3 * Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
4 * by Larry Wall and others
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.
12 =head1 Global Variables
13 These variables are global to an entire process. They are shared between
14 all interpreters and all threads in a process. Any variables not documented
15 here may be changed or removed without notice, so don't use them!
16 If you feel you really do need to use an unlisted variable, first send email to
17 L<perl5-porters@perl.org|mailto:perl5-porters@perl.org>. It may be that
18 someone there will point out a way to accomplish what you need without using an
19 internal variable. But if not, you should get a go-ahead to document and then
25 /* Don't forget to re-run regen/embed.pl to propagate changes! */
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.
32 * The 'G' prefix is only needed for vars that need appropriate #defines
33 * generated in embed*.h. Such symbols are also used to generate
34 * the appropriate export list for win32. */
37 #if defined(USE_ITHREADS)
38 PERLVAR(G, op_mutex, perl_mutex) /* Mutex for op refcounting */
40 PERLVARI(G, curinterp, PerlInterpreter *, NULL)
41 /* currently running interpreter
42 * (initial parent interpreter under
44 #if defined(USE_ITHREADS)
45 PERLVAR(G, thr_key, perl_key) /* key to retrieve per-thread struct */
48 /* XXX does anyone even use this? */
49 PERLVARI(G, do_undump, bool, FALSE) /* -u or dump seen? */
51 #ifndef PERL_USE_SAFE_PUTENV
52 PERLVARI(G, use_safe_putenv, bool, TRUE)
55 #if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS)||defined(FAKE_DEFAULT_SIGNAL_HANDLERS)
56 PERLVARI(G, sig_handlers_initted, int, 0)
58 #ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
59 PERLVARA(G, sig_ignoring, SIG_SIZE, int)
60 /* which signals we are ignoring */
62 #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
63 PERLVARA(G, sig_defaulting, SIG_SIZE, int)
66 /* XXX signals are process-wide anyway, so we
67 * ignore the implications of this for threading */
69 PERLVARI(G, sig_trapped, int, 0)
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. */
75 PERLVAR(G, sigfpe_saved, Sighandler_t)
76 PERLVARI(G, csighandlerp, Sighandler_t, Perl_csighandler)
77 /* Pointer to C-level sighandler */
80 /* This is constant on most architectures, a global on OS/2 */
82 PERLVARI(G, sh_path, char *, SH_PATH) /* full path of shell */
87 # if defined(USE_ITHREADS)
88 PERLVAR(G, perlio_mutex, perl_mutex) /* Mutex for perlio fd refcounts */
91 PERLVARI(G, perlio_fd_refcnt, int *, 0) /* Pointer to array of fd refcounts. */
92 PERLVARI(G, perlio_fd_refcnt_size, int, 0) /* Size of the array */
93 PERLVARI(G, perlio_debug_fd, int, 0) /* the fd to write perlio debug into, 0 means not set yet */
97 PERLVARI(G, mmap_page_size, IV, 0)
100 #if defined(USE_ITHREADS)
101 PERLVAR(G, hints_mutex, perl_mutex) /* Mutex for refcounted he refcounting */
102 # if ! defined(USE_THREAD_SAFE_LOCALE) || defined(TS_W32_BROKEN_LOCALECONV)
103 PERLVAR(G, locale_mutex, perl_mutex) /* Mutex for setlocale() changing */
105 # ifndef USE_THREAD_SAFE_LOCALE
106 PERLVAR(G, lc_numeric_mutex, perl_mutex) /* Mutex for switching LC_NUMERIC */
110 #ifdef USE_POSIX_2008_LOCALE
111 PERLVAR(G, C_locale_obj, locale_t)
115 PERLVARI(G, watch_pvx, char *, NULL)
119 =for apidoc AmU|Perl_check_t *|PL_check
121 Array, indexed by opcode, of functions that will be called for the "check"
122 phase of optree building during compilation of Perl code. For most (but
123 not all) types of op, once the op has been initially built and populated
124 with child ops it will be filtered through the check function referenced
125 by the appropriate element of this array. The new op is passed in as the
126 sole argument to the check function, and the check function returns the
127 completed op. The check function may (as the name suggests) check the op
128 for validity and signal errors. It may also initialise or modify parts of
129 the ops, or perform more radical surgery such as adding or removing child
130 ops, or even throw the op away and return a different op in its place.
132 This array of function pointers is a convenient place to hook into the
133 compilation process. An XS module can put its own custom check function
134 in place of any of the standard ones, to influence the compilation of a
135 particular type of op. However, a custom check function must never fully
136 replace a standard check function (or even a custom check function from
137 another module). A module modifying checking must instead B<wrap> the
138 preexisting check function. A custom check function must be selective
139 about when to apply its custom behaviour. In the usual case where
140 it decides not to do anything special with an op, it must chain the
141 preexisting op function. Check functions are thus linked in a chain,
142 with the core's base checker at the end.
144 For thread safety, modules should not write directly to this array.
145 Instead, use the function L</wrap_op_checker>.
150 #if defined(USE_ITHREADS)
151 PERLVAR(G, check_mutex, perl_mutex) /* Mutex for PL_check */
153 #ifdef PERL_GLOBAL_STRUCT
154 PERLVAR(G, ppaddr, Perl_ppaddr_t *) /* or opcode.h */
155 PERLVAR(G, check, Perl_check_t *) /* or opcode.h */
156 PERLVARA(G, fold_locale, 256, unsigned char) /* or perl.h */
159 #ifdef PERL_NEED_APPCTX
160 PERLVAR(G, appctx, void*) /* the application context */
163 #if defined(HAS_TIMES) && defined(PERL_NEED_TIMESBASE)
164 PERLVAR(G, timesbase, struct tms)
167 /* allocate a unique index to every module that calls MY_CXT_INIT */
169 #ifdef PERL_IMPLICIT_CONTEXT
171 PERLVAR(G, my_ctx_mutex, perl_mutex)
173 PERLVARI(G, my_cxt_index, int, 0)
176 /* this is currently set without MUTEX protection, so keep it a type which
177 * can be set atomically (ie not a bit field) */
178 PERLVARI(G, veto_cleanup, int, FALSE) /* exit without cleanup */
181 =for apidoc AmUx|Perl_keyword_plugin_t|PL_keyword_plugin
183 Function pointer, pointing at a function used to handle extended keywords.
184 The function should be declared as
186 int keyword_plugin_function(pTHX_
187 char *keyword_ptr, STRLEN keyword_len,
190 The function is called from the tokeniser, whenever a possible keyword
191 is seen. C<keyword_ptr> points at the word in the parser's input
192 buffer, and C<keyword_len> gives its length; it is not null-terminated.
193 The function is expected to examine the word, and possibly other state
194 such as L<%^H|perlvar/%^H>, to decide whether it wants to handle it
195 as an extended keyword. If it does not, the function should return
196 C<KEYWORD_PLUGIN_DECLINE>, and the normal parser process will continue.
198 If the function wants to handle the keyword, it first must
199 parse anything following the keyword that is part of the syntax
200 introduced by the keyword. See L</Lexer interface> for details.
202 When a keyword is being handled, the plugin function must build
203 a tree of C<OP> structures, representing the code that was parsed.
204 The root of the tree must be stored in C<*op_ptr>. The function then
205 returns a constant indicating the syntactic role of the construct that
206 it has parsed: C<KEYWORD_PLUGIN_STMT> if it is a complete statement, or
207 C<KEYWORD_PLUGIN_EXPR> if it is an expression. Note that a statement
208 construct cannot be used inside an expression (except via C<do BLOCK>
209 and similar), and an expression is not a complete statement (it requires
210 at least a terminating semicolon).
212 When a keyword is handled, the plugin function may also have
213 (compile-time) side effects. It may modify C<%^H>, define functions, and
214 so on. Typically, if side effects are the main purpose of a handler,
215 it does not wish to generate any ops to be included in the normal
216 compilation. In this case it is still required to supply an op tree,
217 but it suffices to generate a single null op.
219 That's how the C<*PL_keyword_plugin> function needs to behave overall.
220 Conventionally, however, one does not completely replace the existing
221 handler function. Instead, take a copy of C<PL_keyword_plugin> before
222 assigning your own function pointer to it. Your handler function should
223 look for keywords that it is interested in and handle those. Where it
224 is not interested, it should call the saved plugin function, passing on
225 the arguments it received. Thus C<PL_keyword_plugin> actually points
226 at a chain of handler functions, all of which have an opportunity to
227 handle keywords, and only the last function in the chain (built into
228 the Perl core) will normally return C<KEYWORD_PLUGIN_DECLINE>.
230 For thread safety, modules should not set this variable directly.
231 Instead, use the function L</wrap_keyword_plugin>.
236 #if defined(USE_ITHREADS)
237 PERLVAR(G, keyword_plugin_mutex, perl_mutex) /* Mutex for PL_keyword_plugin */
239 PERLVARI(G, keyword_plugin, Perl_keyword_plugin_t, Perl_keyword_plugin_standard)
241 PERLVARI(G, op_sequence, HV *, NULL) /* dump.c */
242 PERLVARI(G, op_seq, UV, 0) /* dump.c */
245 PERLVAR(G, dollarzero_mutex, perl_mutex) /* Modifying $0 */
248 /* Restricted hashes placeholder value.
249 In theory, the contents are never used, only the address.
250 In practice, &PL_sv_placeholder is returned by some APIs, and the calling
251 code is checking SvOK(). */
253 PERLVAR(G, sv_placeholder, SV)
255 #if defined(MYMALLOC) && defined(USE_ITHREADS)
256 PERLVAR(G, malloc_mutex, perl_mutex) /* Mutex for malloc */
259 PERLVARI(G, hash_seed_set, bool, FALSE) /* perl.c */
260 PERLVARA(G, hash_seed, PERL_HASH_SEED_BYTES, unsigned char) /* perl.c and hv.h */
261 #if defined(PERL_HASH_STATE_BYTES)
262 PERLVARA(G, hash_state, PERL_HASH_STATE_BYTES, unsigned char) /* perl.c and hv.h */
264 #if defined(PERL_USE_SINGLE_CHAR_HASH_CACHE)
265 PERLVARA(G, hash_chars, (1+256) * sizeof(U32), unsigned char) /* perl.c and hv.h */
268 /* The path separator can vary depending on whether we're running under DCL or
272 PERLVAR(G, perllib_sep, char)
275 PERLVAR(G, AboveLatin1, SV *)
276 PERLVAR(G, Assigned_invlist, SV *)
277 PERLVAR(G, GCB_invlist, SV *)
278 PERLVAR(G, HasMultiCharFold, SV *)
279 PERLVAR(G, Latin1, SV *)
280 PERLVAR(G, LB_invlist, SV *)
281 PERLVAR(G, NonL1NonFinalFold, SV *)
282 PERLVAR(G, SB_invlist, SV *)
283 PERLVAR(G, SCX_invlist, SV *)
284 PERLVAR(G, UpperLatin1, SV *) /* Code points 128 - 255 */
286 /* List of characters that participate in folds (except marks, etc in
287 * multi-char folds) */
288 PERLVARI(G, utf8_foldable, SV *, NULL)
290 PERLVAR(G, utf8_idcont, SV *)
291 PERLVAR(G, utf8_idstart, SV *)
292 PERLVAR(G, utf8_perl_idcont, SV *)
293 PERLVAR(G, utf8_perl_idstart, SV *)
294 PERLVAR(G, utf8_xidcont, SV *)
295 PERLVAR(G, utf8_xidstart, SV *)
296 PERLVAR(G, WB_invlist, SV *)
297 PERLVARA(G, XPosix_ptrs, POSIX_CC_COUNT, SV *)
298 PERLVARA(G, Posix_ptrs, POSIX_CC_COUNT, SV *)
299 PERLVAR(G, utf8_toupper, SV *)
300 PERLVAR(G, utf8_totitle, SV *)
301 PERLVAR(G, utf8_tolower, SV *)
302 PERLVAR(G, utf8_tofold, SV *)
303 PERLVAR(G, utf8_tosimplefold, SV *)
304 PERLVAR(G, utf8_charname_begin, SV *)
305 PERLVAR(G, utf8_charname_continue, SV *)
307 /* Everything that folds to a given character, for case insensitivity regex
309 PERLVAR(G, utf8_foldclosures, SV *)