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
15 /* Don't forget to re-run regen/embed.pl to propagate changes! */
17 /* This file describes the "global" variables used by perl
18 * This used to be in perl.h directly but we want to abstract out into
19 * distinct files which are per-thread, per-interpreter or really global,
20 * and how they're initialized.
22 * The 'G' prefix is only needed for vars that need appropriate #defines
23 * generated in embed*.h. Such symbols are also used to generate
24 * the appropriate export list for win32. */
27 #if defined(USE_ITHREADS)
28 PERLVAR(Gop_mutex, perl_mutex) /* Mutex for op refcounting */
30 PERLVAR(Gcurinterp, PerlInterpreter *)
31 /* currently running interpreter
32 * (initial parent interpreter under
34 #if defined(USE_ITHREADS)
35 PERLVAR(Gthr_key, perl_key) /* key to retrieve per-thread struct */
38 /* XXX does anyone even use this? */
39 PERLVARI(Gdo_undump, bool, FALSE) /* -u or dump seen? */
41 #ifndef PERL_USE_SAFE_PUTENV
42 PERLVARI(Guse_safe_putenv, bool, TRUE)
45 #if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS)||defined(FAKE_DEFAULT_SIGNAL_HANDLERS)
46 PERLVARI(Gsig_handlers_initted, int, 0)
48 #ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
49 PERLVARA(Gsig_ignoring, SIG_SIZE, int) /* which signals we are ignoring */
51 #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
52 PERLVARA(Gsig_defaulting, SIG_SIZE, int)
55 /* XXX signals are process-wide anyway, so we
56 * ignore the implications of this for threading */
58 PERLVARI(Gsig_trapped, int, 0)
62 /* If Perl has to ignore SIGPFE, this is its saved state.
63 * See perl.h macros PERL_FPU_INIT and PERL_FPU_{PRE,POST}_EXEC. */
64 PERLVAR(Gsigfpe_saved, Sighandler_t)
65 PERLVARI(Gcsighandlerp, Sighandler_t, Perl_csighandler) /* Pointer to C-level sighandler */
68 /* This is constant on most architectures, a global on OS/2 */
70 PERLVARI(Gsh_path, char *, SH_PATH) /* full path of shell */
75 # if defined(USE_ITHREADS)
76 PERLVAR(Gperlio_mutex, perl_mutex) /* Mutex for perlio fd refcounts */
79 PERLVARI(Gperlio_fd_refcnt, int*, 0) /* Pointer to array of fd refcounts. */
80 PERLVARI(Gperlio_fd_refcnt_size, int, 0) /* Size of the array */
81 PERLVARI(Gperlio_debug_fd, int, 0) /* the fd to write perlio debug into, 0 means not set yet */
85 PERLVARI(Gmmap_page_size, IV, 0)
88 #if defined(USE_ITHREADS)
89 PERLVAR(Ghints_mutex, perl_mutex) /* Mutex for refcounted he refcounting */
93 PERLVAR(Gwatch_pvx, char*)
96 #ifdef PERL_GLOBAL_STRUCT
97 PERLVAR(Gppaddr, Perl_ppaddr_t*) /* or opcode.h */
98 PERLVAR(Gcheck, Perl_check_t *) /* or opcode.h */
99 PERLVARA(Gfold_locale, 256, unsigned char) /* or perl.h */
102 #ifdef PERL_NEED_APPCTX
103 PERLVAR(Gappctx, void*) /* the application context */
106 #if defined(HAS_TIMES) && defined(PERL_NEED_TIMESBASE)
107 PERLVAR(Gtimesbase, struct tms)
110 /* allocate a unique index to every module that calls MY_CXT_INIT */
112 #ifdef PERL_IMPLICIT_CONTEXT
114 PERLVAR(Gmy_ctx_mutex, perl_mutex)
116 PERLVARI(Gmy_cxt_index, int, 0)
119 /* this is currently set without MUTEX protection, so keep it a type which
120 * can be set atomically (ie not a bit field) */
121 PERLVARI(Gveto_cleanup, int, FALSE) /* exit without cleanup */
124 =for apidoc AmUx|Perl_keyword_plugin_t|PL_keyword_plugin
126 Function pointer, pointing at a function used to handle extended keywords.
127 The function should be declared as
129 int keyword_plugin_function(pTHX_
130 char *keyword_ptr, STRLEN keyword_len,
133 The function is called from the tokeniser, whenever a possible keyword
134 is seen. C<keyword_ptr> points at the word in the parser's input
135 buffer, and C<keyword_len> gives its length; it is not null-terminated.
136 The function is expected to examine the word, and possibly other state
137 such as L<%^H|perlvar/%^H>, to decide whether it wants to handle it
138 as an extended keyword. If it does not, the function should return
139 C<KEYWORD_PLUGIN_DECLINE>, and the normal parser process will continue.
141 If the function wants to handle the keyword, it first must
142 parse anything following the keyword that is part of the syntax
143 introduced by the keyword. See L</Lexer interface> for details.
145 When a keyword is being handled, the plugin function must build
146 a tree of C<OP> structures, representing the code that was parsed.
147 The root of the tree must be stored in C<*op_ptr>. The function then
148 returns a constant indicating the syntactic role of the construct that
149 it has parsed: C<KEYWORD_PLUGIN_STMT> if it is a complete statement, or
150 C<KEYWORD_PLUGIN_EXPR> if it is an expression. Note that a statement
151 construct cannot be used inside an expression (except via C<do BLOCK>
152 and similar), and an expression is not a complete statement (it requires
153 at least a terminating semicolon).
155 When a keyword is handled, the plugin function may also have
156 (compile-time) side effects. It may modify C<%^H>, define functions, and
157 so on. Typically, if side effects are the main purpose of a handler,
158 it does not wish to generate any ops to be included in the normal
159 compilation. In this case it is still required to supply an op tree,
160 but it suffices to generate a single null op.
162 That's how the C<*PL_keyword_plugin> function needs to behave overall.
163 Conventionally, however, one does not completely replace the existing
164 handler function. Instead, take a copy of C<PL_keyword_plugin> before
165 assigning your own function pointer to it. Your handler function should
166 look for keywords that it is interested in and handle those. Where it
167 is not interested, it should call the saved plugin function, passing on
168 the arguments it received. Thus C<PL_keyword_plugin> actually points
169 at a chain of handler functions, all of which have an opportunity to
170 handle keywords, and only the last function in the chain (built into
171 the Perl core) will normally return C<KEYWORD_PLUGIN_DECLINE>.
176 PERLVARI(Gkeyword_plugin, Perl_keyword_plugin_t, Perl_keyword_plugin_standard)
178 PERLVAR(Gop_sequence, HV*) /* dump.c */
179 PERLVARI(Gop_seq, UV, 0) /* dump.c */
182 PERLVAR(Gdollarzero_mutex, perl_mutex) /* Modifying $0 */
185 /* Restricted hashes placeholder value.
186 * The contents are never used, only the address. */
187 PERLVAR(Gsv_placeholder, SV)
189 #if defined(MYMALLOC) && defined(USE_ITHREADS)
190 PERLVAR(Gmalloc_mutex, perl_mutex) /* Mutex for malloc */