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1/* perlvars.h
2 *
663f364b 3 * Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
54ca4ee7 4 * by Larry Wall and others
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5 *
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
8 *
9 */
10
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11/*
12=head1 Global Variables
e8570548 13These variables are global to an entire process. They are shared between
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14all interpreters and all threads in a process. Any variables not documented
15here may be changed or removed without notice, so don't use them!
16If you feel you really do need to use an unlisted variable, first send email to
17L<perl5-porters@perl.org|mailto:perl5-porters@perl.org>. It may be that
18someone there will point out a way to accomplish what you need without using an
19internal variable. But if not, you should get a go-ahead to document and then
20use the variable.
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21
22=cut
88e1f1a2 23*/
49f531da 24
d7cb65f2 25/* Don't forget to re-run regen/embed.pl to propagate changes! */
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26
27/* This file describes the "global" variables used by perl
28 * This used to be in perl.h directly but we want to abstract out into
29 * distinct files which are per-thread, per-interpreter or really global,
30 * and how they're initialized.
31 *
32 * The 'G' prefix is only needed for vars that need appropriate #defines
22c35a8c 33 * generated in embed*.h. Such symbols are also used to generate
14dd3ad8 34 * the appropriate export list for win32. */
cb68f92d 35
49f531da 36/* global state */
eeb6b841 37#if defined(USE_ITHREADS)
115ff745 38PERLVAR(G, op_mutex, perl_mutex) /* Mutex for op refcounting */
eeb6b841 39#endif
5c64bffd 40PERLVARI(G, curinterp, PerlInterpreter *, NULL)
43165c05 41 /* currently running interpreter
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42 * (initial parent interpreter under
43 * useithreads) */
3db8f154 44#if defined(USE_ITHREADS)
115ff745 45PERLVAR(G, thr_key, perl_key) /* key to retrieve per-thread struct */
ba869deb 46#endif
a0ed51b3 47
43165c05 48/* XXX does anyone even use this? */
115ff745 49PERLVARI(G, do_undump, bool, FALSE) /* -u or dump seen? */
b363f7ed 50
eeb6b841 51#ifndef PERL_USE_SAFE_PUTENV
115ff745 52PERLVARI(G, use_safe_putenv, bool, TRUE)
b363f7ed 53#endif
534825c4 54
eeb6b841 55#if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS)||defined(FAKE_DEFAULT_SIGNAL_HANDLERS)
115ff745 56PERLVARI(G, sig_handlers_initted, int, 0)
534825c4 57#endif
eeb6b841 58#ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
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59PERLVARA(G, sig_ignoring, SIG_SIZE, int)
60 /* which signals we are ignoring */
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61#endif
62#ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
115ff745 63PERLVARA(G, sig_defaulting, SIG_SIZE, int)
d90a703e 64#endif
5c728af0 65
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66/* XXX signals are process-wide anyway, so we
67 * ignore the implications of this for threading */
68#ifndef HAS_SIGACTION
115ff745 69PERLVARI(G, sig_trapped, int, 0)
428eed4a 70#endif
af419de7 71
2f42fcb0 72#ifndef PERL_MICRO
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73/* If Perl has to ignore SIGPFE, this is its saved state.
74 * See perl.h macros PERL_FPU_INIT and PERL_FPU_{PRE,POST}_EXEC. */
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75PERLVAR(G, sigfpe_saved, Sighandler_t)
76PERLVARI(G, csighandlerp, Sighandler_t, Perl_csighandler)
77 /* Pointer to C-level sighandler */
2f42fcb0 78#endif
5c1546dc 79
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80/* This is constant on most architectures, a global on OS/2 */
81#ifdef OS2
115ff745 82PERLVARI(G, sh_path, char *, SH_PATH) /* full path of shell */
50acdf95 83#endif
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84
85#ifdef USE_PERLIO
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86
87# if defined(USE_ITHREADS)
115ff745 88PERLVAR(G, perlio_mutex, perl_mutex) /* Mutex for perlio fd refcounts */
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89# endif
90
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91PERLVARI(G, perlio_fd_refcnt, int *, 0) /* Pointer to array of fd refcounts. */
92PERLVARI(G, perlio_fd_refcnt_size, int, 0) /* Size of the array */
93PERLVARI(G, perlio_debug_fd, int, 0) /* the fd to write perlio debug into, 0 means not set yet */
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94#endif
95
96#ifdef HAS_MMAP
115ff745 97PERLVARI(G, mmap_page_size, IV, 0)
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98#endif
99
eeb6b841 100#if defined(USE_ITHREADS)
115ff745 101PERLVAR(G, hints_mutex, perl_mutex) /* Mutex for refcounted he refcounting */
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102PERLVAR(G, locale_mutex, perl_mutex) /* Mutex for setlocale() changing */
103
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104# ifdef HAS_NEWLOCALE
105PERLVAR(G, C_locale_obj, locale_t)
106# endif
107
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108#endif
109
110#ifdef DEBUGGING
0c5ea019 111PERLVARI(G, watch_pvx, char *, NULL)
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112#endif
113
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114/*
115=for apidoc AmU|Perl_check_t *|PL_check
116
117Array, indexed by opcode, of functions that will be called for the "check"
118phase of optree building during compilation of Perl code. For most (but
119not all) types of op, once the op has been initially built and populated
120with child ops it will be filtered through the check function referenced
121by the appropriate element of this array. The new op is passed in as the
122sole argument to the check function, and the check function returns the
123completed op. The check function may (as the name suggests) check the op
124for validity and signal errors. It may also initialise or modify parts of
125the ops, or perform more radical surgery such as adding or removing child
126ops, or even throw the op away and return a different op in its place.
127
128This array of function pointers is a convenient place to hook into the
129compilation process. An XS module can put its own custom check function
130in place of any of the standard ones, to influence the compilation of a
131particular type of op. However, a custom check function must never fully
132replace a standard check function (or even a custom check function from
133another module). A module modifying checking must instead B<wrap> the
134preexisting check function. A custom check function must be selective
135about when to apply its custom behaviour. In the usual case where
136it decides not to do anything special with an op, it must chain the
137preexisting op function. Check functions are thus linked in a chain,
138with the core's base checker at the end.
139
140For thread safety, modules should not write directly to this array.
141Instead, use the function L</wrap_op_checker>.
142
143=cut
144*/
145
146#if defined(USE_ITHREADS)
147PERLVAR(G, check_mutex, perl_mutex) /* Mutex for PL_check */
148#endif
27da23d5 149#ifdef PERL_GLOBAL_STRUCT
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150PERLVAR(G, ppaddr, Perl_ppaddr_t *) /* or opcode.h */
151PERLVAR(G, check, Perl_check_t *) /* or opcode.h */
152PERLVARA(G, fold_locale, 256, unsigned char) /* or perl.h */
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153#endif
154
155#ifdef PERL_NEED_APPCTX
115ff745 156PERLVAR(G, appctx, void*) /* the application context */
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157#endif
158
27da23d5 159#if defined(HAS_TIMES) && defined(PERL_NEED_TIMESBASE)
115ff745 160PERLVAR(G, timesbase, struct tms)
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161#endif
162
f16dd614 163/* allocate a unique index to every module that calls MY_CXT_INIT */
27da23d5 164
f16dd614 165#ifdef PERL_IMPLICIT_CONTEXT
97aff369 166# ifdef USE_ITHREADS
115ff745 167PERLVAR(G, my_ctx_mutex, perl_mutex)
97aff369 168# endif
115ff745 169PERLVARI(G, my_cxt_index, int, 0)
f16dd614 170#endif
71ad1b0c 171
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172/* this is currently set without MUTEX protection, so keep it a type which
173 * can be set atomically (ie not a bit field) */
115ff745 174PERLVARI(G, veto_cleanup, int, FALSE) /* exit without cleanup */
c301d606 175
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176/*
177=for apidoc AmUx|Perl_keyword_plugin_t|PL_keyword_plugin
178
179Function pointer, pointing at a function used to handle extended keywords.
180The function should be declared as
181
182 int keyword_plugin_function(pTHX_
183 char *keyword_ptr, STRLEN keyword_len,
184 OP **op_ptr)
185
186The function is called from the tokeniser, whenever a possible keyword
187is seen. C<keyword_ptr> points at the word in the parser's input
188buffer, and C<keyword_len> gives its length; it is not null-terminated.
189The function is expected to examine the word, and possibly other state
190such as L<%^H|perlvar/%^H>, to decide whether it wants to handle it
191as an extended keyword. If it does not, the function should return
192C<KEYWORD_PLUGIN_DECLINE>, and the normal parser process will continue.
193
194If the function wants to handle the keyword, it first must
195parse anything following the keyword that is part of the syntax
f0e67a1d 196introduced by the keyword. See L</Lexer interface> for details.
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197
198When a keyword is being handled, the plugin function must build
199a tree of C<OP> structures, representing the code that was parsed.
200The root of the tree must be stored in C<*op_ptr>. The function then
364f83bf 201returns a constant indicating the syntactic role of the construct that
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202it has parsed: C<KEYWORD_PLUGIN_STMT> if it is a complete statement, or
203C<KEYWORD_PLUGIN_EXPR> if it is an expression. Note that a statement
204construct cannot be used inside an expression (except via C<do BLOCK>
205and similar), and an expression is not a complete statement (it requires
206at least a terminating semicolon).
207
208When a keyword is handled, the plugin function may also have
209(compile-time) side effects. It may modify C<%^H>, define functions, and
210so on. Typically, if side effects are the main purpose of a handler,
211it does not wish to generate any ops to be included in the normal
212compilation. In this case it is still required to supply an op tree,
213but it suffices to generate a single null op.
214
215That's how the C<*PL_keyword_plugin> function needs to behave overall.
216Conventionally, however, one does not completely replace the existing
217handler function. Instead, take a copy of C<PL_keyword_plugin> before
218assigning your own function pointer to it. Your handler function should
219look for keywords that it is interested in and handle those. Where it
220is not interested, it should call the saved plugin function, passing on
221the arguments it received. Thus C<PL_keyword_plugin> actually points
222at a chain of handler functions, all of which have an opportunity to
223handle keywords, and only the last function in the chain (built into
224the Perl core) will normally return C<KEYWORD_PLUGIN_DECLINE>.
225
226=cut
227*/
228
115ff745 229PERLVARI(G, keyword_plugin, Perl_keyword_plugin_t, Perl_keyword_plugin_standard)
eeb6b841 230
5c64bffd 231PERLVARI(G, op_sequence, HV *, NULL) /* dump.c */
115ff745 232PERLVARI(G, op_seq, UV, 0) /* dump.c */
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233
234#ifdef USE_ITHREADS
115ff745 235PERLVAR(G, dollarzero_mutex, perl_mutex) /* Modifying $0 */
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236#endif
237
238/* Restricted hashes placeholder value.
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239 In theory, the contents are never used, only the address.
240 In practice, &PL_sv_placeholder is returned by some APIs, and the calling
241 code is checking SvOK(). */
242
115ff745 243PERLVAR(G, sv_placeholder, SV)
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244
245#if defined(MYMALLOC) && defined(USE_ITHREADS)
115ff745 246PERLVAR(G, malloc_mutex, perl_mutex) /* Mutex for malloc */
eeb6b841 247#endif
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248
249PERLVARI(G, hash_seed_set, bool, FALSE) /* perl.c */
6a5b4183 250PERLVARA(G, hash_seed, PERL_HASH_SEED_BYTES, unsigned char) /* perl.c and hv.h */
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251
252/* The path separator can vary depending on whether we're running under DCL or
253 * a Unix shell.
254 */
255#ifdef __VMS
256PERLVAR(G, perllib_sep, char)
257#endif