Introduce SvCANEXISTDELETE in pp.h, which simplify the logic in pp_helem and pp_hslice

[p5sagit/p5-mst-13.2.git] / pp_hot.c

diff --git a/pp_hot.c b/pp_hot.c
index a60a176..88fe838 100644 (file)
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -1754,9 +1754,13 @@ PP(pp_enter)
     I32 gimme = OP_GIMME(PL_op, -1);
 
     if (gimme == -1) {
-       if (cxstack_ix >= 0)
-           gimme = cxstack[cxstack_ix].blk_gimme;
-       else
+       if (cxstack_ix >= 0) {
+           /* If this flag is set, we're just inside a return, so we should
+            * store the caller's context */
+           gimme = (PL_op->op_flags & OPf_SPECIAL)
+               ? block_gimme()
+               : cxstack[cxstack_ix].blk_gimme;
+       } else
            gimme = G_SCALAR;
     }
 
@@ -1779,7 +1783,7 @@ PP(pp_helem)
     const U32 defer = PL_op->op_private & OPpLVAL_DEFER;
     SV *sv;
     const U32 hash = (SvIsCOW_shared_hash(keysv)) ? SvSHARED_HASH(keysv) : 0;
-    I32 preeminent = 0;
+    bool preeminent = TRUE;
 
     if (SvTYPE(hv) != SVt_PVHV)
        RETPUSHUNDEF;
@@ -1787,20 +1791,15 @@ PP(pp_helem)
     if (PL_op->op_private & OPpLVAL_INTRO) {
        MAGIC *mg;
        HV *stash;
-       /* does the element we're localizing already exist? */
-       preeminent = /* can we determine whether it exists? */
-           (    !SvRMAGICAL(hv)
-               || mg_find((const SV *)hv, PERL_MAGIC_env)
-               || (     (mg = mg_find((const SV *)hv, PERL_MAGIC_tied))
-                       /* Try to preserve the existenceness of a tied hash
-                       * element by using EXISTS and DELETE if possible.
-                       * Fallback to FETCH and STORE otherwise */
-                   && (stash = SvSTASH(SvRV(SvTIED_obj(MUTABLE_SV(hv), mg))))
-                   && gv_fetchmethod_autoload(stash, "EXISTS", TRUE)
-                   && gv_fetchmethod_autoload(stash, "DELETE", TRUE)
-               )
-           ) ? hv_exists_ent(hv, keysv, 0) : 1;
+
+       /* If we can determine whether the element exist,
+        * Try to preserve the existenceness of a tied hash
+        * element by using EXISTS and DELETE if possible.
+        * Fallback to FETCH and STORE otherwise. */
+       if (SvCANEXISTDELETE(hv) || mg_find((const SV *)hv, PERL_MAGIC_env))
+           preeminent = hv_exists_ent(hv, keysv, 0);
     }
+
     he = hv_fetch_ent(hv, keysv, lval && !defer, hash);
     svp = he ? &HeVAL(he) : NULL;
     if (lval) {
@@ -1865,13 +1864,7 @@ PP(pp_leave)
 
     POPBLOCK(cx,newpm);
 
-    gimme = OP_GIMME(PL_op, -1);
-    if (gimme == -1) {
-       if (cxstack_ix >= 0)
-           gimme = cxstack[cxstack_ix].blk_gimme;
-       else
-           gimme = G_SCALAR;
-    }
+    gimme = OP_GIMME(PL_op, (cxstack_ix >= 0) ? gimme : G_SCALAR);
 
     TAINT_NOT;
     if (gimme == G_VOID)
@@ -2774,7 +2767,14 @@ try_autoload:
         Perl_get_db_sub(aTHX_ &sv, cv);
         if (CvISXSUB(cv))
             PL_curcopdb = PL_curcop;
-        cv = GvCV(PL_DBsub);
+         if (CvLVALUE(cv)) {
+             /* check for lsub that handles lvalue subroutines */
+            cv = GvCV(gv_HVadd(gv_fetchpv("DB::lsub", GV_ADDMULTI, SVt_PVHV)));
+             /* if lsub not found then fall back to DB::sub */
+            if (!cv) cv = GvCV(PL_DBsub);
+         } else {
+             cv = GvCV(PL_DBsub);
+         }
 
        if (!cv || (!CvXSUB(cv) && !CvSTART(cv)))
            DIE(aTHX_ "No DB::sub routine defined");