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 #define SAVEt_MORTALIZESV       36
  38 #define SAVEt_SHARED_PVREF      37
  39
  40 #ifndef SCOPE_SAVES_SIGNAL_MASK
  41 #define SCOPE_SAVES_SIGNAL_MASK 0
  42 #endif
  43
  44 #define SSCHECK(need) if (PL_savestack_ix + need > PL_savestack_max) savestack_grow()
  45 #define SSPUSHINT(i) (PL_savestack[PL_savestack_ix++].any_i32 = (I32)(i))
  46 #define SSPUSHLONG(i) (PL_savestack[PL_savestack_ix++].any_long = (long)(i))
  47 #define SSPUSHIV(i) (PL_savestack[PL_savestack_ix++].any_iv = (IV)(i))
  48 #define SSPUSHPTR(p) (PL_savestack[PL_savestack_ix++].any_ptr = (void*)(p))
  49 #define SSPUSHDPTR(p) (PL_savestack[PL_savestack_ix++].any_dptr = (p))
  50 #define SSPUSHDXPTR(p) (PL_savestack[PL_savestack_ix++].any_dxptr = (p))
  51 #define SSPOPINT (PL_savestack[--PL_savestack_ix].any_i32)
  52 #define SSPOPLONG (PL_savestack[--PL_savestack_ix].any_long)
  53 #define SSPOPIV (PL_savestack[--PL_savestack_ix].any_iv)
  54 #define SSPOPPTR (PL_savestack[--PL_savestack_ix].any_ptr)
  55 #define SSPOPDPTR (PL_savestack[--PL_savestack_ix].any_dptr)
  56 #define SSPOPDXPTR (PL_savestack[--PL_savestack_ix].any_dxptr)
  57
  58 /*
  59 =head1 Callback Functions
  60
  61 =for apidoc Ams||SAVETMPS
  62 Opening bracket for temporaries on a callback.  See C<FREETMPS> and
  63 L<perlcall>.
  64
  65 =for apidoc Ams||FREETMPS
  66 Closing bracket for temporaries on a callback.  See C<SAVETMPS> and
  67 L<perlcall>.
  68
  69 =for apidoc Ams||ENTER
  70 Opening bracket on a callback.  See C<LEAVE> and L<perlcall>.
  71
  72 =for apidoc Ams||LEAVE
  73 Closing bracket on a callback.  See C<ENTER> and L<perlcall>.
  74
  75 =cut
  76 */
  77
  78 #define SAVETMPS save_int((int*)&PL_tmps_floor), PL_tmps_floor = PL_tmps_ix
  79 #define FREETMPS if (PL_tmps_ix > PL_tmps_floor) free_tmps()
  80
  81 #ifdef DEBUGGING
  82 #define ENTER                                                   \
  83     STMT_START {                                                \
  84         push_scope();                                           \
  85         DEBUG_l(WITH_THR(Perl_deb(aTHX_ "ENTER scope %ld at %s:%d\n",   \
  86                     PL_scopestack_ix, __FILE__, __LINE__)));    \
  87     } STMT_END
  88 #define LEAVE                                                   \
  89     STMT_START {                                                \
  90         DEBUG_l(WITH_THR(Perl_deb(aTHX_ "LEAVE scope %ld at %s:%d\n",   \
  91                     PL_scopestack_ix, __FILE__, __LINE__)));    \
  92         pop_scope();                                            \
  93     } STMT_END
  94 #else
  95 #define ENTER push_scope()
  96 #define LEAVE pop_scope()
  97 #endif
  98 #define LEAVE_SCOPE(old) if (PL_savestack_ix > old) leave_scope(old)
  99
 100 /*
 101  * Not using SOFT_CAST on SAVESPTR, SAVEGENERICSV and SAVEFREESV
 102  * because these are used for several kinds of pointer values
 103  */
 104 #define SAVEI8(i)       save_I8(SOFT_CAST(I8*)&(i))
 105 #define SAVEI16(i)      save_I16(SOFT_CAST(I16*)&(i))
 106 #define SAVEI32(i)      save_I32(SOFT_CAST(I32*)&(i))
 107 #define SAVEINT(i)      save_int(SOFT_CAST(int*)&(i))
 108 #define SAVEIV(i)       save_iv(SOFT_CAST(IV*)&(i))
 109 #define SAVELONG(l)     save_long(SOFT_CAST(long*)&(l))
 110 #define SAVESPTR(s)     save_sptr((SV**)&(s))
 111 #define SAVEPPTR(s)     save_pptr(SOFT_CAST(char**)&(s))
 112 #define SAVEVPTR(s)     save_vptr((void*)&(s))
 113 #define SAVEPADSV(s)    save_padsv(s)
 114 #define SAVEFREESV(s)   save_freesv((SV*)(s))
 115 #define SAVEMORTALIZESV(s)      save_mortalizesv((SV*)(s))
 116 #define SAVEFREEOP(o)   save_freeop(SOFT_CAST(OP*)(o))
 117 #define SAVEFREEPV(p)   save_freepv(SOFT_CAST(char*)(p))
 118 #define SAVECLEARSV(sv) save_clearsv(SOFT_CAST(SV**)&(sv))
 119 #define SAVEGENERICSV(s)        save_generic_svref((SV**)&(s))
 120 #define SAVEGENERICPV(s)        save_generic_pvref((char**)&(s))
 121 #define SAVESHAREDPV(s)         save_shared_pvref((char**)&(s))
 122 #define SAVEDELETE(h,k,l) \
 123           save_delete(SOFT_CAST(HV*)(h), SOFT_CAST(char*)(k), (I32)(l))
 124 #define SAVEDESTRUCTOR(f,p) \
 125           save_destructor((DESTRUCTORFUNC_NOCONTEXT_t)(f), SOFT_CAST(void*)(p))
 126
 127 #define SAVEDESTRUCTOR_X(f,p) \
 128           save_destructor_x((DESTRUCTORFUNC_t)(f), SOFT_CAST(void*)(p))
 129
 130 #define SAVESTACK_POS() \
 131     STMT_START {                                \
 132         SSCHECK(2);                             \
 133         SSPUSHINT(PL_stack_sp - PL_stack_base); \
 134         SSPUSHINT(SAVEt_STACK_POS);             \
 135     } STMT_END
 136
 137 #define SAVEOP()        save_op()
 138
 139 #define SAVEHINTS() \
 140     STMT_START {                                \
 141         if (PL_hints & HINT_LOCALIZE_HH)        \
 142             save_hints();                       \
 143         else {                                  \
 144             SSCHECK(2);                         \
 145             SSPUSHINT(PL_hints);                \
 146             SSPUSHINT(SAVEt_HINTS);             \
 147         }                                       \
 148     } STMT_END
 149
 150 #define SAVECOMPPAD() \
 151     STMT_START {                                                \
 152         if (PL_comppad && PL_curpad == AvARRAY(PL_comppad)) {   \
 153             SSCHECK(2);                                         \
 154             SSPUSHPTR((SV*)PL_comppad);                         \
 155             SSPUSHINT(SAVEt_COMPPAD);                           \
 156         }                                                       \
 157         else {                                                  \
 158             SAVEVPTR(PL_curpad);                                \
 159             SAVESPTR(PL_comppad);                               \
 160         }                                                       \
 161     } STMT_END
 162
 163 #ifdef USE_ITHREADS
 164 #  define SAVECOPSTASH(c)       SAVEPPTR(CopSTASHPV(c))
 165 #  define SAVECOPSTASH_FREE(c)  SAVESHAREDPV(CopSTASHPV(c))
 166 #  define SAVECOPFILE(c)        SAVEPPTR(CopFILE(c))
 167 #  define SAVECOPFILE_FREE(c)   SAVESHAREDPV(CopFILE(c))
 168 #else
 169 #  define SAVECOPSTASH(c)       SAVESPTR(CopSTASH(c))
 170 #  define SAVECOPSTASH_FREE(c)  SAVECOPSTASH(c) /* XXX not refcounted */
 171 #  define SAVECOPFILE(c)        SAVESPTR(CopFILEGV(c))
 172 #  define SAVECOPFILE_FREE(c)   SAVEGENERICSV(CopFILEGV(c))
 173 #endif
 174
 175 #define SAVECOPLINE(c)          SAVEI16(CopLINE(c))
 176
 177 /* SSNEW() temporarily allocates a specified number of bytes of data on the
 178  * savestack.  It returns an integer index into the savestack, because a
 179  * pointer would get broken if the savestack is moved on reallocation.
 180  * SSNEWa() works like SSNEW(), but also aligns the data to the specified
 181  * number of bytes.  MEM_ALIGNBYTES is perhaps the most useful.  The
 182  * alignment will be preserved therough savestack reallocation *only* if
 183  * realloc returns data aligned to a size divisible by `align'!
 184  *
 185  * SSPTR() converts the index returned by SSNEW/SSNEWa() into a pointer.
 186  */
 187
 188 #define SSNEW(size)             Perl_save_alloc(aTHX_ (size), 0)
 189 #define SSNEWt(n,t)             SSNEW((n)*sizeof(t))
 190 #define SSNEWa(size,align)      Perl_save_alloc(aTHX_ (size), \
 191     (align - ((int)((caddr_t)&PL_savestack[PL_savestack_ix]) % align)) % align)
 192 #define SSNEWat(n,t,align)      SSNEWa((n)*sizeof(t), align)
 193
 194 #define SSPTR(off,type)         ((type)  ((char*)PL_savestack + off))
 195 #define SSPTRt(off,type)        ((type*) ((char*)PL_savestack + off))
 196
 197 /* A jmpenv packages the state required to perform a proper non-local jump.
 198  * Note that there is a start_env initialized when perl starts, and top_env
 199  * points to this initially, so top_env should always be non-null.
 200  *
 201  * Existence of a non-null top_env->je_prev implies it is valid to call
 202  * longjmp() at that runlevel (we make sure start_env.je_prev is always
 203  * null to ensure this).
 204  *
 205  * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
 206  * establish a local jmpenv to handle exception traps.  Care must be taken
 207  * to restore the previous value of je_mustcatch before exiting the
 208  * stack frame iff JMPENV_PUSH was not called in that stack frame.
 209  * GSAR 97-03-27
 210  */
 211
 212 struct jmpenv {
 213     struct jmpenv *     je_prev;
 214     Sigjmp_buf          je_buf;         /* only for use if !je_throw */
 215     int                 je_ret;         /* last exception thrown */
 216     bool                je_mustcatch;   /* need to call longjmp()? */
 217 #ifdef PERL_FLEXIBLE_EXCEPTIONS
 218     void                (*je_throw)(int v); /* last for bincompat */
 219     bool                je_noset;       /* no need for setjmp() */
 220 #endif
 221 };
 222
 223 typedef struct jmpenv JMPENV;
 224
 225 #ifdef OP_IN_REGISTER
 226 #define OP_REG_TO_MEM   PL_opsave = op
 227 #define OP_MEM_TO_REG   op = PL_opsave
 228 #else
 229 #define OP_REG_TO_MEM   NOOP
 230 #define OP_MEM_TO_REG   NOOP
 231 #endif
 232
 233 /*
 234  * How to build the first jmpenv.
 235  *
 236  * top_env needs to be non-zero. It points to an area
 237  * in which longjmp() stuff is stored, as C callstack
 238  * info there at least is thread specific this has to
 239  * be per-thread. Otherwise a 'die' in a thread gives
 240  * that thread the C stack of last thread to do an eval {}!
 241  */
 242
 243 #define JMPENV_BOOTSTRAP \
 244     STMT_START {                                \
 245         Zero(&PL_start_env, 1, JMPENV);         \
 246         PL_start_env.je_ret = -1;               \
 247         PL_start_env.je_mustcatch = TRUE;       \
 248         PL_top_env = &PL_start_env;             \
 249     } STMT_END
 250
 251 #ifdef PERL_FLEXIBLE_EXCEPTIONS
 252
 253 /*
 254  * These exception-handling macros are split up to
 255  * ease integration with C++ exceptions.
 256  *
 257  * To use C++ try+catch to catch Perl exceptions, an extension author
 258  * needs to first write an extern "C" function to throw an appropriate
 259  * exception object; typically it will be or contain an integer,
 260  * because Perl's internals use integers to track exception types:
 261  *    extern "C" { static void thrower(int i) { throw i; } }
 262  *
 263  * Then (as shown below) the author needs to use, not the simple
 264  * JMPENV_PUSH, but several of its constitutent macros, to arrange for
 265  * the Perl internals to call thrower() rather than longjmp() to
 266  * report exceptions:
 267  *
 268  *    dJMPENV;
 269  *    JMPENV_PUSH_INIT(thrower);
 270  *    try {
 271  *        ... stuff that may throw exceptions ...
 272  *    }
 273  *    catch (int why) {  // or whatever matches thrower()
 274  *        JMPENV_POST_CATCH;
 275  *        EXCEPT_SET(why);
 276  *        switch (why) {
 277  *          ... // handle various Perl exception codes
 278  *        }
 279  *    }
 280  *    JMPENV_POP;  // don't forget this!
 281  */
 282
 283 /*
 284  * Function that catches/throws, and its callback for the
 285  *  body of protected processing.
 286  */
 287 typedef void *(CPERLscope(*protect_body_t)) (pTHX_ va_list);
 288 typedef void *(CPERLscope(*protect_proc_t)) (pTHX_ volatile JMPENV *pcur_env,
 289                                              int *, protect_body_t, ...);
 290
 291 #define dJMPENV JMPENV cur_env; \
 292                 volatile JMPENV *pcur_env = ((cur_env.je_noset = 0),&cur_env)
 293
 294 #define JMPENV_PUSH_INIT_ENV(ce,THROWFUNC) \
 295     STMT_START {                                        \
 296         (ce).je_throw = (THROWFUNC);                    \
 297         (ce).je_ret = -1;                               \
 298         (ce).je_mustcatch = FALSE;                      \
 299         (ce).je_prev = PL_top_env;                      \
 300         PL_top_env = &(ce);                             \
 301         OP_REG_TO_MEM;                                  \
 302     } STMT_END
 303
 304 #define JMPENV_PUSH_INIT(THROWFUNC) JMPENV_PUSH_INIT_ENV(*(JMPENV*)pcur_env,THROWFUNC)
 305
 306 #define JMPENV_POST_CATCH_ENV(ce) \
 307     STMT_START {                                        \
 308         OP_MEM_TO_REG;                                  \
 309         PL_top_env = &(ce);                             \
 310     } STMT_END
 311
 312 #define JMPENV_POST_CATCH JMPENV_POST_CATCH_ENV(*(JMPENV*)pcur_env)
 313
 314 #define JMPENV_PUSH_ENV(ce,v) \
 315     STMT_START {                                                \
 316         if (!(ce).je_noset) {                                   \
 317             DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n", \
 318                              ce, PL_top_env));                  \
 319             JMPENV_PUSH_INIT_ENV(ce,NULL);                      \
 320             EXCEPT_SET_ENV(ce,PerlProc_setjmp((ce).je_buf, SCOPE_SAVES_SIGNAL_MASK));\
 321             (ce).je_noset = 1;                                  \
 322         }                                                       \
 323         else                                                    \
 324             EXCEPT_SET_ENV(ce,0);                               \
 325         JMPENV_POST_CATCH_ENV(ce);                              \
 326         (v) = EXCEPT_GET_ENV(ce);                               \
 327     } STMT_END
 328
 329 #define JMPENV_PUSH(v) JMPENV_PUSH_ENV(*(JMPENV*)pcur_env,v)
 330
 331 #define JMPENV_POP_ENV(ce) \
 332     STMT_START {                                                \
 333         if (PL_top_env == &(ce))                                \
 334             PL_top_env = (ce).je_prev;                          \
 335     } STMT_END
 336
 337 #define JMPENV_POP  JMPENV_POP_ENV(*(JMPENV*)pcur_env)
 338
 339 #define JMPENV_JUMP(v) \
 340     STMT_START {                                                \
 341         OP_REG_TO_MEM;                                          \
 342         if (PL_top_env->je_prev) {                              \
 343             if (PL_top_env->je_throw)                           \
 344                 PL_top_env->je_throw(v);                        \
 345             else                                                \
 346                 PerlProc_longjmp(PL_top_env->je_buf, (v));      \
 347         }                                                       \
 348         if ((v) == 2)                                           \
 349             PerlProc_exit(STATUS_NATIVE_EXPORT);                \
 350         PerlIO_printf(Perl_error_log, "panic: top_env\n");      \
 351         PerlProc_exit(1);                                       \
 352     } STMT_END
 353
 354 #define EXCEPT_GET_ENV(ce)      ((ce).je_ret)
 355 #define EXCEPT_GET              EXCEPT_GET_ENV(*(JMPENV*)pcur_env)
 356 #define EXCEPT_SET_ENV(ce,v)    ((ce).je_ret = (v))
 357 #define EXCEPT_SET(v)           EXCEPT_SET_ENV(*(JMPENV*)pcur_env,v)
 358
 359 #else /* !PERL_FLEXIBLE_EXCEPTIONS */
 360
 361 #define dJMPENV         JMPENV cur_env
 362
 363 #define JMPENV_PUSH(v) \
 364     STMT_START {                                                        \
 365         DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n",     \
 366                          &cur_env, PL_top_env));                        \
 367         cur_env.je_prev = PL_top_env;                                   \
 368         OP_REG_TO_MEM;                                                  \
 369         cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);              \
 370         OP_MEM_TO_REG;                                                  \
 371         PL_top_env = &cur_env;                                          \
 372         cur_env.je_mustcatch = FALSE;                                   \
 373         (v) = cur_env.je_ret;                                           \
 374     } STMT_END
 375
 376 #define JMPENV_POP \
 377     STMT_START { PL_top_env = cur_env.je_prev; } STMT_END
 378
 379 #define JMPENV_JUMP(v) \
 380     STMT_START {                                                \
 381         OP_REG_TO_MEM;                                          \
 382         if (PL_top_env->je_prev)                                \
 383             PerlProc_longjmp(PL_top_env->je_buf, (v));          \
 384         if ((v) == 2)                                           \
 385             PerlProc_exit(STATUS_NATIVE_EXPORT);                \
 386         PerlIO_printf(PerlIO_stderr(), "panic: top_env\n");     \
 387         PerlProc_exit(1);                                       \
 388     } STMT_END
 389
 390 #endif /* PERL_FLEXIBLE_EXCEPTIONS */
 391
 392 #define CATCH_GET               (PL_top_env->je_mustcatch)
 393 #define CATCH_SET(v)            (PL_top_env->je_mustcatch = (v))