cop.h

   1 /*    cop.h
   2  *
   3  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
   4  *    2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 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  * Control ops (cops) are one of the two ops OP_NEXTSTATE and OP_DBSTATE,
  10  * that (loosely speaking) are statement separators.
  11  * They hold information important for lexical state and error reporting.
  12  * At run time, PL_curcop is set to point to the most recently executed cop,
  13  * and thus can be used to determine our current state.
  14  */
  15
  16 /* A jmpenv packages the state required to perform a proper non-local jump.
  17  * Note that there is a PL_start_env initialized when perl starts, and
  18  * PL_top_env points to this initially, so PL_top_env should always be
  19  * non-null.
  20  *
  21  * Existence of a non-null PL_top_env->je_prev implies it is valid to call
  22  * longjmp() at that runlevel (we make sure PL_start_env.je_prev is always
  23  * null to ensure this).
  24  *
  25  * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
  26  * establish a local jmpenv to handle exception traps.  Care must be taken
  27  * to restore the previous value of je_mustcatch before exiting the
  28  * stack frame iff JMPENV_PUSH was not called in that stack frame.
  29  * GSAR 97-03-27
  30  */
  31
  32 struct jmpenv {
  33     struct jmpenv *     je_prev;
  34     Sigjmp_buf          je_buf;         /* uninit if je_prev is NULL */
  35     int                 je_ret;         /* last exception thrown */
  36     bool                je_mustcatch;   /* need to call longjmp()? */
  37     U16                 je_old_delaymagic; /* saved PL_delaymagic */
  38 };
  39
  40 typedef struct jmpenv JMPENV;
  41
  42 /*
  43  * How to build the first jmpenv.
  44  *
  45  * top_env needs to be non-zero. It points to an area
  46  * in which longjmp() stuff is stored, as C callstack
  47  * info there at least is thread specific this has to
  48  * be per-thread. Otherwise a 'die' in a thread gives
  49  * that thread the C stack of last thread to do an eval {}!
  50  */
  51
  52 #define JMPENV_BOOTSTRAP \
  53     STMT_START {                                \
  54         PERL_POISON_EXPR(PoisonNew(&PL_start_env, 1, JMPENV));\
  55         PL_top_env = &PL_start_env;             \
  56         PL_start_env.je_prev = NULL;            \
  57         PL_start_env.je_ret = -1;               \
  58         PL_start_env.je_mustcatch = TRUE;       \
  59         PL_start_env.je_old_delaymagic = 0;     \
  60     } STMT_END
  61
  62 /*
  63  *   PERL_FLEXIBLE_EXCEPTIONS
  64  *
  65  * All the flexible exceptions code has been removed.
  66  * See the following threads for details:
  67  *
  68  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2004-07/msg00378.html
  69  *
  70  * Joshua's original patches (which weren't applied) and discussion:
  71  *
  72  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01396.html
  73  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01489.html
  74  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01491.html
  75  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01608.html
  76  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02144.html
  77  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02998.html
  78  *
  79  * Chip's reworked patch and discussion:
  80  *
  81  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1999-03/msg00520.html
  82  *
  83  * The flaw in these patches (which went unnoticed at the time) was
  84  * that they moved some code that could potentially die() out of the
  85  * region protected by the setjmp()s.  This caused exceptions within
  86  * END blocks and such to not be handled by the correct setjmp().
  87  *
  88  * The original patches that introduces flexible exceptions were:
  89  *
  90  * http://perl5.git.perl.org/perl.git/commit/312caa8e97f1c7ee342a9895c2f0e749625b4929
  91  * http://perl5.git.perl.org/perl.git/commit/14dd3ad8c9bf82cf09798a22cc89a9862dfd6d1a
  92  *
  93  */
  94
  95 #define dJMPENV         JMPENV cur_env
  96
  97 #define JMPENV_PUSH(v) \
  98     STMT_START {                                                        \
  99         DEBUG_l({                                                       \
 100             int i = 0; JMPENV *p = PL_top_env;                          \
 101             while (p) { i++; p = p->je_prev; }                          \
 102             Perl_deb(aTHX_ "JUMPENV_PUSH level=%d at %s:%d\n",          \
 103                          i,  __FILE__, __LINE__);})                     \
 104         cur_env.je_prev = PL_top_env;                                   \
 105         cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);              \
 106         PL_top_env = &cur_env;                                          \
 107         cur_env.je_mustcatch = FALSE;                                   \
 108         cur_env.je_old_delaymagic = PL_delaymagic;                      \
 109         (v) = cur_env.je_ret;                                           \
 110     } STMT_END
 111
 112 #define JMPENV_POP \
 113     STMT_START {                                                        \
 114         DEBUG_l({                                                       \
 115             int i = -1; JMPENV *p = PL_top_env;                         \
 116             while (p) { i++; p = p->je_prev; }                          \
 117             Perl_deb(aTHX_ "JUMPENV_POP level=%d at %s:%d\n",           \
 118                          i, __FILE__, __LINE__);})                      \
 119         assert(PL_top_env == &cur_env);                                 \
 120         PL_delaymagic = cur_env.je_old_delaymagic;                      \
 121         PL_top_env = cur_env.je_prev;                                   \
 122     } STMT_END
 123
 124 #define JMPENV_JUMP(v) \
 125     STMT_START {                                                \
 126         DEBUG_l({                                               \
 127             int i = -1; JMPENV *p = PL_top_env;                 \
 128             while (p) { i++; p = p->je_prev; }                  \
 129             Perl_deb(aTHX_ "JUMPENV_JUMP(%d) level=%d at %s:%d\n", \
 130                          (int)v, i, __FILE__, __LINE__);})      \
 131         if (PL_top_env->je_prev)                                \
 132             PerlProc_longjmp(PL_top_env->je_buf, (v));          \
 133         if ((v) == 2)                                           \
 134             PerlProc_exit(STATUS_EXIT);                         \
 135         PerlIO_printf(PerlIO_stderr(), "panic: top_env, v=%d\n", (int)v); \
 136         PerlProc_exit(1);                                       \
 137     } STMT_END
 138
 139 #define CATCH_GET               (PL_top_env->je_mustcatch)
 140 #define CATCH_SET(v) \
 141     STMT_START {                                                        \
 142         DEBUG_l(                                                        \
 143             Perl_deb(aTHX_                                              \
 144                 "JUMPLEVEL set catch %d => %d (for %p) at %s:%d\n",     \
 145                  PL_top_env->je_mustcatch, v, (void*)PL_top_env,        \
 146                  __FILE__, __LINE__);)                                  \
 147         PL_top_env->je_mustcatch = (v);                                 \
 148     } STMT_END
 149
 150 /*
 151 =head1 COP Hint Hashes
 152 */
 153
 154 typedef struct refcounted_he COPHH;
 155
 156 #define COPHH_KEY_UTF8 REFCOUNTED_HE_KEY_UTF8
 157
 158 /*
 159 =for apidoc Amx|SV *|cophh_fetch_pvn|const COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|U32 flags
 160
 161 Look up the entry in the cop hints hash C<cophh> with the key specified by
 162 C<keypv> and C<keylen>.  If C<flags> has the C<COPHH_KEY_UTF8> bit set,
 163 the key octets are interpreted as UTF-8, otherwise they are interpreted
 164 as Latin-1.  C<hash> is a precomputed hash of the key string, or zero if
 165 it has not been precomputed.  Returns a mortal scalar copy of the value
 166 associated with the key, or C<&PL_sv_placeholder> if there is no value
 167 associated with the key.
 168
 169 =cut
 170 */
 171
 172 #define cophh_fetch_pvn(cophh, keypv, keylen, hash, flags) \
 173     Perl_refcounted_he_fetch_pvn(aTHX_ cophh, keypv, keylen, hash, flags)
 174
 175 /*
 176 =for apidoc Amx|SV *|cophh_fetch_pvs|const COPHH *cophh|const char *key|U32 flags
 177
 178 Like L</cophh_fetch_pvn>, but takes a literal string instead of a
 179 string/length pair, and no precomputed hash.
 180
 181 =cut
 182 */
 183
 184 #define cophh_fetch_pvs(cophh, key, flags) \
 185     Perl_refcounted_he_fetch_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, flags)
 186
 187 /*
 188 =for apidoc Amx|SV *|cophh_fetch_pv|const COPHH *cophh|const char *key|U32 hash|U32 flags
 189
 190 Like L</cophh_fetch_pvn>, but takes a nul-terminated string instead of
 191 a string/length pair.
 192
 193 =cut
 194 */
 195
 196 #define cophh_fetch_pv(cophh, key, hash, flags) \
 197     Perl_refcounted_he_fetch_pv(aTHX_ cophh, key, hash, flags)
 198
 199 /*
 200 =for apidoc Amx|SV *|cophh_fetch_sv|const COPHH *cophh|SV *key|U32 hash|U32 flags
 201
 202 Like L</cophh_fetch_pvn>, but takes a Perl scalar instead of a
 203 string/length pair.
 204
 205 =cut
 206 */
 207
 208 #define cophh_fetch_sv(cophh, key, hash, flags) \
 209     Perl_refcounted_he_fetch_sv(aTHX_ cophh, key, hash, flags)
 210
 211 /*
 212 =for apidoc Amx|HV *|cophh_2hv|const COPHH *cophh|U32 flags
 213
 214 Generates and returns a standard Perl hash representing the full set of
 215 key/value pairs in the cop hints hash C<cophh>.  C<flags> is currently
 216 unused and must be zero.
 217
 218 =cut
 219 */
 220
 221 #define cophh_2hv(cophh, flags) \
 222     Perl_refcounted_he_chain_2hv(aTHX_ cophh, flags)
 223
 224 /*
 225 =for apidoc Amx|COPHH *|cophh_copy|COPHH *cophh
 226
 227 Make and return a complete copy of the cop hints hash C<cophh>.
 228
 229 =cut
 230 */
 231
 232 #define cophh_copy(cophh) Perl_refcounted_he_inc(aTHX_ cophh)
 233
 234 /*
 235 =for apidoc Amx|void|cophh_free|COPHH *cophh
 236
 237 Discard the cop hints hash C<cophh>, freeing all resources associated
 238 with it.
 239
 240 =cut
 241 */
 242
 243 #define cophh_free(cophh) Perl_refcounted_he_free(aTHX_ cophh)
 244
 245 /*
 246 =for apidoc Amx|COPHH *|cophh_new_empty
 247
 248 Generate and return a fresh cop hints hash containing no entries.
 249
 250 =cut
 251 */
 252
 253 #define cophh_new_empty() ((COPHH *)NULL)
 254
 255 /*
 256 =for apidoc Amx|COPHH *|cophh_store_pvn|COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|SV *value|U32 flags
 257
 258 Stores a value, associated with a key, in the cop hints hash C<cophh>,
 259 and returns the modified hash.  The returned hash pointer is in general
 260 not the same as the hash pointer that was passed in.  The input hash is
 261 consumed by the function, and the pointer to it must not be subsequently
 262 used.  Use L</cophh_copy> if you need both hashes.
 263
 264 The key is specified by C<keypv> and C<keylen>.  If C<flags> has the
 265 C<COPHH_KEY_UTF8> bit set, the key octets are interpreted as UTF-8,
 266 otherwise they are interpreted as Latin-1.  C<hash> is a precomputed
 267 hash of the key string, or zero if it has not been precomputed.
 268
 269 C<value> is the scalar value to store for this key.  C<value> is copied
 270 by this function, which thus does not take ownership of any reference
 271 to it, and later changes to the scalar will not be reflected in the
 272 value visible in the cop hints hash.  Complex types of scalar will not
 273 be stored with referential integrity, but will be coerced to strings.
 274
 275 =cut
 276 */
 277
 278 #define cophh_store_pvn(cophh, keypv, keylen, hash, value, flags) \
 279     Perl_refcounted_he_new_pvn(aTHX_ cophh, keypv, keylen, hash, value, flags)
 280
 281 /*
 282 =for apidoc Amx|COPHH *|cophh_store_pvs|const COPHH *cophh|const char *key|SV *value|U32 flags
 283
 284 Like L</cophh_store_pvn>, but takes a literal string instead of a
 285 string/length pair, and no precomputed hash.
 286
 287 =cut
 288 */
 289
 290 #define cophh_store_pvs(cophh, key, value, flags) \
 291     Perl_refcounted_he_new_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, value, flags)
 292
 293 /*
 294 =for apidoc Amx|COPHH *|cophh_store_pv|const COPHH *cophh|const char *key|U32 hash|SV *value|U32 flags
 295
 296 Like L</cophh_store_pvn>, but takes a nul-terminated string instead of
 297 a string/length pair.
 298
 299 =cut
 300 */
 301
 302 #define cophh_store_pv(cophh, key, hash, value, flags) \
 303     Perl_refcounted_he_new_pv(aTHX_ cophh, key, hash, value, flags)
 304
 305 /*
 306 =for apidoc Amx|COPHH *|cophh_store_sv|const COPHH *cophh|SV *key|U32 hash|SV *value|U32 flags
 307
 308 Like L</cophh_store_pvn>, but takes a Perl scalar instead of a
 309 string/length pair.
 310
 311 =cut
 312 */
 313
 314 #define cophh_store_sv(cophh, key, hash, value, flags) \
 315     Perl_refcounted_he_new_sv(aTHX_ cophh, key, hash, value, flags)
 316
 317 /*
 318 =for apidoc Amx|COPHH *|cophh_delete_pvn|COPHH *cophh|const char *keypv|STRLEN keylen|U32 hash|U32 flags
 319
 320 Delete a key and its associated value from the cop hints hash C<cophh>,
 321 and returns the modified hash.  The returned hash pointer is in general
 322 not the same as the hash pointer that was passed in.  The input hash is
 323 consumed by the function, and the pointer to it must not be subsequently
 324 used.  Use L</cophh_copy> if you need both hashes.
 325
 326 The key is specified by C<keypv> and C<keylen>.  If C<flags> has the
 327 C<COPHH_KEY_UTF8> bit set, the key octets are interpreted as UTF-8,
 328 otherwise they are interpreted as Latin-1.  C<hash> is a precomputed
 329 hash of the key string, or zero if it has not been precomputed.
 330
 331 =cut
 332 */
 333
 334 #define cophh_delete_pvn(cophh, keypv, keylen, hash, flags) \
 335     Perl_refcounted_he_new_pvn(aTHX_ cophh, keypv, keylen, hash, \
 336         (SV *)NULL, flags)
 337
 338 /*
 339 =for apidoc Amx|COPHH *|cophh_delete_pvs|const COPHH *cophh|const char *key|U32 flags
 340
 341 Like L</cophh_delete_pvn>, but takes a literal string instead of a
 342 string/length pair, and no precomputed hash.
 343
 344 =cut
 345 */
 346
 347 #define cophh_delete_pvs(cophh, key, flags) \
 348     Perl_refcounted_he_new_pvn(aTHX_ cophh, STR_WITH_LEN(key), 0, \
 349         (SV *)NULL, flags)
 350
 351 /*
 352 =for apidoc Amx|COPHH *|cophh_delete_pv|const COPHH *cophh|const char *key|U32 hash|U32 flags
 353
 354 Like L</cophh_delete_pvn>, but takes a nul-terminated string instead of
 355 a string/length pair.
 356
 357 =cut
 358 */
 359
 360 #define cophh_delete_pv(cophh, key, hash, flags) \
 361     Perl_refcounted_he_new_pv(aTHX_ cophh, key, hash, (SV *)NULL, flags)
 362
 363 /*
 364 =for apidoc Amx|COPHH *|cophh_delete_sv|const COPHH *cophh|SV *key|U32 hash|U32 flags
 365
 366 Like L</cophh_delete_pvn>, but takes a Perl scalar instead of a
 367 string/length pair.
 368
 369 =cut
 370 */
 371
 372 #define cophh_delete_sv(cophh, key, hash, flags) \
 373     Perl_refcounted_he_new_sv(aTHX_ cophh, key, hash, (SV *)NULL, flags)
 374
 375 #include "mydtrace.h"
 376
 377 struct cop {
 378     BASEOP
 379     /* On LP64 putting this here takes advantage of the fact that BASEOP isn't
 380        an exact multiple of 8 bytes to save structure padding.  */
 381     line_t      cop_line;       /* line # of this command */
 382     /* label for this construct is now stored in cop_hints_hash */
 383 #ifdef USE_ITHREADS
 384     PADOFFSET   cop_stashoff;   /* offset into PL_stashpad, for the
 385                                    package the line was compiled in */
 386     char *      cop_file;       /* file name the following line # is from */
 387 #else
 388     HV *        cop_stash;      /* package line was compiled in */
 389     GV *        cop_filegv;     /* file the following line # is from */
 390 #endif
 391     U32         cop_hints;      /* hints bits from pragmata */
 392     U32         cop_seq;        /* parse sequence number */
 393     /* Beware. mg.c and warnings.pl assume the type of this is STRLEN *:  */
 394     STRLEN *    cop_warnings;   /* lexical warnings bitmask */
 395     /* compile time state of %^H.  See the comment in op.c for how this is
 396        used to recreate a hash to return from caller.  */
 397     COPHH *     cop_hints_hash;
 398 };
 399
 400 #ifdef USE_ITHREADS
 401 #  define CopFILE(c)            ((c)->cop_file)
 402 #  define CopFILEGV(c)          (CopFILE(c) \
 403                                  ? gv_fetchfile(CopFILE(c)) : NULL)
 404
 405 #  ifdef NETWARE
 406 #    define CopFILE_set(c,pv)   ((c)->cop_file = savepv(pv))
 407 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savepvn((pv),(l)))
 408 #  else
 409 #    define CopFILE_set(c,pv)   ((c)->cop_file = savesharedpv(pv))
 410 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savesharedpvn((pv),(l)))
 411 #  endif
 412
 413 #  define CopFILESV(c)          (CopFILE(c) \
 414                                  ? GvSV(gv_fetchfile(CopFILE(c))) : NULL)
 415 #  define CopFILEAV(c)          (CopFILE(c) \
 416                                  ? GvAV(gv_fetchfile(CopFILE(c))) : NULL)
 417 #  define CopFILEAVx(c)         (assert_(CopFILE(c)) \
 418                                    GvAV(gv_fetchfile(CopFILE(c))))
 419
 420 #  define CopSTASH(c)           PL_stashpad[(c)->cop_stashoff]
 421 #  define CopSTASH_set(c,hv)    ((c)->cop_stashoff = (hv)               \
 422                                     ? alloccopstash(hv)                 \
 423                                     : 0)
 424 #  ifdef NETWARE
 425 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
 426 #  else
 427 #    define CopFILE_free(c)     (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = NULL))
 428 #  endif
 429 #else
 430 #  define CopFILEGV(c)          ((c)->cop_filegv)
 431 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
 432 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
 433 #  define CopFILE_setn(c,pv,l)  CopFILEGV_set((c), gv_fetchfile_flags((pv),(l),0))
 434 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : NULL)
 435 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : NULL)
 436 #  ifdef DEBUGGING
 437 #    define CopFILEAVx(c)       (assert(CopFILEGV(c)), GvAV(CopFILEGV(c)))
 438 #  else
 439 #    define CopFILEAVx(c)       (GvAV(CopFILEGV(c)))
 440 # endif
 441 #  define CopFILE(c)            (CopFILEGV(c) \
 442                                     ? GvNAME(CopFILEGV(c))+2 : NULL)
 443 #  define CopSTASH(c)           ((c)->cop_stash)
 444 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
 445 #  define CopFILE_free(c)       (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = NULL))
 446
 447 #endif /* USE_ITHREADS */
 448
 449 #define CopSTASHPV(c)           (CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : NULL)
 450    /* cop_stash is not refcounted */
 451 #define CopSTASHPV_set(c,pv)    CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
 452 #define CopSTASH_eq(c,hv)       (CopSTASH(c) == (hv))
 453
 454 #define CopHINTHASH_get(c)      ((COPHH*)((c)->cop_hints_hash))
 455 #define CopHINTHASH_set(c,h)    ((c)->cop_hints_hash = (h))
 456
 457 /*
 458 =head1 COP Hint Reading
 459 */
 460
 461 /*
 462 =for apidoc Am|SV *|cop_hints_fetch_pvn|const COP *cop|const char *keypv|STRLEN keylen|U32 hash|U32 flags
 463
 464 Look up the hint entry in the cop C<cop> with the key specified by
 465 C<keypv> and C<keylen>.  If C<flags> has the C<COPHH_KEY_UTF8> bit set,
 466 the key octets are interpreted as UTF-8, otherwise they are interpreted
 467 as Latin-1.  C<hash> is a precomputed hash of the key string, or zero if
 468 it has not been precomputed.  Returns a mortal scalar copy of the value
 469 associated with the key, or C<&PL_sv_placeholder> if there is no value
 470 associated with the key.
 471
 472 =cut
 473 */
 474
 475 #define cop_hints_fetch_pvn(cop, keypv, keylen, hash, flags) \
 476     cophh_fetch_pvn(CopHINTHASH_get(cop), keypv, keylen, hash, flags)
 477
 478 /*
 479 =for apidoc Am|SV *|cop_hints_fetch_pvs|const COP *cop|const char *key|U32 flags
 480
 481 Like L</cop_hints_fetch_pvn>, but takes a literal string instead of a
 482 string/length pair, and no precomputed hash.
 483
 484 =cut
 485 */
 486
 487 #define cop_hints_fetch_pvs(cop, key, flags) \
 488     cophh_fetch_pvs(CopHINTHASH_get(cop), key, flags)
 489
 490 /*
 491 =for apidoc Am|SV *|cop_hints_fetch_pv|const COP *cop|const char *key|U32 hash|U32 flags
 492
 493 Like L</cop_hints_fetch_pvn>, but takes a nul-terminated string instead
 494 of a string/length pair.
 495
 496 =cut
 497 */
 498
 499 #define cop_hints_fetch_pv(cop, key, hash, flags) \
 500     cophh_fetch_pv(CopHINTHASH_get(cop), key, hash, flags)
 501
 502 /*
 503 =for apidoc Am|SV *|cop_hints_fetch_sv|const COP *cop|SV *key|U32 hash|U32 flags
 504
 505 Like L</cop_hints_fetch_pvn>, but takes a Perl scalar instead of a
 506 string/length pair.
 507
 508 =cut
 509 */
 510
 511 #define cop_hints_fetch_sv(cop, key, hash, flags) \
 512     cophh_fetch_sv(CopHINTHASH_get(cop), key, hash, flags)
 513
 514 /*
 515 =for apidoc Am|HV *|cop_hints_2hv|const COP *cop|U32 flags
 516
 517 Generates and returns a standard Perl hash representing the full set of
 518 hint entries in the cop C<cop>.  C<flags> is currently unused and must
 519 be zero.
 520
 521 =cut
 522 */
 523
 524 #define cop_hints_2hv(cop, flags) \
 525     cophh_2hv(CopHINTHASH_get(cop), flags)
 526
 527 #define CopLABEL(c)  Perl_cop_fetch_label(aTHX_ (c), NULL, NULL)
 528 #define CopLABEL_len(c,len)  Perl_cop_fetch_label(aTHX_ (c), len, NULL)
 529 #define CopLABEL_len_flags(c,len,flags)  Perl_cop_fetch_label(aTHX_ (c), len, flags)
 530 #define CopLABEL_alloc(pv)      ((pv)?savepv(pv):NULL)
 531
 532 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
 533 #define CopLINE(c)              ((c)->cop_line)
 534 #define CopLINE_inc(c)          (++CopLINE(c))
 535 #define CopLINE_dec(c)          (--CopLINE(c))
 536 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
 537
 538 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
 539 #define OutCopFILE(c) CopFILE(c)
 540
 541 #define CopHINTS_get(c)         ((c)->cop_hints + 0)
 542 #define CopHINTS_set(c, h)      STMT_START {                            \
 543                                     (c)->cop_hints = (h);               \
 544                                 } STMT_END
 545
 546 /*
 547  * Here we have some enormously heavy (or at least ponderous) wizardry.
 548  */
 549
 550 /* subroutine context */
 551 struct block_sub {
 552     OP *        retop;  /* op to execute on exit from sub */
 553     /* Above here is the same for sub, format and eval.  */
 554     PAD         *prevcomppad; /* the caller's PL_comppad */
 555     CV *        cv;
 556     /* Above here is the same for sub and format.  */
 557     I32         olddepth;
 558     AV          *savearray;
 559 };
 560
 561
 562 /* format context */
 563 struct block_format {
 564     OP *        retop;  /* op to execute on exit from sub */
 565     /* Above here is the same for sub, format and eval.  */
 566     PAD         *prevcomppad; /* the caller's PL_comppad */
 567     CV *        cv;
 568     /* Above here is the same for sub and format.  */
 569     GV *        gv;
 570     GV *        dfoutgv;
 571 };
 572
 573 /* free all savestack items back to the watermark of the specified context */
 574
 575 #define CX_LEAVE_SCOPE(cx) LEAVE_SCOPE(cx->cx_old_savestack_ix)
 576
 577 /* base for the next two macros. Don't use directly.
 578  * The context frame holds a reference to the CV so that it can't be
 579  * freed while we're executing it */
 580
 581 #define PUSHSUB_BASE(cx)                                                \
 582         ENTRY_PROBE(CvNAMED(cv)                                         \
 583                         ? HEK_KEY(CvNAME_HEK(cv))                       \
 584                         : GvENAME(CvGV(cv)),                            \
 585                 CopFILE((const COP *)CvSTART(cv)),                      \
 586                 CopLINE((const COP *)CvSTART(cv)),                      \
 587                 CopSTASHPV((const COP *)CvSTART(cv)));                  \
 588                                                                         \
 589         cx->blk_sub.cv = cv;                                            \
 590         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
 591         cx->blk_sub.prevcomppad = PL_comppad;                           \
 592         cx->cx_type |= (hasargs) ? CXp_HASARGS : 0;                     \
 593         cx->blk_sub.retop = NULL;                                       \
 594         SvREFCNT_inc_simple_void_NN(cv);
 595
 596 #define PUSHSUB_GET_LVALUE_MASK(func) \
 597         /* If the context is indeterminate, then only the lvalue */     \
 598         /* flags that the caller also has are applicable.        */     \
 599         (                                                               \
 600            (PL_op->op_flags & OPf_WANT)                                 \
 601                ? OPpENTERSUB_LVAL_MASK                                  \
 602                : !(PL_op->op_private & OPpENTERSUB_LVAL_MASK)           \
 603                    ? 0 : (U8)func(aTHX)                                 \
 604         )
 605
 606 #define PUSHSUB(cx)                                                     \
 607     {                                                                   \
 608         U8 phlags = PUSHSUB_GET_LVALUE_MASK(Perl_was_lvalue_sub);       \
 609         PUSHSUB_BASE(cx)                                                \
 610         cx->blk_u16 = PL_op->op_private &                               \
 611                           (phlags|OPpDEREF);                            \
 612     }
 613
 614 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
 615 #define PUSHSUB_DB(cx)                                                  \
 616         PUSHSUB_BASE(cx)                                                \
 617         cx->blk_u16 = 0;
 618
 619
 620 #define PUSHFORMAT(cx, retop)                                           \
 621         cx->blk_format.cv = cv;                                         \
 622         cx->blk_format.gv = gv;                                         \
 623         cx->blk_format.retop = (retop);                                 \
 624         cx->blk_format.dfoutgv = PL_defoutgv;                           \
 625         cx->blk_format.prevcomppad = PL_comppad;                        \
 626         cx->blk_u16 = 0;                                                \
 627         cx->cx_old_savestack_ix = PL_savestack_ix;                      \
 628         SvREFCNT_inc_simple_void_NN(cv);                                \
 629         CvDEPTH(cv)++;                                                  \
 630         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
 631
 632 /* Restore old @_ */
 633 #define POP_SAVEARRAY()                                         \
 634     STMT_START {                                                        \
 635         AV *av = GvAV(PL_defgv);                                        \
 636         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
 637         SvREFCNT_dec(av);                                               \
 638     } STMT_END
 639
 640 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
 641  * leave any (a fast av_clear(ary), basically) */
 642 #define CLEAR_ARGARRAY(ary) \
 643     STMT_START {                                                        \
 644         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
 645         AvARRAY(ary) = AvALLOC(ary);                                    \
 646         AvFILLp(ary) = -1;                                              \
 647     } STMT_END
 648
 649
 650 /* subsets of POPSUB */
 651
 652 #define POPSUB_COMMON(cx) \
 653     PL_comppad = cx->blk_sub.prevcomppad;                               \
 654     PL_curpad = LIKELY(PL_comppad) ? AvARRAY(PL_comppad) : NULL;        \
 655     CvDEPTH((const CV*)cx->blk_sub.cv) = cx->blk_sub.olddepth;          \
 656     SvREFCNT_dec_NN(cx->blk_sub.cv);
 657
 658
 659 #define POPSUB(cx)                                                      \
 660     STMT_START {                                                        \
 661         if (!(cx->blk_u16 & CxPOPSUB_DONE)) {                           \
 662         cx->blk_u16 |= CxPOPSUB_DONE;                                   \
 663         RETURN_PROBE(CvNAMED(cx->blk_sub.cv)                            \
 664                         ? HEK_KEY(CvNAME_HEK(cx->blk_sub.cv))           \
 665                         : GvENAME(CvGV(cx->blk_sub.cv)),                \
 666                 CopFILE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
 667                 CopLINE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
 668                 CopSTASHPV((COP*)CvSTART((const CV*)cx->blk_sub.cv)));  \
 669                                                                         \
 670         if (CxHASARGS(cx)) {                                            \
 671             AV *av;                                                     \
 672             assert(AvARRAY(MUTABLE_AV(                                  \
 673                 PadlistARRAY(CvPADLIST(cx->blk_sub.cv))[                \
 674                         CvDEPTH(cx->blk_sub.cv)])) == PL_curpad);       \
 675             POP_SAVEARRAY();                                            \
 676             /* abandon @_ if it got reified */                          \
 677             av = MUTABLE_AV(PAD_SVl(0));                                \
 678             if (UNLIKELY(AvREAL(av)))                                   \
 679                 clear_defarray(av, 0);                                  \
 680             else {                                                      \
 681                 CLEAR_ARGARRAY(av);                                     \
 682             }                                                           \
 683         }                                                               \
 684         }                                                               \
 685         POPSUB_COMMON(cx);                                              \
 686     } STMT_END
 687
 688 #define POPFORMAT(cx)                                                   \
 689     STMT_START {                                                        \
 690         if (!(cx->blk_u16 & CxPOPSUB_DONE)) {                           \
 691         CV * const cv = cx->blk_format.cv;                              \
 692         GV * const dfuot = cx->blk_format.dfoutgv;                      \
 693         cx->blk_u16 |= CxPOPSUB_DONE;                                   \
 694         setdefout(dfuot);                                               \
 695         PL_comppad = cx->blk_format.prevcomppad;                        \
 696         PL_curpad = LIKELY(PL_comppad) ? AvARRAY(PL_comppad) : NULL;    \
 697         --CvDEPTH(cv);                                                  \
 698         SvREFCNT_dec_NN(cx->blk_format.cv);                             \
 699         SvREFCNT_dec_NN(dfuot);                                         \
 700         }                                                               \
 701     } STMT_END
 702
 703 /* eval context */
 704 struct block_eval {
 705     OP *        retop;  /* op to execute on exit from eval */
 706     /* Above here is the same for sub, format and eval.  */
 707     SV *        old_namesv;
 708     OP *        old_eval_root;
 709     SV *        cur_text;
 710     CV *        cv;
 711     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
 712 };
 713
 714 /* If we ever need more than 512 op types, change the shift from 7.
 715    blku_gimme is actually also only 2 bits, so could be merged with something.
 716 */
 717
 718 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
 719 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
 720
 721 #define PUSHEVAL(cx,n)                                                  \
 722     STMT_START {                                                        \
 723         assert(!(PL_in_eval & ~0x7F));                                  \
 724         assert(!(PL_op->op_type & ~0x1FF));                             \
 725         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
 726         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
 727         cx->blk_eval.old_eval_root = PL_eval_root;                      \
 728         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
 729         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
 730         cx->blk_eval.retop = NULL;                                      \
 731         cx->blk_eval.cur_top_env = PL_top_env;                          \
 732     } STMT_END
 733
 734 #define POPEVAL(cx)                                                     \
 735     STMT_START {                                                        \
 736         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
 737         optype = CxOLD_OP_TYPE(cx);                                     \
 738         PL_eval_root = cx->blk_eval.old_eval_root;                      \
 739         if (cx->blk_eval.cur_text && SvSCREAM(cx->blk_eval.cur_text))   \
 740             SvREFCNT_dec_NN(cx->blk_eval.cur_text);                     \
 741         if (cx->blk_eval.old_namesv)                                    \
 742             sv_2mortal(cx->blk_eval.old_namesv);                        \
 743     } STMT_END
 744
 745 /* loop context */
 746 struct block_loop {
 747     I32         resetsp;
 748     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
 749     union {     /* different ways of locating the iteration variable */
 750         SV      **svp; /* for lexicals: address of pad slot */
 751         GV      *gv;   /* for package vars */
 752     } itervar_u;
 753     SV          *itersave; /* the original iteration var */
 754     union {
 755         struct { /* valid if type is LOOP_FOR or LOOP_PLAIN (but {NULL,0})*/
 756             AV * ary; /* use the stack if this is NULL */
 757             IV ix;
 758         } ary;
 759         struct { /* valid if type is LOOP_LAZYIV */
 760             IV cur;
 761             IV end;
 762         } lazyiv;
 763         struct { /* valid if type if LOOP_LAZYSV */
 764             SV * cur;
 765             SV * end; /* maxiumum value (or minimum in reverse) */
 766         } lazysv;
 767     } state_u;
 768 #ifdef USE_ITHREADS
 769     PAD *oldcomppad; /* needed to map itervar_u.svp during thread clone */
 770 #endif
 771 };
 772
 773 #define CxITERVAR(c)                                    \
 774         (CxPADLOOP(c)                                   \
 775             ? (c)->blk_loop.itervar_u.svp               \
 776             : ((c)->cx_type & CXp_FOR_GV)               \
 777                 ? &GvSV((c)->blk_loop.itervar_u.gv)     \
 778                 : (SV **)&(c)->blk_loop.itervar_u.gv)
 779
 780 #define CxLABEL(c)      (0 + CopLABEL((c)->blk_oldcop))
 781 #define CxLABEL_len(c,len)      (0 + CopLABEL_len((c)->blk_oldcop, len))
 782 #define CxLABEL_len_flags(c,len,flags)  (0 + CopLABEL_len_flags((c)->blk_oldcop, len, flags))
 783 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
 784 #define CxLVAL(c)       (0 + ((c)->blk_u16 & 0xff))
 785 /* POPSUB has already been performed on this context frame */
 786 #define CxPOPSUB_DONE 0x100
 787
 788
 789 #define PUSHLOOP_PLAIN(cx, s)                                           \
 790         cx->blk_loop.resetsp = s - PL_stack_base;                       \
 791         cx->blk_loop.my_op = cLOOP;                                     \
 792         cx->blk_loop.state_u.ary.ary = NULL;                            \
 793         cx->blk_loop.state_u.ary.ix = 0;                                \
 794         cx->cx_old_savestack_ix = PL_savestack_ix;                      \
 795         cx->blk_loop.itervar_u.svp = NULL;                              \
 796         cx->blk_loop.itersave = NULL;
 797
 798 #ifdef USE_ITHREADS
 799 #  define PUSHLOOP_FOR_setpad(c) (c)->blk_loop.oldcomppad = PL_comppad
 800 #else
 801 #  define PUSHLOOP_FOR_setpad(c) NOOP
 802 #endif
 803
 804 #define PUSHLOOP_FOR(cx, ivar, isave, s)                                \
 805         cx->blk_loop.resetsp = s - PL_stack_base;                       \
 806         cx->blk_loop.my_op = cLOOP;                                     \
 807         cx->blk_loop.state_u.ary.ary = NULL;                            \
 808         cx->blk_loop.state_u.ary.ix = 0;                                \
 809         cx->blk_loop.itervar_u.svp = (SV**)(ivar);                      \
 810         cx->cx_old_savestack_ix = PL_savestack_ix;                      \
 811         cx->blk_loop.itersave = isave;                                  \
 812         PUSHLOOP_FOR_setpad(cx);
 813
 814 #define POPLOOP(cx)                                                     \
 815         if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                            \
 816             SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.cur);           \
 817             SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.end);           \
 818         }                                                               \
 819         else if (CxTYPE(cx) == CXt_LOOP_FOR)                            \
 820             SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);                 \
 821         if (cx->cx_type & (CXp_FOR_PAD|CXp_FOR_GV)) {                   \
 822             SV *cursv;                                                  \
 823             SV **svp = (cx)->blk_loop.itervar_u.svp;                    \
 824             if ((cx->cx_type & CXp_FOR_GV))                             \
 825                 svp = &GvSV((GV*)svp);                                  \
 826             cursv = *svp;                                               \
 827             *svp = cx->blk_loop.itersave;                               \
 828             SvREFCNT_dec(cursv);                                        \
 829         }
 830
 831 /* given/when context */
 832 struct block_givwhen {
 833         OP *leave_op;
 834         SV *defsv_save; /* the original $_ */
 835 };
 836
 837 #define PUSHWHEN(cx)                                                    \
 838         cx->cx_old_savestack_ix = PL_savestack_ix;                      \
 839         cx->blk_givwhen.leave_op = cLOGOP->op_other;
 840
 841 #define PUSHGIVEN(cx, orig_var)                                         \
 842         PUSHWHEN(cx);                                                   \
 843         cx->blk_givwhen.defsv_save = orig_var;
 844
 845 #define POPWHEN(cx)                                                     \
 846         NOOP;
 847
 848 #define POPGIVEN(cx)                                                    \
 849         SvREFCNT_dec(GvSV(PL_defgv));                                   \
 850         GvSV(PL_defgv) = cx->blk_givwhen.defsv_save;
 851
 852
 853 /* basic block, i.e. pp_enter/leave */
 854
 855 #define PUSHBASICBLK(cx)                                                \
 856         cx->cx_old_savestack_ix = PL_savestack_ix;
 857
 858 #define POPBASICBLK(cx)                                                 \
 859         NOOP;
 860
 861
 862 /* context common to subroutines, evals and loops */
 863 struct block {
 864     U8          blku_type;      /* what kind of context this is */
 865     U8          blku_gimme;     /* is this block running in list context? */
 866     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
 867     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
 868     COP *       blku_oldcop;    /* old curcop pointer */
 869     I32         blku_oldmarksp; /* mark stack index */
 870     I32         blku_oldscopesp;        /* scope stack index */
 871     PMOP *      blku_oldpm;     /* values of pattern match vars */
 872     SSize_t     blku_old_tmpsfloor;     /* saved PL_tmps_floor */
 873
 874     union {
 875         struct block_sub        blku_sub;
 876         struct block_format     blku_format;
 877         struct block_eval       blku_eval;
 878         struct block_loop       blku_loop;
 879         struct block_givwhen    blku_givwhen;
 880     } blk_u;
 881 };
 882 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
 883 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
 884 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
 885 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
 886 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
 887 #define blk_gimme       cx_u.cx_blk.blku_gimme
 888 #define blk_u16         cx_u.cx_blk.blku_u16
 889 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
 890 #define blk_format      cx_u.cx_blk.blk_u.blku_format
 891 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
 892 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
 893 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
 894
 895 #define DEBUG_CX(action)                                                \
 896     DEBUG_l(                                                            \
 897         Perl_deb(aTHX_ "CX %ld %s %s (scope %ld,%ld) (save %ld,%ld) at %s:%d\n",\
 898                     (long)cxstack_ix,                                   \
 899                     action,                                             \
 900                     PL_block_type[CxTYPE(&cxstack[cxstack_ix])],        \
 901                     (long)PL_scopestack_ix,                             \
 902                     (long)(cxstack[cxstack_ix].blk_oldscopesp),         \
 903                     (long)PL_savestack_ix,                              \
 904                     (long)(cxstack[cxstack_ix].cx_old_savestack_ix),    \
 905                     __FILE__, __LINE__));
 906
 907 /* Enter a block. */
 908 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
 909         cx->cx_type             = t,                                    \
 910         cx->blk_oldsp           = sp - PL_stack_base,                   \
 911         cx->blk_oldcop          = PL_curcop,                            \
 912         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
 913         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
 914         cx->blk_oldpm           = PL_curpm,                             \
 915         cx->blk_gimme           = (U8)gimme;                            \
 916         cx->cx_u.cx_blk.blku_old_tmpsfloor = PL_tmps_floor;             \
 917         PL_tmps_floor           = PL_tmps_ix;                           \
 918         DEBUG_CX("PUSH");
 919
 920 /* Exit a block (RETURN and LAST). */
 921 #define POPBLOCK(cx)                                                    \
 922         DEBUG_CX("POP");                                                \
 923         PL_curcop        = cx->blk_oldcop,                              \
 924         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 925         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 926         /* LEAVE_SCOPE() should have made this true. /(?{})/ cheats
 927          * and leaves a CX entry lying around for repeated use, so
 928          * skip for multicall */                  \
 929         assert(   (CxTYPE(cx) == CXt_SUB && CxMULTICALL(cx))            \
 930                 || PL_savestack_ix == cx->cx_old_savestack_ix);         \
 931         PL_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;             \
 932         PL_curpm         = cx->blk_oldpm;
 933
 934 /* Continue a block elsewhere (NEXT and REDO). */
 935 #define TOPBLOCK(cx)                                                    \
 936         DEBUG_CX("TOP");                                                \
 937         cx  = &cxstack[cxstack_ix],                                     \
 938         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
 939         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 940         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 941         PL_curpm         = cx->blk_oldpm;
 942
 943 /* substitution context */
 944 struct subst {
 945     U8          sbu_type;       /* what kind of context this is */
 946     U8          sbu_rflags;
 947     U16         sbu_rxtainted;  /* matches struct block */
 948     SSize_t     sbu_iters;
 949     SSize_t     sbu_maxiters;
 950     char *      sbu_orig;
 951     SV *        sbu_dstr;
 952     SV *        sbu_targ;
 953     char *      sbu_s;
 954     char *      sbu_m;
 955     char *      sbu_strend;
 956     void *      sbu_rxres;
 957     REGEXP *    sbu_rx;
 958 };
 959 #define sb_iters        cx_u.cx_subst.sbu_iters
 960 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
 961 #define sb_rflags       cx_u.cx_subst.sbu_rflags
 962 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
 963 #define sb_orig         cx_u.cx_subst.sbu_orig
 964 #define sb_dstr         cx_u.cx_subst.sbu_dstr
 965 #define sb_targ         cx_u.cx_subst.sbu_targ
 966 #define sb_s            cx_u.cx_subst.sbu_s
 967 #define sb_m            cx_u.cx_subst.sbu_m
 968 #define sb_strend       cx_u.cx_subst.sbu_strend
 969 #define sb_rxres        cx_u.cx_subst.sbu_rxres
 970 #define sb_rx           cx_u.cx_subst.sbu_rx
 971
 972 #ifdef PERL_CORE
 973 #  define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],               \
 974         cx->cx_old_savestack_ix = oldsave,                              \
 975         cx->sb_iters            = iters,                                \
 976         cx->sb_maxiters         = maxiters,                             \
 977         cx->sb_rflags           = r_flags,                              \
 978         cx->sb_rxtainted        = rxtainted,                            \
 979         cx->sb_orig             = orig,                                 \
 980         cx->sb_dstr             = dstr,                                 \
 981         cx->sb_targ             = targ,                                 \
 982         cx->sb_s                = s,                                    \
 983         cx->sb_m                = m,                                    \
 984         cx->sb_strend           = strend,                               \
 985         cx->sb_rxres            = NULL,                                 \
 986         cx->sb_rx               = rx,                                   \
 987         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
 988         rxres_save(&cx->sb_rxres, rx);                                  \
 989         (void)ReREFCNT_inc(rx);                                         \
 990         SvREFCNT_inc_void_NN(targ)
 991
 992 #  define POPSUBST(cx) \
 993         rxres_free(&cx->sb_rxres);                                      \
 994         ReREFCNT_dec(cx->sb_rx);                                        \
 995         SvREFCNT_dec_NN(cx->sb_targ)
 996 #endif
 997
 998 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
 999
1000 struct context {
1001     I32                 cx_old_savestack_ix;   /* saved PL_savestack_ix */
1002     union {
1003         struct block    cx_blk;
1004         struct subst    cx_subst;
1005     } cx_u;
1006 };
1007 #define cx_type cx_u.cx_subst.sbu_type
1008
1009 /* If you re-order these, there is also an array of uppercase names in perl.h
1010    and a static array of context names in pp_ctl.c  */
1011 #define CXTYPEMASK      0xf
1012 #define CXt_NULL        0 /* currently only used for sort BLOCK */
1013 #define CXt_WHEN        1
1014 #define CXt_BLOCK       2
1015 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
1016    jump table in pp_ctl.c
1017    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
1018 */
1019 #define CXt_GIVEN       3
1020 /* This is first so that CXt_LOOP_FOR|CXt_LOOP_LAZYIV is CXt_LOOP_LAZYIV */
1021 #define CXt_LOOP_FOR    4
1022 #define CXt_LOOP_PLAIN  5
1023 #define CXt_LOOP_LAZYSV 6
1024 #define CXt_LOOP_LAZYIV 7
1025 #define CXt_SUB         8
1026 #define CXt_FORMAT      9
1027 #define CXt_EVAL       10
1028 #define CXt_SUBST      11
1029 /* SUBST doesn't feature in all switch statements.  */
1030
1031 /* private flags for CXt_SUB and CXt_FORMAT */
1032 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't tear down
1033                                    context on exit). (not CXt_FORMAT) */
1034 #define CXp_HASARGS     0x20
1035 #define CXp_SUB_RE      0x40    /* code called within regex, i.e. (?{}) */
1036 #define CXp_SUB_RE_FAKE 0x80    /* fake sub CX for (?{}) in current scope */
1037
1038 /* private flags for CXt_EVAL */
1039 #define CXp_REAL        0x20    /* truly eval'', not a lookalike */
1040 #define CXp_TRYBLOCK    0x40    /* eval{}, not eval'' or similar */
1041
1042 /* private flags for CXt_LOOP */
1043 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
1044 #define CXp_FOR_LVREF   0x20    /* foreach using \$var */
1045 #define CXp_FOR_GV      0x40    /* foreach using package var */
1046 #define CXp_FOR_PAD     0x80    /* foreach using lexical var */
1047 #define CxPADLOOP(c)    ((c)->cx_type & CXp_FOR_PAD)
1048
1049 /* private flags for CXt_SUBST */
1050 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
1051
1052 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
1053 #define CxTYPE_is_LOOP(c)       (((c)->cx_type & 0xC) == 0x4)
1054 #define CxMULTICALL(c)  ((c)->cx_type & CXp_MULTICALL)
1055 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
1056                          == (CXt_EVAL|CXp_REAL))
1057 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
1058                          == (CXt_EVAL|CXp_TRYBLOCK))
1059 #define CxFOREACH(c)    (CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN)
1060 #define CxFOREACHDEF(c) ((CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN) \
1061                          && ((c)->cx_type & CXp_FOR_DEF))
1062
1063 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
1064
1065 /*
1066 =head1 "Gimme" Values
1067 */
1068
1069 /*
1070 =for apidoc AmU||G_SCALAR
1071 Used to indicate scalar context.  See C<L</GIMME_V>>, C<L</GIMME>>, and
1072 L<perlcall>.
1073
1074 =for apidoc AmU||G_ARRAY
1075 Used to indicate list context.  See C<L</GIMME_V>>, C<L</GIMME>> and
1076 L<perlcall>.
1077
1078 =for apidoc AmU||G_VOID
1079 Used to indicate void context.  See C<L</GIMME_V>> and L<perlcall>.
1080
1081 =for apidoc AmU||G_DISCARD
1082 Indicates that arguments returned from a callback should be discarded.  See
1083 L<perlcall>.
1084
1085 =for apidoc AmU||G_EVAL
1086
1087 Used to force a Perl C<eval> wrapper around a callback.  See
1088 L<perlcall>.
1089
1090 =for apidoc AmU||G_NOARGS
1091
1092 Indicates that no arguments are being sent to a callback.  See
1093 L<perlcall>.
1094
1095 =cut
1096 */
1097
1098 #define G_SCALAR        2
1099 #define G_ARRAY         3
1100 #define G_VOID          1
1101 #define G_WANT          3
1102
1103 /* extra flags for Perl_call_* routines */
1104 #define G_DISCARD       4       /* Call FREETMPS.
1105                                    Don't change this without consulting the
1106                                    hash actions codes defined in hv.h */
1107 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
1108 #define G_NOARGS       16       /* Don't construct a @_ array. */
1109 #define G_KEEPERR      32       /* Warn for errors, don't overwrite $@ */
1110 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
1111 #define G_METHOD      128       /* Calling method. */
1112 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
1113                                    fold_constants. */
1114 #define G_UNDEF_FILL  512       /* Fill the stack with &PL_sv_undef
1115                                    A special case for UNSHIFT in
1116                                    Perl_magic_methcall().  */
1117 #define G_WRITING_TO_STDERR 1024 /* Perl_write_to_stderr() is calling
1118                                     Perl_magic_methcall().  */
1119 #define G_RE_REPARSING 0x800     /* compiling a run-time /(?{..})/ */
1120 #define G_METHOD_NAMED 4096     /* calling named method, eg without :: or ' */
1121
1122 /* flag bits for PL_in_eval */
1123 #define EVAL_NULL       0       /* not in an eval */
1124 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
1125 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
1126 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
1127 #define EVAL_INREQUIRE  8       /* The code is being required. */
1128 #define EVAL_RE_REPARSING 0x10  /* eval_sv() called with G_RE_REPARSING */
1129
1130 /* Support for switching (stack and block) contexts.
1131  * This ensures magic doesn't invalidate local stack and cx pointers.
1132  */
1133
1134 #define PERLSI_UNKNOWN          -1
1135 #define PERLSI_UNDEF            0
1136 #define PERLSI_MAIN             1
1137 #define PERLSI_MAGIC            2
1138 #define PERLSI_SORT             3
1139 #define PERLSI_SIGNAL           4
1140 #define PERLSI_OVERLOAD         5
1141 #define PERLSI_DESTROY          6
1142 #define PERLSI_WARNHOOK         7
1143 #define PERLSI_DIEHOOK          8
1144 #define PERLSI_REQUIRE          9
1145 #define PERLSI_MULTICALL       10
1146
1147 struct stackinfo {
1148     AV *                si_stack;       /* stack for current runlevel */
1149     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
1150     struct stackinfo *  si_prev;
1151     struct stackinfo *  si_next;
1152     I32                 si_cxix;        /* current context index */
1153     I32                 si_cxmax;       /* maximum allocated index */
1154     I32                 si_type;        /* type of runlevel */
1155     I32                 si_markoff;     /* offset where markstack begins for us.
1156                                          * currently used only with DEBUGGING,
1157                                          * but not #ifdef-ed for bincompat */
1158 };
1159
1160 typedef struct stackinfo PERL_SI;
1161
1162 #define cxstack         (PL_curstackinfo->si_cxstack)
1163 #define cxstack_ix      (PL_curstackinfo->si_cxix)
1164 #define cxstack_max     (PL_curstackinfo->si_cxmax)
1165
1166 #ifdef DEBUGGING
1167 #  define       SET_MARK_OFFSET \
1168     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
1169 #else
1170 #  define       SET_MARK_OFFSET NOOP
1171 #endif
1172
1173 #define PUSHSTACKi(type) \
1174     STMT_START {                                                        \
1175         PERL_SI *next = PL_curstackinfo->si_next;                       \
1176         DEBUG_l({                                                       \
1177             int i = 0; PERL_SI *p = PL_curstackinfo;                    \
1178             while (p) { i++; p = p->si_prev; }                          \
1179             Perl_deb(aTHX_ "push STACKINFO %d at %s:%d\n",              \
1180                          i, __FILE__, __LINE__);})                      \
1181         if (!next) {                                                    \
1182             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
1183             next->si_prev = PL_curstackinfo;                            \
1184             PL_curstackinfo->si_next = next;                            \
1185         }                                                               \
1186         next->si_type = type;                                           \
1187         next->si_cxix = -1;                                             \
1188         AvFILLp(next->si_stack) = 0;                                    \
1189         SWITCHSTACK(PL_curstack,next->si_stack);                        \
1190         PL_curstackinfo = next;                                         \
1191         SET_MARK_OFFSET;                                                \
1192     } STMT_END
1193
1194 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
1195
1196 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
1197  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
1198 #define POPSTACK \
1199     STMT_START {                                                        \
1200         dSP;                                                            \
1201         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
1202         DEBUG_l({                                                       \
1203             int i = -1; PERL_SI *p = PL_curstackinfo;                   \
1204             while (p) { i++; p = p->si_prev; }                          \
1205             Perl_deb(aTHX_ "pop  STACKINFO %d at %s:%d\n",              \
1206                          i, __FILE__, __LINE__);})                      \
1207         if (!prev) {                                                    \
1208             Perl_croak_popstack();                                      \
1209         }                                                               \
1210         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
1211         /* don't free prev here, free them all at the END{} */          \
1212         PL_curstackinfo = prev;                                         \
1213     } STMT_END
1214
1215 #define POPSTACK_TO(s) \
1216     STMT_START {                                                        \
1217         while (PL_curstack != s) {                                      \
1218             dounwind(-1);                                               \
1219             POPSTACK;                                                   \
1220         }                                                               \
1221     } STMT_END
1222
1223 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
1224 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
1225
1226 /*
1227 =head1 Multicall Functions
1228
1229 =for apidoc Ams||dMULTICALL
1230 Declare local variables for a multicall.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1231
1232 =for apidoc Ams||PUSH_MULTICALL
1233 Opening bracket for a lightweight callback.
1234 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1235
1236 =for apidoc Ams||MULTICALL
1237 Make a lightweight callback.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1238
1239 =for apidoc Ams||POP_MULTICALL
1240 Closing bracket for a lightweight callback.
1241 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1242
1243 =cut
1244 */
1245
1246 #define dMULTICALL \
1247     SV **newsp;                 /* set by POPBLOCK */                   \
1248     PERL_CONTEXT *cx;                                                   \
1249     CV *multicall_cv;                                                   \
1250     OP *multicall_cop;                                                  \
1251     bool multicall_oldcatch;                                            \
1252     U8 hasargs = 0              /* used by PUSHSUB */
1253
1254 #define PUSH_MULTICALL(the_cv) \
1255     PUSH_MULTICALL_FLAGS(the_cv, 0)
1256
1257 /* Like PUSH_MULTICALL, but allows you to specify extra flags
1258  * for the CX stack entry (this isn't part of the public API) */
1259
1260 #define PUSH_MULTICALL_FLAGS(the_cv, flags) \
1261     STMT_START {                                                        \
1262         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1263         CV * const cv = _nOnclAshIngNamE_;                              \
1264         PADLIST * const padlist = CvPADLIST(cv);                        \
1265         multicall_oldcatch = CATCH_GET;                                 \
1266         CATCH_SET(TRUE);                                                \
1267         PUSHSTACKi(PERLSI_MULTICALL);                                   \
1268         PUSHBLOCK(cx, (CXt_SUB|CXp_MULTICALL|flags), PL_stack_sp);      \
1269         PUSHSUB(cx);                                                    \
1270         cx->cx_old_savestack_ix = PL_savestack_ix;                      \
1271         SAVEVPTR(PL_op);                                                \
1272         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1273             CvDEPTH(cv)++;                                              \
1274         if (CvDEPTH(cv) >= 2) {                                         \
1275             PERL_STACK_OVERFLOW_CHECK();                                \
1276             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1277         }                                                               \
1278         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1279         multicall_cv = cv;                                              \
1280         PERL_UNUSED_VAR(multicall_cv); /* for API */                    \
1281         multicall_cop = CvSTART(cv);                                    \
1282     } STMT_END
1283
1284 #define MULTICALL \
1285     STMT_START {                                                        \
1286         PL_op = multicall_cop;                                          \
1287         CALLRUNOPS(aTHX);                                               \
1288     } STMT_END
1289
1290 #define POP_MULTICALL \
1291     STMT_START {                                                        \
1292         cx = &cxstack[cxstack_ix];                                      \
1293         CX_LEAVE_SCOPE(cx);                                             \
1294         POPSUB_COMMON(cx);                                              \
1295         POPBLOCK(cx);                                                   \
1296         newsp = PL_stack_base + cx->blk_oldsp;                          \
1297         gimme = cx->blk_gimme;                                          \
1298         PERL_UNUSED_VAR(newsp); /* for API */                           \
1299         PERL_UNUSED_VAR(gimme); /* for API */                           \
1300         cxstack_ix--;                                                   \
1301         POPSTACK;                                                       \
1302         CATCH_SET(multicall_oldcatch);                                  \
1303         SPAGAIN;                                                        \
1304     } STMT_END
1305
1306 /* Change the CV of an already-pushed MULTICALL CxSUB block.
1307  * (this isn't part of the public API) */
1308
1309 #define CHANGE_MULTICALL_FLAGS(the_cv, flags) \
1310     STMT_START {                                                        \
1311         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1312         CV * const cv = _nOnclAshIngNamE_;                              \
1313         PADLIST * const padlist = CvPADLIST(cv);                        \
1314         cx = &cxstack[cxstack_ix];                                      \
1315         assert(CxMULTICALL(cx));                                        \
1316         CvDEPTH(multicall_cv) = cx->blk_sub.olddepth;                   \
1317         SvREFCNT_dec_NN(multicall_cv);                                  \
1318         cx->cx_type = (CXt_SUB|CXp_MULTICALL|flags);                    \
1319         {                                                               \
1320             /* save a few things that we don't want PUSHSUB to zap */   \
1321             PAD * const prevcomppad = cx->blk_sub.prevcomppad;          \
1322             PUSHSUB(cx);                                                \
1323             /* undo the stuff that PUSHSUB zapped */                    \
1324             cx->blk_sub.prevcomppad = prevcomppad ;                     \
1325         }                                                               \
1326         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1327             CvDEPTH(cv)++;                                              \
1328         if (CvDEPTH(cv) >= 2) {                                         \
1329             PERL_STACK_OVERFLOW_CHECK();                                \
1330             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1331         }                                                               \
1332         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1333         multicall_cv = cv;                                              \
1334         multicall_cop = CvSTART(cv);                                    \
1335     } STMT_END
1336 /*
1337  * ex: set ts=8 sts=4 sw=4 et:
1338  */