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eb1102fc NIS |
1 | /* perlvars.h |
2 | * | |
663f364b | 3 | * Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, |
54ca4ee7 | 4 | * by Larry Wall and others |
eb1102fc NIS |
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 | ||
88e1f1a2 JV |
11 | /* |
12 | =head1 Global Variables | |
e8570548 | 13 | These variables are global to an entire process. They are shared between |
5a4fed09 KW |
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. | |
e8570548 Z |
21 | |
22 | =cut | |
88e1f1a2 | 23 | */ |
49f531da | 24 | |
d7cb65f2 | 25 | /* Don't forget to re-run regen/embed.pl to propagate changes! */ |
cb68f92d GS |
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 | 38 | PERLVAR(G, op_mutex, perl_mutex) /* Mutex for op refcounting */ |
eeb6b841 | 39 | #endif |
5c64bffd | 40 | PERLVARI(G, curinterp, PerlInterpreter *, NULL) |
43165c05 | 41 | /* currently running interpreter |
ba869deb GS |
42 | * (initial parent interpreter under |
43 | * useithreads) */ | |
3db8f154 | 44 | #if defined(USE_ITHREADS) |
115ff745 | 45 | PERLVAR(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 | 49 | PERLVARI(G, do_undump, bool, FALSE) /* -u or dump seen? */ |
b363f7ed | 50 | |
eeb6b841 | 51 | #ifndef PERL_USE_SAFE_PUTENV |
115ff745 | 52 | PERLVARI(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 | 56 | PERLVARI(G, sig_handlers_initted, int, 0) |
534825c4 | 57 | #endif |
eeb6b841 | 58 | #ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS |
115ff745 NC |
59 | PERLVARA(G, sig_ignoring, SIG_SIZE, int) |
60 | /* which signals we are ignoring */ | |
eeb6b841 NC |
61 | #endif |
62 | #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS | |
115ff745 | 63 | PERLVARA(G, sig_defaulting, SIG_SIZE, int) |
d90a703e | 64 | #endif |
5c728af0 | 65 | |
eeb6b841 NC |
66 | /* XXX signals are process-wide anyway, so we |
67 | * ignore the implications of this for threading */ | |
68 | #ifndef HAS_SIGACTION | |
115ff745 | 69 | PERLVARI(G, sig_trapped, int, 0) |
428eed4a | 70 | #endif |
af419de7 | 71 | |
2f42fcb0 | 72 | #ifndef PERL_MICRO |
b35112e7 CS |
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. */ | |
115ff745 NC |
75 | PERLVAR(G, sigfpe_saved, Sighandler_t) |
76 | PERLVARI(G, csighandlerp, Sighandler_t, Perl_csighandler) | |
77 | /* Pointer to C-level sighandler */ | |
2f42fcb0 | 78 | #endif |
5c1546dc | 79 | |
eeb6b841 NC |
80 | /* This is constant on most architectures, a global on OS/2 */ |
81 | #ifdef OS2 | |
115ff745 | 82 | PERLVARI(G, sh_path, char *, SH_PATH) /* full path of shell */ |
50acdf95 | 83 | #endif |
27da23d5 JH |
84 | |
85 | #ifdef USE_PERLIO | |
eeb6b841 NC |
86 | |
87 | # if defined(USE_ITHREADS) | |
115ff745 | 88 | PERLVAR(G, perlio_mutex, perl_mutex) /* Mutex for perlio fd refcounts */ |
eeb6b841 NC |
89 | # endif |
90 | ||
115ff745 NC |
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 */ | |
27da23d5 JH |
94 | #endif |
95 | ||
96 | #ifdef HAS_MMAP | |
115ff745 | 97 | PERLVARI(G, mmap_page_size, IV, 0) |
27da23d5 JH |
98 | #endif |
99 | ||
eeb6b841 | 100 | #if defined(USE_ITHREADS) |
115ff745 | 101 | PERLVAR(G, hints_mutex, perl_mutex) /* Mutex for refcounted he refcounting */ |
27da23d5 JH |
102 | #endif |
103 | ||
104 | #ifdef DEBUGGING | |
0c5ea019 | 105 | PERLVARI(G, watch_pvx, char *, NULL) |
27da23d5 JH |
106 | #endif |
107 | ||
e8570548 Z |
108 | /* |
109 | =for apidoc AmU|Perl_check_t *|PL_check | |
110 | ||
111 | Array, indexed by opcode, of functions that will be called for the "check" | |
112 | phase of optree building during compilation of Perl code. For most (but | |
113 | not all) types of op, once the op has been initially built and populated | |
114 | with child ops it will be filtered through the check function referenced | |
115 | by the appropriate element of this array. The new op is passed in as the | |
116 | sole argument to the check function, and the check function returns the | |
117 | completed op. The check function may (as the name suggests) check the op | |
118 | for validity and signal errors. It may also initialise or modify parts of | |
119 | the ops, or perform more radical surgery such as adding or removing child | |
120 | ops, or even throw the op away and return a different op in its place. | |
121 | ||
122 | This array of function pointers is a convenient place to hook into the | |
123 | compilation process. An XS module can put its own custom check function | |
124 | in place of any of the standard ones, to influence the compilation of a | |
125 | particular type of op. However, a custom check function must never fully | |
126 | replace a standard check function (or even a custom check function from | |
127 | another module). A module modifying checking must instead B<wrap> the | |
128 | preexisting check function. A custom check function must be selective | |
129 | about when to apply its custom behaviour. In the usual case where | |
130 | it decides not to do anything special with an op, it must chain the | |
131 | preexisting op function. Check functions are thus linked in a chain, | |
132 | with the core's base checker at the end. | |
133 | ||
134 | For thread safety, modules should not write directly to this array. | |
135 | Instead, use the function L</wrap_op_checker>. | |
136 | ||
137 | =cut | |
138 | */ | |
139 | ||
140 | #if defined(USE_ITHREADS) | |
141 | PERLVAR(G, check_mutex, perl_mutex) /* Mutex for PL_check */ | |
142 | #endif | |
27da23d5 | 143 | #ifdef PERL_GLOBAL_STRUCT |
115ff745 NC |
144 | PERLVAR(G, ppaddr, Perl_ppaddr_t *) /* or opcode.h */ |
145 | PERLVAR(G, check, Perl_check_t *) /* or opcode.h */ | |
146 | PERLVARA(G, fold_locale, 256, unsigned char) /* or perl.h */ | |
27da23d5 JH |
147 | #endif |
148 | ||
149 | #ifdef PERL_NEED_APPCTX | |
115ff745 | 150 | PERLVAR(G, appctx, void*) /* the application context */ |
27da23d5 JH |
151 | #endif |
152 | ||
27da23d5 | 153 | #if defined(HAS_TIMES) && defined(PERL_NEED_TIMESBASE) |
115ff745 | 154 | PERLVAR(G, timesbase, struct tms) |
27da23d5 JH |
155 | #endif |
156 | ||
f16dd614 | 157 | /* allocate a unique index to every module that calls MY_CXT_INIT */ |
27da23d5 | 158 | |
f16dd614 | 159 | #ifdef PERL_IMPLICIT_CONTEXT |
97aff369 | 160 | # ifdef USE_ITHREADS |
115ff745 | 161 | PERLVAR(G, my_ctx_mutex, perl_mutex) |
97aff369 | 162 | # endif |
115ff745 | 163 | PERLVARI(G, my_cxt_index, int, 0) |
f16dd614 | 164 | #endif |
71ad1b0c | 165 | |
c301d606 DM |
166 | /* this is currently set without MUTEX protection, so keep it a type which |
167 | * can be set atomically (ie not a bit field) */ | |
115ff745 | 168 | PERLVARI(G, veto_cleanup, int, FALSE) /* exit without cleanup */ |
c301d606 | 169 | |
88e1f1a2 JV |
170 | /* |
171 | =for apidoc AmUx|Perl_keyword_plugin_t|PL_keyword_plugin | |
172 | ||
173 | Function pointer, pointing at a function used to handle extended keywords. | |
174 | The function should be declared as | |
175 | ||
176 | int keyword_plugin_function(pTHX_ | |
177 | char *keyword_ptr, STRLEN keyword_len, | |
178 | OP **op_ptr) | |
179 | ||
180 | The function is called from the tokeniser, whenever a possible keyword | |
181 | is seen. C<keyword_ptr> points at the word in the parser's input | |
182 | buffer, and C<keyword_len> gives its length; it is not null-terminated. | |
183 | The function is expected to examine the word, and possibly other state | |
184 | such as L<%^H|perlvar/%^H>, to decide whether it wants to handle it | |
185 | as an extended keyword. If it does not, the function should return | |
186 | C<KEYWORD_PLUGIN_DECLINE>, and the normal parser process will continue. | |
187 | ||
188 | If the function wants to handle the keyword, it first must | |
189 | parse anything following the keyword that is part of the syntax | |
f0e67a1d | 190 | introduced by the keyword. See L</Lexer interface> for details. |
88e1f1a2 JV |
191 | |
192 | When a keyword is being handled, the plugin function must build | |
193 | a tree of C<OP> structures, representing the code that was parsed. | |
194 | The root of the tree must be stored in C<*op_ptr>. The function then | |
364f83bf | 195 | returns a constant indicating the syntactic role of the construct that |
88e1f1a2 JV |
196 | it has parsed: C<KEYWORD_PLUGIN_STMT> if it is a complete statement, or |
197 | C<KEYWORD_PLUGIN_EXPR> if it is an expression. Note that a statement | |
198 | construct cannot be used inside an expression (except via C<do BLOCK> | |
199 | and similar), and an expression is not a complete statement (it requires | |
200 | at least a terminating semicolon). | |
201 | ||
202 | When a keyword is handled, the plugin function may also have | |
203 | (compile-time) side effects. It may modify C<%^H>, define functions, and | |
204 | so on. Typically, if side effects are the main purpose of a handler, | |
205 | it does not wish to generate any ops to be included in the normal | |
206 | compilation. In this case it is still required to supply an op tree, | |
207 | but it suffices to generate a single null op. | |
208 | ||
209 | That's how the C<*PL_keyword_plugin> function needs to behave overall. | |
210 | Conventionally, however, one does not completely replace the existing | |
211 | handler function. Instead, take a copy of C<PL_keyword_plugin> before | |
212 | assigning your own function pointer to it. Your handler function should | |
213 | look for keywords that it is interested in and handle those. Where it | |
214 | is not interested, it should call the saved plugin function, passing on | |
215 | the arguments it received. Thus C<PL_keyword_plugin> actually points | |
216 | at a chain of handler functions, all of which have an opportunity to | |
217 | handle keywords, and only the last function in the chain (built into | |
218 | the Perl core) will normally return C<KEYWORD_PLUGIN_DECLINE>. | |
219 | ||
220 | =cut | |
221 | */ | |
222 | ||
115ff745 | 223 | PERLVARI(G, keyword_plugin, Perl_keyword_plugin_t, Perl_keyword_plugin_standard) |
eeb6b841 | 224 | |
5c64bffd | 225 | PERLVARI(G, op_sequence, HV *, NULL) /* dump.c */ |
115ff745 | 226 | PERLVARI(G, op_seq, UV, 0) /* dump.c */ |
eeb6b841 NC |
227 | |
228 | #ifdef USE_ITHREADS | |
115ff745 | 229 | PERLVAR(G, dollarzero_mutex, perl_mutex) /* Modifying $0 */ |
eeb6b841 NC |
230 | #endif |
231 | ||
232 | /* Restricted hashes placeholder value. | |
5c64bffd NC |
233 | In theory, the contents are never used, only the address. |
234 | In practice, &PL_sv_placeholder is returned by some APIs, and the calling | |
235 | code is checking SvOK(). */ | |
236 | ||
115ff745 | 237 | PERLVAR(G, sv_placeholder, SV) |
eeb6b841 NC |
238 | |
239 | #if defined(MYMALLOC) && defined(USE_ITHREADS) | |
115ff745 | 240 | PERLVAR(G, malloc_mutex, perl_mutex) /* Mutex for malloc */ |
eeb6b841 | 241 | #endif |
7dc86639 YO |
242 | |
243 | PERLVARI(G, hash_seed_set, bool, FALSE) /* perl.c */ | |
6a5b4183 | 244 | PERLVARA(G, hash_seed, PERL_HASH_SEED_BYTES, unsigned char) /* perl.c and hv.h */ |