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 /* handle the @_ part of leaving a sub */
 659
 660 #define POPSUB_ARGS(cx) \
 661     STMT_START {                                                        \
 662         AV *av;                                                         \
 663         assert(AvARRAY(MUTABLE_AV(                                      \
 664             PadlistARRAY(CvPADLIST(cx->blk_sub.cv))[                    \
 665                     CvDEPTH(cx->blk_sub.cv)])) == PL_curpad);           \
 666         POP_SAVEARRAY();                                                \
 667         /* abandon @_ if it got reified */                              \
 668         av = MUTABLE_AV(PAD_SVl(0));                                    \
 669         if (UNLIKELY(AvREAL(av)))                                       \
 670             clear_defarray(av, 0);                                      \
 671         else {                                                          \
 672             CLEAR_ARGARRAY(av);                                         \
 673         }                                                               \
 674     } STMT_END
 675
 676 #define POPSUB(cx)                                                      \
 677     STMT_START {                                                        \
 678         if (!(cx->blk_u16 & CxPOPSUB_DONE)) {                           \
 679         cx->blk_u16 |= CxPOPSUB_DONE;                                   \
 680         RETURN_PROBE(CvNAMED(cx->blk_sub.cv)                            \
 681                         ? HEK_KEY(CvNAME_HEK(cx->blk_sub.cv))           \
 682                         : GvENAME(CvGV(cx->blk_sub.cv)),                \
 683                 CopFILE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
 684                 CopLINE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
 685                 CopSTASHPV((COP*)CvSTART((const CV*)cx->blk_sub.cv)));  \
 686                                                                         \
 687         if (CxHASARGS(cx)) {                                            \
 688             POPSUB_ARGS(cx);                                            \
 689         }                                                               \
 690         }                                                               \
 691         POPSUB_COMMON(cx);                                              \
 692     } STMT_END
 693
 694 #define POPFORMAT(cx)                                                   \
 695     STMT_START {                                                        \
 696         if (!(cx->blk_u16 & CxPOPSUB_DONE)) {                           \
 697         CV * const cv = cx->blk_format.cv;                              \
 698         GV * const dfuot = cx->blk_format.dfoutgv;                      \
 699         cx->blk_u16 |= CxPOPSUB_DONE;                                   \
 700         setdefout(dfuot);                                               \
 701         PL_comppad = cx->blk_format.prevcomppad;                        \
 702         PL_curpad = LIKELY(PL_comppad) ? AvARRAY(PL_comppad) : NULL;    \
 703         --CvDEPTH(cv);                                                  \
 704         SvREFCNT_dec_NN(cx->blk_format.cv);                             \
 705         SvREFCNT_dec_NN(dfuot);                                         \
 706         }                                                               \
 707     } STMT_END
 708
 709 /* eval context */
 710 struct block_eval {
 711     OP *        retop;  /* op to execute on exit from eval */
 712     /* Above here is the same for sub, format and eval.  */
 713     SV *        old_namesv;
 714     OP *        old_eval_root;
 715     SV *        cur_text;
 716     CV *        cv;
 717     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
 718 };
 719
 720 /* If we ever need more than 512 op types, change the shift from 7.
 721    blku_gimme is actually also only 2 bits, so could be merged with something.
 722 */
 723
 724 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
 725 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
 726
 727 #define PUSHEVAL(cx,n)                                                  \
 728     STMT_START {                                                        \
 729         assert(!(PL_in_eval & ~0x7F));                                  \
 730         assert(!(PL_op->op_type & ~0x1FF));                             \
 731         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
 732         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
 733         cx->blk_eval.old_eval_root = PL_eval_root;                      \
 734         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
 735         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
 736         cx->blk_eval.retop = NULL;                                      \
 737         cx->blk_eval.cur_top_env = PL_top_env;                          \
 738     } STMT_END
 739
 740 #define POPEVAL(cx)                                                     \
 741     STMT_START {                                                        \
 742         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
 743         optype = CxOLD_OP_TYPE(cx);                                     \
 744         PL_eval_root = cx->blk_eval.old_eval_root;                      \
 745         if (cx->blk_eval.cur_text && SvSCREAM(cx->blk_eval.cur_text))   \
 746             SvREFCNT_dec_NN(cx->blk_eval.cur_text);                     \
 747         if (cx->blk_eval.old_namesv)                                    \
 748             sv_2mortal(cx->blk_eval.old_namesv);                        \
 749     } STMT_END
 750
 751 /* loop context */
 752 struct block_loop {
 753     I32         resetsp;
 754     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
 755     union {     /* different ways of locating the iteration variable */
 756         SV      **svp; /* for lexicals: address of pad slot */
 757         GV      *gv;   /* for package vars */
 758     } itervar_u;
 759     SV          *itersave; /* the original iteration var */
 760     union {
 761         struct { /* valid if type is LOOP_FOR or LOOP_PLAIN (but {NULL,0})*/
 762             AV * ary; /* use the stack if this is NULL */
 763             IV ix;
 764         } ary;
 765         struct { /* valid if type is LOOP_LAZYIV */
 766             IV cur;
 767             IV end;
 768         } lazyiv;
 769         struct { /* valid if type if LOOP_LAZYSV */
 770             SV * cur;
 771             SV * end; /* maxiumum value (or minimum in reverse) */
 772         } lazysv;
 773     } state_u;
 774 #ifdef USE_ITHREADS
 775     PAD *oldcomppad; /* needed to map itervar_u.svp during thread clone */
 776 #endif
 777 };
 778
 779 #define CxITERVAR(c)                                    \
 780         (CxPADLOOP(c)                                   \
 781             ? (c)->blk_loop.itervar_u.svp               \
 782             : ((c)->cx_type & CXp_FOR_GV)               \
 783                 ? &GvSV((c)->blk_loop.itervar_u.gv)     \
 784                 : (SV **)&(c)->blk_loop.itervar_u.gv)
 785
 786 #define CxLABEL(c)      (0 + CopLABEL((c)->blk_oldcop))
 787 #define CxLABEL_len(c,len)      (0 + CopLABEL_len((c)->blk_oldcop, len))
 788 #define CxLABEL_len_flags(c,len,flags)  (0 + CopLABEL_len_flags((c)->blk_oldcop, len, flags))
 789 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
 790 #define CxLVAL(c)       (0 + ((c)->blk_u16 & 0xff))
 791 /* POPSUB has already been performed on this context frame */
 792 #define CxPOPSUB_DONE 0x100
 793
 794
 795 #define PUSHLOOP_PLAIN(cx, s)                                           \
 796         cx->blk_loop.resetsp = s - PL_stack_base;                       \
 797         cx->blk_loop.my_op = cLOOP;                                     \
 798         cx->blk_loop.state_u.ary.ary = NULL;                            \
 799         cx->blk_loop.state_u.ary.ix = 0;                                \
 800         cx->cx_old_savestack_ix = PL_savestack_ix;                      \
 801         cx->blk_loop.itervar_u.svp = NULL;                              \
 802         cx->blk_loop.itersave = NULL;
 803
 804 #ifdef USE_ITHREADS
 805 #  define PUSHLOOP_FOR_setpad(c) (c)->blk_loop.oldcomppad = PL_comppad
 806 #else
 807 #  define PUSHLOOP_FOR_setpad(c) NOOP
 808 #endif
 809
 810 #define PUSHLOOP_FOR(cx, ivar, isave, s)                                \
 811         cx->blk_loop.resetsp = s - PL_stack_base;                       \
 812         cx->blk_loop.my_op = cLOOP;                                     \
 813         cx->blk_loop.state_u.ary.ary = NULL;                            \
 814         cx->blk_loop.state_u.ary.ix = 0;                                \
 815         cx->blk_loop.itervar_u.svp = (SV**)(ivar);                      \
 816         cx->cx_old_savestack_ix = PL_savestack_ix;                      \
 817         cx->blk_loop.itersave = isave;                                  \
 818         PUSHLOOP_FOR_setpad(cx);
 819
 820 #define POPLOOP(cx)                                                     \
 821         if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                            \
 822             SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.cur);           \
 823             SvREFCNT_dec_NN(cx->blk_loop.state_u.lazysv.end);           \
 824         }                                                               \
 825         else if (CxTYPE(cx) == CXt_LOOP_FOR)                            \
 826             SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);                 \
 827         if (cx->cx_type & (CXp_FOR_PAD|CXp_FOR_GV)) {                   \
 828             SV *cursv;                                                  \
 829             SV **svp = (cx)->blk_loop.itervar_u.svp;                    \
 830             if ((cx->cx_type & CXp_FOR_GV))                             \
 831                 svp = &GvSV((GV*)svp);                                  \
 832             cursv = *svp;                                               \
 833             *svp = cx->blk_loop.itersave;                               \
 834             SvREFCNT_dec(cursv);                                        \
 835         }
 836
 837 /* given/when context */
 838 struct block_givwhen {
 839         OP *leave_op;
 840         SV *defsv_save; /* the original $_ */
 841 };
 842
 843 #define PUSHWHEN(cx)                                                    \
 844         cx->cx_old_savestack_ix = PL_savestack_ix;                      \
 845         cx->blk_givwhen.leave_op = cLOGOP->op_other;
 846
 847 #define PUSHGIVEN(cx, orig_var)                                         \
 848         PUSHWHEN(cx);                                                   \
 849         cx->blk_givwhen.defsv_save = orig_var;
 850
 851 #define POPWHEN(cx)                                                     \
 852         NOOP;
 853
 854 #define POPGIVEN(cx)                                                    \
 855         SvREFCNT_dec(GvSV(PL_defgv));                                   \
 856         GvSV(PL_defgv) = cx->blk_givwhen.defsv_save;
 857
 858
 859 /* basic block, i.e. pp_enter/leave */
 860
 861 #define PUSHBASICBLK(cx)                                                \
 862         cx->cx_old_savestack_ix = PL_savestack_ix;
 863
 864 #define POPBASICBLK(cx)                                                 \
 865         NOOP;
 866
 867
 868 /* context common to subroutines, evals and loops */
 869 struct block {
 870     U8          blku_type;      /* what kind of context this is */
 871     U8          blku_gimme;     /* is this block running in list context? */
 872     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
 873     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
 874     COP *       blku_oldcop;    /* old curcop pointer */
 875     I32         blku_oldmarksp; /* mark stack index */
 876     I32         blku_oldscopesp;        /* scope stack index */
 877     PMOP *      blku_oldpm;     /* values of pattern match vars */
 878     SSize_t     blku_old_tmpsfloor;     /* saved PL_tmps_floor */
 879
 880     union {
 881         struct block_sub        blku_sub;
 882         struct block_format     blku_format;
 883         struct block_eval       blku_eval;
 884         struct block_loop       blku_loop;
 885         struct block_givwhen    blku_givwhen;
 886     } blk_u;
 887 };
 888 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
 889 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
 890 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
 891 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
 892 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
 893 #define blk_gimme       cx_u.cx_blk.blku_gimme
 894 #define blk_u16         cx_u.cx_blk.blku_u16
 895 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
 896 #define blk_format      cx_u.cx_blk.blk_u.blku_format
 897 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
 898 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
 899 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
 900
 901 #define DEBUG_CX(action)                                                \
 902     DEBUG_l(                                                            \
 903         Perl_deb(aTHX_ "CX %ld %s %s (scope %ld,%ld) (save %ld,%ld) at %s:%d\n",\
 904                     (long)cxstack_ix,                                   \
 905                     action,                                             \
 906                     PL_block_type[CxTYPE(&cxstack[cxstack_ix])],        \
 907                     (long)PL_scopestack_ix,                             \
 908                     (long)(cxstack[cxstack_ix].blk_oldscopesp),         \
 909                     (long)PL_savestack_ix,                              \
 910                     (long)(cxstack[cxstack_ix].cx_old_savestack_ix),    \
 911                     __FILE__, __LINE__));
 912
 913 /* Enter a block. */
 914 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
 915         cx->cx_type             = t,                                    \
 916         cx->blk_oldsp           = sp - PL_stack_base,                   \
 917         cx->blk_oldcop          = PL_curcop,                            \
 918         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
 919         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
 920         cx->blk_oldpm           = PL_curpm,                             \
 921         cx->blk_gimme           = (U8)gimme;                            \
 922         cx->cx_u.cx_blk.blku_old_tmpsfloor = PL_tmps_floor;             \
 923         PL_tmps_floor           = PL_tmps_ix;                           \
 924         DEBUG_CX("PUSH");
 925
 926 /* Exit a block (RETURN and LAST). */
 927 #define POPBLOCK(cx)                                                    \
 928         DEBUG_CX("POP");                                                \
 929         PL_curcop        = cx->blk_oldcop,                              \
 930         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 931         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 932         /* LEAVE_SCOPE() should have made this true. /(?{})/ cheats
 933          * and leaves a CX entry lying around for repeated use, so
 934          * skip for multicall */                  \
 935         assert(   (CxTYPE(cx) == CXt_SUB && CxMULTICALL(cx))            \
 936                 || PL_savestack_ix == cx->cx_old_savestack_ix);         \
 937         PL_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;             \
 938         PL_curpm         = cx->blk_oldpm;
 939
 940 /* Continue a block elsewhere (NEXT and REDO). */
 941 #define TOPBLOCK(cx)                                                    \
 942         DEBUG_CX("TOP");                                                \
 943         cx  = &cxstack[cxstack_ix],                                     \
 944         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
 945         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 946         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 947         PL_curpm         = cx->blk_oldpm;
 948
 949 /* substitution context */
 950 struct subst {
 951     U8          sbu_type;       /* what kind of context this is */
 952     U8          sbu_rflags;
 953     U16         sbu_rxtainted;  /* matches struct block */
 954     SSize_t     sbu_iters;
 955     SSize_t     sbu_maxiters;
 956     char *      sbu_orig;
 957     SV *        sbu_dstr;
 958     SV *        sbu_targ;
 959     char *      sbu_s;
 960     char *      sbu_m;
 961     char *      sbu_strend;
 962     void *      sbu_rxres;
 963     REGEXP *    sbu_rx;
 964 };
 965 #define sb_iters        cx_u.cx_subst.sbu_iters
 966 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
 967 #define sb_rflags       cx_u.cx_subst.sbu_rflags
 968 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
 969 #define sb_orig         cx_u.cx_subst.sbu_orig
 970 #define sb_dstr         cx_u.cx_subst.sbu_dstr
 971 #define sb_targ         cx_u.cx_subst.sbu_targ
 972 #define sb_s            cx_u.cx_subst.sbu_s
 973 #define sb_m            cx_u.cx_subst.sbu_m
 974 #define sb_strend       cx_u.cx_subst.sbu_strend
 975 #define sb_rxres        cx_u.cx_subst.sbu_rxres
 976 #define sb_rx           cx_u.cx_subst.sbu_rx
 977
 978 #ifdef PERL_CORE
 979 #  define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],               \
 980         cx->cx_old_savestack_ix = oldsave,                              \
 981         cx->sb_iters            = iters,                                \
 982         cx->sb_maxiters         = maxiters,                             \
 983         cx->sb_rflags           = r_flags,                              \
 984         cx->sb_rxtainted        = rxtainted,                            \
 985         cx->sb_orig             = orig,                                 \
 986         cx->sb_dstr             = dstr,                                 \
 987         cx->sb_targ             = targ,                                 \
 988         cx->sb_s                = s,                                    \
 989         cx->sb_m                = m,                                    \
 990         cx->sb_strend           = strend,                               \
 991         cx->sb_rxres            = NULL,                                 \
 992         cx->sb_rx               = rx,                                   \
 993         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
 994         rxres_save(&cx->sb_rxres, rx);                                  \
 995         (void)ReREFCNT_inc(rx);                                         \
 996         SvREFCNT_inc_void_NN(targ)
 997
 998 #  define POPSUBST(cx) \
 999         rxres_free(&cx->sb_rxres);                                      \
1000         ReREFCNT_dec(cx->sb_rx);                                        \
1001         SvREFCNT_dec_NN(cx->sb_targ)
1002 #endif
1003
1004 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
1005
1006 struct context {
1007     I32                 cx_old_savestack_ix;   /* saved PL_savestack_ix */
1008     union {
1009         struct block    cx_blk;
1010         struct subst    cx_subst;
1011     } cx_u;
1012 };
1013 #define cx_type cx_u.cx_subst.sbu_type
1014
1015 /* If you re-order these, there is also an array of uppercase names in perl.h
1016    and a static array of context names in pp_ctl.c  */
1017 #define CXTYPEMASK      0xf
1018 #define CXt_NULL        0 /* currently only used for sort BLOCK */
1019 #define CXt_WHEN        1
1020 #define CXt_BLOCK       2
1021 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
1022    jump table in pp_ctl.c
1023    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
1024 */
1025 #define CXt_GIVEN       3
1026 /* This is first so that CXt_LOOP_FOR|CXt_LOOP_LAZYIV is CXt_LOOP_LAZYIV */
1027 #define CXt_LOOP_FOR    4
1028 #define CXt_LOOP_PLAIN  5
1029 #define CXt_LOOP_LAZYSV 6
1030 #define CXt_LOOP_LAZYIV 7
1031 #define CXt_SUB         8
1032 #define CXt_FORMAT      9
1033 #define CXt_EVAL       10
1034 #define CXt_SUBST      11
1035 /* SUBST doesn't feature in all switch statements.  */
1036
1037 /* private flags for CXt_SUB and CXt_FORMAT */
1038 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't tear down
1039                                    context on exit). (not CXt_FORMAT) */
1040 #define CXp_HASARGS     0x20
1041 #define CXp_SUB_RE      0x40    /* code called within regex, i.e. (?{}) */
1042 #define CXp_SUB_RE_FAKE 0x80    /* fake sub CX for (?{}) in current scope */
1043
1044 /* private flags for CXt_EVAL */
1045 #define CXp_REAL        0x20    /* truly eval'', not a lookalike */
1046 #define CXp_TRYBLOCK    0x40    /* eval{}, not eval'' or similar */
1047
1048 /* private flags for CXt_LOOP */
1049 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
1050 #define CXp_FOR_LVREF   0x20    /* foreach using \$var */
1051 #define CXp_FOR_GV      0x40    /* foreach using package var */
1052 #define CXp_FOR_PAD     0x80    /* foreach using lexical var */
1053 #define CxPADLOOP(c)    ((c)->cx_type & CXp_FOR_PAD)
1054
1055 /* private flags for CXt_SUBST */
1056 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
1057
1058 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
1059 #define CxTYPE_is_LOOP(c)       (((c)->cx_type & 0xC) == 0x4)
1060 #define CxMULTICALL(c)  ((c)->cx_type & CXp_MULTICALL)
1061 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
1062                          == (CXt_EVAL|CXp_REAL))
1063 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
1064                          == (CXt_EVAL|CXp_TRYBLOCK))
1065 #define CxFOREACH(c)    (CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN)
1066 #define CxFOREACHDEF(c) ((CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN) \
1067                          && ((c)->cx_type & CXp_FOR_DEF))
1068
1069 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
1070
1071 /*
1072 =head1 "Gimme" Values
1073 */
1074
1075 /*
1076 =for apidoc AmU||G_SCALAR
1077 Used to indicate scalar context.  See C<L</GIMME_V>>, C<L</GIMME>>, and
1078 L<perlcall>.
1079
1080 =for apidoc AmU||G_ARRAY
1081 Used to indicate list context.  See C<L</GIMME_V>>, C<L</GIMME>> and
1082 L<perlcall>.
1083
1084 =for apidoc AmU||G_VOID
1085 Used to indicate void context.  See C<L</GIMME_V>> and L<perlcall>.
1086
1087 =for apidoc AmU||G_DISCARD
1088 Indicates that arguments returned from a callback should be discarded.  See
1089 L<perlcall>.
1090
1091 =for apidoc AmU||G_EVAL
1092
1093 Used to force a Perl C<eval> wrapper around a callback.  See
1094 L<perlcall>.
1095
1096 =for apidoc AmU||G_NOARGS
1097
1098 Indicates that no arguments are being sent to a callback.  See
1099 L<perlcall>.
1100
1101 =cut
1102 */
1103
1104 #define G_SCALAR        2
1105 #define G_ARRAY         3
1106 #define G_VOID          1
1107 #define G_WANT          3
1108
1109 /* extra flags for Perl_call_* routines */
1110 #define G_DISCARD       4       /* Call FREETMPS.
1111                                    Don't change this without consulting the
1112                                    hash actions codes defined in hv.h */
1113 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
1114 #define G_NOARGS       16       /* Don't construct a @_ array. */
1115 #define G_KEEPERR      32       /* Warn for errors, don't overwrite $@ */
1116 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
1117 #define G_METHOD      128       /* Calling method. */
1118 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
1119                                    fold_constants. */
1120 #define G_UNDEF_FILL  512       /* Fill the stack with &PL_sv_undef
1121                                    A special case for UNSHIFT in
1122                                    Perl_magic_methcall().  */
1123 #define G_WRITING_TO_STDERR 1024 /* Perl_write_to_stderr() is calling
1124                                     Perl_magic_methcall().  */
1125 #define G_RE_REPARSING 0x800     /* compiling a run-time /(?{..})/ */
1126 #define G_METHOD_NAMED 4096     /* calling named method, eg without :: or ' */
1127
1128 /* flag bits for PL_in_eval */
1129 #define EVAL_NULL       0       /* not in an eval */
1130 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
1131 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
1132 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
1133 #define EVAL_INREQUIRE  8       /* The code is being required. */
1134 #define EVAL_RE_REPARSING 0x10  /* eval_sv() called with G_RE_REPARSING */
1135
1136 /* Support for switching (stack and block) contexts.
1137  * This ensures magic doesn't invalidate local stack and cx pointers.
1138  */
1139
1140 #define PERLSI_UNKNOWN          -1
1141 #define PERLSI_UNDEF            0
1142 #define PERLSI_MAIN             1
1143 #define PERLSI_MAGIC            2
1144 #define PERLSI_SORT             3
1145 #define PERLSI_SIGNAL           4
1146 #define PERLSI_OVERLOAD         5
1147 #define PERLSI_DESTROY          6
1148 #define PERLSI_WARNHOOK         7
1149 #define PERLSI_DIEHOOK          8
1150 #define PERLSI_REQUIRE          9
1151 #define PERLSI_MULTICALL       10
1152
1153 struct stackinfo {
1154     AV *                si_stack;       /* stack for current runlevel */
1155     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
1156     struct stackinfo *  si_prev;
1157     struct stackinfo *  si_next;
1158     I32                 si_cxix;        /* current context index */
1159     I32                 si_cxmax;       /* maximum allocated index */
1160     I32                 si_type;        /* type of runlevel */
1161     I32                 si_markoff;     /* offset where markstack begins for us.
1162                                          * currently used only with DEBUGGING,
1163                                          * but not #ifdef-ed for bincompat */
1164 };
1165
1166 typedef struct stackinfo PERL_SI;
1167
1168 #define cxstack         (PL_curstackinfo->si_cxstack)
1169 #define cxstack_ix      (PL_curstackinfo->si_cxix)
1170 #define cxstack_max     (PL_curstackinfo->si_cxmax)
1171
1172 #ifdef DEBUGGING
1173 #  define       SET_MARK_OFFSET \
1174     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
1175 #else
1176 #  define       SET_MARK_OFFSET NOOP
1177 #endif
1178
1179 #define PUSHSTACKi(type) \
1180     STMT_START {                                                        \
1181         PERL_SI *next = PL_curstackinfo->si_next;                       \
1182         DEBUG_l({                                                       \
1183             int i = 0; PERL_SI *p = PL_curstackinfo;                    \
1184             while (p) { i++; p = p->si_prev; }                          \
1185             Perl_deb(aTHX_ "push STACKINFO %d at %s:%d\n",              \
1186                          i, __FILE__, __LINE__);})                      \
1187         if (!next) {                                                    \
1188             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
1189             next->si_prev = PL_curstackinfo;                            \
1190             PL_curstackinfo->si_next = next;                            \
1191         }                                                               \
1192         next->si_type = type;                                           \
1193         next->si_cxix = -1;                                             \
1194         AvFILLp(next->si_stack) = 0;                                    \
1195         SWITCHSTACK(PL_curstack,next->si_stack);                        \
1196         PL_curstackinfo = next;                                         \
1197         SET_MARK_OFFSET;                                                \
1198     } STMT_END
1199
1200 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
1201
1202 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
1203  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
1204 #define POPSTACK \
1205     STMT_START {                                                        \
1206         dSP;                                                            \
1207         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
1208         DEBUG_l({                                                       \
1209             int i = -1; PERL_SI *p = PL_curstackinfo;                   \
1210             while (p) { i++; p = p->si_prev; }                          \
1211             Perl_deb(aTHX_ "pop  STACKINFO %d at %s:%d\n",              \
1212                          i, __FILE__, __LINE__);})                      \
1213         if (!prev) {                                                    \
1214             Perl_croak_popstack();                                      \
1215         }                                                               \
1216         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
1217         /* don't free prev here, free them all at the END{} */          \
1218         PL_curstackinfo = prev;                                         \
1219     } STMT_END
1220
1221 #define POPSTACK_TO(s) \
1222     STMT_START {                                                        \
1223         while (PL_curstack != s) {                                      \
1224             dounwind(-1);                                               \
1225             POPSTACK;                                                   \
1226         }                                                               \
1227     } STMT_END
1228
1229 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
1230 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
1231
1232 /*
1233 =head1 Multicall Functions
1234
1235 =for apidoc Ams||dMULTICALL
1236 Declare local variables for a multicall.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1237
1238 =for apidoc Ams||PUSH_MULTICALL
1239 Opening bracket for a lightweight callback.
1240 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1241
1242 =for apidoc Ams||MULTICALL
1243 Make a lightweight callback.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1244
1245 =for apidoc Ams||POP_MULTICALL
1246 Closing bracket for a lightweight callback.
1247 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1248
1249 =cut
1250 */
1251
1252 #define dMULTICALL \
1253     SV **newsp;                 /* set by POPBLOCK */                   \
1254     PERL_CONTEXT *cx;                                                   \
1255     CV *multicall_cv;                                                   \
1256     OP *multicall_cop;                                                  \
1257     bool multicall_oldcatch;                                            \
1258     U8 hasargs = 0              /* used by PUSHSUB */
1259
1260 #define PUSH_MULTICALL(the_cv) \
1261     PUSH_MULTICALL_FLAGS(the_cv, 0)
1262
1263 /* Like PUSH_MULTICALL, but allows you to specify extra flags
1264  * for the CX stack entry (this isn't part of the public API) */
1265
1266 #define PUSH_MULTICALL_FLAGS(the_cv, flags) \
1267     STMT_START {                                                        \
1268         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1269         CV * const cv = _nOnclAshIngNamE_;                              \
1270         PADLIST * const padlist = CvPADLIST(cv);                        \
1271         multicall_oldcatch = CATCH_GET;                                 \
1272         CATCH_SET(TRUE);                                                \
1273         PUSHSTACKi(PERLSI_MULTICALL);                                   \
1274         PUSHBLOCK(cx, (CXt_SUB|CXp_MULTICALL|flags), PL_stack_sp);      \
1275         PUSHSUB(cx);                                                    \
1276         cx->cx_old_savestack_ix = PL_savestack_ix;                      \
1277         SAVEVPTR(PL_op);                                                \
1278         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1279             CvDEPTH(cv)++;                                              \
1280         if (CvDEPTH(cv) >= 2) {                                         \
1281             PERL_STACK_OVERFLOW_CHECK();                                \
1282             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1283         }                                                               \
1284         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1285         multicall_cv = cv;                                              \
1286         PERL_UNUSED_VAR(multicall_cv); /* for API */                    \
1287         multicall_cop = CvSTART(cv);                                    \
1288     } STMT_END
1289
1290 #define MULTICALL \
1291     STMT_START {                                                        \
1292         PL_op = multicall_cop;                                          \
1293         CALLRUNOPS(aTHX);                                               \
1294     } STMT_END
1295
1296 #define POP_MULTICALL \
1297     STMT_START {                                                        \
1298         cx = &cxstack[cxstack_ix];                                      \
1299         CX_LEAVE_SCOPE(cx);                                             \
1300         POPSUB_COMMON(cx);                                              \
1301         POPBLOCK(cx);                                                   \
1302         newsp = PL_stack_base + cx->blk_oldsp;                          \
1303         gimme = cx->blk_gimme;                                          \
1304         PERL_UNUSED_VAR(newsp); /* for API */                           \
1305         PERL_UNUSED_VAR(gimme); /* for API */                           \
1306         cxstack_ix--;                                                   \
1307         POPSTACK;                                                       \
1308         CATCH_SET(multicall_oldcatch);                                  \
1309         SPAGAIN;                                                        \
1310     } STMT_END
1311
1312 /* Change the CV of an already-pushed MULTICALL CxSUB block.
1313  * (this isn't part of the public API) */
1314
1315 #define CHANGE_MULTICALL_FLAGS(the_cv, flags) \
1316     STMT_START {                                                        \
1317         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1318         CV * const cv = _nOnclAshIngNamE_;                              \
1319         PADLIST * const padlist = CvPADLIST(cv);                        \
1320         cx = &cxstack[cxstack_ix];                                      \
1321         assert(CxMULTICALL(cx));                                        \
1322         CvDEPTH(multicall_cv) = cx->blk_sub.olddepth;                   \
1323         SvREFCNT_dec_NN(multicall_cv);                                  \
1324         cx->cx_type = (CXt_SUB|CXp_MULTICALL|flags);                    \
1325         {                                                               \
1326             /* save a few things that we don't want PUSHSUB to zap */   \
1327             PAD * const prevcomppad = cx->blk_sub.prevcomppad;          \
1328             PUSHSUB(cx);                                                \
1329             /* undo the stuff that PUSHSUB zapped */                    \
1330             cx->blk_sub.prevcomppad = prevcomppad ;                     \
1331         }                                                               \
1332         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1333             CvDEPTH(cv)++;                                              \
1334         if (CvDEPTH(cv) >= 2) {                                         \
1335             PERL_STACK_OVERFLOW_CHECK();                                \
1336             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1337         }                                                               \
1338         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1339         multicall_cv = cv;                                              \
1340         multicall_cop = CvSTART(cv);                                    \
1341     } STMT_END
1342 /*
1343  * ex: set ts=8 sts=4 sw=4 et:
1344  */