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 /* return a pointer to the current context */
 574
 575 #define CX_CUR() (&cxstack[cxstack_ix])
 576
 577 /* free all savestack items back to the watermark of the specified context */
 578
 579 #define CX_LEAVE_SCOPE(cx) LEAVE_SCOPE(cx->blk_oldsaveix)
 580
 581 #ifdef DEBUGGING
 582 /* on debugging builds, poison cx afterwards so we know no code
 583  * uses it - because after doing cxstack_ix--, any ties, exceptions etc
 584  * may overwrite the current stack frame */
 585 #  define CX_POP(cx)                                                   \
 586         assert(CX_CUR() == cx);                                        \
 587         cxstack_ix--;                                                  \
 588         cx = NULL;
 589 #else
 590 #  define CX_POP(cx) cxstack_ix--;
 591 #endif
 592
 593
 594 /* base for the next two macros. Don't use directly.
 595  * The context frame holds a reference to the CV so that it can't be
 596  * freed while we're executing it */
 597
 598 #define PUSHSUB_BASE(cx)                                                \
 599         ENTRY_PROBE(CvNAMED(cv)                                         \
 600                         ? HEK_KEY(CvNAME_HEK(cv))                       \
 601                         : GvENAME(CvGV(cv)),                            \
 602                 CopFILE((const COP *)CvSTART(cv)),                      \
 603                 CopLINE((const COP *)CvSTART(cv)),                      \
 604                 CopSTASHPV((const COP *)CvSTART(cv)));                  \
 605                                                                         \
 606         cx->blk_sub.cv = cv;                                            \
 607         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
 608         cx->blk_sub.prevcomppad = PL_comppad;                           \
 609         cx->cx_type |= (hasargs) ? CXp_HASARGS : 0;                     \
 610         cx->blk_sub.retop = NULL;                                       \
 611         SvREFCNT_inc_simple_void_NN(cv);
 612
 613 #define PUSHSUB_GET_LVALUE_MASK(func) \
 614         /* If the context is indeterminate, then only the lvalue */     \
 615         /* flags that the caller also has are applicable.        */     \
 616         (                                                               \
 617            (PL_op->op_flags & OPf_WANT)                                 \
 618                ? OPpENTERSUB_LVAL_MASK                                  \
 619                : !(PL_op->op_private & OPpENTERSUB_LVAL_MASK)           \
 620                    ? 0 : (U8)func(aTHX)                                 \
 621         )
 622
 623 #define PUSHSUB(cx)                                                     \
 624     {                                                                   \
 625         U8 phlags = PUSHSUB_GET_LVALUE_MASK(Perl_was_lvalue_sub);       \
 626         PUSHSUB_BASE(cx)                                                \
 627         cx->blk_u16 = PL_op->op_private &                               \
 628                           (phlags|OPpDEREF);                            \
 629     }
 630
 631 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
 632 #define PUSHSUB_DB(cx)                                                  \
 633         PUSHSUB_BASE(cx)                                                \
 634         cx->blk_u16 = 0;
 635
 636
 637 #define PUSHFORMAT(cx, retop)                                           \
 638         cx->blk_format.cv = cv;                                         \
 639         cx->blk_format.gv = gv;                                         \
 640         cx->blk_format.retop = (retop);                                 \
 641         cx->blk_format.dfoutgv = PL_defoutgv;                           \
 642         cx->blk_format.prevcomppad = PL_comppad;                        \
 643         cx->blk_u16 = 0;                                                \
 644         cx->blk_oldsaveix = PL_savestack_ix;                            \
 645         SvREFCNT_inc_simple_void_NN(cv);                                \
 646         CvDEPTH(cv)++;                                                  \
 647         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
 648
 649 /* Restore old @_ */
 650 #define CX_POP_SAVEARRAY(cx)                                            \
 651     STMT_START {                                                        \
 652         AV *av = GvAV(PL_defgv);                                        \
 653         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
 654         cx->blk_sub.savearray = NULL;                                   \
 655         SvREFCNT_dec(av);                                               \
 656     } STMT_END
 657
 658 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
 659  * leave any (a fast av_clear(ary), basically) */
 660 #define CLEAR_ARGARRAY(ary) \
 661     STMT_START {                                                        \
 662         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
 663         AvARRAY(ary) = AvALLOC(ary);                                    \
 664         AvFILLp(ary) = -1;                                              \
 665     } STMT_END
 666
 667
 668 /* subsets of CX_POPSUB */
 669
 670 #define CX_POPSUB_COMMON(cx) \
 671     STMT_START {                                                        \
 672         CV *cv;                                                         \
 673         assert(CxTYPE(cx) == CXt_SUB);                                  \
 674         PL_comppad = cx->blk_sub.prevcomppad;                           \
 675         PL_curpad = LIKELY(PL_comppad) ? AvARRAY(PL_comppad) : NULL;    \
 676         cv = cx->blk_sub.cv;                                            \
 677         CvDEPTH(cv) = cx->blk_sub.olddepth;                             \
 678         cx->blk_sub.cv = NULL;                                          \
 679         SvREFCNT_dec(cv);                                               \
 680     } STMT_END
 681
 682 /* handle the @_ part of leaving a sub */
 683
 684 #define CX_POPSUB_ARGS(cx) \
 685     STMT_START {                                                        \
 686         AV *av;                                                         \
 687         assert(CxTYPE(cx) == CXt_SUB);                                  \
 688         assert(AvARRAY(MUTABLE_AV(                                      \
 689             PadlistARRAY(CvPADLIST(cx->blk_sub.cv))[                    \
 690                     CvDEPTH(cx->blk_sub.cv)])) == PL_curpad);           \
 691         CX_POP_SAVEARRAY(cx);                                           \
 692         av = MUTABLE_AV(PAD_SVl(0));                                    \
 693         if (UNLIKELY(AvREAL(av)))                                       \
 694             /* abandon @_ if it got reified */                          \
 695             clear_defarray(av, 0);                                      \
 696         else {                                                          \
 697             CLEAR_ARGARRAY(av);                                         \
 698         }                                                               \
 699     } STMT_END
 700
 701 #define CX_POPSUB(cx)                                                   \
 702     STMT_START {                                                        \
 703         assert(CxTYPE(cx) == CXt_SUB);                                  \
 704         RETURN_PROBE(CvNAMED(cx->blk_sub.cv)                            \
 705                         ? HEK_KEY(CvNAME_HEK(cx->blk_sub.cv))           \
 706                         : GvENAME(CvGV(cx->blk_sub.cv)),                \
 707                 CopFILE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
 708                 CopLINE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
 709                 CopSTASHPV((COP*)CvSTART((const CV*)cx->blk_sub.cv)));  \
 710                                                                         \
 711         if (CxHASARGS(cx)) {                                            \
 712             CX_POPSUB_ARGS(cx);                                         \
 713         }                                                               \
 714         CX_POPSUB_COMMON(cx);                                           \
 715     } STMT_END
 716
 717 #define CX_POPFORMAT(cx)                                                \
 718     STMT_START {                                                        \
 719         CV *cv;                                                         \
 720         GV * const dfout = cx->blk_format.dfoutgv;                      \
 721         assert(CxTYPE(cx) == CXt_FORMAT);                               \
 722         setdefout(dfout);                                               \
 723         cx->blk_format.dfoutgv = NULL;                                  \
 724         SvREFCNT_dec_NN(dfout); /* the cx->defoutgv ref */              \
 725         PL_comppad = cx->blk_format.prevcomppad;                        \
 726         PL_curpad = LIKELY(PL_comppad) ? AvARRAY(PL_comppad) : NULL;    \
 727         cv = cx->blk_format.cv;                                         \
 728         cx->blk_format.cv = NULL;;                                      \
 729         --CvDEPTH(cv);                                                  \
 730         SvREFCNT_dec_NN(cv);                                            \
 731     } STMT_END
 732
 733 /* eval context */
 734 struct block_eval {
 735     OP *        retop;  /* op to execute on exit from eval */
 736     /* Above here is the same for sub, format and eval.  */
 737     SV *        old_namesv;
 738     OP *        old_eval_root;
 739     SV *        cur_text;
 740     CV *        cv;
 741     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
 742 };
 743
 744 /* If we ever need more than 512 op types, change the shift from 7.
 745    blku_gimme is actually also only 2 bits, so could be merged with something.
 746 */
 747
 748 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
 749 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
 750
 751 #define PUSHEVAL(cx,n)                                                  \
 752     STMT_START {                                                        \
 753         assert(!(PL_in_eval & ~0x7F));                                  \
 754         assert(!(PL_op->op_type & ~0x1FF));                             \
 755         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
 756         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
 757         cx->blk_eval.old_eval_root = PL_eval_root;                      \
 758         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
 759         cx->blk_eval.cv = NULL; /* set by doeval_compile() as applicable */ \
 760         cx->blk_eval.retop = NULL;                                      \
 761         cx->blk_eval.cur_top_env = PL_top_env;                          \
 762     } STMT_END
 763
 764 #define CX_POPEVAL(cx)                                                  \
 765     STMT_START {                                                        \
 766         SV *sv;                                                         \
 767         assert(CxTYPE(cx) == CXt_EVAL);                                 \
 768         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
 769         PL_eval_root = cx->blk_eval.old_eval_root;                      \
 770         sv = cx->blk_eval.cur_text;                                     \
 771         if (sv && SvSCREAM(sv)) {                                       \
 772             cx->blk_eval.cur_text = NULL;                               \
 773             SvREFCNT_dec_NN(sv);                                        \
 774         }                                                               \
 775         sv = cx->blk_eval.old_namesv;                                   \
 776         if (sv && !SvTEMP(sv))/* TEMP implies CX_POPEVAL re-entrantly called */ \
 777             sv_2mortal(sv);                                             \
 778     } STMT_END
 779
 780 /* loop context */
 781 struct block_loop {
 782     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
 783     union {     /* different ways of locating the iteration variable */
 784         SV      **svp; /* for lexicals: address of pad slot */
 785         GV      *gv;   /* for package vars */
 786     } itervar_u;
 787     SV          *itersave; /* the original iteration var */
 788     union {
 789         struct { /* CXt_LOOP_ARY, C<for (@ary)>  */
 790             AV *ary; /* array being iterated over */
 791             IV  ix;   /* index relative to base of array */
 792         } ary;
 793         struct { /* CXt_LOOP_LIST, C<for (list)> */
 794             I32 basesp; /* first element of list on stack */
 795             IV  ix;      /* index relative to basesp */
 796         } stack;
 797         struct { /* CXt_LOOP_LAZYIV, C<for (1..9)> */
 798             IV cur;
 799             IV end;
 800         } lazyiv;
 801         struct { /* CXt_LOOP_LAZYSV C<for ('a'..'z')> */
 802             SV * cur;
 803             SV * end; /* maxiumum value (or minimum in reverse) */
 804         } lazysv;
 805     } state_u;
 806 #ifdef USE_ITHREADS
 807     PAD *oldcomppad; /* needed to map itervar_u.svp during thread clone */
 808 #endif
 809 };
 810
 811 #define CxITERVAR(c)                                    \
 812         (CxPADLOOP(c)                                   \
 813             ? (c)->blk_loop.itervar_u.svp               \
 814             : ((c)->cx_type & CXp_FOR_GV)               \
 815                 ? &GvSV((c)->blk_loop.itervar_u.gv)     \
 816                 : (SV **)&(c)->blk_loop.itervar_u.gv)
 817
 818 #define CxLABEL(c)      (0 + CopLABEL((c)->blk_oldcop))
 819 #define CxLABEL_len(c,len)      (0 + CopLABEL_len((c)->blk_oldcop, len))
 820 #define CxLABEL_len_flags(c,len,flags)  (0 + CopLABEL_len_flags((c)->blk_oldcop, len, flags))
 821 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
 822 #define CxLVAL(c)       (0 + ((c)->blk_u16 & 0xff))
 823
 824
 825 #define PUSHLOOP_PLAIN(cx)                                              \
 826         cx->blk_loop.my_op = cLOOP;                                     \
 827         cx->blk_oldsaveix = PL_savestack_ix;
 828
 829 #ifdef USE_ITHREADS
 830 #  define PUSHLOOP_FOR_setpad(c) (c)->blk_loop.oldcomppad = PL_comppad
 831 #else
 832 #  define PUSHLOOP_FOR_setpad(c) NOOP
 833 #endif
 834
 835 #define PUSHLOOP_FOR(cx, ivar, isave)                                   \
 836         cx->blk_loop.my_op = cLOOP;                                     \
 837         cx->blk_loop.itervar_u.svp = (SV**)(ivar);                      \
 838         cx->blk_oldsaveix = PL_savestack_ix;                                \
 839         cx->blk_loop.itersave = isave;                                  \
 840         PUSHLOOP_FOR_setpad(cx);
 841
 842 #define CX_POPLOOP(cx)                                                  \
 843         assert(CxTYPE_is_LOOP(cx));                                     \
 844         if (  CxTYPE(cx) == CXt_LOOP_ARY                                \
 845            || CxTYPE(cx) == CXt_LOOP_LAZYSV)                            \
 846         {                                                               \
 847             /* Free ary or cur. This assumes that state_u.ary.ary       \
 848              * aligns with state_u.lazysv.cur. See cx_dup() */          \
 849             SV *sv = cx->blk_loop.state_u.lazysv.cur;                   \
 850             cx->blk_loop.state_u.lazysv.cur = NULL;                     \
 851             SvREFCNT_dec_NN(sv);                                        \
 852             if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                        \
 853                 sv = cx->blk_loop.state_u.lazysv.end;                   \
 854                 cx->blk_loop.state_u.lazysv.end = NULL;                 \
 855                 SvREFCNT_dec_NN(sv);                                    \
 856             }                                                           \
 857         }                                                               \
 858         if (cx->cx_type & (CXp_FOR_PAD|CXp_FOR_GV)) {                   \
 859             SV *cursv;                                                  \
 860             SV **svp = (cx)->blk_loop.itervar_u.svp;                    \
 861             if ((cx->cx_type & CXp_FOR_GV))                             \
 862                 svp = &GvSV((GV*)svp);                                  \
 863             cursv = *svp;                                               \
 864             *svp = cx->blk_loop.itersave;                               \
 865             cx->blk_loop.itersave = NULL;                               \
 866             SvREFCNT_dec(cursv);                                        \
 867         }
 868
 869 /* given/when context */
 870 struct block_givwhen {
 871         OP *leave_op;
 872         SV *defsv_save; /* the original $_ */
 873 };
 874
 875 #define PUSHWHEN(cx)                                                    \
 876         cx->blk_oldsaveix = PL_savestack_ix;                            \
 877         cx->blk_givwhen.leave_op = cLOGOP->op_other;
 878
 879 #define PUSHGIVEN(cx, orig_var)                                         \
 880         PUSHWHEN(cx);                                                   \
 881         cx->blk_givwhen.defsv_save = orig_var;
 882
 883 #define CX_POPWHEN(cx)                                                  \
 884         assert(CxTYPE(cx) == CXt_WHEN);                                 \
 885         NOOP;
 886
 887 #define CX_POPGIVEN(cx)                                                 \
 888     STMT_START {                                                        \
 889         SV *sv = GvSV(PL_defgv);                                        \
 890         assert(CxTYPE(cx) == CXt_GIVEN);                                \
 891         GvSV(PL_defgv) = cx->blk_givwhen.defsv_save;                    \
 892         cx->blk_givwhen.defsv_save = NULL;                              \
 893         SvREFCNT_dec(sv);                                               \
 894     } STMT_END
 895
 896
 897 /* basic block, i.e. pp_enter/leave */
 898
 899 #define PUSHBASICBLK(cx)                                                \
 900         cx->blk_oldsaveix = PL_savestack_ix;
 901
 902 #define CX_POPBASICBLK(cx)                                              \
 903         assert(CxTYPE(cx) == CXt_BLOCK);                                \
 904         NOOP;
 905
 906
 907 /* context common to subroutines, evals and loops */
 908 struct block {
 909     U8          blku_type;      /* what kind of context this is */
 910     U8          blku_gimme;     /* is this block running in list context? */
 911     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
 912     I32         blku_oldsaveix; /* saved PL_savestack_ix */
 913     /* all the fields above must be aligned with same-sized fields as sbu */
 914     I32         blku_oldsp;     /* current sp floor: where nextstate pops to */
 915     I32         blku_oldmarksp; /* mark stack index */
 916     COP *       blku_oldcop;    /* old curcop pointer */
 917     PMOP *      blku_oldpm;     /* values of pattern match vars */
 918     SSize_t     blku_old_tmpsfloor;     /* saved PL_tmps_floor */
 919     I32         blku_oldscopesp;        /* scope stack index */
 920
 921     union {
 922         struct block_sub        blku_sub;
 923         struct block_format     blku_format;
 924         struct block_eval       blku_eval;
 925         struct block_loop       blku_loop;
 926         struct block_givwhen    blku_givwhen;
 927     } blk_u;
 928 };
 929 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
 930 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
 931 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
 932 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
 933 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
 934 #define blk_gimme       cx_u.cx_blk.blku_gimme
 935 #define blk_u16         cx_u.cx_blk.blku_u16
 936 #define blk_oldsaveix   cx_u.cx_blk.blku_oldsaveix
 937 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
 938 #define blk_format      cx_u.cx_blk.blk_u.blku_format
 939 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
 940 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
 941 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
 942
 943 #define CX_DEBUG(cx, action)                                            \
 944     DEBUG_l(                                                            \
 945         Perl_deb(aTHX_ "CX %ld %s %s (scope %ld,%ld) (save %ld,%ld) at %s:%d\n",\
 946                     (long)cxstack_ix,                                   \
 947                     action,                                             \
 948                     PL_block_type[CxTYPE(cx)],                          \
 949                     (long)PL_scopestack_ix,                             \
 950                     (long)(cx->blk_oldscopesp),                         \
 951                     (long)PL_savestack_ix,                              \
 952                     (long)(cx->blk_oldsaveix),                          \
 953                     __FILE__, __LINE__));
 954
 955 /* Enter a block. */
 956 #define PUSHBLOCK(cx,t,sp) CXINC, cx = CX_CUR(),                        \
 957         cx->cx_type             = t,                                    \
 958         cx->blk_oldsp           = sp - PL_stack_base,                   \
 959         cx->blk_oldcop          = PL_curcop,                            \
 960         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
 961         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
 962         cx->blk_oldpm           = PL_curpm,                             \
 963         cx->blk_gimme           = (U8)gimme;                            \
 964         cx->cx_u.cx_blk.blku_old_tmpsfloor = PL_tmps_floor;             \
 965         PL_tmps_floor           = PL_tmps_ix;                           \
 966         CX_DEBUG(cx, "PUSH");
 967
 968 #define _CX_POPBLOCK_COMMON(cx)                                         \
 969         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 970         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 971         PL_curpm         = cx->blk_oldpm,
 972
 973 /* Exit a block (RETURN and LAST). */
 974 #define CX_POPBLOCK(cx)                                                 \
 975         CX_DEBUG(cx, "POP");                                            \
 976         _CX_POPBLOCK_COMMON(cx)                                         \
 977         /* LEAVE_SCOPE() should have made this true. /(?{})/ cheats
 978          * and leaves a CX entry lying around for repeated use, so
 979          * skip for multicall */                  \
 980         assert(   (CxTYPE(cx) == CXt_SUB && CxMULTICALL(cx))            \
 981                 || PL_savestack_ix == cx->blk_oldsaveix);               \
 982         PL_curcop     = cx->blk_oldcop,                                 \
 983         PL_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;             \
 984
 985 /* Continue a block elsewhere (e.g. NEXT, REDO, GOTO).
 986  * Whereas CX_POPBLOCK restores the state to the point just before PUSHBLOCK
 987  * was called,  CX_TOPBLOCK restores it to the point just *after* PUSHBLOCK
 988  * was called. */
 989 #define CX_TOPBLOCK(cx)                                                 \
 990         CX_DEBUG(cx, "TOP");                                            \
 991         _CX_POPBLOCK_COMMON(cx)                                         \
 992         PL_stack_sp      = PL_stack_base + cx->blk_oldsp;
 993
 994 /* substitution context */
 995 struct subst {
 996     U8          sbu_type;       /* same as blku_type */
 997     U8          sbu_rflags;
 998     U16         sbu_rxtainted;
 999     I32         sbu_oldsaveix; /* same as blku_oldsaveix */
1000     /* all the fields above must be aligned with same-sized fields as blk_u */
1001     SSize_t     sbu_iters;
1002     SSize_t     sbu_maxiters;
1003     char *      sbu_orig;
1004     SV *        sbu_dstr;
1005     SV *        sbu_targ;
1006     char *      sbu_s;
1007     char *      sbu_m;
1008     char *      sbu_strend;
1009     void *      sbu_rxres;
1010     REGEXP *    sbu_rx;
1011 };
1012 #define sb_iters        cx_u.cx_subst.sbu_iters
1013 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
1014 #define sb_rflags       cx_u.cx_subst.sbu_rflags
1015 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
1016 #define sb_orig         cx_u.cx_subst.sbu_orig
1017 #define sb_dstr         cx_u.cx_subst.sbu_dstr
1018 #define sb_targ         cx_u.cx_subst.sbu_targ
1019 #define sb_s            cx_u.cx_subst.sbu_s
1020 #define sb_m            cx_u.cx_subst.sbu_m
1021 #define sb_strend       cx_u.cx_subst.sbu_strend
1022 #define sb_rxres        cx_u.cx_subst.sbu_rxres
1023 #define sb_rx           cx_u.cx_subst.sbu_rx
1024
1025 #ifdef PERL_CORE
1026 #  define PUSHSUBST(cx) CXINC, cx = CX_CUR(),                           \
1027         cx->blk_oldsaveix = oldsave,                                    \
1028         cx->sb_iters            = iters,                                \
1029         cx->sb_maxiters         = maxiters,                             \
1030         cx->sb_rflags           = r_flags,                              \
1031         cx->sb_rxtainted        = rxtainted,                            \
1032         cx->sb_orig             = orig,                                 \
1033         cx->sb_dstr             = dstr,                                 \
1034         cx->sb_targ             = targ,                                 \
1035         cx->sb_s                = s,                                    \
1036         cx->sb_m                = m,                                    \
1037         cx->sb_strend           = strend,                               \
1038         cx->sb_rxres            = NULL,                                 \
1039         cx->sb_rx               = rx,                                   \
1040         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
1041         rxres_save(&cx->sb_rxres, rx);                                  \
1042         (void)ReREFCNT_inc(rx);                                         \
1043         SvREFCNT_inc_void_NN(targ)
1044
1045 #  define CX_POPSUBST(cx) \
1046     STMT_START {                                                        \
1047         REGEXP *re;                                                     \
1048         assert(CxTYPE(cx) == CXt_SUBST);                                \
1049         rxres_free(&cx->sb_rxres);                                      \
1050         re = cx->sb_rx;                                                 \
1051         cx->sb_rx = NULL;                                               \
1052         ReREFCNT_dec(re);                                               \
1053         SvREFCNT_dec_NN(cx->sb_targ);                                   \
1054     } STMT_END
1055 #endif
1056
1057 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
1058
1059 struct context {
1060     union {
1061         struct block    cx_blk;
1062         struct subst    cx_subst;
1063     } cx_u;
1064 };
1065 #define cx_type cx_u.cx_subst.sbu_type
1066
1067 /* If you re-order these, there is also an array of uppercase names in perl.h
1068    and a static array of context names in pp_ctl.c  */
1069 #define CXTYPEMASK      0xf
1070 #define CXt_NULL        0 /* currently only used for sort BLOCK */
1071 #define CXt_WHEN        1
1072 #define CXt_BLOCK       2
1073 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
1074    jump table in pp_ctl.c
1075    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
1076 */
1077 #define CXt_GIVEN       3
1078
1079 /* be careful of the ordering of these five. Macros like CxTYPE_is_LOOP,
1080  * CxFOREACH compare ranges */
1081 #define CXt_LOOP_ARY    4 /* for (@ary)     {} */
1082 #define CXt_LOOP_LAZYSV 5 /* for ('a'..'z') {} */
1083 #define CXt_LOOP_LAZYIV 6 /* for (1..9)     {} */
1084 #define CXt_LOOP_LIST   7 /* for (1,2,3)    {} */
1085 #define CXt_LOOP_PLAIN  8 /*                {} */
1086
1087 #define CXt_SUB         9
1088 #define CXt_FORMAT     10
1089 #define CXt_EVAL       11
1090 #define CXt_SUBST      12
1091 /* SUBST doesn't feature in all switch statements.  */
1092
1093 /* private flags for CXt_SUB and CXt_FORMAT */
1094 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't tear down
1095                                    context on exit). (not CXt_FORMAT) */
1096 #define CXp_HASARGS     0x20
1097 #define CXp_SUB_RE      0x40    /* code called within regex, i.e. (?{}) */
1098 #define CXp_SUB_RE_FAKE 0x80    /* fake sub CX for (?{}) in current scope */
1099
1100 /* private flags for CXt_EVAL */
1101 #define CXp_REAL        0x20    /* truly eval'', not a lookalike */
1102 #define CXp_TRYBLOCK    0x40    /* eval{}, not eval'' or similar */
1103
1104 /* private flags for CXt_LOOP */
1105
1106 /* this is only set in conjunction with CXp_FOR_GV */
1107 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
1108 /* these 3 are mutually exclusive */
1109 #define CXp_FOR_LVREF   0x20    /* foreach using \$var */
1110 #define CXp_FOR_GV      0x40    /* foreach using package var */
1111 #define CXp_FOR_PAD     0x80    /* foreach using lexical var */
1112
1113 #define CxPADLOOP(c)    ((c)->cx_type & CXp_FOR_PAD)
1114
1115 /* private flags for CXt_SUBST */
1116 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
1117
1118 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
1119 #define CxTYPE_is_LOOP(c) (   CxTYPE(cx) >= CXt_LOOP_ARY                \
1120                            && CxTYPE(cx) <= CXt_LOOP_PLAIN)
1121 #define CxMULTICALL(c)  ((c)->cx_type & CXp_MULTICALL)
1122 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
1123                          == (CXt_EVAL|CXp_REAL))
1124 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
1125                          == (CXt_EVAL|CXp_TRYBLOCK))
1126 #define CxFOREACH(c)    (   CxTYPE(cx) >= CXt_LOOP_ARY                  \
1127                          && CxTYPE(cx) <= CXt_LOOP_LIST)
1128
1129 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
1130
1131 /*
1132 =head1 "Gimme" Values
1133 */
1134
1135 /*
1136 =for apidoc AmU||G_SCALAR
1137 Used to indicate scalar context.  See C<L</GIMME_V>>, C<L</GIMME>>, and
1138 L<perlcall>.
1139
1140 =for apidoc AmU||G_ARRAY
1141 Used to indicate list context.  See C<L</GIMME_V>>, C<L</GIMME>> and
1142 L<perlcall>.
1143
1144 =for apidoc AmU||G_VOID
1145 Used to indicate void context.  See C<L</GIMME_V>> and L<perlcall>.
1146
1147 =for apidoc AmU||G_DISCARD
1148 Indicates that arguments returned from a callback should be discarded.  See
1149 L<perlcall>.
1150
1151 =for apidoc AmU||G_EVAL
1152
1153 Used to force a Perl C<eval> wrapper around a callback.  See
1154 L<perlcall>.
1155
1156 =for apidoc AmU||G_NOARGS
1157
1158 Indicates that no arguments are being sent to a callback.  See
1159 L<perlcall>.
1160
1161 =cut
1162 */
1163
1164 #define G_SCALAR        2
1165 #define G_ARRAY         3
1166 #define G_VOID          1
1167 #define G_WANT          3
1168
1169 /* extra flags for Perl_call_* routines */
1170 #define G_DISCARD       4       /* Call FREETMPS.
1171                                    Don't change this without consulting the
1172                                    hash actions codes defined in hv.h */
1173 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
1174 #define G_NOARGS       16       /* Don't construct a @_ array. */
1175 #define G_KEEPERR      32       /* Warn for errors, don't overwrite $@ */
1176 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
1177 #define G_METHOD      128       /* Calling method. */
1178 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
1179                                    fold_constants. */
1180 #define G_UNDEF_FILL  512       /* Fill the stack with &PL_sv_undef
1181                                    A special case for UNSHIFT in
1182                                    Perl_magic_methcall().  */
1183 #define G_WRITING_TO_STDERR 1024 /* Perl_write_to_stderr() is calling
1184                                     Perl_magic_methcall().  */
1185 #define G_RE_REPARSING 0x800     /* compiling a run-time /(?{..})/ */
1186 #define G_METHOD_NAMED 4096     /* calling named method, eg without :: or ' */
1187
1188 /* flag bits for PL_in_eval */
1189 #define EVAL_NULL       0       /* not in an eval */
1190 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
1191 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
1192 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
1193 #define EVAL_INREQUIRE  8       /* The code is being required. */
1194 #define EVAL_RE_REPARSING 0x10  /* eval_sv() called with G_RE_REPARSING */
1195
1196 /* Support for switching (stack and block) contexts.
1197  * This ensures magic doesn't invalidate local stack and cx pointers.
1198  */
1199
1200 #define PERLSI_UNKNOWN          -1
1201 #define PERLSI_UNDEF            0
1202 #define PERLSI_MAIN             1
1203 #define PERLSI_MAGIC            2
1204 #define PERLSI_SORT             3
1205 #define PERLSI_SIGNAL           4
1206 #define PERLSI_OVERLOAD         5
1207 #define PERLSI_DESTROY          6
1208 #define PERLSI_WARNHOOK         7
1209 #define PERLSI_DIEHOOK          8
1210 #define PERLSI_REQUIRE          9
1211 #define PERLSI_MULTICALL       10
1212
1213 struct stackinfo {
1214     AV *                si_stack;       /* stack for current runlevel */
1215     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
1216     struct stackinfo *  si_prev;
1217     struct stackinfo *  si_next;
1218     I32                 si_cxix;        /* current context index */
1219     I32                 si_cxmax;       /* maximum allocated index */
1220     I32                 si_type;        /* type of runlevel */
1221     I32                 si_markoff;     /* offset where markstack begins for us.
1222                                          * currently used only with DEBUGGING,
1223                                          * but not #ifdef-ed for bincompat */
1224 };
1225
1226 typedef struct stackinfo PERL_SI;
1227
1228 #define cxstack         (PL_curstackinfo->si_cxstack)
1229 #define cxstack_ix      (PL_curstackinfo->si_cxix)
1230 #define cxstack_max     (PL_curstackinfo->si_cxmax)
1231
1232 #ifdef DEBUGGING
1233 #  define       SET_MARK_OFFSET \
1234     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
1235 #else
1236 #  define       SET_MARK_OFFSET NOOP
1237 #endif
1238
1239 #define PUSHSTACKi(type) \
1240     STMT_START {                                                        \
1241         PERL_SI *next = PL_curstackinfo->si_next;                       \
1242         DEBUG_l({                                                       \
1243             int i = 0; PERL_SI *p = PL_curstackinfo;                    \
1244             while (p) { i++; p = p->si_prev; }                          \
1245             Perl_deb(aTHX_ "push STACKINFO %d at %s:%d\n",              \
1246                          i, __FILE__, __LINE__);})                      \
1247         if (!next) {                                                    \
1248             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
1249             next->si_prev = PL_curstackinfo;                            \
1250             PL_curstackinfo->si_next = next;                            \
1251         }                                                               \
1252         next->si_type = type;                                           \
1253         next->si_cxix = -1;                                             \
1254         AvFILLp(next->si_stack) = 0;                                    \
1255         SWITCHSTACK(PL_curstack,next->si_stack);                        \
1256         PL_curstackinfo = next;                                         \
1257         SET_MARK_OFFSET;                                                \
1258     } STMT_END
1259
1260 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
1261
1262 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
1263  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
1264 #define POPSTACK \
1265     STMT_START {                                                        \
1266         dSP;                                                            \
1267         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
1268         DEBUG_l({                                                       \
1269             int i = -1; PERL_SI *p = PL_curstackinfo;                   \
1270             while (p) { i++; p = p->si_prev; }                          \
1271             Perl_deb(aTHX_ "pop  STACKINFO %d at %s:%d\n",              \
1272                          i, __FILE__, __LINE__);})                      \
1273         if (!prev) {                                                    \
1274             Perl_croak_popstack();                                      \
1275         }                                                               \
1276         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
1277         /* don't free prev here, free them all at the END{} */          \
1278         PL_curstackinfo = prev;                                         \
1279     } STMT_END
1280
1281 #define POPSTACK_TO(s) \
1282     STMT_START {                                                        \
1283         while (PL_curstack != s) {                                      \
1284             dounwind(-1);                                               \
1285             POPSTACK;                                                   \
1286         }                                                               \
1287     } STMT_END
1288
1289 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
1290 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
1291
1292 /*
1293 =head1 Multicall Functions
1294
1295 =for apidoc Ams||dMULTICALL
1296 Declare local variables for a multicall.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1297
1298 =for apidoc Ams||PUSH_MULTICALL
1299 Opening bracket for a lightweight callback.
1300 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1301
1302 =for apidoc Ams||MULTICALL
1303 Make a lightweight callback.  See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1304
1305 =for apidoc Ams||POP_MULTICALL
1306 Closing bracket for a lightweight callback.
1307 See L<perlcall/LIGHTWEIGHT CALLBACKS>.
1308
1309 =cut
1310 */
1311
1312 #define dMULTICALL \
1313     SV **newsp;                 /* set by CX_POPBLOCK */                \
1314     PERL_CONTEXT *cx;                                                   \
1315     CV *multicall_cv;                                                   \
1316     OP *multicall_cop;                                                  \
1317     bool multicall_oldcatch;                                            \
1318     U8 hasargs = 0              /* used by PUSHSUB */
1319
1320 #define PUSH_MULTICALL(the_cv) \
1321     PUSH_MULTICALL_FLAGS(the_cv, 0)
1322
1323 /* Like PUSH_MULTICALL, but allows you to specify extra flags
1324  * for the CX stack entry (this isn't part of the public API) */
1325
1326 #define PUSH_MULTICALL_FLAGS(the_cv, flags) \
1327     STMT_START {                                                        \
1328         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1329         CV * const cv = _nOnclAshIngNamE_;                              \
1330         PADLIST * const padlist = CvPADLIST(cv);                        \
1331         multicall_oldcatch = CATCH_GET;                                 \
1332         CATCH_SET(TRUE);                                                \
1333         PUSHSTACKi(PERLSI_MULTICALL);                                   \
1334         PUSHBLOCK(cx, (CXt_SUB|CXp_MULTICALL|flags), PL_stack_sp);      \
1335         PUSHSUB(cx);                                                    \
1336         cx->blk_oldsaveix = PL_savestack_ix;                            \
1337         SAVEVPTR(PL_op);                                                \
1338         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1339             CvDEPTH(cv)++;                                              \
1340         if (CvDEPTH(cv) >= 2) {                                         \
1341             PERL_STACK_OVERFLOW_CHECK();                                \
1342             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1343         }                                                               \
1344         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1345         multicall_cv = cv;                                              \
1346         PERL_UNUSED_VAR(multicall_cv); /* for API */                    \
1347         multicall_cop = CvSTART(cv);                                    \
1348     } STMT_END
1349
1350 #define MULTICALL \
1351     STMT_START {                                                        \
1352         PL_op = multicall_cop;                                          \
1353         CALLRUNOPS(aTHX);                                               \
1354     } STMT_END
1355
1356 #define POP_MULTICALL \
1357     STMT_START {                                                        \
1358         cx = CX_CUR();                                                  \
1359         CX_LEAVE_SCOPE(cx);                                             \
1360         CX_POPSUB_COMMON(cx);                                           \
1361         newsp = PL_stack_base + cx->blk_oldsp;                          \
1362         gimme = cx->blk_gimme;                                          \
1363         PERL_UNUSED_VAR(newsp); /* for API */                           \
1364         PERL_UNUSED_VAR(gimme); /* for API */                           \
1365         CX_POPBLOCK(cx);                                                \
1366         CX_POP(cx);                                                     \
1367         POPSTACK;                                                       \
1368         CATCH_SET(multicall_oldcatch);                                  \
1369         SPAGAIN;                                                        \
1370     } STMT_END
1371
1372 /* Change the CV of an already-pushed MULTICALL CxSUB block.
1373  * (this isn't part of the public API) */
1374
1375 #define CHANGE_MULTICALL_FLAGS(the_cv, flags) \
1376     STMT_START {                                                        \
1377         CV * const _nOnclAshIngNamE_ = the_cv;                          \
1378         CV * const cv = _nOnclAshIngNamE_;                              \
1379         PADLIST * const padlist = CvPADLIST(cv);                        \
1380         cx = CX_CUR();                                                  \
1381         assert(CxMULTICALL(cx));                                        \
1382         CX_POPSUB_COMMON(cx);                                           \
1383         cx->cx_type = (CXt_SUB|CXp_MULTICALL|flags);                    \
1384         PUSHSUB(cx);                                                    \
1385         if (!(flags & CXp_SUB_RE_FAKE))                                 \
1386             CvDEPTH(cv)++;                                              \
1387         if (CvDEPTH(cv) >= 2) {                                         \
1388             PERL_STACK_OVERFLOW_CHECK();                                \
1389             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
1390         }                                                               \
1391         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
1392         multicall_cv = cv;                                              \
1393         multicall_cop = CvSTART(cv);                                    \
1394     } STMT_END
1395 /*
1396  * ex: set ts=8 sts=4 sw=4 et:
1397  */