pod/perlfaq4.pod

[perl5.git] / pp.c

diff --git a/pp.c b/pp.c
index 6c4f2ff..d7fc6bf 100644 (file)
--- a/pp.c
+++ b/pp.c
@@ -17,6 +17,8 @@
 #include "perl.h"
 #include "keywords.h"
 
+#include "reentr.h"
+
 /* variations on pp_null */
 
 /* XXX I can't imagine anyone who doesn't have this actually _needs_
@@ -62,7 +64,7 @@ PP(pp_padav)
        EXTEND(SP, maxarg);
        if (SvMAGICAL(TARG)) {
            U32 i;
-           for (i=0; i < maxarg; i++) {
+           for (i=0; i < (U32)maxarg; i++) {
                SV **svp = av_fetch((AV*)TARG, i, FALSE);
                SP[i+1] = (svp) ? *svp : &PL_sv_undef;
            }
@@ -954,6 +956,8 @@ PP(pp_pow)
                             result *= base;
                             /* Only bother to clear the bit if it is set.  */
                             power &= ~bit;
+                           /* Avoid squaring base again if we're done. */
+                           if (power == 0) break;
                         }
                     }
                     SP--;
@@ -1185,7 +1189,7 @@ PP(pp_divide)
                     }
                     /* 2s complement assumption */
                     if (result <= (UV)IV_MIN)
-                        SETi( -result );
+                        SETi( -(IV)result );
                     else {
                         /* It's exact but too negative for IV. */
                         SETn( -(NV)result );
@@ -2680,7 +2684,7 @@ S_seed(pTHX)
     u = (U32)SEED_C1 * when[0] + (U32)SEED_C2 * when[1];
 #else
 #  ifdef HAS_GETTIMEOFDAY
-    gettimeofday(&when,(struct timezone *) 0);
+    PerlProc_gettimeofday(&when,NULL);
     u = (U32)SEED_C1 * when.tv_sec + (U32)SEED_C2 * when.tv_usec;
 #  else
     (void)time(&when);
@@ -3161,7 +3165,7 @@ PP(pp_index)
        sv_pos_u2b(big, &offset, 0);
     if (offset < 0)
        offset = 0;
-    else if (offset > biglen)
+    else if (offset > (I32)biglen)
        offset = biglen;
     if (!(tmps2 = fbm_instr((unsigned char*)tmps + offset,
       (unsigned char*)tmps + biglen, little, 0)))
@@ -3202,7 +3206,7 @@ PP(pp_rindex)
     }
     if (offset < 0)
        offset = 0;
-    else if (offset > blen)
+    else if (offset > (I32)blen)
        offset = blen;
     if (!(tmps2 = rninstr(tmps,  tmps  + offset,
                          tmps2, tmps2 + llen)))
@@ -3257,7 +3261,7 @@ PP(pp_chr)
     (void)SvUPGRADE(TARG,SVt_PV);
 
     if (value > 255 && !IN_BYTES) {
-       SvGROW(TARG, UNISKIP(value)+1);
+       SvGROW(TARG, (STRLEN)UNISKIP(value)+1);
        tmps = (char*)uvchr_to_utf8_flags((U8*)SvPVX(TARG), value, 0);
        SvCUR_set(TARG, tmps - SvPVX(TARG));
        *tmps = '\0';
@@ -3270,7 +3274,7 @@ PP(pp_chr)
     SvGROW(TARG,2);
     SvCUR_set(TARG, 1);
     tmps = SvPVX(TARG);
-    *tmps++ = value;
+    *tmps++ = (char)value;
     *tmps = '\0';
     (void)SvPOK_only(TARG);
     if (PL_encoding)
@@ -3303,12 +3307,12 @@ PP(pp_crypt)
 #   else
     sv_setpv(TARG, PerlProc_crypt(tmps, SvPV(right, n_a)));
 #   endif
+    SETs(TARG);
+    RETURN;
 #else
     DIE(aTHX_
       "The crypt() function is unimplemented due to excessive paranoia.");
 #endif
-    SETs(TARG);
-    RETURN;
 }
 
 PP(pp_ucfirst)
@@ -3383,7 +3387,7 @@ PP(pp_lcfirst)
        
        tend = uvchr_to_utf8(tmpbuf, uv);
 
-       if (!SvPADTMP(sv) || tend - tmpbuf != ulen || SvREADONLY(sv)) {
+       if (!SvPADTMP(sv) || (STRLEN)(tend - tmpbuf) != ulen || SvREADONLY(sv)) {
            dTARGET;
            sv_setpvn(TARG, (char*)tmpbuf, tend - tmpbuf);
            sv_catpvn(TARG, (char*)(s + ulen), slen - ulen);
@@ -3823,17 +3827,38 @@ PP(pp_hslice)
     register HV *hv = (HV*)POPs;
     register I32 lval = (PL_op->op_flags & OPf_MOD || LVRET);
     I32 realhv = (SvTYPE(hv) == SVt_PVHV);
+    bool localizing = PL_op->op_private & OPpLVAL_INTRO ? TRUE : FALSE;
+    bool other_magic = FALSE;
+
+    if (localizing) {
+        MAGIC *mg;
+        HV *stash;
 
-    if (!realhv && PL_op->op_private & OPpLVAL_INTRO)
+        other_magic = mg_find((SV*)hv, PERL_MAGIC_env) ||
+            ((mg = mg_find((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((SV*)hv, mg))))
+             && gv_fetchmethod_autoload(stash, "EXISTS", TRUE)
+             && gv_fetchmethod_autoload(stash, "DELETE", TRUE));
+    }
+
+    if (!realhv && localizing)
        DIE(aTHX_ "Can't localize pseudo-hash element");
 
     if (realhv || SvTYPE(hv) == SVt_PVAV) {
        while (++MARK <= SP) {
            SV *keysv = *MARK;
            SV **svp;
-           I32 preeminent = SvRMAGICAL(hv) ? 1 :
-                               realhv ? hv_exists_ent(hv, keysv, 0)
-                                      : avhv_exists_ent((AV*)hv, keysv, 0);
+           bool preeminent = FALSE;
+
+            if (localizing) {
+                preeminent = SvRMAGICAL(hv) && !other_magic ? 1 :
+                    realhv ? hv_exists_ent(hv, keysv, 0)
+                    : avhv_exists_ent((AV*)hv, keysv, 0);
+            }
+
            if (realhv) {
                HE *he = hv_fetch_ent(hv, keysv, lval, 0);
                svp = he ? &HeVAL(he) : 0;
@@ -3846,7 +3871,7 @@ PP(pp_hslice)
                    STRLEN n_a;
                    DIE(aTHX_ PL_no_helem, SvPV(keysv, n_a));
                }
-               if (PL_op->op_private & OPpLVAL_INTRO) {
+               if (localizing) {
                    if (preeminent)
                        save_helem(hv, keysv, svp);
                    else {
@@ -4304,7 +4329,7 @@ PP(pp_reverse)
                        while (down > up) {
                            tmp = *up;
                            *up++ = *down;
-                           *down-- = tmp;
+                           *down-- = (char)tmp;
                        }
                    }
                }
@@ -4314,7 +4339,7 @@ PP(pp_reverse)
            while (down > up) {
                tmp = *up;
                *up++ = *down;
-               *down-- = tmp;
+               *down-- = (char)tmp;
            }
            (void)SvPOK_only_UTF8(TARG);
        }
@@ -4544,7 +4569,7 @@ PP(pp_split)
                (void)SvUTF8_on(dstr);
            XPUSHs(dstr);
            if (rx->nparens) {
-               for (i = 1; i <= rx->nparens; i++) {
+               for (i = 1; i <= (I32)rx->nparens; i++) {
                    s = rx->startp[i] + orig;
                    m = rx->endp[i] + orig;
 
@@ -4586,8 +4611,12 @@ PP(pp_split)
        iters++;
     }
     else if (!origlimit) {
-       while (iters > 0 && (!TOPs || !SvANY(TOPs) || SvCUR(TOPs) == 0))
-           iters--, SP--;
+       while (iters > 0 && (!TOPs || !SvANY(TOPs) || SvCUR(TOPs) == 0)) {
+           if (TOPs && !make_mortal)
+               sv_2mortal(TOPs);
+           iters--;
+           SP--;
+       }
     }
 
     if (realarray) {