., suppress "Used once" warnings). void gv_init_pvn(GV* gv, HV* stash, const char* name, STRLEN len, U32 flags) =for hackers Found in file gv.c =item gv_init_sv X Same as C, but takes an SV * for the name instead of separate char * and length parameters. C is currently unused. void gv_init_sv(GV* gv, HV* stash, SV* namesv, U32 flags) =for hackers Found in file gv.c =item gv_stashpv X Returns a pointer to the stash for a specified package. Uses C to determine the length of C, then calls C. HV* gv_stashpv(const char* name, I32 flags) =for hackers Found in file gv.c =item gv_stashpvn X Returns a pointer to the stash for a specified package. The C parameter indicates the length of the C, in bytes. C is passed to C, so if set to C then the package will be created if it does not already exist. If the package does not exist and C is 0 (or any other setting that does not create packages) then C is returned. Flags may be one of: GV_ADD SVf_UTF8 GV_NOADD_NOINIT GV_NOINIT GV_NOEXPAND GV_ADDMG The most important of which are probably C and C. Note, use of C instead of C where possible is strongly recommended for performance reasons. HV* gv_stashpvn(const char* name, U32 namelen, I32 flags) =for hackers Found in file gv.c =item gv_stashpvs X Like C, but takes a C-terminated literal string instead of a string/length pair. HV* gv_stashpvs(const char* name, I32 create) =for hackers Found in file handy.h =item gv_stashsv X Returns a pointer to the stash for a specified package. See C>. Note this interface is strongly preferred over C for performance reasons. HV* gv_stashsv(SV* sv, I32 flags) =for hackers Found in file gv.c =item GvSV X Return the SV from the GV. SV* GvSV(GV* gv) =for hackers Found in file gv.h =item setdefout X Sets C, the default file handle for output, to the passed in typeglob. As C "owns" a reference on its typeglob, the reference count of the passed in typeglob is increased by one, and the reference count of the typeglob that C points to is decreased by one. void setdefout(GV* gv) =for hackers Found in file pp_sys.c =back =head1 Handy Values =over 8 =item Nullav X Null AV pointer. (deprecated - use C<(AV *)NULL> instead) =for hackers Found in file av.h =item Nullch X Null character pointer. (No longer available when C is defined.) =for hackers Found in file handy.h =item Nullcv X Null CV pointer. (deprecated - use C<(CV *)NULL> instead) =for hackers Found in file cv.h =item Nullhv X Null HV pointer. (deprecated - use C<(HV *)NULL> instead) =for hackers Found in file hv.h =item Nullsv X Null SV pointer. (No longer available when C is defined.) =for hackers Found in file handy.h =back =head1 Hash Manipulation Functions A HV structure represents a Perl hash. It consists mainly of an array of pointers, each of which points to a linked list of HE structures. The array is indexed by the hash function of the key, so each linked list represents all the hash entries with the same hash value. Each HE contains a pointer to the actual value, plus a pointer to a HEK structure which holds the key and hash value. =over 8 =item cop_fetch_label X NOTE: this function is experimental and may change or be removed without notice. Returns the label attached to a cop. The flags pointer may be set to C or 0. const char * cop_fetch_label(COP *const cop, STRLEN *len, U32 *flags) =for hackers Found in file hv.c =item cop_store_label X NOTE: this function is experimental and may change or be removed without notice. Save a label into a C. You need to set flags to C for a UTF-8 label. void cop_store_label(COP *const cop, const char *label, STRLEN len, U32 flags) =for hackers Found in file hv.c =item get_hv X Returns the HV of the specified Perl hash. C are passed to C. If C is set and the Perl variable does not exist then it will be created. If C is zero and the variable does not exist then C is returned. NOTE: the perl_ form of this function is deprecated. HV* get_hv(const char *name, I32 flags) =for hackers Found in file perl.c =item HEf_SVKEY X This flag, used in the length slot of hash entries and magic structures, specifies the structure contains an C pointer where a C pointer is to be expected. (For information only--not to be used). =for hackers Found in file hv.h =item HeHASH X Returns the computed hash stored in the hash entry. U32 HeHASH(HE* he) =for hackers Found in file hv.h =item HeKEY X Returns the actual pointer stored in the key slot of the hash entry. The pointer may be either C or C, depending on the value of C. Can be assigned to. The C or C macros are usually preferable for finding the value of a key. void* HeKEY(HE* he) =for hackers Found in file hv.h =item HeKLEN X If this is negative, and amounts to C, it indicates the entry holds an C key. Otherwise, holds the actual length of the key. Can be assigned to. The C macro is usually preferable for finding key lengths. STRLEN HeKLEN(HE* he) =for hackers Found in file hv.h =item HePV X Returns the key slot of the hash entry as a C value, doing any necessary dereferencing of possibly C keys. The length of the string is placed in C (this is a macro, so do I use C<&len>). If you do not care about what the length of the key is, you may use the global variable C, though this is rather less efficient than using a local variable. Remember though, that hash keys in perl are free to contain embedded nulls, so using C or similar is not a good way to find the length of hash keys. This is very similar to the C macro described elsewhere in this document. See also C>. If you are using C to get values to pass to C to create a new SV, you should consider using C as it is more efficient. char* HePV(HE* he, STRLEN len) =for hackers Found in file hv.h =item HeSVKEY X Returns the key as an C, or C if the hash entry does not contain an C key. SV* HeSVKEY(HE* he) =for hackers Found in file hv.h =item HeSVKEY_force X Returns the key as an C. Will create and return a temporary mortal C if the hash entry contains only a C key. SV* HeSVKEY_force(HE* he) =for hackers Found in file hv.h =item HeSVKEY_set X Sets the key to a given C, taking care to set the appropriate flags to indicate the presence of an C key, and returns the same C. SV* HeSVKEY_set(HE* he, SV* sv) =for hackers Found in file hv.h =item HeUTF8 X Returns whether the C value returned by C is encoded in UTF-8, doing any necessary dereferencing of possibly C keys. The value returned will be 0 or non-0, not necessarily 1 (or even a value with any low bits set), so B blindly assign this to a C variable, as C may be a typedef for C. U32 HeUTF8(HE* he) =for hackers Found in file hv.h =item HeVAL X Returns the value slot (type C) stored in the hash entry. Can be assigned to. SV *foo= HeVAL(hv); HeVAL(hv)= sv; SV* HeVAL(HE* he) =for hackers Found in file hv.h =item hv_assert X Check that a hash is in an internally consistent state. void hv_assert(HV *hv) =for hackers Found in file hv.c =item hv_clear X Frees the all the elements of a hash, leaving it empty. The XS equivalent of C<%hash = ()>. See also L. See L for a note about the hash possibly being invalid on return. void hv_clear(HV *hv) =for hackers Found in file hv.c =item hv_clear_placeholders X Clears any placeholders from a hash. If a restricted hash has any of its keys marked as readonly and the key is subsequently deleted, the key is not actually deleted but is marked by assigning it a value of C<&PL_sv_placeholder>. This tags it so it will be ignored by future operations such as iterating over the hash, but will still allow the hash to have a value reassigned to the key at some future point. This function clears any such placeholder keys from the hash. See C> for an example of its use. void hv_clear_placeholders(HV *hv) =for hackers Found in file hv.c =item hv_copy_hints_hv X A specialised version of L for copying C<%^H>. C must be a pointer to a hash (which may have C<%^H> magic, but should be generally non-magical), or C (interpreted as an empty hash). The content of C is copied to a new hash, which has the C<%^H>-specific magic added to it. A pointer to the new hash is returned. HV * hv_copy_hints_hv(HV *ohv) =for hackers Found in file hv.c =item hv_delete X Deletes a key/value pair in the hash. The value's SV is removed from the hash, made mortal, and returned to the caller. The absolute value of C is the length of the key. If C is negative the key is assumed to be in UTF-8-encoded Unicode. The C value will normally be zero; if set to C then C will be returned. C will also be returned if the key is not found. SV* hv_delete(HV *hv, const char *key, I32 klen, I32 flags) =for hackers Found in file hv.c =item hv_delete_ent X Deletes a key/value pair in the hash. The value SV is removed from the hash, made mortal, and returned to the caller. The C value will normally be zero; if set to C then C will be returned. C will also be returned if the key is not found. C can be a valid precomputed hash value, or 0 to ask for it to be computed. SV* hv_delete_ent(HV *hv, SV *keysv, I32 flags, U32 hash) =for hackers Found in file hv.c =item HvENAME X Returns the effective name of a stash, or NULL if there is none. The effective name represents a location in the symbol table where this stash resides. It is updated automatically when packages are aliased or deleted. A stash that is no longer in the symbol table has no effective name. This name is preferable to C for use in MRO linearisations and isa caches. char* HvENAME(HV* stash) =for hackers Found in file hv.h =item HvENAMELEN X Returns the length of the stash's effective name. STRLEN HvENAMELEN(HV *stash) =for hackers Found in file hv.h =item HvENAMEUTF8 X Returns true if the effective name is in UTF-8 encoding. unsigned char HvENAMEUTF8(HV *stash) =for hackers Found in file hv.h =item hv_exists X Returns a boolean indicating whether the specified hash key exists. The absolute value of C is the length of the key. If C is negative the key is assumed to be in UTF-8-encoded Unicode. bool hv_exists(HV *hv, const char *key, I32 klen) =for hackers Found in file hv.c =item hv_exists_ent X Returns a boolean indicating whether the specified hash key exists. C can be a valid precomputed hash value, or 0 to ask for it to be computed. bool hv_exists_ent(HV *hv, SV *keysv, U32 hash) =for hackers Found in file hv.c =item hv_fetch X Returns the SV which corresponds to the specified key in the hash. The absolute value of C is the length of the key. If C is negative the key is assumed to be in UTF-8-encoded Unicode. If C is set then the fetch will be part of a store. This means that if there is no value in the hash associated with the given key, then one is created and a pointer to it is returned. The C it points to can be assigned to. But always check that the return value is non-null before dereferencing it to an C. See L for more information on how to use this function on tied hashes. SV** hv_fetch(HV *hv, const char *key, I32 klen, I32 lval) =for hackers Found in file hv.c =item hv_fetchs X Like C, but takes a C-terminated literal string instead of a string/length pair. SV** hv_fetchs(HV* tb, const char* key, I32 lval) =for hackers Found in file handy.h =item hv_fetch_ent X Returns the hash entry which corresponds to the specified key in the hash. C must be a valid precomputed hash number for the given C, or 0 if you want the function to compute it. IF C is set then the fetch will be part of a store. Make sure the return value is non-null before accessing it. The return value when C is a tied hash is a pointer to a static location, so be sure to make a copy of the structure if you need to store it somewhere. See L for more information on how to use this function on tied hashes. HE* hv_fetch_ent(HV *hv, SV *keysv, I32 lval, U32 hash) =for hackers Found in file hv.c =item hv_fill X Returns the number of hash buckets that happen to be in use. This function is wrapped by the macro C. Previously this value was always stored in the HV structure, which created an overhead on every hash (and pretty much every object) for something that was rarely used. Now we calculate it on demand the first time that it is needed, and cache it if that calculation is going to be costly to repeat. The cached value is updated by insertions and deletions, but (currently) discarded if the hash is split. STRLEN hv_fill(HV *const hv) =for hackers Found in file hv.c =item hv_iterinit X Prepares a starting point to traverse a hash table. Returns the number of keys in the hash (i.e. the same as C). The return value is currently only meaningful for hashes without tie magic. NOTE: Before version 5.004_65, C used to return the number of hash buckets that happen to be in use. If you still need that esoteric value, you can get it through the macro C. I32 hv_iterinit(HV *hv) =for hackers Found in file hv.c =item hv_iterkey X Returns the key from the current position of the hash iterator. See C>. char* hv_iterkey(HE* entry, I32* retlen) =for hackers Found in file hv.c =item hv_iterkeysv X Returns the key as an C from the current position of the hash iterator. The return value will always be a mortal copy of the key. Also see C>. SV* hv_iterkeysv(HE* entry) =for hackers Found in file hv.c =item hv_iternext X Returns entries from a hash iterator. See C>. You may call C or C on the hash entry that the iterator currently points to, without losing your place or invalidating your iterator. Note that in this case the current entry is deleted from the hash with your iterator holding the last reference to it. Your iterator is flagged to free the entry on the next call to C, so you must not discard your iterator immediately else the entry will leak - call C to trigger the resource deallocation. HE* hv_iternext(HV *hv) =for hackers Found in file hv.c =item hv_iternextsv X Performs an C, C, and C in one operation. SV* hv_iternextsv(HV *hv, char **key, I32 *retlen) =for hackers Found in file hv.c =item hv_iternext_flags X NOTE: this function is experimental and may change or be removed without notice. Returns entries from a hash iterator. See C> and C>. The C value will normally be zero; if C is set the placeholders keys (for restricted hashes) will be returned in addition to normal keys. By default placeholders are automatically skipped over. Currently a placeholder is implemented with a value that is C<&PL_sv_placeholder>. Note that the implementation of placeholders and restricted hashes may change, and the implementation currently is insufficiently abstracted for any change to be tidy. HE* hv_iternext_flags(HV *hv, I32 flags) =for hackers Found in file hv.c =item hv_iterval X Returns the value from the current position of the hash iterator. See C>. SV* hv_iterval(HV *hv, HE *entry) =for hackers Found in file hv.c =item hv_magic X Adds magic to a hash. See C>. void hv_magic(HV *hv, GV *gv, int how) =for hackers Found in file hv.c =item HvNAME X Returns the package name of a stash, or C if C isn't a stash. See C>, C>. char* HvNAME(HV* stash) =for hackers Found in file hv.h =item HvNAMELEN X Returns the length of the stash's name. STRLEN HvNAMELEN(HV *stash) =for hackers Found in file hv.h =item HvNAMEUTF8 X Returns true if the name is in UTF-8 encoding. unsigned char HvNAMEUTF8(HV *stash) =for hackers Found in file hv.h =item hv_scalar X Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied. SV* hv_scalar(HV *hv) =for hackers Found in file hv.c =item hv_store X Stores an SV in a hash. The hash key is specified as C and the absolute value of C is the length of the key. If C is negative the key is assumed to be in UTF-8-encoded Unicode. The C parameter is the precomputed hash value; if it is zero then Perl will compute it. The return value will be C if the operation failed or if the value did not need to be actually stored within the hash (as in the case of tied hashes). Otherwise it can be dereferenced to get the original C. Note that the caller is responsible for suitably incrementing the reference count of C before the call, and decrementing it if the function returned C. Effectively a successful C takes ownership of one reference to C. This is usually what you want; a newly created SV has a reference count of one, so if all your code does is create SVs then store them in a hash, C will own the only reference to the new SV, and your code doesn't need to do anything further to tidy up. C is not implemented as a call to C, and does not create a temporary SV for the key, so if your key data is not already in SV form then use C in preference to C. See L for more information on how to use this function on tied hashes. SV** hv_store(HV *hv, const char *key, I32 klen, SV *val, U32 hash) =for hackers Found in file hv.c =item hv_stores X Like C, but takes a C-terminated literal string instead of a string/length pair and omits the hash parameter. SV** hv_stores(HV* tb, const char* key, NULLOK SV* val) =for hackers Found in file handy.h =item hv_store_ent X Stores C in a hash. The hash key is specified as C. The C parameter is the precomputed hash value; if it is zero then Perl will compute it. The return value is the new hash entry so created. It will be C if the operation failed or if the value did not need to be actually stored within the hash (as in the case of tied hashes). Otherwise the contents of the return value can be accessed using the C macros described here. Note that the caller is responsible for suitably incrementing the reference count of C before the call, and decrementing it if the function returned NULL. Effectively a successful C takes ownership of one reference to C. This is usually what you want; a newly created SV has a reference count of one, so if all your code does is create SVs then store them in a hash, C will own the only reference to the new SV, and your code doesn't need to do anything further to tidy up. Note that C only reads the C; unlike C it does not take ownership of it, so maintaining the correct reference count on C is entirely the caller's responsibility. C is not implemented as a call to C, and does not create a temporary SV for the key, so if your key data is not already in SV form then use C in preference to C. See L for more information on how to use this function on tied hashes. HE* hv_store_ent(HV *hv, SV *key, SV *val, U32 hash) =for hackers Found in file hv.c =item hv_undef X Undefines the hash. The XS equivalent of C. As well as freeing all the elements of the hash (like C), this also frees any auxiliary data and storage associated with the hash. See L for a note about the hash possibly being invalid on return. void hv_undef(HV *hv) =for hackers Found in file hv.c =item newHV X Creates a new HV. The reference count is set to 1. HV* newHV() =for hackers Found in file hv.h =back =head1 Hook manipulation These functions provide convenient and thread-safe means of manipulating hook variables. =over 8 =item wrap_op_checker X Puts a C function into the chain of check functions for a specified op type. This is the preferred way to manipulate the L array. C specifies which type of op is to be affected. C is a pointer to the C function that is to be added to that opcode's check chain, and C points to the storage location where a pointer to the next function in the chain will be stored. The value of C is written into the L array, while the value previously stored there is written to C<*old_checker_p>. The function should be defined like this: static OP *new_checker(pTHX_ OP *op) { ... } It is intended to be called in this manner: new_checker(aTHX_ op) C should be defined like this: static Perl_check_t old_checker_p; L is global to an entire process, and a module wishing to hook op checking may find itself invoked more than once per process, typically in different threads. To handle that situation, this function is idempotent. The location C<*old_checker_p> must initially (once per process) contain a null pointer. A C variable of static duration (declared at file scope, typically also marked C to give it internal linkage) will be implicitly initialised appropriately, if it does not have an explicit initialiser. This function will only actually modify the check chain if it finds C<*old_checker_p> to be null. This function is also thread safe on the small scale. It uses appropriate locking to avoid race conditions in accessing L. When this function is called, the function referenced by C must be ready to be called, except for C<*old_checker_p> being unfilled. In a threading situation, C may be called immediately, even before this function has returned. C<*old_checker_p> will always be appropriately set before C is called. If C decides not to do anything special with an op that it is given (which is the usual case for most uses of op check hooking), it must chain the check function referenced by C<*old_checker_p>. If you want to influence compilation of calls to a specific subroutine, then use L rather than hooking checking of all C ops. void wrap_op_checker(Optype opcode, Perl_check_t new_checker, Perl_check_t *old_checker_p) =for hackers Found in file op.c =back =head1 Lexer interface This is the lower layer of the Perl parser, managing characters and tokens. =over 8 =item lex_bufutf8 X NOTE: this function is experimental and may change or be removed without notice. Indicates whether the octets in the lexer buffer (Llinestr>) should be interpreted as the UTF-8 encoding of Unicode characters. If not, they should be interpreted as Latin-1 characters. This is analogous to the C flag for scalars. In UTF-8 mode, it is not guaranteed that the lexer buffer actually contains valid UTF-8. Lexing code must be robust in the face of invalid encoding. The actual C flag of the Llinestr> scalar is significant, but not the whole story regarding the input character encoding. Normally, when a file is being read, the scalar contains octets and its C flag is off, but the octets should be interpreted as UTF-8 if the C pragma is in effect. During a string eval, however, the scalar may have the C flag on, and in this case its octets should be interpreted as UTF-8 unless the C pragma is in effect. This logic may change in the future; use this function instead of implementing the logic yourself. bool lex_bufutf8() =for hackers Found in file toke.c =item lex_discard_to X NOTE: this function is experimental and may change or be removed without notice. Discards the first part of the Llinestr> buffer, up to C. The remaining content of the buffer will be moved, and all pointers into the buffer updated appropriately. C must not be later in the buffer than the position of Lbufptr>: it is not permitted to discard text that has yet to be lexed. Normally it is not necessarily to do this directly, because it suffices to use the implicit discarding behaviour of L and things based on it. However, if a token stretches across multiple lines, and the lexing code has kept multiple lines of text in the buffer for that purpose, then after completion of the token it would be wise to explicitly discard the now-unneeded earlier lines, to avoid future multi-line tokens growing the buffer without bound. void lex_discard_to(char *ptr) =for hackers Found in file toke.c =item lex_grow_linestr X NOTE: this function is experimental and may change or be removed without notice. Reallocates the lexer buffer (Llinestr>) to accommodate at least C octets (including terminating C). Returns a pointer to the reallocated buffer. This is necessary before making any direct modification of the buffer that would increase its length. L provides a more convenient way to insert text into the buffer. Do not use C or C directly on Clinestr>; this function updates all of the lexer's variables that point directly into the buffer. char * lex_grow_linestr(STRLEN len) =for hackers Found in file toke.c =item lex_next_chunk X NOTE: this function is experimental and may change or be removed without notice. Reads in the next chunk of text to be lexed, appending it to Llinestr>. This should be called when lexing code has looked to the end of the current chunk and wants to know more. It is usual, but not necessary, for lexing to have consumed the entirety of the current chunk at this time. If Lbufptr> is pointing to the very end of the current chunk (i.e., the current chunk has been entirely consumed), normally the current chunk will be discarded at the same time that the new chunk is read in. If C has the C bit set, the current chunk will not be discarded. If the current chunk has not been entirely consumed, then it will not be discarded regardless of the flag. Returns true if some new text was added to the buffer, or false if the buffer has reached the end of the input text. bool lex_next_chunk(U32 flags) =for hackers Found in file toke.c =item lex_peek_unichar X NOTE: this function is experimental and may change or be removed without notice. Looks ahead one (Unicode) character in the text currently being lexed. Returns the codepoint (unsigned integer value) of the next character, or -1 if lexing has reached the end of the input text. To consume the peeked character, use L. If the next character is in (or extends into) the next chunk of input text, the next chunk will be read in. Normally the current chunk will be discarded at the same time, but if C has the C bit set, then the current chunk will not be discarded. If the input is being interpreted as UTF-8 and a UTF-8 encoding error is encountered, an exception is generated. I32 lex_peek_unichar(U32 flags) =for hackers Found in file toke.c =item lex_read_space X NOTE: this function is experimental and may change or be removed without notice. Reads optional spaces, in Perl style, in the text currently being lexed. The spaces may include ordinary whitespace characters and Perl-style comments. C<#line> directives are processed if encountered. Lbufptr> is moved past the spaces, so that it points at a non-space character (or the end of the input text). If spaces extend into the next chunk of input text, the next chunk will be read in. Normally the current chunk will be discarded at the same time, but if C has the C bit set, then the current chunk will not be discarded. void lex_read_space(U32 flags) =for hackers Found in file toke.c =item lex_read_to X NOTE: this function is experimental and may change or be removed without notice. Consume text in the lexer buffer, from Lbufptr> up to C. This advances Lbufptr> to match C, performing the correct bookkeeping whenever a newline character is passed. This is the normal way to consume lexed text. Interpretation of the buffer's octets can be abstracted out by using the slightly higher-level functions L and L. void lex_read_to(char *ptr) =for hackers Found in file toke.c =item lex_read_unichar X NOTE: this function is experimental and may change or be removed without notice. Reads the next (Unicode) character in the text currently being lexed. Returns the codepoint (unsigned integer value) of the character read, and moves Lbufptr> past the character, or returns -1 if lexing has reached the end of the input text. To non-destructively examine the next character, use L instead. If the next character is in (or extends into) the next chunk of input text, the next chunk will be read in. Normally the current chunk will be discarded at the same time, but if C has the C bit set, then the current chunk will not be discarded. If the input is being interpreted as UTF-8 and a UTF-8 encoding error is encountered, an exception is generated. I32 lex_read_unichar(U32 flags) =for hackers Found in file toke.c =item lex_start X NOTE: this function is experimental and may change or be removed without notice. Creates and initialises a new lexer/parser state object, supplying a context in which to lex and parse from a new source of Perl code. A pointer to the new state object is placed in L. An entry is made on the save stack so that upon unwinding the new state object will be destroyed and the former value of L will be restored. Nothing else need be done to clean up the parsing context. The code to be parsed comes from C and C. C, if non-null, provides a string (in SV form) containing code to be parsed. A copy of the string is made, so subsequent modification of C does not affect parsing. C, if non-null, provides an input stream from which code will be read to be parsed. If both are non-null, the code in C comes first and must consist of complete lines of input, and C supplies the remainder of the source. The C parameter is reserved for future use. Currently it is only used by perl internally, so extensions should always pass zero. void lex_start(SV *line, PerlIO *rsfp, U32 flags) =for hackers Found in file toke.c =item lex_stuff_pv X NOTE: this function is experimental and may change or be removed without notice. Insert characters into the lexer buffer (Llinestr>), immediately after the current lexing point (Lbufptr>), reallocating the buffer if necessary. This means that lexing code that runs later will see the characters as if they had appeared in the input. It is not recommended to do this as part of normal parsing, and most uses of this facility run the risk of the inserted characters being interpreted in an unintended manner. The string to be inserted is represented by octets starting at C and continuing to the first nul. These octets are interpreted as either UTF-8 or Latin-1, according to whether the C flag is set in C. The characters are recoded for the lexer buffer, according to how the buffer is currently being interpreted (L). If it is not convenient to nul-terminate a string to be inserted, the L function is more appropriate. void lex_stuff_pv(const char *pv, U32 flags) =for hackers Found in file toke.c =item lex_stuff_pvn X NOTE: this function is experimental and may change or be removed without notice. Insert characters into the lexer buffer (Llinestr>), immediately after the current lexing point (Lbufptr>), reallocating the buffer if necessary. This means that lexing code that runs later will see the characters as if they had appeared in the input. It is not recommended to do this as part of normal parsing, and most uses of this facility run the risk of the inserted characters being interpreted in an unintended manner. The string to be inserted is represented by C octets starting at C. These octets are interpreted as either UTF-8 or Latin-1, according to whether the C flag is set in C. The characters are recoded for the lexer buffer, according to how the buffer is currently being interpreted (L). If a string to be inserted is available as a Perl scalar, the L function is more convenient. void lex_stuff_pvn(const char *pv, STRLEN len, U32 flags) =for hackers Found in file toke.c =item lex_stuff_pvs X NOTE: this function is experimental and may change or be removed without notice. Like L, but takes a C-terminated literal string instead of a string/length pair. void lex_stuff_pvs(const char *pv, U32 flags) =for hackers Found in file handy.h =item lex_stuff_sv X NOTE: this function is experimental and may change or be removed without notice. Insert characters into the lexer buffer (Llinestr>), immediately after the current lexing point (Lbufptr>), reallocating the buffer if necessary. This means that lexing code that runs later will see the characters as if they had appeared in the input. It is not recommended to do this as part of normal parsing, and most uses of this facility run the risk of the inserted characters being interpreted in an unintended manner. The string to be inserted is the string value of C. The characters are recoded for the lexer buffer, according to how the buffer is currently being interpreted (L). If a string to be inserted is not already a Perl scalar, the L function avoids the need to construct a scalar. void lex_stuff_sv(SV *sv, U32 flags) =for hackers Found in file toke.c =item lex_unstuff X NOTE: this function is experimental and may change or be removed without notice. Discards text about to be lexed, from Lbufptr> up to C. Text following C will be moved, and the buffer shortened. This hides the discarded text from any lexing code that runs later, as if the text had never appeared. This is not the normal way to consume lexed text. For that, use L. void lex_unstuff(char *ptr) =for hackers Found in file toke.c =item parse_arithexpr X NOTE: this function is experimental and may change or be removed without notice. Parse a Perl arithmetic expression. This may contain operators of precedence down to the bit shift operators. The expression must be followed (and thus terminated) either by a comparison or lower-precedence operator or by something that would normally terminate an expression such as semicolon. If C has the C bit set, then the expression is optional, otherwise it is mandatory. It is up to the caller to ensure that the dynamic parser state (L et al) is correctly set to reflect the source of the code to be parsed and the lexical context for the expression. The op tree representing the expression is returned. If an optional expression is absent, a null pointer is returned, otherwise the pointer will be non-null. If an error occurs in parsing or compilation, in most cases a valid op tree is returned anyway. The error is reflected in the parser state, normally resulting in a single exception at the top level of parsing which covers all the compilation errors that occurred. Some compilation errors, however, will throw an exception immediately. OP * parse_arithexpr(U32 flags) =for hackers Found in file toke.c =item parse_barestmt X NOTE: this function is experimental and may change or be removed without notice. Parse a single unadorned Perl statement. This may be a normal imperative statement or a declaration that has compile-time effect. It does not include any label or other affixture. It is up to the caller to ensure that the dynamic parser state (L et al) is correctly set to reflect the source of the code to be parsed and the lexical context for the statement. The op tree representing the statement is returned. This may be a null pointer if the statement is null, for example if it was actually a subroutine definition (which has compile-time side effects). If not null, it will be ops directly implementing the statement, suitable to pass to L. It will not normally include a C or equivalent op (except for those embedded in a scope contained entirely within the statement). If an error occurs in parsing or compilation, in most cases a valid op tree (most likely null) is returned anyway. The error is reflected in the parser state, normally resulting in a single exception at the top level of parsing which covers all the compilation errors that occurred. Some compilation errors, however, will throw an exception immediately. The C parameter is reserved for future use, and must always be zero. OP * parse_barestmt(U32 flags) =for hackers Found in file toke.c =item parse_block X NOTE: this function is experimental and may change or be removed without notice. Parse a single complete Perl code block. This consists of an opening brace, a sequence of statements, and a closing brace. The block constitutes a lexical scope, so C variables and various compile-time effects can be contained within it. It is up to the caller to ensure that the dynamic parser state (L et al) is correctly set to reflect the source of the code to be parsed and the lexical context for the statement. The op tree representing the code block is returned. This is always a real op, never a null pointer. It will normally be a C list, including C or equivalent ops. No ops to construct any kind of runtime scope are included by virtue of it being a block. If an error occurs in parsing or compilation, in most cases a valid op tree (most likely null) is returned anyway. The error is reflected in the parser state, normally resulting in a single exception at the top level of parsing which covers all the compilation errors that occurred. Some compilation errors, however, will throw an exception immediately. The C parameter is reserved for future use, and must always be zero. OP * parse_block(U32 flags) =for hackers Found in file toke.c =item parse_fullexpr X NOTE: this function is experimental and may change or be removed without notice. Parse a single complete Perl expression. This allows the full expression grammar, including the lowest-precedence operators such as C. The expression must be followed (and thus terminated) by a token that an expression would normally be terminated by: end-of-file, closing bracketing punctuation, semicolon, or one of the keywords that signals a postfix expression-statement modifier. If C has the C bit set, then the expression is optional, otherwise it is mandatory. It is up to the caller to ensure that the dynamic parser state (L et al) is correctly set to reflect the source of the code to be parsed and the lexical context for the expression. The op tree representing the expression is returned. If an optional expression is absent, a null pointer is returned, otherwise the pointer will be non-null. If an error occurs in parsing or compilation, in most cases a valid op tree is returned anyway. The error is reflected in the parser state, normally resulting in a single exception at the top level of parsing which covers all the compilation errors that occurred. Some compilation errors, however, will throw an exception immediately. OP * parse_fullexpr(U32 flags) =for hackers Found in file toke.c =item parse_fullstmt X NOTE: this function is experimental and may change or be removed without notice. Parse a single complete Perl statement. This may be a normal imperative statement or a declaration that has compile-time effect, and may include optional labels. It is up to the caller to ensure that the dynamic parser state (L et al) is correctly set to reflect the source of the code to be parsed and the lexical context for the statement. The op tree representing the statement is returned. This may be a null pointer if the statement is null, for example if it was actually a subroutine definition (which has compile-time side effects). If not null, it will be the result of a L call, normally including a C or equivalent op. If an error occurs in parsing or compilation, in most cases a valid op tree (most likely null) is returned anyway. The error is reflected in the parser state, normally resulting in a single exception at the top level of parsing which covers all the compilation errors that occurred. Some compilation errors, however, will throw an exception immediately. The C parameter is reserved for future use, and must always be zero. OP * parse_fullstmt(U32 flags) =for hackers Found in file toke.c =item parse_label X NOTE: this function is experimental and may change or be removed without notice. Parse a single label, possibly optional, of the type that may prefix a Perl statement. It is up to the caller to ensure that the dynamic parser state (L et al) is correctly set to reflect the source of the code to be parsed. If C has the C bit set, then the label is optional, otherwise it is mandatory. The name of the label is returned in the form of a fresh scalar. If an optional label is absent, a null pointer is returned. If an error occurs in parsing, which can only occur if the label is mandatory, a valid label is returned anyway. The error is reflected in the parser state, normally resulting in a single exception at the top level of parsing which covers all the compilation errors that occurred. SV * parse_label(U32 flags) =for hackers Found in file toke.c =item parse_listexpr X NOTE: this function is experimental and may change or be removed without notice. Parse a Perl list expression. This may contain operators of precedence down to the comma operator. The expression must be followed (and thus terminated) either by a low-precedence logic operator such as C or by something that would normally terminate an expression such as semicolon. If C has the C bit set, then the expression is optional, otherwise it is mandatory. It is up to the caller to ensure that the dynamic parser state (L et al) is correctly set to reflect the source of the code to be parsed and the lexical context for the expression. The op tree representing the expression is returned. If an optional expression is absent, a null pointer is returned, otherwise the pointer will be non-null. If an error occurs in parsing or compilation, in most cases a valid op tree is returned anyway. The error is reflected in the parser state, normally resulting in a single exception at the top level of parsing which covers all the compilation errors that occurred. Some compilation errors, however, will throw an exception immediately. OP * parse_listexpr(U32 flags) =for hackers Found in file toke.c =item parse_stmtseq X NOTE: this function is experimental and may change or be removed without notice. Parse a sequence of zero or more Perl statements. These may be normal imperative statements, including optional labels, or declarations that have compile-time effect, or any mixture thereof. The statement sequence ends when a closing brace or end-of-file is encountered in a place where a new statement could have validly started. It is up to the caller to ensure that the dynamic parser state (L et al) is correctly set to reflect the source of the code to be parsed and the lexical context for the statements. The op tree representing the statement sequence is returned. This may be a null pointer if the statements were all null, for example if there were no statements or if there were only subroutine definitions (which have compile-time side effects). If not null, it will be a C list, normally including C or equivalent ops. If an error occurs in parsing or compilation, in most cases a valid op tree is returned anyway. The error is reflected in the parser state, normally resulting in a single exception at the top level of parsing which covers all the compilation errors that occurred. Some compilation errors, however, will throw an exception immediately. The C parameter is reserved for future use, and must always be zero. OP * parse_stmtseq(U32 flags) =for hackers Found in file toke.c =item parse_termexpr X NOTE: this function is experimental and may change or be removed without notice. Parse a Perl term expression. This may contain operators of precedence down to the assignment operators. The expression must be followed (and thus terminated) either by a comma or lower-precedence operator or by something that would normally terminate an expression such as semicolon. If C has the C bit set, then the expression is optional, otherwise it is mandatory. It is up to the caller to ensure that the dynamic parser state (L et al) is correctly set to reflect the source of the code to be parsed and the lexical context for the expression. The op tree representing the expression is returned. If an optional expression is absent, a null pointer is returned, otherwise the pointer will be non-null. If an error occurs in parsing or compilation, in most cases a valid op tree is returned anyway. The error is reflected in the parser state, normally resulting in a single exception at the top level of parsing which covers all the compilation errors that occurred. Some compilation errors, however, will throw an exception immediately. OP * parse_termexpr(U32 flags) =for hackers Found in file toke.c =item PL_parser X Pointer to a structure encapsulating the state of the parsing operation currently in progress. The pointer can be locally changed to perform a nested parse without interfering with the state of an outer parse. Individual members of C have their own documentation. =for hackers Found in file toke.c =item PL_parser-Ebufend Xbufend> NOTE: this function is experimental and may change or be removed without notice. Direct pointer to the end of the chunk of text currently being lexed, the end of the lexer buffer. This is equal to Clinestr) + SvCUR(PL_parser-Elinestr)>. A C character (zero octet) is always located at the end of the buffer, and does not count as part of the buffer's contents. =for hackers Found in file toke.c =item PL_parser-Ebufptr Xbufptr> NOTE: this function is experimental and may change or be removed without notice. Points to the current position of lexing inside the lexer buffer. Characters around this point may be freely examined, within the range delimited by Clinestr>)> and Lbufend>. The octets of the buffer may be intended to be interpreted as either UTF-8 or Latin-1, as indicated by L. Lexing code (whether in the Perl core or not) moves this pointer past the characters that it consumes. It is also expected to perform some bookkeeping whenever a newline character is consumed. This movement can be more conveniently performed by the function L, which handles newlines appropriately. Interpretation of the buffer's octets can be abstracted out by using the slightly higher-level functions L and L. =for hackers Found in file toke.c =item PL_parser-Elinestart Xlinestart> NOTE: this function is experimental and may change or be removed without notice. Points to the start of the current line inside the lexer buffer. This is useful for indicating at which column an error occurred, and not much else. This must be updated by any lexing code that consumes a newline; the function L handles this detail. =for hackers Found in file toke.c =item PL_parser-Elinestr Xlinestr> NOTE: this function is experimental and may change or be removed without notice. Buffer scalar containing the chunk currently under consideration of the text currently being lexed. This is always a plain string scalar (for which C is true). It is not intended to be used as a scalar by normal scalar means; instead refer to the buffer directly by the pointer variables described below. The lexer maintains various C pointers to things in the Clinestr> buffer. If Clinestr> is ever reallocated, all of these pointers must be updated. Don't attempt to do this manually, but rather use L if you need to reallocate the buffer. The content of the text chunk in the buffer is commonly exactly one complete line of input, up to and including a newline terminator, but there are situations where it is otherwise. The octets of the buffer may be intended to be interpreted as either UTF-8 or Latin-1. The function L tells you which. Do not use the C flag on this scalar, which may disagree with it. For direct examination of the buffer, the variable Lbufend> points to the end of the buffer. The current lexing position is pointed to by Lbufptr>. Direct use of these pointers is usually preferable to examination of the scalar through normal scalar means. =for hackers Found in file toke.c =back =head1 Locale-related functions and macros =over 8 =item DECLARATION_FOR_LC_NUMERIC_MANIPULATION X This macro should be used as a statement. It declares a private variable (whose name begins with an underscore) that is needed by the other macros in this section. Failing to include this correctly should lead to a syntax error. For compatibility with C89 C compilers it should be placed in a block before any executable statements. void DECLARATION_FOR_LC_NUMERIC_MANIPULATION =for hackers Found in file perl.h =item RESTORE_LC_NUMERIC X This is used in conjunction with one of the macros L and L to properly restore the C state. A call to L must have been made to declare at compile time a private variable used by this macro and the two C ones. This macro should be called as a single statement, not an expression, but with an empty argument list, like this: { DECLARATION_FOR_LC_NUMERIC_MANIPULATION; ... RESTORE_LC_NUMERIC(); ... } void RESTORE_LC_NUMERIC() =for hackers Found in file perl.h =item STORE_LC_NUMERIC_FORCE_TO_UNDERLYING X This is used by XS code that that is C locale-aware to force the locale for category C to be what perl thinks is the current underlying locale. (The perl interpreter could be wrong about what the underlying locale actually is if some C or XS code has called the C library function L behind its back; calling L before calling this macro will update perl's records.) A call to L must have been made to declare at compile time a private variable used by this macro. This macro should be called as a single statement, not an expression, but with an empty argument list, like this: { DECLARATION_FOR_LC_NUMERIC_MANIPULATION; ... STORE_LC_NUMERIC_FORCE_TO_UNDERLYING(); ... RESTORE_LC_NUMERIC(); ... } The private variable is used to save the current locale state, so that the requisite matching call to L can restore it. void STORE_LC_NUMERIC_FORCE_TO_UNDERLYING() =for hackers Found in file perl.h =item STORE_LC_NUMERIC_SET_TO_NEEDED X This is used to help wrap XS or C code that that is C locale-aware. This locale category is generally kept set to the C locale by Perl for backwards compatibility, and because most XS code that reads floating point values can cope only with the decimal radix character being a dot. This macro makes sure the current C state is set properly, to be aware of locale if the call to the XS or C code from the Perl program is from within the scope of a S>; or to ignore locale if the call is instead from outside such scope. This macro is the start of wrapping the C or XS code; the wrap ending is done by calling the L macro after the operation. Otherwise the state can be changed that will adversely affect other XS code. A call to L must have been made to declare at compile time a private variable used by this macro. This macro should be called as a single statement, not an expression, but with an empty argument list, like this: { DECLARATION_FOR_LC_NUMERIC_MANIPULATION; ... STORE_LC_NUMERIC_SET_TO_NEEDED(); ... RESTORE_LC_NUMERIC(); ... } void STORE_LC_NUMERIC_SET_TO_NEEDED() =for hackers Found in file perl.h =item sync_locale X Changing the program's locale should be avoided by XS code. Nevertheless, certain non-Perl libraries called from XS, such as C do so. When this happens, Perl needs to be told that the locale has changed. Use this function to do so, before returning to Perl. void sync_locale() =for hackers Found in file locale.c =back =head1 Magical Functions =over 8 =item mg_clear X Clear something magical that the SV represents. See C>. int mg_clear(SV* sv) =for hackers Found in file mg.c =item mg_copy X Copies the magic from one SV to another. See C>. int mg_copy(SV *sv, SV *nsv, const char *key, I32 klen) =for hackers Found in file mg.c =item mg_find X Finds the magic pointer for C matching the SV. See C>. MAGIC* mg_find(const SV* sv, int type) =for hackers Found in file mg.c =item mg_findext X Finds the magic pointer of C with the given C for the C. See C>. MAGIC* mg_findext(const SV* sv, int type, const MGVTBL *vtbl) =for hackers Found in file mg.c =item mg_free X Free any magic storage used by the SV. See C>. int mg_free(SV* sv) =for hackers Found in file mg.c =item mg_free_type X Remove any magic of type C from the SV C. See L. void mg_free_type(SV *sv, int how) =for hackers Found in file mg.c =item mg_get X Do magic before a value is retrieved from the SV. The type of SV must be >= C. See C>. int mg_get(SV* sv) =for hackers Found in file mg.c =item mg_length X DEPRECATED! It is planned to remove this function from a future release of Perl. Do not use it for new code; remove it from existing code. Reports on the SV's length in bytes, calling length magic if available, but does not set the UTF8 flag on C. It will fall back to 'get' magic if there is no 'length' magic, but with no indication as to whether it called 'get' magic. It assumes C is a C or higher. Use C instead. U32 mg_length(SV* sv) =for hackers Found in file mg.c =item mg_magical X Turns on the magical status of an SV. See C>. void mg_magical(SV* sv) =for hackers Found in file mg.c =item mg_set X Do magic after a value is assigned to the SV. See C>. int mg_set(SV* sv) =for hackers Found in file mg.c =item SvGETMAGIC X Invokes C on an SV if it has 'get' magic. For example, this will call C on a tied variable. This macro evaluates its argument more than once. void SvGETMAGIC(SV* sv) =for hackers Found in file sv.h =item SvLOCK X Arranges for a mutual exclusion lock to be obtained on C if a suitable module has been loaded. void SvLOCK(SV* sv) =for hackers Found in file sv.h =item SvSETMAGIC X Invokes C on an SV if it has 'set' magic. This is necessary after modifying a scalar, in case it is a magical variable like C<$|> or a tied variable (it calls C). This macro evaluates its argument more than once. void SvSETMAGIC(SV* sv) =for hackers Found in file sv.h =item SvSetMagicSV X Like C, but does any set magic required afterwards. void SvSetMagicSV(SV* dsv, SV* ssv) =for hackers Found in file sv.h =item SvSetMagicSV_nosteal X Like C, but does any set magic required afterwards. void SvSetMagicSV_nosteal(SV* dsv, SV* ssv) =for hackers Found in file sv.h =item SvSetSV X Calls C if C is not the same as C. May evaluate arguments more than once. Does not handle 'set' magic on the destination SV. void SvSetSV(SV* dsv, SV* ssv) =for hackers Found in file sv.h =item SvSetSV_nosteal X Calls a non-destructive version of C if C is not the same as C. May evaluate arguments more than once. void SvSetSV_nosteal(SV* dsv, SV* ssv) =for hackers Found in file sv.h =item SvSHARE X Arranges for C to be shared between threads if a suitable module has been loaded. void SvSHARE(SV* sv) =for hackers Found in file sv.h =item SvUNLOCK X Releases a mutual exclusion lock on C if a suitable module has been loaded. void SvUNLOCK(SV* sv) =for hackers Found in file sv.h =back =head1 Memory Management =over 8 =item Copy X The XSUB-writer's interface to the C C function. The C is the source, C is the destination, C is the number of items, and C is the type. May fail on overlapping copies. See also C>. void Copy(void* src, void* dest, int nitems, type) =for hackers Found in file handy.h =item CopyD X Like C but returns C. Useful for encouraging compilers to tail-call optimise. void * CopyD(void* src, void* dest, int nitems, type) =for hackers Found in file handy.h =item Move X The XSUB-writer's interface to the C C function. The C is the source, C is the destination, C is the number of items, and C is the type. Can do overlapping moves. See also C>. void Move(void* src, void* dest, int nitems, type) =for hackers Found in file handy.h =item MoveD X Like C but returns C. Useful for encouraging compilers to tail-call optimise. void * MoveD(void* src, void* dest, int nitems, type) =for hackers Found in file handy.h =item Newx X The XSUB-writer's interface to the C C function. Memory obtained by this should B be freed with L<"Safefree">. In 5.9.3, Newx() and friends replace the older New() API, and drops the first parameter, I, a debug aid which allowed callers to identify themselves. This aid has been superseded by a new build option, PERL_MEM_LOG (see L). The older API is still there for use in XS modules supporting older perls. void Newx(void* ptr, int nitems, type) =for hackers Found in file handy.h =item Newxc X The XSUB-writer's interface to the C C function, with cast. See also C>. Memory obtained by this should B be freed with L<"Safefree">. void Newxc(void* ptr, int nitems, type, cast) =for hackers Found in file handy.h =item Newxz X The XSUB-writer's interface to the C C function. The allocated memory is zeroed with C. See also C>. Memory obtained by this should B be freed with L<"Safefree">. void Newxz(void* ptr, int nitems, type) =for hackers Found in file handy.h =item Poison X PoisonWith(0xEF) for catching access to freed memory. void Poison(void* dest, int nitems, type) =for hackers Found in file handy.h =item PoisonFree X PoisonWith(0xEF) for catching access to freed memory. void PoisonFree(void* dest, int nitems, type) =for hackers Found in file handy.h =item PoisonNew X PoisonWith(0xAB) for catching access to allocated but uninitialized memory. void PoisonNew(void* dest, int nitems, type) =for hackers Found in file handy.h =item PoisonWith X Fill up memory with a byte pattern (a byte repeated over and over again) that hopefully catches attempts to access uninitialized memory. void PoisonWith(void* dest, int nitems, type, U8 byte) =for hackers Found in file handy.h =item Renew X The XSUB-writer's interface to the C C function. Memory obtained by this should B be freed with L<"Safefree">. void Renew(void* ptr, int nitems, type) =for hackers Found in file handy.h =item Renewc X The XSUB-writer's interface to the C C function, with cast. Memory obtained by this should B be freed with L<"Safefree">. void Renewc(void* ptr, int nitems, type, cast) =for hackers Found in file handy.h =item Safefree X The XSUB-writer's interface to the C C function. This should B be used on memory obtained using L<"Newx"> and friends. void Safefree(void* ptr) =for hackers Found in file handy.h =item savepv X Perl's version of C. Returns a pointer to a newly allocated string which is a duplicate of C. The size of the string is determined by C, which means it may not contain embedded C characters and must have a trailing C. The memory allocated for the new string can be freed with the C function. On some platforms, Windows for example, all allocated memory owned by a thread is deallocated when that thread ends. So if you need that not to happen, you need to use the shared memory functions, such as C>. char* savepv(const char* pv) =for hackers Found in file util.c =item savepvn X Perl's version of what C would be if it existed. Returns a pointer to a newly allocated string which is a duplicate of the first C bytes from C, plus a trailing C byte. The memory allocated for the new string can be freed with the C function. On some platforms, Windows for example, all allocated memory owned by a thread is deallocated when that thread ends. So if you need that not to happen, you need to use the shared memory functions, such as C>. char* savepvn(const char* pv, I32 len) =for hackers Found in file util.c =item savepvs X Like C, but takes a C-terminated literal string instead of a string/length pair. char* savepvs(const char* s) =for hackers Found in file handy.h =item savesharedpv X A version of C which allocates the duplicate string in memory which is shared between threads. char* savesharedpv(const char* pv) =for hackers Found in file util.c =item savesharedpvn X A version of C which allocates the duplicate string in memory which is shared between threads. (With the specific difference that a C pointer is not acceptable) char* savesharedpvn(const char *const pv, const STRLEN len) =for hackers Found in file util.c =item savesharedpvs X A version of C which allocates the duplicate string in memory which is shared between threads. char* savesharedpvs(const char* s) =for hackers Found in file handy.h =item savesharedsvpv X A version of C which allocates the duplicate string in memory which is shared between threads. char* savesharedsvpv(SV *sv) =for hackers Found in file util.c =item savesvpv X A version of C/C which gets the string to duplicate from the passed in SV using C On some platforms, Windows for example, all allocated memory owned by a thread is deallocated when that thread ends. So if you need that not to happen, you need to use the shared memory functions, such as C>. char* savesvpv(SV* sv) =for hackers Found in file util.c =item StructCopy X This is an architecture-independent macro to copy one structure to another. void StructCopy(type *src, type *dest, type) =for hackers Found in file handy.h =item Zero X The XSUB-writer's interface to the C C function. The C is the destination, C is the number of items, and C is the type. void Zero(void* dest, int nitems, type) =for hackers Found in file handy.h =item ZeroD X Like C but returns dest. Useful for encouraging compilers to tail-call optimise. void * ZeroD(void* dest, int nitems, type) =for hackers Found in file handy.h =back =head1 Miscellaneous Functions =over 8 =item dump_c_backtrace X Dumps the C backtrace to the given C. Returns true if a backtrace could be retrieved, false if not. bool dump_c_backtrace(PerlIO* fp, int max_depth, int skip) =for hackers Found in file util.c =item fbm_compile X Analyses the string in order to make fast searches on it using C -- the Boyer-Moore algorithm. void fbm_compile(SV* sv, U32 flags) =for hackers Found in file util.c =item fbm_instr X Returns the location of the SV in the string delimited by C and C (C) is the char following the last char). It returns C if the string can't be found. The C does not have to be C, but the search will not be as fast then. char* fbm_instr(unsigned char* big, unsigned char* bigend, SV* littlestr, U32 flags) =for hackers Found in file util.c =item foldEQ X Returns true if the leading C bytes of the strings C and C are the same case-insensitively; false otherwise. Uppercase and lowercase ASCII range bytes match themselves and their opposite case counterparts. Non-cased and non-ASCII range bytes match only themselves. I32 foldEQ(const char* a, const char* b, I32 len) =for hackers Found in file util.c =item foldEQ_locale X Returns true if the leading C bytes of the strings C and C are the same case-insensitively in the current locale; false otherwise. I32 foldEQ_locale(const char* a, const char* b, I32 len) =for hackers Found in file util.c =item form X

Takes a sprintf-style format pattern and conventional (non-SV) arguments and returns the formatted string. (char *) Perl_form(pTHX_ const char* pat, ...) can be used any place a string (char *) is required: char * s = Perl_form("%d.%d",major,minor); Uses a single private buffer so if you want to format several strings you must explicitly copy the earlier strings away (and free the copies when you are done). char* form(const char* pat, ...) =for hackers Found in file util.c =item getcwd_sv X Fill C with current working directory int getcwd_sv(SV* sv) =for hackers Found in file util.c =item get_c_backtrace_dump X Returns a SV containing a dump of C frames of the call stack, skipping the C innermost ones. C of 20 is usually enough. The appended output looks like: ... 1 10e004812:0082 Perl_croak util.c:1716 /usr/bin/perl 2 10df8d6d2:1d72 perl_parse perl.c:3975 /usr/bin/perl ... The fields are tab-separated. The first column is the depth (zero being the innermost non-skipped frame). In the hex:offset, the hex is where the program counter was in C, and the :offset (might be missing) tells how much inside the C the program counter was. The C is the source code file and line number. The F is obvious (hopefully). Unknowns are C<"-">. Unknowns can happen unfortunately quite easily: if the platform doesn't support retrieving the information; if the binary is missing the debug information; if the optimizer has transformed the code by for example inlining. SV* get_c_backtrace_dump(int max_depth, int skip) =for hackers Found in file util.c =item ibcmp X This is a synonym for S> I32 ibcmp(const char* a, const char* b, I32 len) =for hackers Found in file util.h =item ibcmp_locale X This is a synonym for S> I32 ibcmp_locale(const char* a, const char* b, I32 len) =for hackers Found in file util.h =item is_safe_syscall X Test that the given C doesn't contain any internal C characters. If it does, set C to C, optionally warn, and return FALSE. Return TRUE if the name is safe. Used by the C macro. bool is_safe_syscall(const char *pv, STRLEN len, const char *what, const char *op_name) =for hackers Found in file inline.h =item memEQ X Test two buffers (which may contain embedded C characters, to see if they are equal. The C parameter indicates the number of bytes to compare. Returns zero if equal, or non-zero if non-equal. bool memEQ(char* s1, char* s2, STRLEN len) =for hackers Found in file handy.h =item memNE X Test two buffers (which may contain embedded C characters, to see if they are not equal. The C parameter indicates the number of bytes to compare. Returns zero if non-equal, or non-zero if equal. bool memNE(char* s1, char* s2, STRLEN len) =for hackers Found in file handy.h =item mess X Take a sprintf-style format pattern and argument list. These are used to generate a string message. If the message does not end with a newline, then it will be extended with some indication of the current location in the code, as described for L. Normally, the resulting message is returned in a new mortal SV. During global destruction a single SV may be shared between uses of this function. SV * mess(const char *pat, ...) =for hackers Found in file util.c =item mess_sv X Expands a message, intended for the user, to include an indication of the current location in the code, if the message does not already appear to be complete. C is the initial message or object. If it is a reference, it will be used as-is and will be the result of this function. Otherwise it is used as a string, and if it already ends with a newline, it is taken to be complete, and the result of this function will be the same string. If the message does not end with a newline, then a segment such as C will be appended, and possibly other clauses indicating the current state of execution. The resulting message will end with a dot and a newline. Normally, the resulting message is returned in a new mortal SV. During global destruction a single SV may be shared between uses of this function. If C is true, then the function is permitted (but not required) to modify and return C instead of allocating a new SV. SV * mess_sv(SV *basemsg, bool consume) =for hackers Found in file util.c =item my_snprintf X The C library C functionality, if available and standards-compliant (uses C, actually). However, if the C is not available, will unfortunately use the unsafe C which can overrun the buffer (there is an overrun check, but that may be too late). Consider using C instead, or getting C. int my_snprintf(char *buffer, const Size_t len, const char *format, ...) =for hackers Found in file util.c =item my_sprintf X The C library C, wrapped if necessary, to ensure that it will return the length of the string written to the buffer. Only rare pre-ANSI systems need the wrapper function - usually this is a direct call to C. int my_sprintf(char *buffer, const char *pat, ...) =for hackers Found in file util.c =item my_strlcat X The C library C if available, or a Perl implementation of it. This operates on C C-terminated strings. C appends string C to the end of C. It will append at most S> characters. It will then C-terminate, unless C is 0 or the original C string was longer than C (in practice this should not happen as it means that either C is incorrect or that C is not a proper C-terminated string). Note that C is the full size of the destination buffer and the result is guaranteed to be C-terminated if there is room. Note that room for the C should be included in C. Size_t my_strlcat(char *dst, const char *src, Size_t size) =for hackers Found in file util.c =item my_strlcpy X The C library C if available, or a Perl implementation of it. This operates on C C-terminated strings. C copies up to S> characters from the string C to C, C-terminating the result if C is not 0. Size_t my_strlcpy(char *dst, const char *src, Size_t size) =for hackers Found in file util.c =item my_vsnprintf X The C library C if available and standards-compliant. However, if if the C is not available, will unfortunately use the unsafe C which can overrun the buffer (there is an overrun check, but that may be too late). Consider using C instead, or getting C. int my_vsnprintf(char *buffer, const Size_t len, const char *format, va_list ap) =for hackers Found in file util.c =item ninstr X Find the first (leftmost) occurrence of a sequence of bytes within another sequence. This is the Perl version of C, extended to handle arbitrary sequences, potentially containing embedded C characters (C is what the initial C in the function name stands for; some systems have an equivalent, C, but with a somewhat different API). Another way of thinking about this function is finding a needle in a haystack. C points to the first byte in the haystack. C points to one byte beyond the final byte in the haystack. C points to the first byte in the needle. C points to one byte beyond the final byte in the needle. All the parameters must be non-C. The function returns C if there is no occurrence of C within C. If C is the empty string, C is returned. Because this function operates at the byte level, and because of the inherent characteristics of UTF-8 (or UTF-EBCDIC), it will work properly if both the needle and the haystack are strings with the same UTF-8ness, but not if the UTF-8ness differs. char * ninstr(char * big, char * bigend, char * little, char * little_end) =for hackers Found in file util.c =item PERL_SYS_INIT X Provides system-specific tune up of the C runtime environment necessary to run Perl interpreters. This should be called only once, before creating any Perl interpreters. void PERL_SYS_INIT(int *argc, char*** argv) =for hackers Found in file perl.h =item PERL_SYS_INIT3 X Provides system-specific tune up of the C runtime environment necessary to run Perl interpreters. This should be called only once, before creating any Perl interpreters. void PERL_SYS_INIT3(int *argc, char*** argv, char*** env) =for hackers Found in file perl.h =item PERL_SYS_TERM X Provides system-specific clean up of the C runtime environment after running Perl interpreters. This should be called only once, after freeing any remaining Perl interpreters. void PERL_SYS_TERM() =for hackers Found in file perl.h =item quadmath_format_needed X C returns true if the C string seems to contain at least one non-Q-prefixed C<%[efgaEFGA]> format specifier, or returns false otherwise. The format specifier detection is not complete printf-syntax detection, but it should catch most common cases. If true is returned, those arguments B in theory be processed with C, but in case there is more than one such format specifier (see L), and if there is anything else beyond that one (even just a single byte), they B be processed because C is very strict, accepting only one format spec, and nothing else. In this case, the code should probably fail. bool quadmath_format_needed(const char* format) =for hackers Found in file util.c =item quadmath_format_single X C is very strict about its C string and will fail, returning -1, if the format is invalid. It accepts exactly one format spec. C checks that the intended single spec looks sane: begins with C<%>, has only one C<%>, ends with C<[efgaEFGA]>, and has C before it. This is not a full "printf syntax check", just the basics. Returns the format if it is valid, NULL if not. C can and will actually patch in the missing C, if necessary. In this case it will return the modified copy of the format, B See also L. const char* quadmath_format_single(const char* format) =for hackers Found in file util.c =item READ_XDIGIT X Returns the value of an ASCII-range hex digit and advances the string pointer. Behaviour is only well defined when isXDIGIT(*str) is true. U8 READ_XDIGIT(char str*) =for hackers Found in file handy.h =item rninstr X Like C>, but instead finds the final (rightmost) occurrence of a sequence of bytes within another sequence, returning C if there is no such occurrence. char * rninstr(char * big, char * bigend, char * little, char * little_end) =for hackers Found in file util.c =item strEQ X Test two C-terminated strings to see if they are equal. Returns true or false. bool strEQ(char* s1, char* s2) =for hackers Found in file handy.h =item strGE X Test two C-terminated strings to see if the first, C, is greater than or equal to the second, C. Returns true or false. bool strGE(char* s1, char* s2) =for hackers Found in file handy.h =item strGT X Test two C-terminated strings to see if the first, C, is greater than the second, C. Returns true or false. bool strGT(char* s1, char* s2) =for hackers Found in file handy.h =item strLE X Test two C-terminated strings to see if the first, C, is less than or equal to the second, C. Returns true or false. bool strLE(char* s1, char* s2) =for hackers Found in file handy.h =item strLT X Test two C-terminated strings to see if the first, C, is less than the second, C. Returns true or false. bool strLT(char* s1, char* s2) =for hackers Found in file handy.h =item strNE X Test two C-terminated strings to see if they are different. Returns true or false. bool strNE(char* s1, char* s2) =for hackers Found in file handy.h =item strnEQ X Test two C-terminated strings to see if they are equal. The C parameter indicates the number of bytes to compare. Returns true or false. (A wrapper for C). bool strnEQ(char* s1, char* s2, STRLEN len) =for hackers Found in file handy.h =item strnNE X Test two C-terminated strings to see if they are different. The C parameter indicates the number of bytes to compare. Returns true or false. (A wrapper for C). bool strnNE(char* s1, char* s2, STRLEN len) =for hackers Found in file handy.h =item sv_destroyable X Dummy routine which reports that object can be destroyed when there is no sharing module present. It ignores its single SV argument, and returns 'true'. Exists to avoid test for a C function pointer and because it could potentially warn under some level of strict-ness. bool sv_destroyable(SV *sv) =for hackers Found in file util.c =item sv_nosharing X Dummy routine which "shares" an SV when there is no sharing module present. Or "locks" it. Or "unlocks" it. In other words, ignores its single SV argument. Exists to avoid test for a C function pointer and because it could potentially warn under some level of strict-ness. void sv_nosharing(SV *sv) =for hackers Found in file util.c =item vmess X C and C are a sprintf-style format pattern and encapsulated argument list, respectively. These are used to generate a string message. If the message does not end with a newline, then it will be extended with some indication of the current location in the code, as described for L. Normally, the resulting message is returned in a new mortal SV. During global destruction a single SV may be shared between uses of this function. SV * vmess(const char *pat, va_list *args) =for hackers Found in file util.c =back =head1 MRO Functions These functions are related to the method resolution order of perl classes =over 8 =item mro_get_linear_isa X Returns the mro linearisation for the given stash. By default, this will be whatever C returns unless some other MRO is in effect for the stash. The return value is a read-only AV*. You are responsible for C on the return value if you plan to store it anywhere semi-permanently (otherwise it might be deleted out from under you the next time the cache is invalidated). AV* mro_get_linear_isa(HV* stash) =for hackers Found in file mro_core.c =item mro_method_changed_in X Invalidates method caching on any child classes of the given stash, so that they might notice the changes in this one. Ideally, all instances of C in perl source outside of F should be replaced by calls to this. Perl automatically handles most of the common ways a method might be redefined. However, there are a few ways you could change a method in a stash without the cache code noticing, in which case you need to call this method afterwards: 1) Directly manipulating the stash HV entries from XS code. 2) Assigning a reference to a readonly scalar constant into a stash entry in order to create a constant subroutine (like F does). This same method is available from pure perl via, C. void mro_method_changed_in(HV* stash) =for hackers Found in file mro_core.c =item mro_register X Registers a custom mro plugin. See L for details. void mro_register(const struct mro_alg *mro) =for hackers Found in file mro_core.c =back =head1 Multicall Functions =over 8 =item dMULTICALL X Declare local variables for a multicall. See L. dMULTICALL; =for hackers Found in file cop.h =item MULTICALL X Make a lightweight callback. See L. MULTICALL; =for hackers Found in file cop.h =item POP_MULTICALL X Closing bracket for a lightweight callback. See L. POP_MULTICALL; =for hackers Found in file cop.h =item PUSH_MULTICALL X Opening bracket for a lightweight callback. See L. PUSH_MULTICALL; =for hackers Found in file cop.h =back =head1 Numeric functions =over 8 =item grok_bin X converts a string representing a binary number to numeric form. On entry C and C<*len> give the string to scan, C<*flags> gives conversion flags, and C should be C or a pointer to an NV. The scan stops at the end of the string, or the first invalid character. Unless C is set in C<*flags>, encountering an invalid character will also trigger a warning. On return C<*len> is set to the length of the scanned string, and C<*flags> gives output flags. If the value is <= C it is returned as a UV, the output flags are clear, and nothing is written to C<*result>. If the value is > C, C returns C, sets C in the output flags, and writes the value to C<*result> (or the value is discarded if C is NULL). The binary number may optionally be prefixed with C<"0b"> or C<"b"> unless C is set in C<*flags> on entry. If C is set in C<*flags> then the binary number may use C<"_"> characters to separate digits. UV grok_bin(const char* start, STRLEN* len_p, I32* flags, NV *result) =for hackers Found in file numeric.c =item grok_hex X converts a string representing a hex number to numeric form. On entry C and C<*len_p> give the string to scan, C<*flags> gives conversion flags, and C should be C or a pointer to an NV. The scan stops at the end of the string, or the first invalid character. Unless C is set in C<*flags>, encountering an invalid character will also trigger a warning. On return C<*len> is set to the length of the scanned string, and C<*flags> gives output flags. If the value is <= C it is returned as a UV, the output flags are clear, and nothing is written to C<*result>. If the value is > C, C returns C, sets C in the output flags, and writes the value to C<*result> (or the value is discarded if C is C). The hex number may optionally be prefixed with C<"0x"> or C<"x"> unless C is set in C<*flags> on entry. If C is set in C<*flags> then the hex number may use C<"_"> characters to separate digits. UV grok_hex(const char* start, STRLEN* len_p, I32* flags, NV *result) =for hackers Found in file numeric.c =item grok_infnan X Helper for C, accepts various ways of spelling "infinity" or "not a number", and returns one of the following flag combinations: IS_NUMBER_INFINITE IS_NUMBER_NAN IS_NUMBER_INFINITE | IS_NUMBER_NEG IS_NUMBER_NAN | IS_NUMBER_NEG 0 possibly |-ed with C. If an infinity or a not-a-number is recognized, C<*sp> will point to one byte past the end of the recognized string. If the recognition fails, zero is returned, and C<*sp> will not move. int grok_infnan(const char** sp, const char *send) =for hackers Found in file numeric.c =item grok_number X Identical to C with C set to zero. int grok_number(const char *pv, STRLEN len, UV *valuep) =for hackers Found in file numeric.c =item grok_number_flags X Recognise (or not) a number. The type of the number is returned (0 if unrecognised), otherwise it is a bit-ORed combination of C, C, C, C, C, C (defined in perl.h). If the value of the number can fit in a UV, it is returned in C<*valuep>. C will be set to indicate that C<*valuep> is valid, C will never be set unless C<*valuep> is valid, but C<*valuep> may have been assigned to during processing even though C is not set on return. If C is C, C will be set for the same cases as when C is non-C, but no actual assignment (or SEGV) will occur. C will be set with C if trailing decimals were seen (in which case C<*valuep> gives the true value truncated to an integer), and C if the number is negative (in which case C<*valuep> holds the absolute value). C is not set if e notation was used or the number is larger than a UV. C allows only C, which allows for trailing non-numeric text on an otherwise successful I, setting C on the result. int grok_number_flags(const char *pv, STRLEN len, UV *valuep, U32 flags) =for hackers Found in file numeric.c =item grok_numeric_radix X Scan and skip for a numeric decimal separator (radix). bool grok_numeric_radix(const char **sp, const char *send) =for hackers Found in file numeric.c =item grok_oct X converts a string representing an octal number to numeric form. On entry C and C<*len> give the string to scan, C<*flags> gives conversion flags, and C should be C or a pointer to an NV. The scan stops at the end of the string, or the first invalid character. Unless C is set in C<*flags>, encountering an 8 or 9 will also trigger a warning. On return C<*len> is set to the length of the scanned string, and C<*flags> gives output flags. If the value is <= C it is returned as a UV, the output flags are clear, and nothing is written to C<*result>. If the value is > C, C returns C, sets C in the output flags, and writes the value to C<*result> (or the value is discarded if C is C). If C is set in C<*flags> then the octal number may use C<"_"> characters to separate digits. UV grok_oct(const char* start, STRLEN* len_p, I32* flags, NV *result) =for hackers Found in file numeric.c =item isinfnan X C is utility function that returns true if the NV argument is either an infinity or a C, false otherwise. To test in more detail, use C and C. This is also the logical inverse of Perl_isfinite(). bool isinfnan(NV nv) =for hackers Found in file numeric.c =item Perl_signbit X NOTE: this function is experimental and may change or be removed without notice. Return a non-zero integer if the sign bit on an NV is set, and 0 if it is not. If F detects this system has a C that will work with our NVs, then we just use it via the C<#define> in F. Otherwise, fall back on this implementation. The main use of this function is catching C<-0.0>. C notes: This function is called C<'Perl_signbit'> instead of a plain C<'signbit'> because it is easy to imagine a system having a C function or macro that doesn't happen to work with our particular choice of NVs. We shouldn't just re-C<#define> C as C and expect the standard system headers to be happy. Also, this is a no-context function (no C) because C is usually re-C<#defined> in F as a simple macro call to the system's C. Users should just always call C. int Perl_signbit(NV f) =for hackers Found in file numeric.c =item scan_bin X For backwards compatibility. Use C instead. NV scan_bin(const char* start, STRLEN len, STRLEN* retlen) =for hackers Found in file numeric.c =item scan_hex X For backwards compatibility. Use C instead. NV scan_hex(const char* start, STRLEN len, STRLEN* retlen) =for hackers Found in file numeric.c =item scan_oct X For backwards compatibility. Use C instead. NV scan_oct(const char* start, STRLEN len, STRLEN* retlen) =for hackers Found in file numeric.c =back =head1 Obsolete backwards compatibility functions Some of these are also deprecated. You can exclude these from your compiled Perl by adding this option to Configure: C<-Accflags='-DNO_MATHOMS'> =over 8 =item custom_op_desc X Return the description of a given custom op. This was once used by the C macro, but is no longer: it has only been kept for compatibility, and should not be used. const char * custom_op_desc(const OP *o) =for hackers Found in file mathoms.c =item custom_op_name X Return the name for a given custom op. This was once used by the C macro, but is no longer: it has only been kept for compatibility, and should not be used. const char * custom_op_name(const OP *o) =for hackers Found in file mathoms.c =item gv_fetchmethod X See L. GV* gv_fetchmethod(HV* stash, const char* name) =for hackers Found in file mathoms.c =item is_utf8_char X DEPRECATED! It is planned to remove this function from a future release of Perl. Do not use it for new code; remove it from existing code. Tests if some arbitrary number of bytes begins in a valid UTF-8 character. Note that an INVARIANT (i.e. ASCII on non-EBCDIC machines) character is a valid UTF-8 character. The actual number of bytes in the UTF-8 character will be returned if it is valid, otherwise 0. This function is deprecated due to the possibility that malformed input could cause reading beyond the end of the input buffer. Use L instead. STRLEN is_utf8_char(const U8 *s) =for hackers Found in file mathoms.c =item is_utf8_char_buf X This is identical to the macro L. STRLEN is_utf8_char_buf(const U8 *buf, const U8 *buf_end) =for hackers Found in file mathoms.c =item pack_cat X The engine implementing C Perl function. Note: parameters C and C are not used. This call should not be used; use C instead. void pack_cat(SV *cat, const char *pat, const char *patend, SV **beglist, SV **endlist, SV ***next_in_list, U32 flags) =for hackers Found in file mathoms.c =item pad_compname_type X Looks up the type of the lexical variable at position C in the currently-compiling pad. If the variable is typed, the stash of the class to which it is typed is returned. If not, C is returned. HV * pad_compname_type(PADOFFSET po) =for hackers Found in file mathoms.c =item sv_2pvbyte_nolen X Return a pointer to the byte-encoded representation of the SV. May cause the SV to be downgraded from UTF-8 as a side-effect. Usually accessed via the C macro. char* sv_2pvbyte_nolen(SV* sv) =for hackers Found in file mathoms.c =item sv_2pvutf8_nolen X Return a pointer to the UTF-8-encoded representation of the SV. May cause the SV to be upgraded to UTF-8 as a side-effect. Usually accessed via the C macro. char* sv_2pvutf8_nolen(SV* sv) =for hackers Found in file mathoms.c =item sv_2pv_nolen X Like C, but doesn't return the length too. You should usually use the macro wrapper C instead. char* sv_2pv_nolen(SV* sv) =for hackers Found in file mathoms.c =item sv_catpvn_mg X Like C, but also handles 'set' magic. void sv_catpvn_mg(SV *sv, const char *ptr, STRLEN len) =for hackers Found in file mathoms.c =item sv_catsv_mg X Like C, but also handles 'set' magic. void sv_catsv_mg(SV *dsv, SV *ssv) =for hackers Found in file mathoms.c =item sv_force_normal X Undo various types of fakery on an SV: if the PV is a shared string, make a private copy; if we're a ref, stop refing; if we're a glob, downgrade to an C. See also C>. void sv_force_normal(SV *sv) =for hackers Found in file mathoms.c =item sv_iv X A private implementation of the C macro for compilers which can't cope with complex macro expressions. Always use the macro instead. IV sv_iv(SV* sv) =for hackers Found in file mathoms.c =item sv_nolocking X Dummy routine which "locks" an SV when there is no locking module present. Exists to avoid test for a C function pointer and because it could potentially warn under some level of strict-ness. "Superseded" by C. void sv_nolocking(SV *sv) =for hackers Found in file mathoms.c =item sv_nounlocking X Dummy routine which "unlocks" an SV when there is no locking module present. Exists to avoid test for a C function pointer and because it could potentially warn under some level of strict-ness. "Superseded" by C. void sv_nounlocking(SV *sv) =for hackers Found in file mathoms.c =item sv_nv X A private implementation of the C macro for compilers which can't cope with complex macro expressions. Always use the macro instead. NV sv_nv(SV* sv) =for hackers Found in file mathoms.c =item sv_pv X Use the C macro instead char* sv_pv(SV *sv) =for hackers Found in file mathoms.c =item sv_pvbyte X Use C instead. char* sv_pvbyte(SV *sv) =for hackers Found in file mathoms.c =item sv_pvbyten X A private implementation of the C macro for compilers which can't cope with complex macro expressions. Always use the macro instead. char* sv_pvbyten(SV *sv, STRLEN *lp) =for hackers Found in file mathoms.c =item sv_pvn X A private implementation of the C macro for compilers which can't cope with complex macro expressions. Always use the macro instead. char* sv_pvn(SV *sv, STRLEN *lp) =for hackers Found in file mathoms.c =item sv_pvutf8 X Use the C macro instead char* sv_pvutf8(SV *sv) =for hackers Found in file mathoms.c =item sv_pvutf8n X A private implementation of the C macro for compilers which can't cope with complex macro expressions. Always use the macro instead. char* sv_pvutf8n(SV *sv, STRLEN *lp) =for hackers Found in file mathoms.c =item sv_taint X Taint an SV. Use C instead. void sv_taint(SV* sv) =for hackers Found in file mathoms.c =item sv_unref X Unsets the RV status of the SV, and decrements the reference count of whatever was being referenced by the RV. This can almost be thought of as a reversal of C. This is C with the C being zero. See C>. void sv_unref(SV* sv) =for hackers Found in file mathoms.c =item sv_usepvn X Tells an SV to use C to find its string value. Implemented by calling C with C of 0, hence does not handle 'set' magic. See C>. void sv_usepvn(SV* sv, char* ptr, STRLEN len) =for hackers Found in file mathoms.c =item sv_usepvn_mg X Like C, but also handles 'set' magic. void sv_usepvn_mg(SV *sv, char *ptr, STRLEN len) =for hackers Found in file mathoms.c =item sv_uv X A private implementation of the C macro for compilers which can't cope with complex macro expressions. Always use the macro instead. UV sv_uv(SV* sv) =for hackers Found in file mathoms.c =item unpack_str X The engine implementing C Perl function. Note: parameters C, C and C are not used. This call should not be used, use C instead. I32 unpack_str(const char *pat, const char *patend, const char *s, const char *strbeg, const char *strend, char **new_s, I32 ocnt, U32 flags) =for hackers Found in file mathoms.c =item utf8_to_uvchr X DEPRECATED! It is planned to remove this function from a future release of Perl. Do not use it for new code; remove it from existing code. Returns the native code point of the first character in the string C which is assumed to be in UTF-8 encoding; C will be set to the length, in bytes, of that character. Some, but not all, UTF-8 malformations are detected, and in fact, some malformed input could cause reading beyond the end of the input buffer, which is why this function is deprecated. Use L instead. If C points to one of the detected malformations, and UTF8 warnings are enabled, zero is returned and C<*retlen> is set (if C isn't C) to -1. If those warnings are off, the computed value if well-defined (or the Unicode REPLACEMENT CHARACTER, if not) is silently returned, and C<*retlen> is set (if C isn't NULL) so that (S + C<*retlen>>) is the next possible position in C that could begin a non-malformed character. See L for details on when the REPLACEMENT CHARACTER is returned. UV utf8_to_uvchr(const U8 *s, STRLEN *retlen) =for hackers Found in file mathoms.c =item utf8_to_uvuni X DEPRECATED! It is planned to remove this function from a future release of Perl. Do not use it for new code; remove it from existing code. Returns the Unicode code point of the first character in the string C which is assumed to be in UTF-8 encoding; C will be set to the length, in bytes, of that character. Some, but not all, UTF-8 malformations are detected, and in fact, some malformed input could cause reading beyond the end of the input buffer, which is one reason why this function is deprecated. The other is that only in extremely limited circumstances should the Unicode versus native code point be of any interest to you. See L for alternatives. If C points to one of the detected malformations, and UTF8 warnings are enabled, zero is returned and C<*retlen> is set (if C doesn't point to NULL) to -1. If those warnings are off, the computed value if well-defined (or the Unicode REPLACEMENT CHARACTER, if not) is silently returned, and C<*retlen> is set (if C isn't NULL) so that (S + C<*retlen>>) is the next possible position in C that could begin a non-malformed character. See L for details on when the REPLACEMENT CHARACTER is returned. UV utf8_to_uvuni(const U8 *s, STRLEN *retlen) =for hackers Found in file mathoms.c =back =head1 Optree construction =over 8 =item newASSIGNOP X Constructs, checks, and returns an assignment op. C and C supply the parameters of the assignment; they are consumed by this function and become part of the constructed op tree. If C is C, C, or C, then a suitable conditional optree is constructed. If C is the opcode of a binary operator, such as C, then an op is constructed that performs the binary operation and assigns the result to the left argument. Either way, if C is non-zero then C has no effect. If C is zero, then a plain scalar or list assignment is constructed. Which type of assignment it is is automatically determined. C gives the eight bits of C, except that C will be set automatically, and, shifted up eight bits, the eight bits of C, except that the bit with value 1 or 2 is automatically set as required. OP * newASSIGNOP(I32 flags, OP *left, I32 optype, OP *right) =for hackers Found in file op.c =item newBINOP X Constructs, checks, and returns an op of any binary type. C is the opcode. C gives the eight bits of C, except that C will be set automatically, and, shifted up eight bits, the eight bits of C, except that the bit with value 1 or 2 is automatically set as required. C and C supply up to two ops to be the direct children of the binary op; they are consumed by this function and become part of the constructed op tree. OP * newBINOP(I32 type, I32 flags, OP *first, OP *last) =for hackers Found in file op.c =item newCONDOP X Constructs, checks, and returns a conditional-expression (C) op. C gives the eight bits of C, except that C will be set automatically, and, shifted up eight bits, the eight bits of C, except that the bit with value 1 is automatically set. C supplies the expression selecting between the two branches, and C and C supply the branches; they are consumed by this function and become part of the constructed op tree. OP * newCONDOP(I32 flags, OP *first, OP *trueop, OP *falseop) =for hackers Found in file op.c =item newDEFSVOP X Constructs and returns an op to access C<$_>. OP * newDEFSVOP() =for hackers Found in file op.c =item newFOROP X Constructs, checks, and returns an op tree expressing a C loop (iteration through a list of values). This is a heavyweight loop, with structure that allows exiting the loop by C and suchlike. C optionally supplies the variable that will be aliased to each item in turn; if null, it defaults to C<$_>. C supplies the list of values to iterate over. C supplies the main body of the loop, and C optionally supplies a C block that operates as a second half of the body. All of these optree inputs are consumed by this function and become part of the constructed op tree. C gives the eight bits of C for the C op and, shifted up eight bits, the eight bits of C for the C op, except that (in both cases) some bits will be set automatically. OP * newFOROP(I32 flags, OP *sv, OP *expr, OP *block, OP *cont) =for hackers Found in file op.c =item newGIVENOP X Constructs, checks, and returns an op tree expressing a C block. C supplies the expression that will be locally assigned to a lexical variable, and C supplies the body of the C construct; they are consumed by this function and become part of the constructed op tree. C must be zero (it used to identity the pad slot of lexical $_). OP * newGIVENOP(OP *cond, OP *block, PADOFFSET defsv_off) =for hackers Found in file op.c =item newGVOP X Constructs, checks, and returns an op of any type that involves an embedded reference to a GV. C is the opcode. C gives the eight bits of C. C identifies the GV that the op should reference; calling this function does not transfer ownership of any reference to it. OP * newGVOP(I32 type, I32 flags, GV *gv) =for hackers Found in file op.c =item newLISTOP X Constructs, checks, and returns an op of any list type. C is the opcode. C gives the eight bits of C, except that C will be set automatically if required. C and C supply up to two ops to be direct children of the list op; they are consumed by this function and become part of the constructed op tree. For most list operators, the check function expects all the kid ops to be present already, so calling C (e.g.) is not appropriate. What you want to do in that case is create an op of type C, append more children to it, and then call L. See L for more information. OP * newLISTOP(I32 type, I32 flags, OP *first, OP *last) =for hackers Found in file op.c =item newLOGOP X Constructs, checks, and returns a logical (flow control) op. C is the opcode. C gives the eight bits of C, except that C will be set automatically, and, shifted up eight bits, the eight bits of C, except that the bit with value 1 is automatically set. C supplies the expression controlling the flow, and C supplies the side (alternate) chain of ops; they are consumed by this function and become part of the constructed op tree. OP * newLOGOP(I32 type, I32 flags, OP *first, OP *other) =for hackers Found in file op.c =item newLOOPEX X Constructs, checks, and returns a loop-exiting op (such as C or C). C is the opcode. C