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 #define SAVEt_GENERIC_PVREF     34
  36 #define SAVEt_PADSV             35
  37
  38 #ifndef SCOPE_SAVES_SIGNAL_MASK
  39 #define SCOPE_SAVES_SIGNAL_MASK 0
  40 #endif
  41
  42 #define SSCHECK(need) if (PL_savestack_ix + need > PL_savestack_max) savestack_grow()
  43 #define SSPUSHINT(i) (PL_savestack[PL_savestack_ix++].any_i32 = (I32)(i))
  44 #define SSPUSHLONG(i) (PL_savestack[PL_savestack_ix++].any_long = (long)(i))
  45 #define SSPUSHIV(i) (PL_savestack[PL_savestack_ix++].any_iv = (IV)(i))
  46 #define SSPUSHPTR(p) (PL_savestack[PL_savestack_ix++].any_ptr = (void*)(p))
  47 #define SSPUSHDPTR(p) (PL_savestack[PL_savestack_ix++].any_dptr = (p))
  48 #define SSPUSHDXPTR(p) (PL_savestack[PL_savestack_ix++].any_dxptr = (p))
  49 #define SSPOPINT (PL_savestack[--PL_savestack_ix].any_i32)
  50 #define SSPOPLONG (PL_savestack[--PL_savestack_ix].any_long)
  51 #define SSPOPIV (PL_savestack[--PL_savestack_ix].any_iv)
  52 #define SSPOPPTR (PL_savestack[--PL_savestack_ix].any_ptr)
  53 #define SSPOPDPTR (PL_savestack[--PL_savestack_ix].any_dptr)
  54 #define SSPOPDXPTR (PL_savestack[--PL_savestack_ix].any_dxptr)
  55
  56 /*
  57 =for apidoc Ams||SAVETMPS
  58 Opening bracket for temporaries on a callback.  See C<FREETMPS> and
  59 L<perlcall>.
  60
  61 =for apidoc Ams||FREETMPS
  62 Closing bracket for temporaries on a callback.  See C<SAVETMPS> and
  63 L<perlcall>.
  64
  65 =for apidoc Ams||ENTER
  66 Opening bracket on a callback.  See C<LEAVE> and L<perlcall>.
  67
  68 =for apidoc Ams||LEAVE
  69 Closing bracket on a callback.  See C<ENTER> and L<perlcall>.
  70
  71 =cut
  72 */
  73
  74 #define SAVETMPS save_int((int*)&PL_tmps_floor), PL_tmps_floor = PL_tmps_ix
  75 #define FREETMPS if (PL_tmps_ix > PL_tmps_floor) free_tmps()
  76
  77 #ifdef DEBUGGING
  78 #define ENTER                                                   \
  79     STMT_START {                                                \
  80         push_scope();                                           \
  81         DEBUG_l(WITH_THR(Perl_deb(aTHX_ "ENTER scope %ld at %s:%d\n",   \
  82                     PL_scopestack_ix, __FILE__, __LINE__)));    \
  83     } STMT_END
  84 #define LEAVE                                                   \
  85     STMT_START {                                                \
  86         DEBUG_l(WITH_THR(Perl_deb(aTHX_ "LEAVE scope %ld at %s:%d\n",   \
  87                     PL_scopestack_ix, __FILE__, __LINE__)));    \
  88         pop_scope();                                            \
  89     } STMT_END
  90 #else
  91 #define ENTER push_scope()
  92 #define LEAVE pop_scope()
  93 #endif
  94 #define LEAVE_SCOPE(old) if (PL_savestack_ix > old) leave_scope(old)
  95
  96 /*
  97  * Not using SOFT_CAST on SAVESPTR, SAVEGENERICSV and SAVEFREESV
  98  * because these are used for several kinds of pointer values
  99  */
 100 #define SAVEI8(i)       save_I8(SOFT_CAST(I8*)&(i))
 101 #define SAVEI16(i)      save_I16(SOFT_CAST(I16*)&(i))
 102 #define SAVEI32(i)      save_I32(SOFT_CAST(I32*)&(i))
 103 #define SAVEINT(i)      save_int(SOFT_CAST(int*)&(i))
 104 #define SAVEIV(i)       save_iv(SOFT_CAST(IV*)&(i))
 105 #define SAVELONG(l)     save_long(SOFT_CAST(long*)&(l))
 106 #define SAVESPTR(s)     save_sptr((SV**)&(s))
 107 #define SAVEPPTR(s)     save_pptr(SOFT_CAST(char**)&(s))
 108 #define SAVEVPTR(s)     save_vptr((void*)&(s))
 109 #define SAVEPADSV(s)    save_padsv(s)
 110 #define SAVEFREESV(s)   save_freesv((SV*)(s))
 111 #define SAVEFREEOP(o)   save_freeop(SOFT_CAST(OP*)(o))
 112 #define SAVEFREEPV(p)   save_freepv(SOFT_CAST(char*)(p))
 113 #define SAVECLEARSV(sv) save_clearsv(SOFT_CAST(SV**)&(sv))
 114 #define SAVEGENERICSV(s)        save_generic_svref((SV**)&(s))
 115 #define SAVEGENERICPV(s)        save_generic_pvref((char**)&(s))
 116 #define SAVEDELETE(h,k,l) \
 117           save_delete(SOFT_CAST(HV*)(h), SOFT_CAST(char*)(k), (I32)(l))
 118 #define SAVEDESTRUCTOR(f,p) \
 119           save_destructor((DESTRUCTORFUNC_NOCONTEXT_t)(f), SOFT_CAST(void*)(p))
 120
 121 #define SAVEDESTRUCTOR_X(f,p) \
 122           save_destructor_x((DESTRUCTORFUNC_t)(f), SOFT_CAST(void*)(p))
 123
 124 #define SAVESTACK_POS() \
 125     STMT_START {                                \
 126         SSCHECK(2);                             \
 127         SSPUSHINT(PL_stack_sp - PL_stack_base); \
 128         SSPUSHINT(SAVEt_STACK_POS);             \
 129     } STMT_END
 130
 131 #define SAVEOP()        save_op()
 132
 133 #define SAVEHINTS() \
 134     STMT_START {                                \
 135         if (PL_hints & HINT_LOCALIZE_HH)        \
 136             save_hints();                       \
 137         else {                                  \
 138             SSCHECK(2);                         \
 139             SSPUSHINT(PL_hints);                \
 140             SSPUSHINT(SAVEt_HINTS);             \
 141         }                                       \
 142     } STMT_END
 143
 144 #define SAVECOMPPAD() \
 145     STMT_START {                                                \
 146         if (PL_comppad && PL_curpad == AvARRAY(PL_comppad)) {   \
 147             SSCHECK(2);                                         \
 148             SSPUSHPTR((SV*)PL_comppad);                         \
 149             SSPUSHINT(SAVEt_COMPPAD);                           \
 150         }                                                       \
 151         else {                                                  \
 152             SAVEVPTR(PL_curpad);                                \
 153             SAVESPTR(PL_comppad);                               \
 154         }                                                       \
 155     } STMT_END
 156
 157 #ifdef USE_ITHREADS
 158 #  define SAVECOPSTASH(c)       SAVEPPTR(CopSTASHPV(c))
 159 #  define SAVECOPSTASH_FREE(c)  SAVEGENERICPV(CopSTASHPV(c))
 160 #  define SAVECOPFILE(c)        SAVEPPTR(CopFILE(c))
 161 #  define SAVECOPFILE_FREE(c)   SAVEGENERICPV(CopFILE(c))
 162 #else
 163 #  define SAVECOPSTASH(c)       SAVESPTR(CopSTASH(c))
 164 #  define SAVECOPSTASH_FREE(c)  SAVECOPSTASH(c) /* XXX not refcounted */
 165 #  define SAVECOPFILE(c)        SAVESPTR(CopFILEGV(c))
 166 #  define SAVECOPFILE_FREE(c)   SAVEGENERICSV(CopFILEGV(c))
 167 #endif
 168
 169 #define SAVECOPLINE(c)          SAVEI16(CopLINE(c))
 170
 171 /* SSNEW() temporarily allocates a specified number of bytes of data on the
 172  * savestack.  It returns an integer index into the savestack, because a
 173  * pointer would get broken if the savestack is moved on reallocation.
 174  * SSNEWa() works like SSNEW(), but also aligns the data to the specified
 175  * number of bytes.  MEM_ALIGNBYTES is perhaps the most useful.  The
 176  * alignment will be preserved therough savestack reallocation *only* if
 177  * realloc returns data aligned to a size divisible by `align'!
 178  *
 179  * SSPTR() converts the index returned by SSNEW/SSNEWa() into a pointer.
 180  */
 181
 182 #define SSNEW(size)             Perl_save_alloc(aTHX_ (size), 0)
 183 #define SSNEWt(n,t)             SSNEW((n)*sizeof(t))
 184 #define SSNEWa(size,align)      Perl_save_alloc(aTHX_ (size), \
 185     (align - ((int)((caddr_t)&PL_savestack[PL_savestack_ix]) % align)) % align)
 186 #define SSNEWat(n,t,align)      SSNEWa((n)*sizeof(t), align)
 187
 188 #define SSPTR(off,type)         ((type)  ((char*)PL_savestack + off))
 189 #define SSPTRt(off,type)        ((type*) ((char*)PL_savestack + off))
 190
 191 /* A jmpenv packages the state required to perform a proper non-local jump.
 192  * Note that there is a start_env initialized when perl starts, and top_env
 193  * points to this initially, so top_env should always be non-null.
 194  *
 195  * Existence of a non-null top_env->je_prev implies it is valid to call
 196  * longjmp() at that runlevel (we make sure start_env.je_prev is always
 197  * null to ensure this).
 198  *
 199  * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
 200  * establish a local jmpenv to handle exception traps.  Care must be taken
 201  * to restore the previous value of je_mustcatch before exiting the
 202  * stack frame iff JMPENV_PUSH was not called in that stack frame.
 203  * GSAR 97-03-27
 204  */
 205
 206 struct jmpenv {
 207     struct jmpenv *     je_prev;
 208     Sigjmp_buf          je_buf;         /* only for use if !je_throw */
 209     int                 je_ret;         /* last exception thrown */
 210     bool                je_mustcatch;   /* need to call longjmp()? */
 211 #ifdef PERL_FLEXIBLE_EXCEPTIONS
 212     void                (*je_throw)(int v); /* last for bincompat */
 213     bool                je_noset;       /* no need for setjmp() */
 214 #endif
 215 };
 216
 217 typedef struct jmpenv JMPENV;
 218
 219 #ifdef OP_IN_REGISTER
 220 #define OP_REG_TO_MEM   PL_opsave = op
 221 #define OP_MEM_TO_REG   op = PL_opsave
 222 #else
 223 #define OP_REG_TO_MEM   NOOP
 224 #define OP_MEM_TO_REG   NOOP
 225 #endif
 226
 227 /*
 228  * How to build the first jmpenv.
 229  *
 230  * top_env needs to be non-zero. It points to an area
 231  * in which longjmp() stuff is stored, as C callstack
 232  * info there at least is thread specific this has to
 233  * be per-thread. Otherwise a 'die' in a thread gives
 234  * that thread the C stack of last thread to do an eval {}!
 235  */
 236
 237 #define JMPENV_BOOTSTRAP \
 238     STMT_START {                                \
 239         Zero(&PL_start_env, 1, JMPENV);         \
 240         PL_start_env.je_ret = -1;               \
 241         PL_start_env.je_mustcatch = TRUE;       \
 242         PL_top_env = &PL_start_env;             \
 243     } STMT_END
 244
 245 #ifdef PERL_FLEXIBLE_EXCEPTIONS
 246
 247 /*
 248  * These exception-handling macros are split up to
 249  * ease integration with C++ exceptions.
 250  *
 251  * To use C++ try+catch to catch Perl exceptions, an extension author
 252  * needs to first write an extern "C" function to throw an appropriate
 253  * exception object; typically it will be or contain an integer,
 254  * because Perl's internals use integers to track exception types:
 255  *    extern "C" { static void thrower(int i) { throw i; } }
 256  *
 257  * Then (as shown below) the author needs to use, not the simple
 258  * JMPENV_PUSH, but several of its constitutent macros, to arrange for
 259  * the Perl internals to call thrower() rather than longjmp() to
 260  * report exceptions:
 261  *
 262  *    dJMPENV;
 263  *    JMPENV_PUSH_INIT(thrower);
 264  *    try {
 265  *        ... stuff that may throw exceptions ...
 266  *    }
 267  *    catch (int why) {  // or whatever matches thrower()
 268  *        JMPENV_POST_CATCH;
 269  *        EXCEPT_SET(why);
 270  *        switch (why) {
 271  *          ... // handle various Perl exception codes
 272  *        }
 273  *    }
 274  *    JMPENV_POP;  // don't forget this!
 275  */
 276
 277 /*
 278  * Function that catches/throws, and its callback for the
 279  *  body of protected processing.
 280  */
 281 typedef void *(CPERLscope(*protect_body_t)) (pTHX_ va_list);
 282 typedef void *(CPERLscope(*protect_proc_t)) (pTHX_ volatile JMPENV *pcur_env,
 283                                              int *, protect_body_t, ...);
 284
 285 #define dJMPENV JMPENV cur_env; \
 286                 volatile JMPENV *pcur_env = ((cur_env.je_noset = 0),&cur_env)
 287
 288 #define JMPENV_PUSH_INIT_ENV(ce,THROWFUNC) \
 289     STMT_START {                                        \
 290         (ce).je_throw = (THROWFUNC);                    \
 291         (ce).je_ret = -1;                               \
 292         (ce).je_mustcatch = FALSE;                      \
 293         (ce).je_prev = PL_top_env;                      \
 294         PL_top_env = &(ce);                             \
 295         OP_REG_TO_MEM;                                  \
 296     } STMT_END
 297
 298 #define JMPENV_PUSH_INIT(THROWFUNC) JMPENV_PUSH_INIT_ENV(*(JMPENV*)pcur_env,THROWFUNC)
 299
 300 #define JMPENV_POST_CATCH_ENV(ce) \
 301     STMT_START {                                        \
 302         OP_MEM_TO_REG;                                  \
 303         PL_top_env = &(ce);                             \
 304     } STMT_END
 305
 306 #define JMPENV_POST_CATCH JMPENV_POST_CATCH_ENV(*(JMPENV*)pcur_env)
 307
 308 #define JMPENV_PUSH_ENV(ce,v) \
 309     STMT_START {                                                \
 310         if (!(ce).je_noset) {                                   \
 311             DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n", \
 312                              ce, PL_top_env));                  \
 313             JMPENV_PUSH_INIT_ENV(ce,NULL);                      \
 314             EXCEPT_SET_ENV(ce,PerlProc_setjmp((ce).je_buf, SCOPE_SAVES_SIGNAL_MASK));\
 315             (ce).je_noset = 1;                                  \
 316         }                                                       \
 317         else                                                    \
 318             EXCEPT_SET_ENV(ce,0);                               \
 319         JMPENV_POST_CATCH_ENV(ce);                              \
 320         (v) = EXCEPT_GET_ENV(ce);                               \
 321     } STMT_END
 322
 323 #define JMPENV_PUSH(v) JMPENV_PUSH_ENV(*(JMPENV*)pcur_env,v)
 324
 325 #define JMPENV_POP_ENV(ce) \
 326     STMT_START {                                                \
 327         if (PL_top_env == &(ce))                                \
 328             PL_top_env = (ce).je_prev;                          \
 329     } STMT_END
 330
 331 #define JMPENV_POP  JMPENV_POP_ENV(*(JMPENV*)pcur_env)
 332
 333 #define JMPENV_JUMP(v) \
 334     STMT_START {                                                \
 335         OP_REG_TO_MEM;                                          \
 336         if (PL_top_env->je_prev) {                              \
 337             if (PL_top_env->je_throw)                           \
 338                 PL_top_env->je_throw(v);                        \
 339             else                                                \
 340                 PerlProc_longjmp(PL_top_env->je_buf, (v));      \
 341         }                                                       \
 342         if ((v) == 2)                                           \
 343             PerlProc_exit(STATUS_NATIVE_EXPORT);                \
 344         PerlIO_printf(Perl_error_log, "panic: top_env\n");      \
 345         PerlProc_exit(1);                                       \
 346     } STMT_END
 347
 348 #define EXCEPT_GET_ENV(ce)      ((ce).je_ret)
 349 #define EXCEPT_GET              EXCEPT_GET_ENV(*(JMPENV*)pcur_env)
 350 #define EXCEPT_SET_ENV(ce,v)    ((ce).je_ret = (v))
 351 #define EXCEPT_SET(v)           EXCEPT_SET_ENV(*(JMPENV*)pcur_env,v)
 352
 353 #else /* !PERL_FLEXIBLE_EXCEPTIONS */
 354
 355 #define dJMPENV         JMPENV cur_env
 356
 357 #define JMPENV_PUSH(v) \
 358     STMT_START {                                                        \
 359         DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n",     \
 360                          &cur_env, PL_top_env));                        \
 361         cur_env.je_prev = PL_top_env;                                   \
 362         OP_REG_TO_MEM;                                                  \
 363         cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);              \
 364         OP_MEM_TO_REG;                                                  \
 365         PL_top_env = &cur_env;                                          \
 366         cur_env.je_mustcatch = FALSE;                                   \
 367         (v) = cur_env.je_ret;                                           \
 368     } STMT_END
 369
 370 #define JMPENV_POP \
 371     STMT_START { PL_top_env = cur_env.je_prev; } STMT_END
 372
 373 #define JMPENV_JUMP(v) \
 374     STMT_START {                                                \
 375         OP_REG_TO_MEM;                                          \
 376         if (PL_top_env->je_prev)                                \
 377             PerlProc_longjmp(PL_top_env->je_buf, (v));          \
 378         if ((v) == 2)                                           \
 379             PerlProc_exit(STATUS_NATIVE_EXPORT);                \
 380         PerlIO_printf(PerlIO_stderr(), "panic: top_env\n");     \
 381         PerlProc_exit(1);                                       \
 382     } STMT_END
 383
 384 #endif /* PERL_FLEXIBLE_EXCEPTIONS */
 385
 386 #define CATCH_GET               (PL_top_env->je_mustcatch)
 387 #define CATCH_SET(v)            (PL_top_env->je_mustcatch = (v))