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