1 /*    perlvars.h
2  *
3  *    Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
4  *    by Larry Wall and others
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 
11 /*
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
20 use the variable.
21 
22 =cut
23 */
24 
25 /* Don't forget to re-run regen/embed.pl to propagate changes! */
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
33  * generated in embed*.h.  Such symbols are also used to generate
34  * the appropriate export list for win32. */
35 
36 /* global state */
37 #if defined(USE_ITHREADS)
38 PERLVAR(G, op_mutex,	perl_mutex)	/* Mutex for op refcounting */
39 #endif
40 PERLVARI(G, curinterp,	PerlInterpreter *, NULL)
41 					/* currently running interpreter
42 					 * (initial parent interpreter under
43 					 * useithreads) */
44 #if defined(USE_ITHREADS)
45 PERLVAR(G, thr_key,	perl_key)	/* key to retrieve per-thread struct */
46 #endif
47 
48 /* XXX does anyone even use this? */
49 PERLVARI(G, do_undump,	bool,	FALSE)	/* -u or dump seen? */
50 
51 #ifndef PERL_USE_SAFE_PUTENV
52 PERLVARI(G, use_safe_putenv, bool, TRUE)
53 #endif
54 
55 #if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS)||defined(FAKE_DEFAULT_SIGNAL_HANDLERS)
56 PERLVARI(G, sig_handlers_initted, int, 0)
57 #endif
58 #ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
59 PERLVARA(G, sig_ignoring, SIG_SIZE, int)
60 					/* which signals we are ignoring */
61 #endif
62 #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
63 PERLVARA(G, sig_defaulting, SIG_SIZE, int)
64 #endif
65 
66 /* XXX signals are process-wide anyway, so we
67  * ignore the implications of this for threading */
68 #ifndef HAS_SIGACTION
69 PERLVARI(G, sig_trapped, int,	0)
70 #endif
71 
72 #ifndef PERL_MICRO
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 */
78 #endif
79 
80 /* This is constant on most architectures, a global on OS/2 */
81 #ifdef OS2
82 PERLVARI(G, sh_path,	char *, SH_PATH) /* full path of shell */
83 #endif
84 
85 #ifdef USE_PERLIO
86 
87 #  if defined(USE_ITHREADS)
88 PERLVAR(G, perlio_mutex, perl_mutex)    /* Mutex for perlio fd refcounts */
89 #  endif
90 
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 */
94 #endif
95 
96 #ifdef HAS_MMAP
97 PERLVARI(G, mmap_page_size, IV, 0)
98 #endif
99 
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 */
104 #  endif
105 #  ifndef USE_THREAD_SAFE_LOCALE
106 PERLVAR(G, lc_numeric_mutex, perl_mutex)   /* Mutex for switching LC_NUMERIC */
107 #  endif
108 #endif
109 
110 #ifdef USE_POSIX_2008_LOCALE
111 PERLVAR(G, C_locale_obj, locale_t)
112 #endif
113 
114 PERLVARI(G, watch_pvx,	char *, NULL)
115 
116 /*
117 =for apidoc AmU|Perl_check_t *|PL_check
118 
119 Array, indexed by opcode, of functions that will be called for the "check"
120 phase of optree building during compilation of Perl code.  For most (but
121 not all) types of op, once the op has been initially built and populated
122 with child ops it will be filtered through the check function referenced
123 by the appropriate element of this array.  The new op is passed in as the
124 sole argument to the check function, and the check function returns the
125 completed op.  The check function may (as the name suggests) check the op
126 for validity and signal errors.  It may also initialise or modify parts of
127 the ops, or perform more radical surgery such as adding or removing child
128 ops, or even throw the op away and return a different op in its place.
129 
130 This array of function pointers is a convenient place to hook into the
131 compilation process.  An XS module can put its own custom check function
132 in place of any of the standard ones, to influence the compilation of a
133 particular type of op.  However, a custom check function must never fully
134 replace a standard check function (or even a custom check function from
135 another module).  A module modifying checking must instead B<wrap> the
136 preexisting check function.  A custom check function must be selective
137 about when to apply its custom behaviour.  In the usual case where
138 it decides not to do anything special with an op, it must chain the
139 preexisting op function.  Check functions are thus linked in a chain,
140 with the core's base checker at the end.
141 
142 For thread safety, modules should not write directly to this array.
143 Instead, use the function L</wrap_op_checker>.
144 
145 =cut
146 */
147 
148 #if defined(USE_ITHREADS)
149 PERLVAR(G, check_mutex,	perl_mutex)	/* Mutex for PL_check */
150 #endif
151 #ifdef PERL_GLOBAL_STRUCT
152 PERLVAR(G, ppaddr,	Perl_ppaddr_t *) /* or opcode.h */
153 PERLVAR(G, check,	Perl_check_t *) /* or opcode.h */
154 PERLVARA(G, fold_locale, 256, unsigned char) /* or perl.h */
155 #endif
156 
157 #ifdef PERL_NEED_APPCTX
158 PERLVAR(G, appctx,	void*)		/* the application context */
159 #endif
160 
161 #if defined(HAS_TIMES) && defined(PERL_NEED_TIMESBASE)
162 PERLVAR(G, timesbase,	struct tms)
163 #endif
164 
165 /* allocate a unique index to every module that calls MY_CXT_INIT */
166 
167 #ifdef PERL_IMPLICIT_CONTEXT
168 # ifdef USE_ITHREADS
169 PERLVAR(G, my_ctx_mutex, perl_mutex)
170 # endif
171 PERLVARI(G, my_cxt_index, int,	0)
172 #endif
173 
174 /* this is currently set without MUTEX protection, so keep it a type which
175  * can be set atomically (ie not a bit field) */
176 PERLVARI(G, veto_cleanup, int, FALSE)	/* exit without cleanup */
177 
178 /*
179 =for apidoc AmUx|Perl_keyword_plugin_t|PL_keyword_plugin
180 
181 Function pointer, pointing at a function used to handle extended keywords.
182 The function should be declared as
183 
184 	int keyword_plugin_function(pTHX_
185 		char *keyword_ptr, STRLEN keyword_len,
186 		OP **op_ptr)
187 
188 The function is called from the tokeniser, whenever a possible keyword
189 is seen.  C<keyword_ptr> points at the word in the parser's input
190 buffer, and C<keyword_len> gives its length; it is not null-terminated.
191 The function is expected to examine the word, and possibly other state
192 such as L<%^H|perlvar/%^H>, to decide whether it wants to handle it
193 as an extended keyword.  If it does not, the function should return
194 C<KEYWORD_PLUGIN_DECLINE>, and the normal parser process will continue.
195 
196 If the function wants to handle the keyword, it first must
197 parse anything following the keyword that is part of the syntax
198 introduced by the keyword.  See L</Lexer interface> for details.
199 
200 When a keyword is being handled, the plugin function must build
201 a tree of C<OP> structures, representing the code that was parsed.
202 The root of the tree must be stored in C<*op_ptr>.  The function then
203 returns a constant indicating the syntactic role of the construct that
204 it has parsed: C<KEYWORD_PLUGIN_STMT> if it is a complete statement, or
205 C<KEYWORD_PLUGIN_EXPR> if it is an expression.  Note that a statement
206 construct cannot be used inside an expression (except via C<do BLOCK>
207 and similar), and an expression is not a complete statement (it requires
208 at least a terminating semicolon).
209 
210 When a keyword is handled, the plugin function may also have
211 (compile-time) side effects.  It may modify C<%^H>, define functions, and
212 so on.  Typically, if side effects are the main purpose of a handler,
213 it does not wish to generate any ops to be included in the normal
214 compilation.  In this case it is still required to supply an op tree,
215 but it suffices to generate a single null op.
216 
217 That's how the C<*PL_keyword_plugin> function needs to behave overall.
218 Conventionally, however, one does not completely replace the existing
219 handler function.  Instead, take a copy of C<PL_keyword_plugin> before
220 assigning your own function pointer to it.  Your handler function should
221 look for keywords that it is interested in and handle those.  Where it
222 is not interested, it should call the saved plugin function, passing on
223 the arguments it received.  Thus C<PL_keyword_plugin> actually points
224 at a chain of handler functions, all of which have an opportunity to
225 handle keywords, and only the last function in the chain (built into
226 the Perl core) will normally return C<KEYWORD_PLUGIN_DECLINE>.
227 
228 For thread safety, modules should not set this variable directly.
229 Instead, use the function L</wrap_keyword_plugin>.
230 
231 =cut
232 */
233 
234 #if defined(USE_ITHREADS)
235 PERLVAR(G, keyword_plugin_mutex, perl_mutex)   /* Mutex for PL_keyword_plugin */
236 #endif
237 PERLVARI(G, keyword_plugin, Perl_keyword_plugin_t, Perl_keyword_plugin_standard)
238 
239 PERLVARI(G, op_sequence, HV *, NULL)	/* dump.c */
240 PERLVARI(G, op_seq,	UV,	0)	/* dump.c */
241 
242 #ifdef USE_ITHREADS
243 PERLVAR(G, dollarzero_mutex, perl_mutex) /* Modifying $0 */
244 #endif
245 
246 /* Restricted hashes placeholder value.
247    In theory, the contents are never used, only the address.
248    In practice, &PL_sv_placeholder is returned by some APIs, and the calling
249    code is checking SvOK().  */
250 
251 PERLVAR(G, sv_placeholder, SV)
252 
253 #if defined(MYMALLOC) && defined(USE_ITHREADS)
254 PERLVAR(G, malloc_mutex, perl_mutex)	/* Mutex for malloc */
255 #endif
256 
257 PERLVARI(G, hash_seed_set, bool, FALSE)	/* perl.c */
258 PERLVARA(G, hash_seed, PERL_HASH_SEED_BYTES, unsigned char) /* perl.c and hv.h */
259 #if defined(PERL_HASH_STATE_BYTES)
260 PERLVARA(G, hash_state, PERL_HASH_STATE_BYTES, unsigned char) /* perl.c and hv.h */
261 #endif
262 #if defined(PERL_USE_SINGLE_CHAR_HASH_CACHE)
263 PERLVARA(G, hash_chars, (1+256) * sizeof(U32), unsigned char) /* perl.c and hv.h */
264 #endif
265 
266 /* The path separator can vary depending on whether we're running under DCL or
267  * a Unix shell.
268  */
269 #ifdef __VMS
270 PERLVAR(G, perllib_sep, char)
271 #endif
272 
273 PERLVAR(G, AboveLatin1,	SV *)
274 PERLVAR(G, Assigned_invlist, SV *)
275 PERLVAR(G, GCB_invlist, SV *)
276 PERLVAR(G, HasMultiCharFold,   SV *)
277 PERLVAR(G, InMultiCharFold,   SV *)
278 PERLVAR(G, Latin1,	SV *)
279 PERLVAR(G, LB_invlist, SV *)
280 PERLVAR(G, NonFinalFold,   SV *)
281 PERLVAR(G, SB_invlist, SV *)
282 PERLVAR(G, SCX_invlist, SV *)
283 PERLVAR(G, UpperLatin1,	SV *)   /* Code points 128 - 255 */
284 
285 /* List of characters that participate in any fold defined by Unicode */
286 PERLVAR(G, in_some_fold, SV *)
287 
288 PERLVAR(G, utf8_idcont,	SV *)
289 PERLVAR(G, utf8_idstart, SV *)
290 PERLVAR(G, utf8_perl_idcont, SV *)
291 PERLVAR(G, utf8_perl_idstart, SV *)
292 PERLVAR(G, utf8_xidcont, SV *)
293 PERLVAR(G, utf8_xidstart, SV *)
294 PERLVAR(G, WB_invlist, SV *)
295 PERLVARA(G, XPosix_ptrs, POSIX_CC_COUNT, SV *)
296 PERLVARA(G,  Posix_ptrs, POSIX_CC_COUNT, SV *)
297 PERLVAR(G, utf8_toupper, SV *)
298 PERLVAR(G, utf8_totitle, SV *)
299 PERLVAR(G, utf8_tolower, SV *)
300 PERLVAR(G, utf8_tofold,	SV *)
301 PERLVAR(G, utf8_tosimplefold,	SV *)
302 PERLVAR(G, utf8_charname_begin, SV *)
303 PERLVAR(G, utf8_charname_continue, SV *)
304 PERLVAR(G, utf8_mark,	SV *)
305 PERLVARI(G, InBitmap,	SV *, NULL)
306 PERLVAR(G, CCC_non0_non230,	SV *)
307 PERLVAR(G, Private_Use,	SV *)
308 
309 /* Definitions of user-defined \p{} properties, as the subs that define them
310  * are only called once */
311 PERLVARI(G, user_def_props,	HV *, NULL)
312 
313 #if defined(USE_ITHREADS)
314 PERLVAR(G, user_def_props_aTHX, PerlInterpreter *)  /* aTHX that user_def_props
315                                                        was defined in */
316 PERLVAR(G, user_prop_mutex, perl_mutex)    /* Mutex for manipulating
317                                               PL_user_defined_properties */
318 #endif
319 
320 /* Everything that folds to a given character, for case insensitivity regex
321  * matching */
322 PERLVAR(G, utf8_foldclosures, SV *)
323 
324 /* these record the best way to to perform certain IO operations while
325  * atomically setting FD_CLOEXEC. On the first call, a probe is done
326  * and the result recorded for use by subsequent calls.
327  * In theory these variables aren't thread-safe, but the worst that can
328  * happen is that two treads will both do an initial probe
329  */
330 PERLVARI(G, strategy_dup,        int, 0)	/* doio.c */
331 PERLVARI(G, strategy_dup2,       int, 0)	/* doio.c */
332 PERLVARI(G, strategy_open,       int, 0)	/* doio.c */
333 PERLVARI(G, strategy_open3,      int, 0)	/* doio.c */
334 PERLVARI(G, strategy_mkstemp,    int, 0)	/* doio.c */
335 PERLVARI(G, strategy_socket,     int, 0)	/* doio.c */
336 PERLVARI(G, strategy_accept,     int, 0)	/* doio.c */
337 PERLVARI(G, strategy_pipe,       int, 0)	/* doio.c */
338 PERLVARI(G, strategy_socketpair, int, 0)	/* doio.c */
339 
340 #ifdef PERL_IMPLICIT_CONTEXT
341 #  ifdef PERL_GLOBAL_STRUCT_PRIVATE
342 /* per-module array of pointers to MY_CXT_KEY constants.
343  * It simulates each module having a static my_cxt_index var on builds
344  * which don't allow static vars */
345 PERLVARI(G, my_cxt_keys, const char **, NULL)
346 PERLVARI(G, my_cxt_keys_size, int,	0)	/* size of PL_my_cxt_keys */
347 #  endif
348 #endif
349