scope.h

   1 #define SAVEt_ITEM              0
   2 #define SAVEt_SV                1
   3 #define SAVEt_AV                2
   4 #define SAVEt_HV                3
   5 #define SAVEt_INT               4
   6 #define SAVEt_LONG              5
   7 #define SAVEt_I32               6
   8 #define SAVEt_IV                7
   9 #define SAVEt_SPTR              8
  10 #define SAVEt_APTR              9
  11 #define SAVEt_HPTR              10
  12 #define SAVEt_PPTR              11
  13 #define SAVEt_NSTAB             12
  14 #define SAVEt_SVREF             13
  15 #define SAVEt_GP                14
  16 #define SAVEt_FREESV            15
  17 #define SAVEt_FREEOP            16
  18 #define SAVEt_FREEPV            17
  19 #define SAVEt_CLEARSV           18
  20 #define SAVEt_DELETE            19
  21 #define SAVEt_DESTRUCTOR        20
  22 #define SAVEt_REGCONTEXT        21
  23 #define SAVEt_STACK_POS         22
  24 #define SAVEt_I16               23
  25 #define SAVEt_AELEM             24
  26 #define SAVEt_HELEM             25
  27 #define SAVEt_OP                26
  28 #define SAVEt_HINTS             27
  29 #define SAVEt_ALLOC             28
  30 #define SAVEt_GENERIC_SVREF     29
  31 #define SAVEt_DESTRUCTOR_X      30
  32 #define SAVEt_VPTR              31
  33 #define SAVEt_I8                32
  34 #define SAVEt_COMPPAD           33
  35
  36 #define SSCHECK(need) if (PL_savestack_ix + need > PL_savestack_max) savestack_grow()
  37 #define SSPUSHINT(i) (PL_savestack[PL_savestack_ix++].any_i32 = (I32)(i))
  38 #define SSPUSHLONG(i) (PL_savestack[PL_savestack_ix++].any_long = (long)(i))
  39 #define SSPUSHIV(i) (PL_savestack[PL_savestack_ix++].any_iv = (IV)(i))
  40 #define SSPUSHPTR(p) (PL_savestack[PL_savestack_ix++].any_ptr = (void*)(p))
  41 #define SSPUSHDPTR(p) (PL_savestack[PL_savestack_ix++].any_dptr = (p))
  42 #define SSPUSHDXPTR(p) (PL_savestack[PL_savestack_ix++].any_dxptr = (p))
  43 #define SSPOPINT (PL_savestack[--PL_savestack_ix].any_i32)
  44 #define SSPOPLONG (PL_savestack[--PL_savestack_ix].any_long)
  45 #define SSPOPIV (PL_savestack[--PL_savestack_ix].any_iv)
  46 #define SSPOPPTR (PL_savestack[--PL_savestack_ix].any_ptr)
  47 #define SSPOPDPTR (PL_savestack[--PL_savestack_ix].any_dptr)
  48 #define SSPOPDXPTR (PL_savestack[--PL_savestack_ix].any_dxptr)
  49
  50 /*
  51 =for apidoc Ams||SAVETMPS
  52 Opening bracket for temporaries on a callback.  See C<FREETMPS> and
  53 L<perlcall>.
  54
  55 =for apidoc Ams||FREETMPS
  56 Closing bracket for temporaries on a callback.  See C<SAVETMPS> and
  57 L<perlcall>.
  58
  59 =for apidoc Ams||ENTER
  60 Opening bracket on a callback.  See C<LEAVE> and L<perlcall>.
  61
  62 =for apidoc Ams||LEAVE
  63 Closing bracket on a callback.  See C<ENTER> and L<perlcall>.
  64
  65 =cut
  66 */
  67
  68 #define SAVETMPS save_int((int*)&PL_tmps_floor), PL_tmps_floor = PL_tmps_ix
  69 #define FREETMPS if (PL_tmps_ix > PL_tmps_floor) free_tmps()
  70
  71 #ifdef DEBUGGING
  72 #define ENTER                                                   \
  73     STMT_START {                                                \
  74         push_scope();                                           \
  75         DEBUG_l(WITH_THR(Perl_deb(aTHX_ "ENTER scope %ld at %s:%d\n",   \
  76                     PL_scopestack_ix, __FILE__, __LINE__)));    \
  77     } STMT_END
  78 #define LEAVE                                                   \
  79     STMT_START {                                                \
  80         DEBUG_l(WITH_THR(Perl_deb(aTHX_ "LEAVE scope %ld at %s:%d\n",   \
  81                     PL_scopestack_ix, __FILE__, __LINE__)));    \
  82         pop_scope();                                            \
  83     } STMT_END
  84 #else
  85 #define ENTER push_scope()
  86 #define LEAVE pop_scope()
  87 #endif
  88 #define LEAVE_SCOPE(old) if (PL_savestack_ix > old) leave_scope(old)
  89
  90 /*
  91  * Not using SOFT_CAST on SAVESPTR, SAVEGENERICSV and SAVEFREESV
  92  * because these are used for several kinds of pointer values
  93  */
  94 #define SAVEI8(i)       save_I8(SOFT_CAST(I8*)&(i))
  95 #define SAVEI16(i)      save_I16(SOFT_CAST(I16*)&(i))
  96 #define SAVEI32(i)      save_I32(SOFT_CAST(I32*)&(i))
  97 #define SAVEINT(i)      save_int(SOFT_CAST(int*)&(i))
  98 #define SAVEIV(i)       save_iv(SOFT_CAST(IV*)&(i))
  99 #define SAVELONG(l)     save_long(SOFT_CAST(long*)&(l))
 100 #define SAVESPTR(s)     save_sptr((SV**)&(s))
 101 #define SAVEPPTR(s)     save_pptr(SOFT_CAST(char**)&(s))
 102 #define SAVEVPTR(s)     save_vptr((void*)&(s))
 103 #define SAVEFREESV(s)   save_freesv((SV*)(s))
 104 #define SAVEFREEOP(o)   save_freeop(SOFT_CAST(OP*)(o))
 105 #define SAVEFREEPV(p)   save_freepv(SOFT_CAST(char*)(p))
 106 #define SAVECLEARSV(sv) save_clearsv(SOFT_CAST(SV**)&(sv))
 107 #define SAVEGENERICSV(s)        save_generic_svref((SV**)&(s))
 108 #define SAVEDELETE(h,k,l) \
 109           save_delete(SOFT_CAST(HV*)(h), SOFT_CAST(char*)(k), (I32)(l))
 110 #define SAVEDESTRUCTOR(f,p) \
 111           save_destructor((DESTRUCTORFUNC_NOCONTEXT_t)(f), SOFT_CAST(void*)(p))
 112
 113 #define SAVEDESTRUCTOR_X(f,p) \
 114           save_destructor_x((DESTRUCTORFUNC_t)(f), SOFT_CAST(void*)(p))
 115
 116 #define SAVESTACK_POS() \
 117     STMT_START {                                \
 118         SSCHECK(2);                             \
 119         SSPUSHINT(PL_stack_sp - PL_stack_base); \
 120         SSPUSHINT(SAVEt_STACK_POS);             \
 121     } STMT_END
 122
 123 #define SAVEOP()        save_op()
 124
 125 #define SAVEHINTS() \
 126     STMT_START {                                \
 127         if (PL_hints & HINT_LOCALIZE_HH)        \
 128             save_hints();                       \
 129         else {                                  \
 130             SSCHECK(2);                         \
 131             SSPUSHINT(PL_hints);                \
 132             SSPUSHINT(SAVEt_HINTS);             \
 133         }                                       \
 134     } STMT_END
 135
 136 #define SAVECOMPPAD() \
 137     STMT_START {                                                \
 138         if (PL_comppad && PL_curpad == AvARRAY(PL_comppad)) {   \
 139             SSCHECK(2);                                         \
 140             SSPUSHPTR((SV*)PL_comppad);                         \
 141             SSPUSHINT(SAVEt_COMPPAD);                           \
 142         }                                                       \
 143         else {                                                  \
 144             SAVEVPTR(PL_curpad);                                \
 145             SAVESPTR(PL_comppad);                               \
 146         }                                                       \
 147     } STMT_END
 148
 149 #ifdef USE_ITHREADS
 150 #  define SAVECOPSTASH(cop)     SAVEPPTR(CopSTASHPV(cop))
 151 #  define SAVECOPFILE(cop)      SAVEPPTR(CopFILE(cop))
 152 #else
 153 #  define SAVECOPSTASH(cop)     SAVESPTR(CopSTASH(cop))
 154 #  define SAVECOPFILE(cop)      SAVESPTR(CopFILEGV(cop))
 155 #endif
 156
 157 #define SAVECOPLINE(cop)        SAVEI16(CopLINE(cop))
 158
 159 /* SSNEW() temporarily allocates a specified number of bytes of data on the
 160  * savestack.  It returns an integer index into the savestack, because a
 161  * pointer would get broken if the savestack is moved on reallocation.
 162  * SSNEWa() works like SSNEW(), but also aligns the data to the specified
 163  * number of bytes.  MEM_ALIGNBYTES is perhaps the most useful.  The
 164  * alignment will be preserved therough savestack reallocation *only* if
 165  * realloc returns data aligned to a size divisible by `align'!
 166  *
 167  * SSPTR() converts the index returned by SSNEW/SSNEWa() into a pointer.
 168  */
 169
 170 #define SSNEW(size)             save_alloc(size, 0)
 171 #define SSNEWa(size,align)      save_alloc(size, \
 172     (align - ((int)((caddr_t)&PL_savestack[PL_savestack_ix]) % align)) % align)
 173
 174 #define SSPTR(off,type)         ((type) ((char*)PL_savestack + off))
 175
 176 /* A jmpenv packages the state required to perform a proper non-local jump.
 177  * Note that there is a start_env initialized when perl starts, and top_env
 178  * points to this initially, so top_env should always be non-null.
 179  *
 180  * Existence of a non-null top_env->je_prev implies it is valid to call
 181  * longjmp() at that runlevel (we make sure start_env.je_prev is always
 182  * null to ensure this).
 183  *
 184  * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
 185  * establish a local jmpenv to handle exception traps.  Care must be taken
 186  * to restore the previous value of je_mustcatch before exiting the
 187  * stack frame iff JMPENV_PUSH was not called in that stack frame.
 188  * GSAR 97-03-27
 189  */
 190
 191 struct jmpenv {
 192     struct jmpenv *     je_prev;
 193     Sigjmp_buf          je_buf;         /* only for use if !je_throw */
 194     int                 je_ret;         /* last exception thrown */
 195     bool                je_mustcatch;   /* need to call longjmp()? */
 196 #ifdef PERL_FLEXIBLE_EXCEPTIONS
 197     void                (*je_throw)(int v); /* last for bincompat */
 198     bool                je_noset;       /* no need for setjmp() */
 199 #endif
 200 };
 201
 202 typedef struct jmpenv JMPENV;
 203
 204 #ifdef OP_IN_REGISTER
 205 #define OP_REG_TO_MEM   PL_opsave = op
 206 #define OP_MEM_TO_REG   op = PL_opsave
 207 #else
 208 #define OP_REG_TO_MEM   NOOP
 209 #define OP_MEM_TO_REG   NOOP
 210 #endif
 211
 212 /*
 213  * How to build the first jmpenv.
 214  *
 215  * top_env needs to be non-zero. It points to an area
 216  * in which longjmp() stuff is stored, as C callstack
 217  * info there at least is thread specific this has to
 218  * be per-thread. Otherwise a 'die' in a thread gives
 219  * that thread the C stack of last thread to do an eval {}!
 220  */
 221
 222 #define JMPENV_BOOTSTRAP \
 223     STMT_START {                                \
 224         Zero(&PL_start_env, 1, JMPENV);         \
 225         PL_start_env.je_ret = -1;               \
 226         PL_start_env.je_mustcatch = TRUE;       \
 227         PL_top_env = &PL_start_env;             \
 228     } STMT_END
 229
 230 #ifdef PERL_FLEXIBLE_EXCEPTIONS
 231
 232 /*
 233  * These exception-handling macros are split up to
 234  * ease integration with C++ exceptions.
 235  *
 236  * To use C++ try+catch to catch Perl exceptions, an extension author
 237  * needs to first write an extern "C" function to throw an appropriate
 238  * exception object; typically it will be or contain an integer,
 239  * because Perl's internals use integers to track exception types:
 240  *    extern "C" { static void thrower(int i) { throw i; } }
 241  *
 242  * Then (as shown below) the author needs to use, not the simple
 243  * JMPENV_PUSH, but several of its constitutent macros, to arrange for
 244  * the Perl internals to call thrower() rather than longjmp() to
 245  * report exceptions:
 246  *
 247  *    dJMPENV;
 248  *    JMPENV_PUSH_INIT(thrower);
 249  *    try {
 250  *        ... stuff that may throw exceptions ...
 251  *    }
 252  *    catch (int why) {  // or whatever matches thrower()
 253  *        JMPENV_POST_CATCH;
 254  *        EXCEPT_SET(why);
 255  *        switch (why) {
 256  *          ... // handle various Perl exception codes
 257  *        }
 258  *    }
 259  *    JMPENV_POP;  // don't forget this!
 260  */
 261
 262 /*
 263  * Function that catches/throws, and its callback for the
 264  *  body of protected processing.
 265  */
 266 typedef void *(CPERLscope(*protect_body_t)) (pTHX_ va_list);
 267 typedef void *(CPERLscope(*protect_proc_t)) (pTHX_ volatile JMPENV *pcur_env,
 268                                              int *, protect_body_t, ...);
 269
 270 #define dJMPENV JMPENV cur_env; \
 271                 volatile JMPENV *pcur_env = ((cur_env.je_noset = 0),&cur_env)
 272
 273 #define JMPENV_PUSH_INIT_ENV(ce,THROWFUNC) \
 274     STMT_START {                                        \
 275         (ce).je_throw = (THROWFUNC);                    \
 276         (ce).je_ret = -1;                               \
 277         (ce).je_mustcatch = FALSE;                      \
 278         (ce).je_prev = PL_top_env;                      \
 279         PL_top_env = &(ce);                             \
 280         OP_REG_TO_MEM;                                  \
 281     } STMT_END
 282
 283 #define JMPENV_PUSH_INIT(THROWFUNC) JMPENV_PUSH_INIT_ENV(*(JMPENV*)pcur_env,THROWFUNC)
 284
 285 #define JMPENV_POST_CATCH_ENV(ce) \
 286     STMT_START {                                        \
 287         OP_MEM_TO_REG;                                  \
 288         PL_top_env = &(ce);                             \
 289     } STMT_END
 290
 291 #define JMPENV_POST_CATCH JMPENV_POST_CATCH_ENV(*(JMPENV*)pcur_env)
 292
 293 #define JMPENV_PUSH_ENV(ce,v) \
 294     STMT_START {                                                \
 295         if (!(ce).je_noset) {                                   \
 296             DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n", \
 297                              ce, PL_top_env));                  \
 298             JMPENV_PUSH_INIT_ENV(ce,NULL);                      \
 299             EXCEPT_SET_ENV(ce,PerlProc_setjmp((ce).je_buf, 1));\
 300             (ce).je_noset = 1;                                  \
 301         }                                                       \
 302         else                                                    \
 303             EXCEPT_SET_ENV(ce,0);                               \
 304         JMPENV_POST_CATCH_ENV(ce);                              \
 305         (v) = EXCEPT_GET_ENV(ce);                               \
 306     } STMT_END
 307
 308 #define JMPENV_PUSH(v) JMPENV_PUSH_ENV(*(JMPENV*)pcur_env,v)
 309
 310 #define JMPENV_POP_ENV(ce) \
 311     STMT_START {                                                \
 312         if (PL_top_env == &(ce))                                \
 313             PL_top_env = (ce).je_prev;                          \
 314     } STMT_END
 315
 316 #define JMPENV_POP  JMPENV_POP_ENV(*(JMPENV*)pcur_env)
 317
 318 #define JMPENV_JUMP(v) \
 319     STMT_START {                                                \
 320         OP_REG_TO_MEM;                                          \
 321         if (PL_top_env->je_prev) {                              \
 322             if (PL_top_env->je_throw)                           \
 323                 PL_top_env->je_throw(v);                        \
 324             else                                                \
 325                 PerlProc_longjmp(PL_top_env->je_buf, (v));      \
 326         }                                                       \
 327         if ((v) == 2)                                           \
 328             PerlProc_exit(STATUS_NATIVE_EXPORT);                \
 329         PerlIO_printf(Perl_error_log, "panic: top_env\n");      \
 330         PerlProc_exit(1);                                       \
 331     } STMT_END
 332
 333 #define EXCEPT_GET_ENV(ce)      ((ce).je_ret)
 334 #define EXCEPT_GET              EXCEPT_GET_ENV(*(JMPENV*)pcur_env)
 335 #define EXCEPT_SET_ENV(ce,v)    ((ce).je_ret = (v))
 336 #define EXCEPT_SET(v)           EXCEPT_SET_ENV(*(JMPENV*)pcur_env,v)
 337
 338 #else /* !PERL_FLEXIBLE_EXCEPTIONS */
 339
 340 #define dJMPENV         JMPENV cur_env
 341
 342 #define JMPENV_PUSH(v) \
 343     STMT_START {                                                        \
 344         DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n",     \
 345                          &cur_env, PL_top_env));                        \
 346         cur_env.je_prev = PL_top_env;                                   \
 347         OP_REG_TO_MEM;                                                  \
 348         cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, 1);            \
 349         OP_MEM_TO_REG;                                                  \
 350         PL_top_env = &cur_env;                                          \
 351         cur_env.je_mustcatch = FALSE;                                   \
 352         (v) = cur_env.je_ret;                                           \
 353     } STMT_END
 354
 355 #define JMPENV_POP \
 356     STMT_START { PL_top_env = cur_env.je_prev; } STMT_END
 357
 358 #define JMPENV_JUMP(v) \
 359     STMT_START {                                                \
 360         OP_REG_TO_MEM;                                          \
 361         if (PL_top_env->je_prev)                                \
 362             PerlProc_longjmp(PL_top_env->je_buf, (v));          \
 363         if ((v) == 2)                                           \
 364             PerlProc_exit(STATUS_NATIVE_EXPORT);                \
 365         PerlIO_printf(PerlIO_stderr(), "panic: top_env\n");     \
 366         PerlProc_exit(1);                                       \
 367     } STMT_END
 368
 369 #endif /* PERL_FLEXIBLE_EXCEPTIONS */
 370
 371 #define CATCH_GET               (PL_top_env->je_mustcatch)
 372 #define CATCH_SET(v)            (PL_top_env->je_mustcatch = (v))