This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
In makedef.pl, move handling of $ARGS{TARG_DIR} to the open statements.
[perl5.git] / pp_ctl.c
index 06952b2..dc1b055 100644 (file)
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -43,13 +43,20 @@ PP(pp_wantarray)
     dVAR;
     dSP;
     I32 cxix;
+    const PERL_CONTEXT *cx;
     EXTEND(SP, 1);
 
-    cxix = dopoptosub(cxstack_ix);
-    if (cxix < 0)
+    if (PL_op->op_private & OPpOFFBYONE) {
+       if (!(cx = caller_cx(1,NULL))) RETPUSHUNDEF;
+    }
+    else {
+      cxix = dopoptosub(cxstack_ix);
+      if (cxix < 0)
        RETPUSHUNDEF;
+      cx = &cxstack[cxix];
+    }
 
-    switch (cxstack[cxix].blk_gimme) {
+    switch (cx->blk_gimme) {
     case G_ARRAY:
        RETPUSHYES;
     case G_SCALAR:
@@ -298,6 +305,13 @@ PP(pp_substcont)
        s -= RX_GOFS(rx);
 
        /* Are we done */
+       /* I believe that we can't set REXEC_SCREAM here if
+          SvSCREAM(cx->sb_targ) is true because SvPVX(cx->sb_targ) isn't always
+          equal to s.  [See the comment before Perl_re_intuit_start(), which is
+          called from Perl_regexec_flags(), which says that it should be when
+          SvSCREAM() is true.]  s, cx->sb_strend and orig will be consistent
+          with SvPVX(cx->sb_targ), as substconst doesn't modify cx->sb_targ
+          during the match.  */
        if (CxONCE(cx) || s < orig ||
                !CALLREGEXEC(rx, s, cx->sb_strend, orig,
                             (s == m) + RX_GOFS(rx), cx->sb_targ, NULL,
@@ -305,7 +319,7 @@ PP(pp_substcont)
                              ? (REXEC_IGNOREPOS|REXEC_NOT_FIRST)
                              : (REXEC_COPY_STR|REXEC_IGNOREPOS|REXEC_NOT_FIRST))))
        {
-           SV * const targ = cx->sb_targ;
+           SV *targ = cx->sb_targ;
 
            assert(cx->sb_strend >= s);
            if(cx->sb_strend > s) {
@@ -317,27 +331,32 @@ PP(pp_substcont)
            if (RX_MATCH_TAINTED(rx)) /* run time pattern taint, eg locale */
                cx->sb_rxtainted |= SUBST_TAINT_PAT;
 
+           if (pm->op_pmflags & PMf_NONDESTRUCT) {
+               PUSHs(dstr);
+               /* From here on down we're using the copy, and leaving the
+                  original untouched.  */
+               targ = dstr;
+           }
+           else {
 #ifdef PERL_OLD_COPY_ON_WRITE
-           if (SvIsCOW(targ)) {
-               sv_force_normal_flags(targ, SV_COW_DROP_PV);
-           } else
+               if (SvIsCOW(targ)) {
+                   sv_force_normal_flags(targ, SV_COW_DROP_PV);
+               } else
 #endif
-           {
-               SvPV_free(targ);
-           }
-           SvPV_set(targ, SvPVX(dstr));
-           SvCUR_set(targ, SvCUR(dstr));
-           SvLEN_set(targ, SvLEN(dstr));
-           if (DO_UTF8(dstr))
-               SvUTF8_on(targ);
-           SvPV_set(dstr, NULL);
-
-           if (pm->op_pmflags & PMf_NONDESTRUCT)
-               PUSHs(targ);
-           else
+               {
+                   SvPV_free(targ);
+               }
+               SvPV_set(targ, SvPVX(dstr));
+               SvCUR_set(targ, SvCUR(dstr));
+               SvLEN_set(targ, SvLEN(dstr));
+               if (DO_UTF8(dstr))
+                   SvUTF8_on(targ);
+               SvPV_set(dstr, NULL);
+
                mPUSHi(saviters - 1);
 
-           (void)SvPOK_only_UTF8(targ);
+               (void)SvPOK_only_UTF8(targ);
+           }
 
            /* update the taint state of various various variables in
             * preparation for final exit.
@@ -384,7 +403,8 @@ PP(pp_substcont)
     }
     cx->sb_s = RX_OFFS(rx)[0].end + orig;
     { /* Update the pos() information. */
-       SV * const sv = cx->sb_targ;
+       SV * const sv
+           = (pm->op_pmflags & PMf_NONDESTRUCT) ? cx->sb_dstr : cx->sb_targ;
        MAGIC *mg;
        SvUPGRADE(sv, SVt_PVMG);
        if (!(mg = mg_find(sv, PERL_MAGIC_regex_global))) {
@@ -414,7 +434,8 @@ PP(pp_substcont)
 
        if (cx->sb_iters > 1 && (cx->sb_rxtainted & 
                        (SUBST_TAINT_STR|SUBST_TAINT_PAT|SUBST_TAINT_REPL)))
-           SvTAINTED_on(cx->sb_targ);
+           SvTAINTED_on((pm->op_pmflags & PMf_NONDESTRUCT)
+                        ? cx->sb_dstr : cx->sb_targ);
        TAINT_NOT;
     }
     rxres_save(&cx->sb_rxres, rx);
@@ -519,6 +540,9 @@ S_rxres_free(pTHX_ void **rsp)
     }
 }
 
+#define FORM_NUM_BLANK (1<<30)
+#define FORM_NUM_POINT (1<<29)
+
 PP(pp_formline)
 {
     dVAR; dSP; dMARK; dORIGMARK;
@@ -535,18 +559,18 @@ PP(pp_formline)
     I32 lines = 0;         /* number of lines that have been output */
     bool chopspace = (strchr(PL_chopset, ' ') != NULL); /* does $: have space */
     const char *chophere = NULL; /* where to chop current item */
-    char *linemark = NULL;  /* pos of start of line in output */
+    STRLEN linemark = 0;    /* pos of start of line in output */
     NV value;
     bool gotsome = FALSE;   /* seen at least one non-blank item on this line */
     STRLEN len;
-    STRLEN fudge;          /* estimate of output size in bytes */
+    STRLEN linemax;        /* estimate of output size in bytes */
     bool item_is_utf8 = FALSE;
     bool targ_is_utf8 = FALSE;
-    SV * nsv = NULL;
     const char *fmt;
     MAGIC *mg = NULL;
     U8 *source;                    /* source of bytes to append */
     STRLEN to_copy;        /* how may bytes to append */
+    char trans;                    /* what chars to translate */
 
     mg = doparseform(tmpForm);
 
@@ -561,8 +585,9 @@ PP(pp_formline)
        SvTAINTED_on(PL_formtarget);
     if (DO_UTF8(PL_formtarget))
        targ_is_utf8 = TRUE;
-    fudge = (SvCUR(formsv) * (IN_BYTES ? 1 : 3) + 1);
-    t = SvGROW(PL_formtarget, len + fudge + 1);  /* XXX SvCUR bad */
+    linemax = (SvCUR(formsv) * (IN_BYTES ? 1 : 3) + 1);
+    t = SvGROW(PL_formtarget, len + linemax + 1);
+    /* XXX from now onwards, SvCUR(PL_formtarget) is invalid */
     t += len;
     f = SvPV_const(formsv, len);
 
@@ -598,46 +623,18 @@ PP(pp_formline)
        } );
        switch (*fpc++) {
        case FF_LINEMARK:
-           linemark = t;
+           linemark = t - SvPVX(PL_formtarget);
            lines++;
            gotsome = FALSE;
            break;
 
        case FF_LITERAL:
-           arg = *fpc++;
+           to_copy = *fpc++;
+           source = (U8 *)f;
+           f += to_copy;
+           trans = '~';
            item_is_utf8 = targ_is_utf8 ? !!DO_UTF8(formsv) : !!SvUTF8(formsv);
-           if (targ_is_utf8 && !item_is_utf8) {
-               char *s;
-               SvCUR_set(PL_formtarget, t - SvPVX_const(PL_formtarget));
-
-               /* this is an unrolled sv_catpvn_utf8_upgrade(),
-                * but with the addition of s/~/ /g */
-               if (!(nsv))
-                   nsv = newSVpvn_flags(f, arg, SVs_TEMP);
-               else
-                   sv_setpvn(nsv, f, arg);
-               SvUTF8_off(nsv);
-               for (s = SvPVX(nsv); s <= SvEND(nsv); s++)
-                   if (*s == '~')
-                       *s = ' ';
-               sv_utf8_upgrade(nsv);
-               sv_catsv(PL_formtarget, nsv);
-
-               t = SvEND(PL_formtarget);
-               f += arg;
-               break;
-           }
-           if (!targ_is_utf8 && item_is_utf8) {
-               SvCUR_set(PL_formtarget, t - SvPVX_const(PL_formtarget));
-               sv_utf8_upgrade_flags_grow(PL_formtarget, 0, arg);
-               t = SvEND(PL_formtarget);
-               targ_is_utf8 = TRUE;
-           }
-           while (arg--) {
-               *t++ = (*f == '~') ? ' ' : *f;
-               f++;
-           }
-           break;
+           goto append;
 
        case FF_SKIP:
            f += *fpc++;
@@ -808,66 +805,17 @@ PP(pp_formline)
            break;
 
        case FF_ITEM:
-           {
-               const char *s = item;
-               arg = itemsize;
-               if (item_is_utf8) {
-                   if (!targ_is_utf8) {
-                       SvCUR_set(PL_formtarget, t - SvPVX_const(PL_formtarget));
-                       sv_utf8_upgrade_flags_grow(PL_formtarget, 0, arg);
-                       t = SvEND(PL_formtarget);
-                       targ_is_utf8 = TRUE;
-                   }
-                   while (arg--) {
-                       if (UTF8_IS_CONTINUED(*s)) {
-                           STRLEN skip = UTF8SKIP(s);
-                           switch (skip) {
-                           default:
-                               Move(s,t,skip,char);
-                               s += skip;
-                               t += skip;
-                               break;
-                           case 7: *t++ = *s++;
-                           case 6: *t++ = *s++;
-                           case 5: *t++ = *s++;
-                           case 4: *t++ = *s++;
-                           case 3: *t++ = *s++;
-                           case 2: *t++ = *s++;
-                           case 1: *t++ = *s++;
-                           }
-                       }
-                       else {
-                           if ( !((*t++ = *s++) & ~31) )
-                               t[-1] = ' ';
-                       }
-                   }
-                   break;
-               }
-               if (targ_is_utf8 && !item_is_utf8) {
-                   SvCUR_set(PL_formtarget, t - SvPVX_const(PL_formtarget));
-                   sv_catpvn_utf8_upgrade(PL_formtarget, s, arg, nsv);
-                   for (; t < SvEND(PL_formtarget); t++) {
-#ifdef EBCDIC
-                       const int ch = *t;
-                       if (iscntrl(ch))
-#else
-                           if (!(*t & ~31))
-#endif
-                               *t = ' ';
-                   }
-                   break;
-               }
-               while (arg--) {
-#ifdef EBCDIC
-                   const int ch = *t++ = *s++;
-                   if (iscntrl(ch))
-#else
-                   if ( !((*t++ = *s++) & ~31) )
-#endif
-                           t[-1] = ' ';
-               }
-               break;
+           to_copy = itemsize;
+           source = (U8 *)item;
+           trans = 1;
+           if (item_is_utf8) {
+               /* convert to_copy from chars to bytes */
+               U8 *s = source;
+               while (to_copy--)
+                  s += UTF8SKIP(s);
+               to_copy = s - source;
            }
+           goto append;
 
        case FF_CHOP:
            {
@@ -892,6 +840,7 @@ PP(pp_formline)
                item_is_utf8 = DO_UTF8(sv);
                if (!len)
                    break;
+               trans = 0;
                gotsome = TRUE;
                chophere = s + len;
                source = (U8 *) s;
@@ -912,8 +861,13 @@ PP(pp_formline)
                }
            }
 
+       append:
+           /* append to_copy bytes from source to PL_formstring.
+            * item_is_utf8 implies source is utf8.
+            * if trans, translate certain characters during the copy */
            {
                U8 *tmp = NULL;
+               STRLEN grow = 0;
 
                SvCUR_set(PL_formtarget,
                          t - SvPVX_const(PL_formtarget));
@@ -922,20 +876,57 @@ PP(pp_formline)
                    source = tmp = bytes_to_utf8(source, &to_copy);
                } else {
                    if (item_is_utf8 && !targ_is_utf8) {
+                       U8 *s;
                        /* Upgrade targ to UTF8, and then we reduce it to
                           a problem we have a simple solution for.
                           Don't need get magic.  */
                        sv_utf8_upgrade_nomg(PL_formtarget);
                        targ_is_utf8 = TRUE;
+                       /* re-calculate linemark */
+                       s = (U8*)SvPVX(PL_formtarget);
+                       /* the bytes we initially allocated to append the
+                        * whole line may have been gobbled up during the
+                        * upgrade, so allocate a whole new line's worth
+                        * for safety */
+                       grow = linemax;
+                       while (linemark--)
+                           s += UTF8SKIP(s);
+                       linemark = s - (U8*)SvPVX(PL_formtarget);
                    }
                    /* Easy. They agree.  */
                    assert (item_is_utf8 == targ_is_utf8);
                }
-               SvGROW(PL_formtarget,
-                      SvCUR(PL_formtarget) + to_copy + 1);
+               if (!trans)
+                   /* @* and ^* are the only things that can exceed
+                    * the linemax, so grow by the output size, plus
+                    * a whole new form's worth in case of any further
+                    * output */
+                   grow = linemax + to_copy;
+               if (grow)
+                   SvGROW(PL_formtarget, SvCUR(PL_formtarget) + grow + 1);
                t = SvPVX(PL_formtarget) + SvCUR(PL_formtarget);
 
                Copy(source, t, to_copy, char);
+               if (trans) {
+                   /* blank out ~ or control chars, depending on trans.
+                    * works on bytes not chars, so relies on not
+                    * matching utf8 continuation bytes */
+                   U8 *s = (U8*)t;
+                   U8 *send = s + to_copy;
+                   while (s < send) {
+                       const int ch = *s;
+                       if (trans == '~' ? (ch == '~') :
+#ifdef EBCDIC
+                              iscntrl(ch)
+#else
+                              (!(ch & ~31))
+#endif
+                       )
+                           *s = ' ';
+                       s++;
+                   }
+               }
+
                t += to_copy;
                SvCUR_set(PL_formtarget, SvCUR(PL_formtarget) + to_copy);
                if (tmp)
@@ -947,11 +938,11 @@ PP(pp_formline)
            arg = *fpc++;
 #if defined(USE_LONG_DOUBLE)
            fmt = (const char *)
-               ((arg & 256) ?
+               ((arg & FORM_NUM_POINT) ?
                 "%#0*.*" PERL_PRIfldbl : "%0*.*" PERL_PRIfldbl);
 #else
            fmt = (const char *)
-               ((arg & 256) ?
+               ((arg & FORM_NUM_POINT) ?
                 "%#0*.*f"              : "%0*.*f");
 #endif
            goto ff_dec;
@@ -959,15 +950,15 @@ PP(pp_formline)
            arg = *fpc++;
 #if defined(USE_LONG_DOUBLE)
            fmt = (const char *)
-               ((arg & 256) ? "%#*.*" PERL_PRIfldbl : "%*.*" PERL_PRIfldbl);
+               ((arg & FORM_NUM_POINT) ? "%#*.*" PERL_PRIfldbl : "%*.*" PERL_PRIfldbl);
 #else
             fmt = (const char *)
-               ((arg & 256) ? "%#*.*f"              : "%*.*f");
+               ((arg & FORM_NUM_POINT) ? "%#*.*f"              : "%*.*f");
 #endif
        ff_dec:
            /* If the field is marked with ^ and the value is undefined,
               blank it out. */
-           if ((arg & 512) && !SvOK(sv)) {
+           if ((arg & FORM_NUM_BLANK) && !SvOK(sv)) {
                arg = fieldsize;
                while (arg--)
                    *t++ = ' ';
@@ -985,7 +976,8 @@ PP(pp_formline)
            /* Formats aren't yet marked for locales, so assume "yes". */
            {
                STORE_NUMERIC_STANDARD_SET_LOCAL();
-               my_snprintf(t, SvLEN(PL_formtarget) - (t - SvPVX(PL_formtarget)), fmt, (int) fieldsize, (int) arg & 255, value);
+               arg &= ~(FORM_NUM_POINT|FORM_NUM_BLANK);
+               my_snprintf(t, SvLEN(PL_formtarget) - (t - SvPVX(PL_formtarget)), fmt, (int) fieldsize, (int) arg, value);
                RESTORE_NUMERIC_STANDARD();
            }
            t += fieldsize;
@@ -993,7 +985,7 @@ PP(pp_formline)
 
        case FF_NEWLINE:
            f++;
-           while (t-- > linemark && *t == ' ') ;
+           while (t-- > (SvPVX(PL_formtarget) + linemark) && *t == ' ') ;
            t++;
            *t++ = '\n';
            break;
@@ -1007,7 +999,7 @@ PP(pp_formline)
                }
            }
            else {
-               t = linemark;
+               t = SvPVX(PL_formtarget) + linemark;
                lines--;
            }
            break;
@@ -1484,6 +1476,20 @@ Perl_is_lvalue_sub(pTHX)
        return 0;
 }
 
+/* only used by PUSHSUB */
+I32
+Perl_was_lvalue_sub(pTHX)
+{
+    dVAR;
+    const I32 cxix = dopoptosub(cxstack_ix-1);
+    assert(cxix >= 0);  /* We should only be called from inside subs */
+
+    if (CxLVAL(cxstack + cxix) && CvLVALUE(cxstack[cxix].blk_sub.cv))
+       return CxLVAL(cxstack + cxix);
+    else
+       return 0;
+}
+
 STATIC I32
 S_dopoptosub_at(pTHX_ const PERL_CONTEXT *cxstk, I32 startingblock)
 {
@@ -1606,6 +1612,9 @@ Perl_dounwind(pTHX_ I32 cxix)
     dVAR;
     I32 optype;
 
+    if (!PL_curstackinfo) /* can happen if die during thread cloning */
+       return;
+
     while (cxstack_ix > cxix) {
        SV *sv;
         register PERL_CONTEXT *cx = &cxstack[cxstack_ix];
@@ -1948,7 +1957,7 @@ PP(pp_caller)
        AV * const ary = cx->blk_sub.argarray;
        const int off = AvARRAY(ary) - AvALLOC(ary);
 
-       if (!PL_dbargs)
+       if (!PL_dbargs || AvREAL(PL_dbargs))
            Perl_init_dbargs(aTHX);
 
        if (AvMAX(PL_dbargs) < AvFILLp(ary) + off)
@@ -2062,6 +2071,79 @@ PP(pp_dbstate)
        return NORMAL;
 }
 
+STATIC SV **
+S_adjust_stack_on_leave(pTHX_ SV **newsp, SV **sp, SV **mark, I32 gimme, U32 flags)
+{
+    PERL_ARGS_ASSERT_ADJUST_STACK_ON_LEAVE;
+
+    if (gimme == G_SCALAR) {
+       if (MARK < SP)
+           *++newsp = (SvFLAGS(*SP) & flags) ? *SP : sv_mortalcopy(*SP);
+       else {
+           /* MEXTEND() only updates MARK, so reuse it instead of newsp. */
+           MARK = newsp;
+           MEXTEND(MARK, 1);
+           *++MARK = &PL_sv_undef;
+           return MARK;
+       }
+    }
+    else if (gimme == G_ARRAY) {
+       /* in case LEAVE wipes old return values */
+       while (++MARK <= SP) {
+           if (SvFLAGS(*MARK) & flags)
+               *++newsp = *MARK;
+           else {
+               *++newsp = sv_mortalcopy(*MARK);
+               TAINT_NOT;      /* Each item is independent */
+           }
+       }
+       /* When this function was called with MARK == newsp, we reach this
+        * point with SP == newsp. */
+    }
+
+    return newsp;
+}
+
+PP(pp_enter)
+{
+    dVAR; dSP;
+    register PERL_CONTEXT *cx;
+    I32 gimme = GIMME_V;
+
+    ENTER_with_name("block");
+
+    SAVETMPS;
+    PUSHBLOCK(cx, CXt_BLOCK, SP);
+
+    RETURN;
+}
+
+PP(pp_leave)
+{
+    dVAR; dSP;
+    register PERL_CONTEXT *cx;
+    SV **newsp;
+    PMOP *newpm;
+    I32 gimme;
+
+    if (PL_op->op_flags & OPf_SPECIAL) {
+       cx = &cxstack[cxstack_ix];
+       cx->blk_oldpm = PL_curpm;       /* fake block should preserve $1 et al */
+    }
+
+    POPBLOCK(cx,newpm);
+
+    gimme = OP_GIMME(PL_op, (cxstack_ix >= 0) ? gimme : G_SCALAR);
+
+    TAINT_NOT;
+    SP = adjust_stack_on_leave(newsp, SP, newsp, gimme, SVs_PADTMP|SVs_TEMP);
+    PL_curpm = newpm;  /* Don't pop $1 et al till now */
+
+    LEAVE_with_name("block");
+
+    RETURN;
+}
+
 PP(pp_enteriter)
 {
     dVAR; dSP; dMARK;
@@ -2215,21 +2297,7 @@ PP(pp_leaveloop)
     newsp = PL_stack_base + cx->blk_loop.resetsp;
 
     TAINT_NOT;
-    if (gimme == G_VOID)
-       NOOP;
-    else if (gimme == G_SCALAR) {
-       if (mark < SP)
-           *++newsp = sv_mortalcopy(*SP);
-       else
-           *++newsp = &PL_sv_undef;
-    }
-    else {
-       while (mark < SP) {
-           *++newsp = sv_mortalcopy(*++mark);
-           TAINT_NOT;          /* Each item is independent */
-       }
-    }
-    SP = newsp;
+    SP = adjust_stack_on_leave(newsp, SP, MARK, gimme, 0);
     PUTBACK;
 
     POPLOOP(cx);       /* Stack values are safe: release loop vars ... */
@@ -2241,6 +2309,113 @@ PP(pp_leaveloop)
     return NORMAL;
 }
 
+STATIC void
+S_return_lvalues(pTHX_ SV **mark, SV **sp, SV **newsp, I32 gimme,
+                       PERL_CONTEXT *cx, PMOP *newpm)
+{
+    const bool ref = !!(CxLVAL(cx) & OPpENTERSUB_INARGS);
+    if (gimme == G_SCALAR) {
+       if (CxLVAL(cx) && !ref) {     /* Leave it as it is if we can. */
+           SV *sv;
+           const char *what = NULL;
+           if (MARK < SP) {
+               assert(MARK+1 == SP);
+               if ((SvPADTMP(TOPs) ||
+                    (SvFLAGS(TOPs) & (SVf_READONLY | SVf_FAKE))
+                      == SVf_READONLY
+                   ) &&
+                   !SvSMAGICAL(TOPs)) {
+                   what =
+                       SvREADONLY(TOPs) ? (TOPs == &PL_sv_undef) ? "undef"
+                       : "a readonly value" : "a temporary";
+               }
+               else goto copy_sv;
+           }
+           else {
+               /* sub:lvalue{} will take us here. */
+               what = "undef";
+           }
+           LEAVE;
+           cxstack_ix--;
+           POPSUB(cx,sv);
+           PL_curpm = newpm;
+           LEAVESUB(sv);
+           Perl_croak(aTHX_
+                     "Can't return %s from lvalue subroutine", what
+           );
+       }
+       if (MARK < SP) {
+             copy_sv:
+               if (cx->blk_sub.cv && CvDEPTH(cx->blk_sub.cv) > 1) {
+                       *++newsp = SvREFCNT_inc(*SP);
+                       FREETMPS;
+                       sv_2mortal(*newsp);
+               }
+               else
+                   *++newsp =
+                       !SvTEMP(*SP)
+                         ? sv_2mortal(SvREFCNT_inc_simple_NN(*SP))
+                         : *SP;
+       }
+       else {
+           EXTEND(newsp,1);
+           *++newsp = &PL_sv_undef;
+       }
+       if (CxLVAL(cx) & OPpENTERSUB_DEREF) {
+           SvGETMAGIC(TOPs);
+           if (!SvOK(TOPs)) {
+               U8 deref_type;
+               if (cx->blk_sub.retop->op_type == OP_RV2SV)
+                   deref_type = OPpDEREF_SV;
+               else if (cx->blk_sub.retop->op_type == OP_RV2AV)
+                   deref_type = OPpDEREF_AV;
+               else {
+                   assert(cx->blk_sub.retop->op_type == OP_RV2HV);
+                   deref_type = OPpDEREF_HV;
+               }
+               TOPs = vivify_ref(TOPs, deref_type);
+           }
+       }
+    }
+    else if (gimme == G_ARRAY) {
+       assert (!(CxLVAL(cx) & OPpENTERSUB_DEREF));
+       if (ref || !CxLVAL(cx))
+           while (++MARK <= SP)
+               *++newsp =
+                    SvTEMP(*MARK)
+                      ? *MARK
+                      : ref && SvFLAGS(*MARK) & SVs_PADTMP
+                          ? sv_mortalcopy(*MARK)
+                          : sv_2mortal(SvREFCNT_inc_simple_NN(*MARK));
+       else while (++MARK <= SP) {
+           if (*MARK != &PL_sv_undef
+                   && (SvPADTMP(*MARK)
+                      || (SvFLAGS(*MARK) & (SVf_READONLY|SVf_FAKE))
+                            == SVf_READONLY
+                      )
+           ) {
+                   SV *sv;
+                   /* Might be flattened array after $#array =  */
+                   PUTBACK;
+                   LEAVE;
+                   cxstack_ix--;
+                   POPSUB(cx,sv);
+                   PL_curpm = newpm;
+                   LEAVESUB(sv);
+                   Perl_croak(aTHX_
+                       "Can't return a %s from lvalue subroutine",
+                       SvREADONLY(TOPs) ? "readonly value" : "temporary");
+           }
+           else
+               *++newsp =
+                   SvTEMP(*MARK)
+                      ? *MARK
+                      : sv_2mortal(SvREFCNT_inc_simple_NN(*MARK));
+       }
+    }
+    PL_stack_sp = newsp;
+}
+
 PP(pp_return)
 {
     dVAR; dSP; dMARK;
@@ -2319,11 +2494,13 @@ PP(pp_return)
     }
 
     TAINT_NOT;
-    if (gimme == G_SCALAR) {
+    if (lval) S_return_lvalues(aTHX_ MARK, SP, newsp, gimme, cx, newpm);
+    else {
+      if (gimme == G_SCALAR) {
        if (MARK < SP) {
            if (popsub2) {
                if (cx->blk_sub.cv && CvDEPTH(cx->blk_sub.cv) > 1) {
-                   if (SvTEMP(TOPs)) {
+                   if (SvTEMP(TOPs) && SvREFCNT(TOPs) == 1) {
                        *++newsp = SvREFCNT_inc(*SP);
                        FREETMPS;
                        sv_2mortal(*newsp);
@@ -2335,24 +2512,27 @@ PP(pp_return)
                        SvREFCNT_dec(sv);
                    }
                }
+               else if (SvTEMP(*SP) && SvREFCNT(*SP) == 1) {
+                   *++newsp = *SP;
+               }
                else
-                   *++newsp =
-                       (lval || SvTEMP(*SP)) ? *SP : sv_mortalcopy(*SP);
+                   *++newsp = sv_mortalcopy(*SP);
            }
            else
                *++newsp = sv_mortalcopy(*SP);
        }
        else
            *++newsp = &PL_sv_undef;
-    }
-    else if (gimme == G_ARRAY) {
+      }
+      else if (gimme == G_ARRAY) {
        while (++MARK <= SP) {
-           *++newsp = popsub2 && (lval || SvTEMP(*MARK))
+           *++newsp = popsub2 && SvTEMP(*MARK) && SvREFCNT(*MARK) == 1
                        ? *MARK : sv_mortalcopy(*MARK);
            TAINT_NOT;          /* Each item is independent */
        }
+      }
+      PL_stack_sp = newsp;
     }
-    PL_stack_sp = newsp;
 
     LEAVE;
     /* Stack values are safe: */
@@ -2371,6 +2551,37 @@ PP(pp_return)
     return retop;
 }
 
+/* This duplicates parts of pp_leavesub, so that it can share code with
+ * pp_return */
+PP(pp_leavesublv)
+{
+    dVAR; dSP;
+    SV **newsp;
+    PMOP *newpm;
+    I32 gimme;
+    register PERL_CONTEXT *cx;
+    SV *sv;
+
+    if (CxMULTICALL(&cxstack[cxstack_ix]))
+       return 0;
+
+    POPBLOCK(cx,newpm);
+    cxstack_ix++; /* temporarily protect top context */
+    assert(CvLVALUE(cx->blk_sub.cv));
+
+    TAINT_NOT;
+
+    S_return_lvalues(aTHX_ newsp, SP, newsp, gimme, cx, newpm);
+
+    LEAVE;
+    cxstack_ix--;
+    POPSUB(cx,sv);     /* Stack values are safe: release CV and @_ ... */
+    PL_curpm = newpm;  /* ... and pop $1 et al */
+
+    LEAVESUB(sv);
+    return cx->blk_sub.retop;
+}
+
 PP(pp_last)
 {
     dVAR; dSP;
@@ -2428,21 +2639,8 @@ PP(pp_last)
     }
 
     TAINT_NOT;
-    if (gimme == G_SCALAR) {
-       if (MARK < SP)
-           *++newsp = ((pop2 == CXt_SUB) && SvTEMP(*SP))
-                       ? *SP : sv_mortalcopy(*SP);
-       else
-           *++newsp = &PL_sv_undef;
-    }
-    else if (gimme == G_ARRAY) {
-       while (++MARK <= SP) {
-           *++newsp = ((pop2 == CXt_SUB) && SvTEMP(*MARK))
-                       ? *MARK : sv_mortalcopy(*MARK);
-           TAINT_NOT;          /* Each item is independent */
-       }
-    }
-    SP = newsp;
+    SP = adjust_stack_on_leave(newsp, SP, MARK, gimme,
+                               pop2 == CXt_SUB ? SVs_TEMP : 0);
     PUTBACK;
 
     LEAVE;
@@ -3276,6 +3474,7 @@ S_doeval(pTHX_ int gimme, OP** startop, CV* outside, U32 seq)
     CvEVAL_on(PL_compcv);
     assert(CxTYPE(&cxstack[cxstack_ix]) == CXt_EVAL);
     cxstack[cxstack_ix].blk_eval.cv = PL_compcv;
+    cxstack[cxstack_ix].blk_gimme = gimme;
 
     CvOUTSIDE_SEQ(PL_compcv) = seq;
     CvOUTSIDE(PL_compcv) = MUTABLE_CV(SvREFCNT_inc_simple(outside));
@@ -3327,11 +3526,13 @@ S_doeval(pTHX_ int gimme, OP** startop, CV* outside, U32 seq)
 
     if (yystatus || PL_parser->error_count || !PL_eval_root) {
        SV **newsp;                     /* Used by POPBLOCK. */
-       PERL_CONTEXT *cx = NULL;
+       PERL_CONTEXT *cx;
        I32 optype;                     /* Used by POPEVAL. */
-       SV *namesv = NULL;
+       SV *namesv;
        const char *msg;
 
+       cx = NULL;
+       namesv = NULL;
        PERL_UNUSED_VAR(newsp);
        PERL_UNUSED_VAR(optype);
 
@@ -3391,15 +3592,6 @@ S_doeval(pTHX_ int gimme, OP** startop, CV* outside, U32 seq)
     } else
        SAVEFREEOP(PL_eval_root);
 
-    /* Set the context for this new optree.
-     * Propagate the context from the eval(). */
-    if ((gimme & G_WANT) == G_VOID)
-       scalarvoid(PL_eval_root);
-    else if ((gimme & G_WANT) == G_ARRAY)
-       list(PL_eval_root);
-    else
-       scalar(PL_eval_root);
-
     DEBUG_x(dump_eval());
 
     /* Register with debugger: */
@@ -3986,14 +4178,14 @@ PP(pp_entereval)
     SAVECOMPILEWARNINGS();
     PL_compiling.cop_warnings = DUP_WARNINGS(PL_curcop->cop_warnings);
     cophh_free(CopHINTHASH_get(&PL_compiling));
-    if (Perl_fetch_cop_label(aTHX_ PL_curcop, NULL, NULL)) {
+    if (Perl_cop_fetch_label(aTHX_ PL_curcop, NULL, NULL)) {
        /* The label, if present, is the first entry on the chain. So rather
           than writing a blank label in front of it (which involves an
           allocation), just use the next entry in the chain.  */
        PL_compiling.cop_hints_hash
            = cophh_copy(PL_curcop->cop_hints_hash->refcounted_he_next);
        /* Check the assumption that this removed the label.  */
-       assert(Perl_fetch_cop_label(aTHX_ &PL_compiling, NULL, NULL) == NULL);
+       assert(Perl_cop_fetch_label(aTHX_ &PL_compiling, NULL, NULL) == NULL);
     }
     else
        PL_compiling.cop_hints_hash = cophh_copy(PL_curcop->cop_hints_hash);
@@ -4047,7 +4239,6 @@ PP(pp_entereval)
 PP(pp_leaveeval)
 {
     dVAR; dSP;
-    register SV **mark;
     SV **newsp;
     PMOP *newpm;
     I32 gimme;
@@ -4064,31 +4255,8 @@ PP(pp_leaveeval)
     retop = cx->blk_eval.retop;
 
     TAINT_NOT;
-    if (gimme == G_VOID)
-       MARK = newsp;
-    else if (gimme == G_SCALAR) {
-       MARK = newsp + 1;
-       if (MARK <= SP) {
-           if (SvFLAGS(TOPs) & SVs_TEMP)
-               *MARK = TOPs;
-           else
-               *MARK = sv_mortalcopy(TOPs);
-       }
-       else {
-           MEXTEND(mark,0);
-           *MARK = &PL_sv_undef;
-       }
-       SP = MARK;
-    }
-    else {
-       /* in case LEAVE wipes old return values */
-       for (mark = newsp + 1; mark <= SP; mark++) {
-           if (!(SvFLAGS(*mark) & SVs_TEMP)) {
-               *mark = sv_mortalcopy(*mark);
-               TAINT_NOT;      /* Each item is independent */
-           }
-       }
-    }
+    SP = adjust_stack_on_leave((gimme == G_VOID) ? SP : newsp, SP, newsp,
+                               gimme, SVs_TEMP);
     PL_curpm = newpm;  /* Don't pop $1 et al till now */
 
 #ifdef DEBUGGING
@@ -4185,33 +4353,7 @@ PP(pp_leavetry)
     PERL_UNUSED_VAR(optype);
 
     TAINT_NOT;
-    if (gimme == G_VOID)
-       SP = newsp;
-    else if (gimme == G_SCALAR) {
-       register SV **mark;
-       MARK = newsp + 1;
-       if (MARK <= SP) {
-           if (SvFLAGS(TOPs) & (SVs_PADTMP|SVs_TEMP))
-               *MARK = TOPs;
-           else
-               *MARK = sv_mortalcopy(TOPs);
-       }
-       else {
-           MEXTEND(mark,0);
-           *MARK = &PL_sv_undef;
-       }
-       SP = MARK;
-    }
-    else {
-       /* in case LEAVE wipes old return values */
-       register SV **mark;
-       for (mark = newsp + 1; mark <= SP; mark++) {
-           if (!(SvFLAGS(*mark) & (SVs_PADTMP|SVs_TEMP))) {
-               *mark = sv_mortalcopy(*mark);
-               TAINT_NOT;      /* Each item is independent */
-           }
-       }
-    }
+    SP = adjust_stack_on_leave(newsp, SP, newsp, gimme, SVs_PADTMP|SVs_TEMP);
     PL_curpm = newpm;  /* Don't pop $1 et al till now */
 
     LEAVE_with_name("eval_scope");
@@ -4249,33 +4391,7 @@ PP(pp_leavegiven)
     assert(CxTYPE(cx) == CXt_GIVEN);
 
     TAINT_NOT;
-    if (gimme == G_VOID)
-       SP = newsp;
-    else if (gimme == G_SCALAR) {
-       register SV **mark;
-       MARK = newsp + 1;
-       if (MARK <= SP) {
-           if (SvFLAGS(TOPs) & (SVs_PADTMP|SVs_TEMP))
-               *MARK = TOPs;
-           else
-               *MARK = sv_mortalcopy(TOPs);
-       }
-       else {
-           MEXTEND(mark,0);
-           *MARK = &PL_sv_undef;
-       }
-       SP = MARK;
-    }
-    else {
-       /* in case LEAVE wipes old return values */
-       register SV **mark;
-       for (mark = newsp + 1; mark <= SP; mark++) {
-           if (!(SvFLAGS(*mark) & (SVs_PADTMP|SVs_TEMP))) {
-               *mark = sv_mortalcopy(*mark);
-               TAINT_NOT;      /* Each item is independent */
-           }
-       }
-    }
+    SP = adjust_stack_on_leave(newsp, SP, newsp, gimme, SVs_PADTMP|SVs_TEMP);
     PL_curpm = newpm;  /* Don't pop $1 et al till now */
 
     LEAVE_with_name("given");
@@ -4825,7 +4941,7 @@ PP(pp_enterwhen)
     if ((0 == (PL_op->op_flags & OPf_SPECIAL)) && !SvTRUEx(POPs))
        RETURNOP(cLOGOP->op_other->op_next);
 
-    ENTER_with_name("eval");
+    ENTER_with_name("when");
     SAVETMPS;
 
     PUSHBLOCK(cx, CXt_WHEN, SP);
@@ -4837,43 +4953,71 @@ PP(pp_enterwhen)
 PP(pp_leavewhen)
 {
     dVAR; dSP;
+    I32 cxix;
     register PERL_CONTEXT *cx;
-    I32 gimme __attribute__unused__;
+    I32 gimme;
     SV **newsp;
     PMOP *newpm;
 
+    cxix = dopoptogiven(cxstack_ix);
+    if (cxix < 0)
+       DIE(aTHX_ "Can't use when() outside a topicalizer");
+
     POPBLOCK(cx,newpm);
     assert(CxTYPE(cx) == CXt_WHEN);
 
-    SP = newsp;
-    PUTBACK;
-
+    TAINT_NOT;
+    SP = adjust_stack_on_leave(newsp, SP, newsp, gimme, SVs_PADTMP|SVs_TEMP);
     PL_curpm = newpm;   /* pop $1 et al */
 
-    LEAVE_with_name("eval");
-    return NORMAL;
+    LEAVE_with_name("when");
+
+    if (cxix < cxstack_ix)
+        dounwind(cxix);
+
+    cx = &cxstack[cxix];
+
+    if (CxFOREACH(cx)) {
+       /* clear off anything above the scope we're re-entering */
+       I32 inner = PL_scopestack_ix;
+
+       TOPBLOCK(cx);
+       if (PL_scopestack_ix < inner)
+           leave_scope(PL_scopestack[PL_scopestack_ix]);
+       PL_curcop = cx->blk_oldcop;
+
+       return cx->blk_loop.my_op->op_nextop;
+    }
+    else
+       RETURNOP(cx->blk_givwhen.leave_op);
 }
 
 PP(pp_continue)
 {
-    dVAR;   
+    dVAR; dSP;
     I32 cxix;
     register PERL_CONTEXT *cx;
-    I32 inner;
+    I32 gimme;
+    SV **newsp;
+    PMOP *newpm;
+
+    PERL_UNUSED_VAR(gimme);
     
     cxix = dopoptowhen(cxstack_ix); 
     if (cxix < 0)   
        DIE(aTHX_ "Can't \"continue\" outside a when block");
+
     if (cxix < cxstack_ix)
         dounwind(cxix);
     
-    /* clear off anything above the scope we're re-entering */
-    inner = PL_scopestack_ix;
-    TOPBLOCK(cx);
-    if (PL_scopestack_ix < inner)
-        leave_scope(PL_scopestack[PL_scopestack_ix]);
-    PL_curcop = cx->blk_oldcop;
-    return cx->blk_givwhen.leave_op;
+    POPBLOCK(cx,newpm);
+    assert(CxTYPE(cx) == CXt_WHEN);
+
+    SP = newsp;
+    PL_curpm = newpm;   /* pop $1 et al */
+
+    LEAVE_with_name("when");
+    RETURNOP(cx->blk_givwhen.leave_op->op_next);
 }
 
 PP(pp_break)
@@ -4881,34 +5025,22 @@ PP(pp_break)
     dVAR;   
     I32 cxix;
     register PERL_CONTEXT *cx;
-    I32 inner;
-    dSP;
 
     cxix = dopoptogiven(cxstack_ix); 
-    if (cxix < 0) {
-       if (PL_op->op_flags & OPf_SPECIAL)
-           DIE(aTHX_ "Can't use when() outside a topicalizer");
-       else
-           DIE(aTHX_ "Can't \"break\" outside a given block");
-    }
-    if (CxFOREACH(&cxstack[cxix]) && (0 == (PL_op->op_flags & OPf_SPECIAL)))
+    if (cxix < 0)
+       DIE(aTHX_ "Can't \"break\" outside a given block");
+
+    cx = &cxstack[cxix];
+    if (CxFOREACH(cx))
        DIE(aTHX_ "Can't \"break\" in a loop topicalizer");
 
     if (cxix < cxstack_ix)
         dounwind(cxix);
-    
-    /* clear off anything above the scope we're re-entering */
-    inner = PL_scopestack_ix;
+
+    /* Restore the sp at the time we entered the given block */
     TOPBLOCK(cx);
-    if (PL_scopestack_ix < inner)
-        leave_scope(PL_scopestack[PL_scopestack_ix]);
-    PL_curcop = cx->blk_oldcop;
 
-    if (CxFOREACH(cx))
-       return (cx)->blk_loop.my_op->op_nextop;
-    else
-       /* RETURNOP calls PUTBACK which restores the old old sp */
-       RETURNOP(cx->blk_givwhen.leave_op);
+    return cx->blk_givwhen.leave_op;
 }
 
 static MAGIC *
@@ -5019,14 +5151,14 @@ S_doparseform(pTHX_ SV *sv)
                if (postspace)
                    *fpc++ = FF_SPACE;
                *fpc++ = FF_LITERAL;
-               *fpc++ = (U16)arg;
+               *fpc++ = (U32)arg;
            }
            postspace = FALSE;
            if (s <= send)
                skipspaces--;
            if (skipspaces) {
                *fpc++ = FF_SKIP;
-               *fpc++ = (U16)skipspaces;
+               *fpc++ = (U32)skipspaces;
            }
            skipspaces = 0;
            if (s <= send)
@@ -5037,7 +5169,7 @@ S_doparseform(pTHX_ SV *sv)
                    arg = fpc - linepc + 1;
                else
                    arg = 0;
-               *fpc++ = (U16)arg;
+               *fpc++ = (U32)arg;
            }
            if (s < send) {
                linepc = fpc;
@@ -5060,7 +5192,7 @@ S_doparseform(pTHX_ SV *sv)
            arg = (s - base) - 1;
            if (arg) {
                *fpc++ = FF_LITERAL;
-               *fpc++ = (U16)arg;
+               *fpc++ = (U32)arg;
            }
 
            base = s - 1;
@@ -5075,7 +5207,7 @@ S_doparseform(pTHX_ SV *sv)
                    *fpc++ = FF_LINEGLOB;
            }
            else if (*s == '#' || (*s == '.' && s[1] == '#')) { /* @###, ^### */
-               arg = ischop ? 512 : 0;
+               arg = ischop ? FORM_NUM_BLANK : 0;
                base = s - 1;
                while (*s == '#')
                    s++;
@@ -5083,15 +5215,15 @@ S_doparseform(pTHX_ SV *sv)
                     const char * const f = ++s;
                    while (*s == '#')
                        s++;
-                   arg |= 256 + (s - f);
+                   arg |= FORM_NUM_POINT + (s - f);
                }
                *fpc++ = s - base;              /* fieldsize for FETCH */
                *fpc++ = FF_DECIMAL;
-                *fpc++ = (U16)arg;
+                *fpc++ = (U32)arg;
                 unchopnum |= ! ischop;
             }
             else if (*s == '0' && s[1] == '#') {  /* Zero padded decimals */
-                arg = ischop ? 512 : 0;
+                arg = ischop ? FORM_NUM_BLANK : 0;
                base = s - 1;
                 s++;                                /* skip the '0' first */
                 while (*s == '#')
@@ -5100,11 +5232,11 @@ S_doparseform(pTHX_ SV *sv)
                     const char * const f = ++s;
                     while (*s == '#')
                         s++;
-                    arg |= 256 + (s - f);
+                    arg |= FORM_NUM_POINT + (s - f);
                 }
                 *fpc++ = s - base;                /* fieldsize for FETCH */
                 *fpc++ = FF_0DECIMAL;
-               *fpc++ = (U16)arg;
+               *fpc++ = (U32)arg;
                 unchopnum |= ! ischop;
            }
            else {                              /* text field */
@@ -5134,7 +5266,7 @@ S_doparseform(pTHX_ SV *sv)
                *fpc++ = ischop ? FF_CHECKCHOP : FF_CHECKNL;
 
                if (prespace)
-                   *fpc++ = (U16)prespace; /* add SPACE or HALFSPACE */
+                   *fpc++ = (U32)prespace; /* add SPACE or HALFSPACE */
                *fpc++ = FF_ITEM;
                if (ismore)
                    *fpc++ = FF_MORE;
@@ -5172,9 +5304,9 @@ S_num_overflow(NV value, I32 fldsize, I32 frcsize)
     bool res = FALSE;
     int intsize = fldsize - (value < 0 ? 1 : 0);
 
-    if (frcsize & 256)
+    if (frcsize & FORM_NUM_POINT)
         intsize--;
-    frcsize &= 255;
+    frcsize &= ~(FORM_NUM_POINT|FORM_NUM_BLANK);
     intsize -= frcsize;
 
     while (intsize--) pwr *= 10.0;
@@ -5272,11 +5404,14 @@ S_run_user_filter(pTHX_ int idx, SV *buf_sv, int maxlen)
        int count;
 
        ENTER_with_name("call_filter_sub");
-       SAVE_DEFSV;
+       save_gp(PL_defgv, 0);
+       GvINTRO_off(PL_defgv);
+       SAVEGENERICSV(GvSV(PL_defgv));
        SAVETMPS;
        EXTEND(SP, 2);
 
        DEFSV_set(upstream);
+       SvREFCNT_inc_simple_void_NN(upstream);
        PUSHMARK(SP);
        mPUSHi(0);
        if (filter_state) {