This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
Abstract all the accesses to cop_arybase (apart from ByteLoader)
[perl5.git] / cop.h
diff --git a/cop.h b/cop.h
index 5b47884..da9fd5b 100644 (file)
--- a/cop.h
+++ b/cop.h
 /*    cop.h
  *
- *    Copyright (c) 1991-2000, Larry Wall
+ *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
+ *    2000, 2001, 2002, 2003, 2004, 2005, 2006 by Larry Wall and others
  *
  *    You may distribute under the terms of either the GNU General Public
  *    License or the Artistic License, as specified in the README file.
  *
+ * Control ops (cops) are one of the three ops OP_NEXTSTATE, OP_DBSTATE,
+ * and OP_SETSTATE that (loosely speaking) are separate statements.
+ * They hold information important for lexical state and error reporting.
+ * At run time, PL_curcop is set to point to the most recently executed cop,
+ * and thus can be used to determine our current state.
  */
 
+/* A jmpenv packages the state required to perform a proper non-local jump.
+ * Note that there is a start_env initialized when perl starts, and top_env
+ * points to this initially, so top_env should always be non-null.
+ *
+ * Existence of a non-null top_env->je_prev implies it is valid to call
+ * longjmp() at that runlevel (we make sure start_env.je_prev is always
+ * null to ensure this).
+ *
+ * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
+ * establish a local jmpenv to handle exception traps.  Care must be taken
+ * to restore the previous value of je_mustcatch before exiting the
+ * stack frame iff JMPENV_PUSH was not called in that stack frame.
+ * GSAR 97-03-27
+ */
+
+struct jmpenv {
+    struct jmpenv *    je_prev;
+    Sigjmp_buf         je_buf;         /* only for use if !je_throw */
+    int                        je_ret;         /* last exception thrown */
+    bool               je_mustcatch;   /* need to call longjmp()? */
+};
+
+typedef struct jmpenv JMPENV;
+
+#ifdef OP_IN_REGISTER
+#define OP_REG_TO_MEM  PL_opsave = op
+#define OP_MEM_TO_REG  op = PL_opsave
+#else
+#define OP_REG_TO_MEM  NOOP
+#define OP_MEM_TO_REG  NOOP
+#endif
+
+/*
+ * How to build the first jmpenv.
+ *
+ * top_env needs to be non-zero. It points to an area
+ * in which longjmp() stuff is stored, as C callstack
+ * info there at least is thread specific this has to
+ * be per-thread. Otherwise a 'die' in a thread gives
+ * that thread the C stack of last thread to do an eval {}!
+ */
+
+#define JMPENV_BOOTSTRAP \
+    STMT_START {                               \
+       Zero(&PL_start_env, 1, JMPENV);         \
+       PL_start_env.je_ret = -1;               \
+       PL_start_env.je_mustcatch = TRUE;       \
+       PL_top_env = &PL_start_env;             \
+    } STMT_END
+
+/*
+ *   PERL_FLEXIBLE_EXCEPTIONS
+ * 
+ * All the flexible exceptions code has been removed.
+ * See the following threads for details:
+ *
+ *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2004-07/msg00378.html
+ * 
+ * Joshua's original patches (which weren't applied) and discussion:
+ * 
+ *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01396.html
+ *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01489.html
+ *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01491.html
+ *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01608.html
+ *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02144.html
+ *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02998.html
+ * 
+ * Chip's reworked patch and discussion:
+ * 
+ *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1999-03/msg00520.html
+ * 
+ * The flaw in these patches (which went unnoticed at the time) was
+ * that they moved some code that could potentially die() out of the
+ * region protected by the setjmp()s.  This caused exceptions within
+ * END blocks and such to not be handled by the correct setjmp().
+ * 
+ * The original patches that introduces flexible exceptions were:
+ *
+ *   http://public.activestate.com/cgi-bin/perlbrowse?patch=3386
+ *   http://public.activestate.com/cgi-bin/perlbrowse?patch=5162
+ */
+
+#define dJMPENV                JMPENV cur_env
+
+#define JMPENV_PUSH(v) \
+    STMT_START {                                                       \
+       DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n",     \
+                        &cur_env, PL_top_env));                        \
+       cur_env.je_prev = PL_top_env;                                   \
+       OP_REG_TO_MEM;                                                  \
+       cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);              \
+       OP_MEM_TO_REG;                                                  \
+       PL_top_env = &cur_env;                                          \
+       cur_env.je_mustcatch = FALSE;                                   \
+       (v) = cur_env.je_ret;                                           \
+    } STMT_END
+
+#define JMPENV_POP \
+    STMT_START {                                                       \
+       DEBUG_l(Perl_deb(aTHX_ "popping jumplevel was %p, now %p\n",    \
+                        PL_top_env, cur_env.je_prev));                 \
+       PL_top_env = cur_env.je_prev;                                   \
+    } STMT_END
+
+#define JMPENV_JUMP(v) \
+    STMT_START {                                               \
+       OP_REG_TO_MEM;                                          \
+       if (PL_top_env->je_prev)                                \
+           PerlProc_longjmp(PL_top_env->je_buf, (v));          \
+       if ((v) == 2)                                           \
+           PerlProc_exit(STATUS_EXIT);                         \
+       PerlIO_printf(PerlIO_stderr(), "panic: top_env\n");     \
+       PerlProc_exit(1);                                       \
+    } STMT_END
+
+#define CATCH_GET              (PL_top_env->je_mustcatch)
+#define CATCH_SET(v)           (PL_top_env->je_mustcatch = (v))
+
+
+
 struct cop {
     BASEOP
     char *     cop_label;      /* label for this construct */
@@ -21,41 +147,73 @@ struct cop {
     I32                cop_arybase;    /* array base this line was compiled with */
     line_t      cop_line;       /* line # of this command */
     SV *       cop_warnings;   /* lexical warnings bitmask */
+    SV *       cop_io;         /* lexical IO defaults */
+    /* compile time state of %^H.  See the comment in op.c for how this is
+       used to recreate a hash to return from caller.  */
+    struct refcounted_he * cop_hints;
 };
 
-#define Nullcop Null(COP*)
-
 #ifdef USE_ITHREADS
 #  define CopFILE(c)           ((c)->cop_file)
 #  define CopFILEGV(c)         (CopFILE(c) \
-                                ? gv_fetchfile(CopFILE(c)) : Nullgv)
-#  define CopFILE_set(c,pv)    ((c)->cop_file = savepv(pv))
+                                ? gv_fetchfile(CopFILE(c)) : NULL)
+                                
+#  ifdef NETWARE
+#    define CopFILE_set(c,pv)  ((c)->cop_file = savepv(pv))
+#  else
+#    define CopFILE_set(c,pv)  ((c)->cop_file = savesharedpv(pv))
+#  endif
+
 #  define CopFILESV(c)         (CopFILE(c) \
-                                ? GvSV(gv_fetchfile(CopFILE(c))) : Nullsv)
+                                ? GvSV(gv_fetchfile(CopFILE(c))) : NULL)
 #  define CopFILEAV(c)         (CopFILE(c) \
-                                ? GvAV(gv_fetchfile(CopFILE(c))) : Nullav)
+                                ? GvAV(gv_fetchfile(CopFILE(c))) : NULL)
+#  ifdef DEBUGGING
+#    define CopFILEAVx(c)      (assert(CopFILE(c)), \
+                                  GvAV(gv_fetchfile(CopFILE(c))))
+#  else
+#    define CopFILEAVx(c)      (GvAV(gv_fetchfile(CopFILE(c))))
+#  endif
 #  define CopSTASHPV(c)                ((c)->cop_stashpv)
-#  define CopSTASHPV_set(c,pv) ((c)->cop_stashpv = ((pv) ? savepv(pv) : Nullch))
+
+#  ifdef NETWARE
+#    define CopSTASHPV_set(c,pv)       ((c)->cop_stashpv = ((pv) ? savepv(pv) : NULL))
+#  else
+#    define CopSTASHPV_set(c,pv)       ((c)->cop_stashpv = savesharedpv(pv))
+#  endif
+
 #  define CopSTASH(c)          (CopSTASHPV(c) \
-                                ? gv_stashpv(CopSTASHPV(c),GV_ADD) : Nullhv)
-#  define CopSTASH_set(c,hv)   CopSTASHPV_set(c, (hv) ? HvNAME(hv) : Nullch)
-#  define CopSTASH_eq(c,hv)    ((hv)                                   \
-                                && (CopSTASHPV(c) == HvNAME(hv)        \
-                                    || (CopSTASHPV(c) && HvNAME(hv)    \
-                                        && strEQ(CopSTASHPV(c), HvNAME(hv)))))
+                                ? gv_stashpv(CopSTASHPV(c),GV_ADD) : NULL)
+#  define CopSTASH_set(c,hv)   CopSTASHPV_set(c, (hv) ? HvNAME_get(hv) : NULL)
+#  define CopSTASH_eq(c,hv)    ((hv) && stashpv_hvname_match(c,hv))
+#  ifdef NETWARE
+#    define CopSTASH_free(c) SAVECOPSTASH_FREE(c)
+#    define CopFILE_free(c) SAVECOPFILE_FREE(c)
+#  else
+#    define CopSTASH_free(c)   PerlMemShared_free(CopSTASHPV(c))
+#    define CopFILE_free(c)    (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = NULL))
+#  endif
 #else
 #  define CopFILEGV(c)         ((c)->cop_filegv)
 #  define CopFILEGV_set(c,gv)  ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
 #  define CopFILE_set(c,pv)    CopFILEGV_set((c), gv_fetchfile(pv))
-#  define CopFILESV(c)         (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : Nullsv)
-#  define CopFILEAV(c)         (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : Nullav)
-#  define CopFILE(c)           (CopFILESV(c) ? SvPVX(CopFILESV(c)) : Nullch)
+#  define CopFILESV(c)         (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : NULL)
+#  define CopFILEAV(c)         (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : NULL)
+#  ifdef DEBUGGING
+#    define CopFILEAVx(c)      (assert(CopFILEGV(c)), GvAV(CopFILEGV(c)))
+#  else
+#    define CopFILEAVx(c)      (GvAV(CopFILEGV(c)))
+# endif
+#  define CopFILE(c)           (CopFILESV(c) ? SvPVX(CopFILESV(c)) : NULL)
 #  define CopSTASH(c)          ((c)->cop_stash)
 #  define CopSTASH_set(c,hv)   ((c)->cop_stash = (hv))
-#  define CopSTASHPV(c)                (CopSTASH(c) ? HvNAME(CopSTASH(c)) : Nullch)
+#  define CopSTASHPV(c)                (CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : NULL)
    /* cop_stash is not refcounted */
 #  define CopSTASHPV_set(c,pv) CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
 #  define CopSTASH_eq(c,hv)    (CopSTASH(c) == (hv))
+#  define CopSTASH_free(c)     
+#  define CopFILE_free(c)      (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = NULL))
+
 #endif /* USE_ITHREADS */
 
 #define CopSTASH_ne(c,hv)      (!CopSTASH_eq(c,hv))
@@ -64,6 +222,18 @@ struct cop {
 #define CopLINE_dec(c)         (--CopLINE(c))
 #define CopLINE_set(c,l)       (CopLINE(c) = (l))
 
+/* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
+#ifdef MACOS_TRADITIONAL
+#  define OutCopFILE(c) MacPerl_MPWFileName(CopFILE(c))
+#else
+#  define OutCopFILE(c) CopFILE(c)
+#endif
+
+/* CopARYBASE is likely to be removed soon.  */
+#define CopARYBASE(c)          ((c)->cop_arybase)
+#define CopARYBASE_get(c)      ((c)->cop_arybase + 0)
+#define CopARYBASE_set(c, b)   STMT_START { (c)->cop_arybase = (b); } STMT_END
+
 /*
  * Here we have some enormously heavy (or at least ponderous) wizardry.
  */
@@ -73,46 +243,62 @@ struct block_sub {
     CV *       cv;
     GV *       gv;
     GV *       dfoutgv;
-#ifndef USE_THREADS
     AV *       savearray;
-#endif /* USE_THREADS */
     AV *       argarray;
-    U16                olddepth;
+    I32                olddepth;
     U8         hasargs;
     U8         lval;           /* XXX merge lval and hasargs? */
-    SV **      oldcurpad;
+    PAD                *oldcomppad;
+    OP *       retop;  /* op to execute on exit from sub */
 };
 
-#define PUSHSUB(cx)                                                    \
+/* base for the next two macros. Don't use directly.
+ * Note that the refcnt of the cv is incremented twice;  The CX one is
+ * decremented by LEAVESUB, the other by LEAVE. */
+
+#define PUSHSUB_BASE(cx)                                               \
        cx->blk_sub.cv = cv;                                            \
        cx->blk_sub.olddepth = CvDEPTH(cv);                             \
        cx->blk_sub.hasargs = hasargs;                                  \
+       cx->blk_sub.retop = NULL;                                       \
+       if (!CvDEPTH(cv)) {                                             \
+           SvREFCNT_inc_void(cv);                                      \
+           SvREFCNT_inc_void(cv);                                      \
+           SAVEFREESV(cv);                                             \
+       }
+
+
+#define PUSHSUB(cx)                                                    \
+       PUSHSUB_BASE(cx)                                                \
        cx->blk_sub.lval = PL_op->op_private &                          \
                              (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
 
+/* variant for use by OP_DBSTATE, where op_private holds hint bits */
+#define PUSHSUB_DB(cx)                                                 \
+       PUSHSUB_BASE(cx)                                                \
+       cx->blk_sub.lval = 0;
+
+
 #define PUSHFORMAT(cx)                                                 \
        cx->blk_sub.cv = cv;                                            \
        cx->blk_sub.gv = gv;                                            \
+       cx->blk_sub.retop = NULL;                                       \
        cx->blk_sub.hasargs = 0;                                        \
        cx->blk_sub.dfoutgv = PL_defoutgv;                              \
-       (void)SvREFCNT_inc(cx->blk_sub.dfoutgv)
+       SvREFCNT_inc_void(cx->blk_sub.dfoutgv)
 
-#ifdef USE_THREADS
-#  define POP_SAVEARRAY() NOOP
-#else
-#  define POP_SAVEARRAY()                                              \
+#define POP_SAVEARRAY()                                                \
     STMT_START {                                                       \
        SvREFCNT_dec(GvAV(PL_defgv));                                   \
        GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
     } STMT_END
-#endif /* USE_THREADS */
 
 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
  * leave any (a fast av_clear(ary), basically) */
 #define CLEAR_ARGARRAY(ary) \
     STMT_START {                                                       \
        AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
-       SvPVX(ary) = (char*)AvALLOC(ary);                               \
+       SvPV_set(ary, (char*)AvALLOC(ary));                             \
        AvFILLp(ary) = -1;                                              \
     } STMT_END
 
@@ -126,8 +312,8 @@ struct block_sub {
                SvREFCNT_dec(cx->blk_sub.argarray);                     \
                cx->blk_sub.argarray = newAV();                         \
                av_extend(cx->blk_sub.argarray, fill);                  \
-               AvFLAGS(cx->blk_sub.argarray) = AVf_REIFY;              \
-               cx->blk_sub.oldcurpad[0] = (SV*)cx->blk_sub.argarray;   \
+               AvREIFY_only(cx->blk_sub.argarray);                     \
+               CX_CURPAD_SV(cx->blk_sub, 0) = (SV*)cx->blk_sub.argarray;       \
            }                                                           \
            else {                                                      \
                CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
@@ -135,7 +321,7 @@ struct block_sub {
        }                                                               \
        sv = (SV*)cx->blk_sub.cv;                                       \
        if (sv && (CvDEPTH((CV*)sv) = cx->blk_sub.olddepth))            \
-           sv = Nullsv;                                                \
+           sv = NULL;                                          \
     } STMT_END
 
 #define LEAVESUB(sv)                                                   \
@@ -155,15 +341,21 @@ struct block_eval {
     SV *       old_namesv;
     OP *       old_eval_root;
     SV *       cur_text;
+    CV *       cv;
+    OP *       retop;  /* op to execute on exit from eval */
+    JMPENV *   cur_top_env; /* value of PL_top_env when eval CX created */
 };
 
 #define PUSHEVAL(cx,n,fgv)                                             \
     STMT_START {                                                       \
        cx->blk_eval.old_in_eval = PL_in_eval;                          \
        cx->blk_eval.old_op_type = PL_op->op_type;                      \
-       cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : Nullsv);          \
+       cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
        cx->blk_eval.old_eval_root = PL_eval_root;                      \
        cx->blk_eval.cur_text = PL_linestr;                             \
+       cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
+       cx->blk_eval.retop = NULL;                                      \
+       cx->blk_eval.cur_top_env = PL_top_env;                          \
     } STMT_END
 
 #define POPEVAL(cx)                                                    \
@@ -184,7 +376,7 @@ struct block_loop {
     OP *       last_op;
 #ifdef USE_ITHREADS
     void *     iterdata;
-    SV **      oldcurpad;
+    PAD                *oldcomppad;
 #else
     SV **      itervar;
 #endif
@@ -199,18 +391,23 @@ struct block_loop {
 #  define CxITERVAR(c)                                                 \
        ((c)->blk_loop.iterdata                                         \
         ? (CxPADLOOP(cx)                                               \
-           ? &((c)->blk_loop.oldcurpad)[(PADOFFSET)(c)->blk_loop.iterdata]     \
+           ? &CX_CURPAD_SV( (c)->blk_loop,                             \
+                   INT2PTR(PADOFFSET, (c)->blk_loop.iterdata))         \
            : &GvSV((GV*)(c)->blk_loop.iterdata))                       \
         : (SV**)NULL)
 #  define CX_ITERDATA_SET(cx,idata)                                    \
-       cx->blk_loop.oldcurpad = PL_curpad;                             \
+       CX_CURPAD_SAVE(cx->blk_loop);                                   \
        if ((cx->blk_loop.iterdata = (idata)))                          \
-           cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));
+           cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
+       else                                                            \
+           cx->blk_loop.itersave = NULL;
 #else
 #  define CxITERVAR(c)         ((c)->blk_loop.itervar)
 #  define CX_ITERDATA_SET(cx,ivar)                                     \
        if ((cx->blk_loop.itervar = (SV**)(ivar)))                      \
-           cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));
+           cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
+       else                                                            \
+           cx->blk_loop.itersave = NULL;
 #endif
 
 #define PUSHLOOP(cx, dat, s)                                           \
@@ -219,26 +416,40 @@ struct block_loop {
        cx->blk_loop.redo_op = cLOOP->op_redoop;                        \
        cx->blk_loop.next_op = cLOOP->op_nextop;                        \
        cx->blk_loop.last_op = cLOOP->op_lastop;                        \
-       cx->blk_loop.iterlval = Nullsv;                                 \
-       cx->blk_loop.iterary = Nullav;                                  \
+       cx->blk_loop.iterlval = NULL;                                   \
+       cx->blk_loop.iterary = NULL;                                    \
        cx->blk_loop.iterix = -1;                                       \
        CX_ITERDATA_SET(cx,dat);
 
 #define POPLOOP(cx)                                                    \
        SvREFCNT_dec(cx->blk_loop.iterlval);                            \
        if (CxITERVAR(cx)) {                                            \
-           SV **s_v_p = CxITERVAR(cx);                                 \
-           sv_2mortal(*s_v_p);                                         \
-           *s_v_p = cx->blk_loop.itersave;                             \
+            if (SvPADMY(cx->blk_loop.itersave)) {                      \
+               SV ** const s_v_p = CxITERVAR(cx);                      \
+               sv_2mortal(*s_v_p);                                     \
+               *s_v_p = cx->blk_loop.itersave;                         \
+           }                                                           \
+           else {                                                      \
+               SvREFCNT_dec(cx->blk_loop.itersave);                    \
+           }                                                           \
        }                                                               \
        if (cx->blk_loop.iterary && cx->blk_loop.iterary != PL_curstack)\
            SvREFCNT_dec(cx->blk_loop.iterary);
 
+/* given/when context */
+struct block_givwhen {
+       OP *leave_op;
+};
+
+#define PUSHGIVEN(cx)                                                  \
+       cx->blk_givwhen.leave_op = cLOGOP->op_other;
+
+#define PUSHWHEN PUSHGIVEN
+
 /* context common to subroutines, evals and loops */
 struct block {
     I32                blku_oldsp;     /* stack pointer to copy stuff down to */
     COP *      blku_oldcop;    /* old curcop pointer */
-    I32                blku_oldretsp;  /* return stack index */
     I32                blku_oldmarksp; /* mark stack index */
     I32                blku_oldscopesp;        /* scope stack index */
     PMOP *     blku_oldpm;     /* values of pattern match vars */
@@ -248,11 +459,11 @@ struct block {
        struct block_sub        blku_sub;
        struct block_eval       blku_eval;
        struct block_loop       blku_loop;
+       struct block_givwhen    blku_givwhen;
     } blk_u;
 };
 #define blk_oldsp      cx_u.cx_blk.blku_oldsp
 #define blk_oldcop     cx_u.cx_blk.blku_oldcop
-#define blk_oldretsp   cx_u.cx_blk.blku_oldretsp
 #define blk_oldmarksp  cx_u.cx_blk.blku_oldmarksp
 #define blk_oldscopesp cx_u.cx_blk.blku_oldscopesp
 #define blk_oldpm      cx_u.cx_blk.blku_oldpm
@@ -260,6 +471,7 @@ struct block {
 #define blk_sub                cx_u.cx_blk.blk_u.blku_sub
 #define blk_eval       cx_u.cx_blk.blk_u.blku_eval
 #define blk_loop       cx_u.cx_blk.blk_u.blku_loop
+#define blk_givwhen    cx_u.cx_blk.blk_u.blku_givwhen
 
 /* Enter a block. */
 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],           \
@@ -268,9 +480,8 @@ struct block {
        cx->blk_oldcop          = PL_curcop,                            \
        cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
        cx->blk_oldscopesp      = PL_scopestack_ix,                     \
-       cx->blk_oldretsp        = PL_retstack_ix,                       \
        cx->blk_oldpm           = PL_curpm,                             \
-       cx->blk_gimme           = gimme;                                \
+       cx->blk_gimme           = (U8)gimme;                            \
        DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n", \
                    (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
 
@@ -280,9 +491,9 @@ struct block {
        PL_curcop        = cx->blk_oldcop,                              \
        PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
        PL_scopestack_ix = cx->blk_oldscopesp,                          \
-       PL_retstack_ix   = cx->blk_oldretsp,                            \
        pm               = cx->blk_oldpm,                               \
        gimme            = cx->blk_gimme;                               \
+       DEBUG_SCOPE("POPBLOCK");                                        \
        DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",          \
                    (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
 
@@ -291,8 +502,8 @@ struct block {
        PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
        PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
        PL_scopestack_ix = cx->blk_oldscopesp,                          \
-       PL_retstack_ix   = cx->blk_oldretsp,                            \
-       PL_curpm         = cx->blk_oldpm
+       PL_curpm         = cx->blk_oldpm;                               \
+       DEBUG_SCOPE("TOPBLOCK");
 
 /* substitution context */
 struct subst {
@@ -339,7 +550,7 @@ struct subst {
        cx->sb_s                = s,                                    \
        cx->sb_m                = m,                                    \
        cx->sb_strend           = strend,                               \
-       cx->sb_rxres            = Null(void*),                          \
+       cx->sb_rxres            = NULL,                                 \
        cx->sb_rx               = rx,                                   \
        cx->cx_type             = CXt_SUBST;                            \
        rxres_save(&cx->sb_rxres, rx)
@@ -363,13 +574,21 @@ struct context {
 #define CXt_SUBST      4
 #define CXt_BLOCK      5
 #define CXt_FORMAT     6
+#define CXt_GIVEN      7
+#define CXt_WHEN       8
+
+/* private flags for CXt_SUB and CXt_NULL */
+#define CXp_MULTICALL  0x00000400      /* part of a multicall (so don't
+                                          tear down context on exit). */ 
 
 /* private flags for CXt_EVAL */
 #define CXp_REAL       0x00000100      /* truly eval'', not a lookalike */
 #define CXp_TRYBLOCK   0x00000200      /* eval{}, not eval'' or similar */
 
-#ifdef USE_ITHREADS
 /* private flags for CXt_LOOP */
+#define CXp_FOREACH    0x00000200      /* a foreach loop */
+#define CXp_FOR_DEF    0x00000400      /* foreach using $_ */
+#ifdef USE_ITHREADS
 #  define CXp_PADVAR   0x00000100      /* itervar lives on pad, iterdata
                                           has pad offset; if not set,
                                           iterdata holds GV* */
@@ -378,14 +597,22 @@ struct context {
 #endif
 
 #define CxTYPE(c)      ((c)->cx_type & CXTYPEMASK)
+#define CxMULTICALL(c) (((c)->cx_type & CXp_MULTICALL)                 \
+                        == CXp_MULTICALL)
 #define CxREALEVAL(c)  (((c)->cx_type & (CXt_EVAL|CXp_REAL))           \
                         == (CXt_EVAL|CXp_REAL))
 #define CxTRYBLOCK(c)  (((c)->cx_type & (CXt_EVAL|CXp_TRYBLOCK))       \
                         == (CXt_EVAL|CXp_TRYBLOCK))
+#define CxFOREACH(c)   (((c)->cx_type & (CXt_LOOP|CXp_FOREACH))        \
+                         == (CXt_LOOP|CXp_FOREACH))
+#define CxFOREACHDEF(c)        (((c)->cx_type & (CXt_LOOP|CXp_FOREACH|CXp_FOR_DEF))\
+                        == (CXt_LOOP|CXp_FOREACH|CXp_FOR_DEF))
 
 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
 
-/* "gimme" values */
+/* 
+=head1 "Gimme" Values
+*/
 
 /*
 =for apidoc AmU||G_SCALAR
@@ -427,12 +654,15 @@ L<perlcall>.
 #define G_KEEPERR      16      /* Append errors to $@, don't overwrite it */
 #define G_NODEBUG      32      /* Disable debugging at toplevel.  */
 #define G_METHOD       64       /* Calling method. */
+#define G_FAKINGEVAL  256      /* Faking en eval context for call_sv or
+                                  fold_constants. */
 
 /* flag bits for PL_in_eval */
 #define EVAL_NULL      0       /* not in an eval */
 #define EVAL_INEVAL    1       /* some enclosing scope is an eval */
 #define EVAL_WARNONLY  2       /* used by yywarn() when calling yyerror() */
 #define EVAL_KEEPERR   4       /* set by Perl_call_sv if G_KEEPERR */
+#define EVAL_INREQUIRE 8       /* The code is being required. */
 
 /* Support for switching (stack and block) contexts.
  * This ensures magic doesn't invalidate local stack and cx pointers.
@@ -498,8 +728,8 @@ typedef struct stackinfo PERL_SI;
  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
 #define POPSTACK \
     STMT_START {                                                       \
-       djSP;                                                           \
-       PERL_SI *prev = PL_curstackinfo->si_prev;                       \
+       dSP;                                                            \
+       PERL_SI * const prev = PL_curstackinfo->si_prev;                \
        if (!prev) {                                                    \
            PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
            my_exit(1);                                                 \
@@ -516,3 +746,80 @@ typedef struct stackinfo PERL_SI;
            POPSTACK;                                                   \
        }                                                               \
     } STMT_END
+
+#define IN_PERL_COMPILETIME    (PL_curcop == &PL_compiling)
+#define IN_PERL_RUNTIME                (PL_curcop != &PL_compiling)
+
+/*
+=head1 Multicall Functions
+
+=for apidoc Ams||dMULTICALL
+Declare local variables for a multicall. See L<perlcall/Lightweight Callbacks>.
+
+=for apidoc Ams||PUSH_MULTICALL
+Opening bracket for a lightweight callback.
+See L<perlcall/Lightweight Callbacks>.
+
+=for apidoc Ams||MULTICALL
+Make a lightweight callback. See L<perlcall/Lightweight Callbacks>.
+
+=for apidoc Ams||POP_MULTICALL
+Closing bracket for a lightweight callback.
+See L<perlcall/Lightweight Callbacks>.
+
+=cut
+*/
+
+#define dMULTICALL \
+    SV **newsp;                        /* set by POPBLOCK */                   \
+    PERL_CONTEXT *cx;                                                  \
+    CV *multicall_cv;                                                  \
+    OP *multicall_cop;                                                 \
+    bool multicall_oldcatch;                                           \
+    U8 hasargs = 0             /* used by PUSHSUB */
+
+#define PUSH_MULTICALL(the_cv) \
+    STMT_START {                                                       \
+       CV * const _nOnclAshIngNamE_ = the_cv;                          \
+       CV * const cv = _nOnclAshIngNamE_;                              \
+       AV * const padlist = CvPADLIST(cv);                             \
+       ENTER;                                                          \
+       multicall_oldcatch = CATCH_GET;                                 \
+       SAVETMPS; SAVEVPTR(PL_op);                                      \
+       CATCH_SET(TRUE);                                                \
+       PUSHBLOCK(cx, CXt_SUB|CXp_MULTICALL, PL_stack_sp);              \
+       PUSHSUB(cx);                                                    \
+       if (++CvDEPTH(cv) >= 2) {                                       \
+           PERL_STACK_OVERFLOW_CHECK();                                \
+           Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
+       }                                                               \
+       SAVECOMPPAD();                                                  \
+       PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
+       multicall_cv = cv;                                              \
+       multicall_cop = CvSTART(cv);                                    \
+    } STMT_END
+
+#define MULTICALL \
+    STMT_START {                                                       \
+       PL_op = multicall_cop;                                          \
+       CALLRUNOPS(aTHX);                                               \
+    } STMT_END
+
+#define POP_MULTICALL \
+    STMT_START {                                                       \
+       LEAVESUB(multicall_cv);                                         \
+       CvDEPTH(multicall_cv)--;                                        \
+       POPBLOCK(cx,PL_curpm);                                          \
+       CATCH_SET(multicall_oldcatch);                                  \
+       LEAVE;                                                          \
+    } STMT_END
+
+/*
+ * Local variables:
+ * c-indentation-style: bsd
+ * c-basic-offset: 4
+ * indent-tabs-mode: t
+ * End:
+ *
+ * ex: set ts=8 sts=4 sw=4 noet:
+ */