X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/626ed49c374dc371a27e6734ce3d3399c07e2bb4..8aef2117c820d82091fcbab49e8ae3bc5312b954:/pp_sort.c?ds=sidebyside

diff --git a/pp_sort.c b/pp_sort.c
index 3203f4c..bfd7fa2 100644
--- a/pp_sort.c
+++ b/pp_sort.c
@@ -1432,7 +1432,7 @@ Sort an array.  Here is an example:
 
     sortsv(AvARRAY(av), av_top_index(av)+1, Perl_sv_cmp_locale);
 
-Currently this always uses mergesort.  See sortsv_flags for a more
+Currently this always uses mergesort.  See C<L</sortsv_flags>> for a more
 flexible routine.
 
 =cut
@@ -1642,8 +1642,8 @@ PP(pp_sort)
 	    PERL_CONTEXT *cx;
 	    SV** newsp;
 	    const bool oldcatch = CATCH_GET;
+            I32 old_savestack_ix = PL_savestack_ix;
 
-	    SAVETMPS;
 	    SAVEOP();
 
 	    CATCH_SET(TRUE);
@@ -1657,19 +1657,21 @@ PP(pp_sort)
 		PL_secondgv = MUTABLE_GV(SvREFCNT_inc(
 		    gv_fetchpvs("b", GV_ADD|GV_NOTQUAL, SVt_PV)
 		));
+                /* make sure the GP isn't removed out from under us for
+                 * the SAVESPTR() */
+                save_gp(PL_firstgv, 0);
+                save_gp(PL_secondgv, 0);
+                /* we don't want modifications localized */
+                GvINTRO_off(PL_firstgv);
+                GvINTRO_off(PL_secondgv);
 		SAVESPTR(GvSV(PL_firstgv));
 		SAVESPTR(GvSV(PL_secondgv));
 	    }
 
+            gimme = G_SCALAR;
 	    PUSHBLOCK(cx, CXt_NULL, PL_stack_base);
 	    if (!(flags & OPf_SPECIAL)) {
 		cx->cx_type = CXt_SUB;
-		cx->blk_gimme = G_SCALAR;
-		/* If our comparison routine is already active (CvDEPTH is
-		 * is not 0),  then PUSHSUB does not increase the refcount,
-		 * so we have to do it ourselves, because the LEAVESUB fur-
-		 * ther down lowers it. */
-		if (CvDEPTH(cv)) SvREFCNT_inc_simple_void_NN(cv);
 		PUSHSUB(cx);
 		if (!is_xsub) {
 		    PADLIST * const padlist = CvPADLIST(cv);
@@ -1678,7 +1680,6 @@ PP(pp_sort)
 			PERL_STACK_OVERFLOW_CHECK();
 			pad_push(padlist, CvDEPTH(cv));
 		    }
-		    SAVECOMPPAD();
 		    PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));
 
 		    if (hasargs) {
@@ -1687,12 +1688,18 @@ PP(pp_sort)
 
 			cx->blk_sub.savearray = GvAV(PL_defgv);
 			GvAV(PL_defgv) = MUTABLE_AV(SvREFCNT_inc_simple(av));
-			CX_CURPAD_SAVE(cx->blk_sub);
-			cx->blk_sub.argarray = av;
 		    }
 
 		}
 	    }
+            else {
+                /* mimic PUSHSUB. Note that we're cheating and using a
+                 * CXt_NULL block as a CXt_SUB block */
+                cx->cx_u.cx_blk.blku_old_tmpsfloor = PL_tmps_floor;
+                PL_tmps_floor = PL_tmps_ix;
+            }
+            cx->cx_u.cx_blk.blku_old_savestack_ix = old_savestack_ix;
+
 	    cx->cx_type |= CXp_MULTICALL;
 	    
 	    start = p1 - max;
@@ -1708,6 +1715,10 @@ PP(pp_sort)
 		POPSUB(cx, sv);
 		LEAVESUB(sv);
 	    }
+            else
+                /* mimic POPSUB */
+                PL_tmps_floor = cx->cx_u.cx_blk.blku_old_tmpsfloor;
+
 	    POPBLOCK(cx,PL_curpm);
 	    PL_stack_sp = newsp;
 	    POPSTACK;
@@ -1782,12 +1793,10 @@ S_sortcv(pTHX_ SV *const a, SV *const b)
     PL_op = PL_sortcop;
     CALLRUNOPS(aTHX);
     PL_curcop = cop;
-    if (PL_stack_sp != PL_stack_base + 1) {
-	assert(PL_stack_sp == PL_stack_base);
-	result = SvIV(&PL_sv_undef);
-    }
-    else
-        result = SvIV(*PL_stack_sp);
+    /* entry zero of a stack is always PL_sv_undef, which
+     * simplifies converting a '()' return into undef in scalar context */
+    assert(PL_stack_sp > PL_stack_base || *PL_stack_base == &PL_sv_undef);
+    result = SvIV(*PL_stack_sp);
 
     while (PL_scopestack_ix > oldscopeix) {
 	LEAVE;
@@ -1835,12 +1844,10 @@ S_sortcv_stacked(pTHX_ SV *const a, SV *const b)
     PL_op = PL_sortcop;
     CALLRUNOPS(aTHX);
     PL_curcop = cop;
-    if (PL_stack_sp != PL_stack_base + 1) {
-	assert(PL_stack_sp == PL_stack_base);
-	result = SvIV(&PL_sv_undef);
-    }
-    else
-        result = SvIV(*PL_stack_sp);
+    /* entry zero of a stack is always PL_sv_undef, which
+     * simplifies converting a '()' return into undef in scalar context */
+    assert(PL_stack_sp > PL_stack_base || *PL_stack_base == &PL_sv_undef);
+    result = SvIV(*PL_stack_sp);
 
     while (PL_scopestack_ix > oldscopeix) {
 	LEAVE;
@@ -1869,9 +1876,11 @@ S_sortcv_xsub(pTHX_ SV *const a, SV *const b)
     *++SP = b;
     PUTBACK;
     (void)(*CvXSUB(cv))(aTHX_ cv);
-    if (PL_stack_sp != PL_stack_base + 1)
-	Perl_croak(aTHX_ "Sort subroutine didn't return single value");
+    /* entry zero of a stack is always PL_sv_undef, which
+     * simplifies converting a '()' return into undef in scalar context */
+    assert(PL_stack_sp > PL_stack_base || *PL_stack_base == &PL_sv_undef);
     result = SvIV(*PL_stack_sp);
+
     while (PL_scopestack_ix > oldscopeix) {
 	LEAVE;
     }