X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/66e4e5d58b6f1a43b01a82c3d198f3a5add40b57..565590b5d66dafeef2ec402e8f2aecb5e1fc2a60:/gv.c

diff --git a/gv.c b/gv.c
index a75203b..da79403 100644
--- a/gv.c
+++ b/gv.c
@@ -33,6 +33,7 @@ Perl stores its global variables.
 #include "EXTERN.h"
 #define PERL_IN_GV_C
 #include "perl.h"
+#include "overload.c"
 
 static const char S_autoload[] = "AUTOLOAD";
 static const STRLEN S_autolen = sizeof(S_autoload)-1;
@@ -42,6 +43,8 @@ static const STRLEN S_autolen = sizeof(S_autoload)-1;
 GV *
 Perl_gv_SVadd(pTHX_ GV *gv)
 {
+    PERL_ARGS_ASSERT_GV_SVADD;
+
     if (!gv || SvTYPE((SV*)gv) != SVt_PVGV)
 	Perl_croak(aTHX_ "Bad symbol for scalar");
     if (!GvSV(gv))
@@ -53,6 +56,8 @@ Perl_gv_SVadd(pTHX_ GV *gv)
 GV *
 Perl_gv_AVadd(pTHX_ register GV *gv)
 {
+    PERL_ARGS_ASSERT_GV_AVADD;
+
     if (!gv || SvTYPE((SV*)gv) != SVt_PVGV)
 	Perl_croak(aTHX_ "Bad symbol for array");
     if (!GvAV(gv))
@@ -63,6 +68,8 @@ Perl_gv_AVadd(pTHX_ register GV *gv)
 GV *
 Perl_gv_HVadd(pTHX_ register GV *gv)
 {
+    PERL_ARGS_ASSERT_GV_HVADD;
+
     if (!gv || SvTYPE((SV*)gv) != SVt_PVGV)
 	Perl_croak(aTHX_ "Bad symbol for hash");
     if (!GvHV(gv))
@@ -74,6 +81,9 @@ GV *
 Perl_gv_IOadd(pTHX_ register GV *gv)
 {
     dVAR;
+
+    PERL_ARGS_ASSERT_GV_IOADD;
+
     if (!gv || SvTYPE((SV*)gv) != SVt_PVGV) {
 
         /*
@@ -104,6 +114,7 @@ Perl_gv_IOadd(pTHX_ register GV *gv)
 GV *
 Perl_gv_fetchfile(pTHX_ const char *name)
 {
+    PERL_ARGS_ASSERT_GV_FETCHFILE;
     return gv_fetchfile_flags(name, strlen(name), 0);
 }
 
@@ -117,6 +128,7 @@ Perl_gv_fetchfile_flags(pTHX_ const char *const name, const STRLEN namelen,
     const STRLEN tmplen = namelen + 2;
     GV *gv;
 
+    PERL_ARGS_ASSERT_GV_FETCHFILE_FLAGS;
     PERL_UNUSED_ARG(flags);
 
     if (!PL_defstash)
@@ -160,6 +172,8 @@ NULL.
 SV *
 Perl_gv_const_sv(pTHX_ GV *gv)
 {
+    PERL_ARGS_ASSERT_GV_CONST_SV;
+
     if (SvTYPE(gv) == SVt_PVGV)
 	return cv_const_sv(GvCVu(gv));
     return SvROK(gv) ? SvRV(gv) : NULL;
@@ -169,10 +183,26 @@ GP *
 Perl_newGP(pTHX_ GV *const gv)
 {
     GP *gp;
+    U32 hash;
+#ifdef USE_ITHREADS
     const char *const file
 	= (PL_curcop && CopFILE(PL_curcop)) ? CopFILE(PL_curcop) : "";
-    STRLEN len = strlen(file);
-    U32 hash;
+    const STRLEN len = strlen(file);
+#else
+    SV *const temp_sv = CopFILESV(PL_curcop);
+    const char *file;
+    STRLEN len;
+
+    PERL_ARGS_ASSERT_NEWGP;
+
+    if (temp_sv) {
+	file = SvPVX(temp_sv);
+	len = SvCUR(temp_sv);
+    } else {
+	file = "";
+	len = 0;
+    }
+#endif
 
     PERL_HASH(hash, file, len);
 
@@ -198,10 +228,12 @@ Perl_gv_init(pTHX_ GV *gv, HV *stash, const char *name, STRLEN len, int multi)
     dVAR;
     const U32 old_type = SvTYPE(gv);
     const bool doproto = old_type > SVt_NULL;
-    const char * const proto = (doproto && SvPOK(gv)) ? SvPVX_const(gv) : NULL;
+    char * const proto = (doproto && SvPOK(gv)) ? SvPVX(gv) : NULL;
+    const STRLEN protolen = proto ? SvCUR(gv) : 0;
     SV *const has_constant = doproto && SvROK(gv) ? SvRV(gv) : NULL;
     const U32 exported_constant = has_constant ? SvPCS_IMPORTED(gv) : 0;
 
+    PERL_ARGS_ASSERT_GV_INIT;
     assert (!(proto && has_constant));
 
     if (has_constant) {
@@ -260,20 +292,22 @@ Perl_gv_init(pTHX_ GV *gv, HV *stash, const char *name, STRLEN len, int multi)
 	}
 	LEAVE;
 
-	PL_sub_generation++;
+        mro_method_changed_in(GvSTASH(gv)); /* sub Foo::bar($) { (shift) } sub ASDF::baz($); *ASDF::baz = \&Foo::bar */
 	CvGV(GvCV(gv)) = gv;
 	CvFILE_set_from_cop(GvCV(gv), PL_curcop);
 	CvSTASH(GvCV(gv)) = PL_curstash;
 	if (proto) {
-	    sv_setpv((SV*)GvCV(gv), proto);
-	    Safefree(proto);
+	    sv_usepvn_flags((SV*)GvCV(gv), proto, protolen,
+			    SV_HAS_TRAILING_NUL);
 	}
     }
 }
 
 STATIC void
-S_gv_init_sv(pTHX_ GV *gv, I32 sv_type)
+S_gv_init_sv(pTHX_ GV *gv, const svtype sv_type)
 {
+    PERL_ARGS_ASSERT_GV_INIT_SV;
+
     switch (sv_type) {
     case SVt_PVIO:
 	(void)GvIOn(gv);
@@ -291,7 +325,11 @@ S_gv_init_sv(pTHX_ GV *gv, I32 sv_type)
     case SVt_PVGV:
 	break;
     default:
-	(void)GvSVn(gv);
+	if(GvSVn(gv)) {
+	    /* Work round what appears to be a bug in Sun C++ 5.8 2005/10/13
+	       If we just cast GvSVn(gv) to void, it ignores evaluating it for
+	       its side effect */
+	}
 #endif
     }
 }
@@ -306,7 +344,7 @@ accessible via @ISA and UNIVERSAL::.
 The argument C<level> should be either 0 or -1.  If C<level==0>, as a
 side-effect creates a glob with the given C<name> in the given C<stash>
 which in the case of success contains an alias for the subroutine, and sets
-up caching info for this glob.  Similarly for all the searched stashes.
+up caching info for this glob.
 
 This function grants C<"SUPER"> token as a postfix of the stash name. The
 GV returned from C<gv_fetchmeth> may be a method cache entry, which is not
@@ -317,133 +355,140 @@ obtained from the GV with the C<GvCV> macro.
 =cut
 */
 
+/* NOTE: No support for tied ISA */
+
 GV *
 Perl_gv_fetchmeth(pTHX_ HV *stash, const char *name, STRLEN len, I32 level)
 {
     dVAR;
-    AV* av;
-    GV* topgv;
-    GV* gv;
     GV** gvp;
-    CV* cv;
+    AV* linear_av;
+    SV** linear_svp;
+    SV* linear_sv;
+    HV* cstash;
+    GV* candidate = NULL;
+    CV* cand_cv = NULL;
+    CV* old_cv;
+    GV* topgv = NULL;
     const char *hvname;
-    HV* lastchance = NULL;
+    I32 create = (level >= 0) ? 1 : 0;
+    I32 items;
+    STRLEN packlen;
+    U32 topgen_cmp;
+
+    PERL_ARGS_ASSERT_GV_FETCHMETH;
 
     /* UNIVERSAL methods should be callable without a stash */
     if (!stash) {
-	level = -1;  /* probably appropriate */
+	create = 0;  /* probably appropriate */
 	if(!(stash = gv_stashpvs("UNIVERSAL", 0)))
 	    return 0;
     }
 
+    assert(stash);
+
     hvname = HvNAME_get(stash);
     if (!hvname)
-      Perl_croak(aTHX_
-		 "Can't use anonymous symbol table for method lookup");
+      Perl_croak(aTHX_ "Can't use anonymous symbol table for method lookup");
 
-    if ((level > 100) || (level < -100))
-	Perl_croak(aTHX_ "Recursive inheritance detected while looking for method '%s' in package '%s'",
-	      name, hvname);
+    assert(hvname);
+    assert(name);
 
     DEBUG_o( Perl_deb(aTHX_ "Looking for method %s in package %s\n",name,hvname) );
 
-    gvp = (GV**)hv_fetch(stash, name, len, (level >= 0));
-    if (!gvp)
-	topgv = NULL;
-    else {
-	topgv = *gvp;
-	if (SvTYPE(topgv) != SVt_PVGV)
-	    gv_init(topgv, stash, name, len, TRUE);
-	if ((cv = GvCV(topgv))) {
-	    /* If genuine method or valid cache entry, use it */
-	    if (!GvCVGEN(topgv) || GvCVGEN(topgv) == PL_sub_generation)
-		return topgv;
-	    /* Stale cached entry: junk it */
-	    SvREFCNT_dec(cv);
-	    GvCV(topgv) = cv = NULL;
-	    GvCVGEN(topgv) = 0;
-	}
-	else if (GvCVGEN(topgv) == PL_sub_generation)
-	    return 0;  /* cache indicates sub doesn't exist */
+    topgen_cmp = HvMROMETA(stash)->cache_gen + PL_sub_generation;
+
+    /* check locally for a real method or a cache entry */
+    gvp = (GV**)hv_fetch(stash, name, len, create);
+    if(gvp) {
+        topgv = *gvp;
+        assert(topgv);
+        if (SvTYPE(topgv) != SVt_PVGV)
+            gv_init(topgv, stash, name, len, TRUE);
+        if ((cand_cv = GvCV(topgv))) {
+            /* If genuine method or valid cache entry, use it */
+            if (!GvCVGEN(topgv) || GvCVGEN(topgv) == topgen_cmp) {
+                return topgv;
+            }
+            else {
+                /* stale cache entry, junk it and move on */
+	        SvREFCNT_dec(cand_cv);
+	        GvCV(topgv) = cand_cv = NULL;
+	        GvCVGEN(topgv) = 0;
+            }
+        }
+        else if (GvCVGEN(topgv) == topgen_cmp) {
+            /* cache indicates no such method definitively */
+            return 0;
+        }
     }
 
-    gvp = (GV**)hv_fetchs(stash, "ISA", FALSE);
-    av = (gvp && (gv = *gvp) && isGV_with_GP(gv)) ? GvAV(gv) : NULL;
-
-    /* create and re-create @.*::SUPER::ISA on demand */
-    if (!av || !SvMAGIC(av)) {
-	STRLEN packlen = HvNAMELEN_get(stash);
-
-	if (packlen >= 7 && strEQ(hvname + packlen - 7, "::SUPER")) {
-	    HV* basestash;
-
-	    packlen -= 7;
-	    basestash = gv_stashpvn(hvname, packlen, GV_ADD);
-	    gvp = (GV**)hv_fetchs(basestash, "ISA", FALSE);
-	    if (gvp && (gv = *gvp) && isGV_with_GP(gv) && (av = GvAV(gv))) {
-		gvp = (GV**)hv_fetchs(stash, "ISA", TRUE);
-		if (!gvp || !(gv = *gvp))
-		    Perl_croak(aTHX_ "Cannot create %s::ISA", hvname);
-		if (SvTYPE(gv) != SVt_PVGV)
-		    gv_init(gv, stash, "ISA", 3, TRUE);
-		SvREFCNT_dec(GvAV(gv));
-		GvAV(gv) = (AV*)SvREFCNT_inc_simple(av);
-	    }
-	}
+    packlen = HvNAMELEN_get(stash);
+    if (packlen >= 7 && strEQ(hvname + packlen - 7, "::SUPER")) {
+        HV* basestash;
+        packlen -= 7;
+        basestash = gv_stashpvn(hvname, packlen, GV_ADD);
+        linear_av = mro_get_linear_isa(basestash);
     }
-
-    if (av) {
-	SV** svp = AvARRAY(av);
-	/* NOTE: No support for tied ISA */
-	I32 items = AvFILLp(av) + 1;
-	while (items--) {
-	    SV* const sv = *svp++;
-	    HV* const basestash = gv_stashsv(sv, 0);
-	    if (!basestash) {
-		if (ckWARN(WARN_MISC))
-		    Perl_warner(aTHX_ packWARN(WARN_MISC), "Can't locate package %"SVf" for @%s::ISA",
-			SVfARG(sv), hvname);
-		continue;
-	    }
-	    gv = gv_fetchmeth(basestash, name, len,
-			      (level >= 0) ? level + 1 : level - 1);
-	    if (gv)
-		goto gotcha;
-	}
+    else {
+        linear_av = mro_get_linear_isa(stash); /* has ourselves at the top of the list */
     }
 
-    /* if at top level, try UNIVERSAL */
+    linear_svp = AvARRAY(linear_av) + 1; /* skip over self */
+    items = AvFILLp(linear_av); /* no +1, to skip over self */
+    while (items--) {
+        linear_sv = *linear_svp++;
+        assert(linear_sv);
+        cstash = gv_stashsv(linear_sv, 0);
+
+        if (!cstash) {
+            if (ckWARN(WARN_SYNTAX))
+                Perl_warner(aTHX_ packWARN(WARN_SYNTAX), "Can't locate package %"SVf" for @%s::ISA",
+                    SVfARG(linear_sv), hvname);
+            continue;
+        }
 
-    if (level == 0 || level == -1) {
-	lastchance = gv_stashpvs("UNIVERSAL", 0);
+        assert(cstash);
+
+        gvp = (GV**)hv_fetch(cstash, name, len, 0);
+        if (!gvp) continue;
+        candidate = *gvp;
+        assert(candidate);
+        if (SvTYPE(candidate) != SVt_PVGV) gv_init(candidate, cstash, name, len, TRUE);
+        if (SvTYPE(candidate) == SVt_PVGV && (cand_cv = GvCV(candidate)) && !GvCVGEN(candidate)) {
+            /*
+             * Found real method, cache method in topgv if:
+             *  1. topgv has no synonyms (else inheritance crosses wires)
+             *  2. method isn't a stub (else AUTOLOAD fails spectacularly)
+             */
+            if (topgv && (GvREFCNT(topgv) == 1) && (CvROOT(cand_cv) || CvXSUB(cand_cv))) {
+                  if ((old_cv = GvCV(topgv))) SvREFCNT_dec(old_cv);
+                  SvREFCNT_inc_simple_void_NN(cand_cv);
+                  GvCV(topgv) = cand_cv;
+                  GvCVGEN(topgv) = topgen_cmp;
+            }
+	    return candidate;
+        }
+    }
 
-	if (lastchance) {
-	    if ((gv = gv_fetchmeth(lastchance, name, len,
-				  (level >= 0) ? level + 1 : level - 1)))
-	    {
-	  gotcha:
-		/*
-		 * Cache method in topgv if:
-		 *  1. topgv has no synonyms (else inheritance crosses wires)
-		 *  2. method isn't a stub (else AUTOLOAD fails spectacularly)
-		 */
-		if (topgv &&
-		    GvREFCNT(topgv) == 1 &&
-		    (cv = GvCV(gv)) &&
-		    (CvROOT(cv) || CvXSUB(cv)))
-		{
-		    if ((cv = GvCV(topgv)))
-			SvREFCNT_dec(cv);
-		    GvCV(topgv) = (CV*)SvREFCNT_inc(GvCV(gv));
-		    GvCVGEN(topgv) = PL_sub_generation;
-		}
-		return gv;
-	    }
-	    else if (topgv && GvREFCNT(topgv) == 1) {
-		/* cache the fact that the method is not defined */
-		GvCVGEN(topgv) = PL_sub_generation;
-	    }
-	}
+    /* Check UNIVERSAL without caching */
+    if(level == 0 || level == -1) {
+        candidate = gv_fetchmeth(NULL, name, len, 1);
+        if(candidate) {
+            cand_cv = GvCV(candidate);
+            if (topgv && (GvREFCNT(topgv) == 1) && (CvROOT(cand_cv) || CvXSUB(cand_cv))) {
+                  if ((old_cv = GvCV(topgv))) SvREFCNT_dec(old_cv);
+                  SvREFCNT_inc_simple_void_NN(cand_cv);
+                  GvCV(topgv) = cand_cv;
+                  GvCVGEN(topgv) = topgen_cmp;
+            }
+            return candidate;
+        }
+    }
+
+    if (topgv && GvREFCNT(topgv) == 1) {
+        /* cache the fact that the method is not defined */
+        GvCVGEN(topgv) = topgen_cmp;
     }
 
     return 0;
@@ -467,13 +512,15 @@ Perl_gv_fetchmeth_autoload(pTHX_ HV *stash, const char *name, STRLEN len, I32 le
 {
     GV *gv = gv_fetchmeth(stash, name, len, level);
 
+    PERL_ARGS_ASSERT_GV_FETCHMETH_AUTOLOAD;
+
     if (!gv) {
 	CV *cv;
 	GV **gvp;
 
 	if (!stash)
 	    return NULL;	/* UNIVERSAL::AUTOLOAD could cause trouble */
-	if (len == S_autolen && strnEQ(name, S_autoload, S_autolen))
+	if (len == S_autolen && memEQ(name, S_autoload, S_autolen))
 	    return NULL;
 	if (!(gv = gv_fetchmeth(stash, S_autoload, S_autolen, FALSE)))
 	    return NULL;
@@ -519,35 +566,89 @@ C<call_sv> apply equally to these functions.
 =cut
 */
 
+STATIC HV*
+S_gv_get_super_pkg(pTHX_ const char* name, I32 namelen)
+{
+    AV* superisa;
+    GV** gvp;
+    GV* gv;
+    HV* stash;
+
+    PERL_ARGS_ASSERT_GV_GET_SUPER_PKG;
+
+    stash = gv_stashpvn(name, namelen, 0);
+    if(stash) return stash;
+
+    /* If we must create it, give it an @ISA array containing
+       the real package this SUPER is for, so that it's tied
+       into the cache invalidation code correctly */
+    stash = gv_stashpvn(name, namelen, GV_ADD);
+    gvp = (GV**)hv_fetchs(stash, "ISA", TRUE);
+    gv = *gvp;
+    gv_init(gv, stash, "ISA", 3, TRUE);
+    superisa = GvAVn(gv);
+    GvMULTI_on(gv);
+    sv_magic((SV*)superisa, (SV*)gv, PERL_MAGIC_isa, NULL, 0);
+#ifdef USE_ITHREADS
+    av_push(superisa, newSVpv(CopSTASHPV(PL_curcop), 0));
+#else
+    av_push(superisa, newSVhek(CopSTASH(PL_curcop)
+			       ? HvNAME_HEK(CopSTASH(PL_curcop)) : NULL));
+#endif
+
+    return stash;
+}
+
 GV *
 Perl_gv_fetchmethod_autoload(pTHX_ HV *stash, const char *name, I32 autoload)
 {
+    PERL_ARGS_ASSERT_GV_FETCHMETHOD_AUTOLOAD;
+
+    return gv_fetchmethod_flags(stash, name, autoload ? GV_AUTOLOAD : 0);
+}
+
+/* Don't merge this yet, as it's likely to get a len parameter, and possibly
+   even a U32 hash */
+GV *
+Perl_gv_fetchmethod_flags(pTHX_ HV *stash, const char *name, U32 flags)
+{
     dVAR;
     register const char *nend;
     const char *nsplit = NULL;
     GV* gv;
     HV* ostash = stash;
+    const char * const origname = name;
+    SV *const error_report = (SV *)stash;
+    const U32 autoload = flags & GV_AUTOLOAD;
+    const U32 do_croak = flags & GV_CROAK;
 
-    if (stash && SvTYPE(stash) < SVt_PVHV)
+    PERL_ARGS_ASSERT_GV_FETCHMETHOD_FLAGS;
+
+    if (SvTYPE(stash) < SVt_PVHV)
 	stash = NULL;
+    else {
+	/* The only way stash can become NULL later on is if nsplit is set,
+	   which in turn means that there is no need for a SVt_PVHV case
+	   the error reporting code.  */
+    }
 
     for (nend = name; *nend; nend++) {
-	if (*nend == '\'')
+	if (*nend == '\'') {
 	    nsplit = nend;
-	else if (*nend == ':' && *(nend + 1) == ':')
-	    nsplit = ++nend;
+	    name = nend + 1;
+	}
+	else if (*nend == ':' && *(nend + 1) == ':') {
+	    nsplit = nend++;
+	    name = nend + 1;
+	}
     }
     if (nsplit) {
-	const char * const origname = name;
-	name = nsplit + 1;
-	if (*nsplit == ':')
-	    --nsplit;
-	if ((nsplit - origname) == 5 && strnEQ(origname, "SUPER", 5)) {
+	if ((nsplit - origname) == 5 && memEQ(origname, "SUPER", 5)) {
 	    /* ->SUPER::method should really be looked up in original stash */
 	    SV * const tmpstr = sv_2mortal(Perl_newSVpvf(aTHX_ "%s::SUPER",
 						  CopSTASHPV(PL_curcop)));
 	    /* __PACKAGE__::SUPER stash should be autovivified */
-	    stash = gv_stashpvn(SvPVX_const(tmpstr), SvCUR(tmpstr), GV_ADD);
+	    stash = gv_get_super_pkg(SvPVX_const(tmpstr), SvCUR(tmpstr));
 	    DEBUG_o( Perl_deb(aTHX_ "Treating %s as %s::%s\n",
 			 origname, HvNAME_get(stash), name) );
 	}
@@ -560,7 +661,7 @@ Perl_gv_fetchmethod_autoload(pTHX_ HV *stash, const char *name, I32 autoload)
 	    if (!stash && (nsplit - origname) >= 7 &&
 		strnEQ(nsplit - 7, "::SUPER", 7) &&
 		gv_stashpvn(origname, nsplit - origname - 7, 0))
-	      stash = gv_stashpvn(origname, nsplit - origname, GV_ADD);
+	      stash = gv_get_super_pkg(origname, nsplit - origname);
 	}
 	ostash = stash;
     }
@@ -571,6 +672,31 @@ Perl_gv_fetchmethod_autoload(pTHX_ HV *stash, const char *name, I32 autoload)
 	    gv = (GV*)&PL_sv_yes;
 	else if (autoload)
 	    gv = gv_autoload4(ostash, name, nend - name, TRUE);
+	if (!gv && do_croak) {
+	    /* Right now this is exclusively for the benefit of S_method_common
+	       in pp_hot.c  */
+	    if (stash) {
+		Perl_croak(aTHX_
+			   "Can't locate object method \"%s\" via package \"%.*s\"",
+			   name, (int)HvNAMELEN_get(stash), HvNAME_get(stash));
+	    }
+	    else {
+		STRLEN packlen;
+		const char *packname;
+
+		if (nsplit) {
+		    packlen = nsplit - origname;
+		    packname = origname;
+		} else {
+		    packname = SvPV_const(error_report, packlen);
+		}
+
+		Perl_croak(aTHX_
+			   "Can't locate object method \"%s\" via package \"%.*s\""
+			   " (perhaps you forgot to load \"%.*s\"?)",
+			   name, (int)packlen, packname, (int)packlen, packname);
+	    }
+	}
     }
     else if (autoload) {
 	CV* const cv = GvCV(gv);
@@ -607,7 +733,9 @@ Perl_gv_autoload4(pTHX_ HV *stash, const char *name, STRLEN len, I32 method)
     const char *packname = "";
     STRLEN packname_len = 0;
 
-    if (len == S_autolen && strnEQ(name, S_autoload, S_autolen))
+    PERL_ARGS_ASSERT_GV_AUTOLOAD4;
+
+    if (len == S_autolen && memEQ(name, S_autoload, S_autolen))
 	return NULL;
     if (stash) {
 	if (SvTYPE(stash) < SVt_PVHV) {
@@ -691,17 +819,20 @@ S_require_tie_mod(pTHX_ GV *gv, const char *varpv, SV* namesv, const char *methp
     dVAR;
     HV* stash = gv_stashsv(namesv, 0);
 
+    PERL_ARGS_ASSERT_REQUIRE_TIE_MOD;
+
     if (!stash || !(gv_fetchmethod(stash, methpv))) {
 	SV *module = newSVsv(namesv);
 	char varname = *varpv; /* varpv might be clobbered by load_module,
 				  so save it. For the moment it's always
 				  a single char. */
 	dSP;
-	PUTBACK;
 	ENTER;
 	if ( flags & 1 )
 	    save_scalar(gv);
+	PUSHSTACKi(PERLSI_MAGIC);
 	Perl_load_module(aTHX_ PERL_LOADMOD_NOIMPORT, module, NULL);
+	POPSTACK;
 	LEAVE;
 	SPAGAIN;
 	stash = gv_stashsv(namesv, 0);
@@ -728,6 +859,7 @@ determine the length of C<name>, then calls C<gv_stashpvn()>.
 HV*
 Perl_gv_stashpv(pTHX_ const char *name, I32 create)
 {
+    PERL_ARGS_ASSERT_GV_STASHPV;
     return gv_stashpvn(name, strlen(name), create);
 }
 
@@ -753,6 +885,8 @@ Perl_gv_stashpvn(pTHX_ const char *name, U32 namelen, I32 flags)
     HV *stash;
     GV *tmpgv;
 
+    PERL_ARGS_ASSERT_GV_STASHPVN;
+
     if (namelen + 2 <= sizeof smallbuf)
 	tmpbuf = smallbuf;
     else
@@ -786,25 +920,30 @@ Perl_gv_stashsv(pTHX_ SV *sv, I32 flags)
 {
     STRLEN len;
     const char * const ptr = SvPV_const(sv,len);
+
+    PERL_ARGS_ASSERT_GV_STASHSV;
+
     return gv_stashpvn(ptr, len, flags);
 }
 
 
 GV *
-Perl_gv_fetchpv(pTHX_ const char *nambeg, I32 add, I32 sv_type) {
+Perl_gv_fetchpv(pTHX_ const char *nambeg, I32 add, const svtype sv_type) {
+    PERL_ARGS_ASSERT_GV_FETCHPV;
     return gv_fetchpvn_flags(nambeg, strlen(nambeg), add, sv_type);
 }
 
 GV *
-Perl_gv_fetchsv(pTHX_ SV *name, I32 flags, I32 sv_type) {
+Perl_gv_fetchsv(pTHX_ SV *name, I32 flags, const svtype sv_type) {
     STRLEN len;
     const char * const nambeg = SvPV_const(name, len);
+    PERL_ARGS_ASSERT_GV_FETCHSV;
     return gv_fetchpvn_flags(nambeg, len, flags | SvUTF8(name), sv_type);
 }
 
 GV *
 Perl_gv_fetchpvn_flags(pTHX_ const char *nambeg, STRLEN full_len, I32 flags,
-		       I32 sv_type)
+		       const svtype sv_type)
 {
     dVAR;
     register const char *name = nambeg;
@@ -818,6 +957,9 @@ Perl_gv_fetchpvn_flags(pTHX_ const char *nambeg, STRLEN full_len, I32 flags,
     const I32 add = flags & ~GV_NOADD_MASK;
     const char *const name_end = nambeg + full_len;
     const char *const name_em1 = name_end - 1;
+    U32 faking_it;
+
+    PERL_ARGS_ASSERT_GV_FETCHPVN_FLAGS;
 
     if (flags & GV_NOTQUAL) {
 	/* Caller promised that there is no stash, so we can skip the check. */
@@ -1004,7 +1146,7 @@ Perl_gv_fetchpvn_flags(pTHX_ const char *nambeg, STRLEN full_len, I32 flags,
 	        if (*name == '!')
 		    require_tie_mod(gv, "!", newSVpvs("Errno"), "TIEHASH", 1);
 		else if (*name == '-' || *name == '+')
-		    require_tie_mod(gv, name, newSVpvs("re::Tie::Hash::NamedCapture"), "FETCH", 0);
+		    require_tie_mod(gv, name, newSVpvs("Tie::Hash::NamedCapture"), "TIEHASH", 0);
 	    }
 	}
 	return gv;
@@ -1014,12 +1156,19 @@ Perl_gv_fetchpvn_flags(pTHX_ const char *nambeg, STRLEN full_len, I32 flags,
 	return gv;
     }
 
-    /* Adding a new symbol */
+    /* Adding a new symbol.
+       Unless of course there was already something non-GV here, in which case
+       we want to behave as if there was always a GV here, containing some sort
+       of subroutine.
+       Otherwise we run the risk of creating things like GvIO, which can cause
+       subtle bugs. eg the one that tripped up SQL::Translator  */
+
+    faking_it = SvOK(gv);
 
     if (add & GV_ADDWARN && ckWARN_d(WARN_INTERNAL))
 	Perl_warner(aTHX_ packWARN(WARN_INTERNAL), "Had to create %s unexpectedly", nambeg);
     gv_init(gv, stash, name, len, add & GV_ADDMULTI);
-    gv_init_sv(gv, sv_type);
+    gv_init_sv(gv, faking_it ? SVt_PVCV : sv_type);
 
     if (isALPHA(name[0]) && ! (isLEXWARN_on ? ckWARN(WARN_ONCE)
 			                    : (PL_dowarn & G_WARN_ON ) ) )
@@ -1117,14 +1266,14 @@ Perl_gv_fetchpvn_flags(pTHX_ const char *nambeg, STRLEN full_len, I32 flags,
 		break;
             case '\015':        /* $^MATCH */
                 if (strEQ(name2, "ATCH"))
-		    goto ro_magicalize;
+		    goto magicalize;
 	    case '\017':	/* $^OPEN */
 		if (strEQ(name2, "PEN"))
 		    goto magicalize;
 		break;
 	    case '\020':        /* $^PREMATCH  $^POSTMATCH */
 	        if (strEQ(name2, "REMATCH") || strEQ(name2, "OSTMATCH"))
-		    goto ro_magicalize;  
+		    goto magicalize;  
 	    case '\024':	/* ${^TAINT} */
 		if (strEQ(name2, "AINT"))
 		    goto ro_magicalize;
@@ -1151,14 +1300,14 @@ Perl_gv_fetchpvn_flags(pTHX_ const char *nambeg, STRLEN full_len, I32 flags,
 	    case '8':
 	    case '9':
 	    {
-		/* ensures variable is only digits */
-		/* ${"1foo"} fails this test (and is thus writeable) */
-		/* added by japhy, but borrowed from is_gv_magical */
+		/* Ensures that we have an all-digit variable, ${"1foo"} fails
+		   this test  */
+		/* This snippet is taken from is_gv_magical */
 		const char *end = name + len;
 		while (--end > name) {
-		    if (!isDIGIT(*end)) return gv;
+		    if (!isDIGIT(*end))	return gv;
 		}
-		goto ro_magicalize;
+		goto magicalize;
 	    }
 	    }
 	}
@@ -1177,7 +1326,7 @@ Perl_gv_fetchpvn_flags(pTHX_ const char *nambeg, STRLEN full_len, I32 flags,
 		sv_type == SVt_PVIO
 		) { break; }
 	    PL_sawampersand = TRUE;
-	    goto ro_magicalize;
+	    goto magicalize;
 
 	case ':':
 	    sv_setpv(GvSVn(gv),PL_chopset);
@@ -1190,13 +1339,13 @@ Perl_gv_fetchpvn_flags(pTHX_ const char *nambeg, STRLEN full_len, I32 flags,
 	    goto magicalize;
 
 	case '!':
-	GvMULTI_on(gv);    
+	    GvMULTI_on(gv);
 	    /* If %! has been used, automatically load Errno.pm. */
 
 	    sv_magic(GvSVn(gv), (SV*)gv, PERL_MAGIC_sv, name, len);
 
             /* magicalization must be done before require_tie_mod is called */
-	    if (sv_type == SVt_PVHV)
+	    if (sv_type == SVt_PVHV || sv_type == SVt_PVGV)
 		require_tie_mod(gv, "!", newSVpvs("Errno"), "TIEHASH", 1);
 
 	    break;
@@ -1204,34 +1353,23 @@ Perl_gv_fetchpvn_flags(pTHX_ const char *nambeg, STRLEN full_len, I32 flags,
 	case '+':
 	GvMULTI_on(gv); /* no used once warnings here */
         {
-            bool plus = (*name == '+');
-            SV *stashname = newSVpvs("re::Tie::Hash::NamedCapture");
             AV* const av = GvAVn(gv);
-    	    HV *const hv = GvHVn(gv);
-    	    HV *const hv_tie = newHV();
-            SV *tie = newRV_noinc((SV*)hv_tie);
+	    SV* const avc = (*name == '+') ? (SV*)av : NULL;
 
-	    sv_bless(tie, gv_stashsv(stashname, GV_ADD));
-	    hv_magic(hv, (GV*)tie, PERL_MAGIC_tied);
-            sv_magic((SV*)av, (plus ? (SV*)av : NULL), PERL_MAGIC_regdata, NULL, 0);
+	    sv_magic((SV*)av, avc, PERL_MAGIC_regdata, NULL, 0);
             sv_magic(GvSVn(gv), (SV*)gv, PERL_MAGIC_sv, name, len);
-
-            if (plus)
+            if (avc)
                 SvREADONLY_on(GvSVn(gv));
-            else
-                Perl_hv_store(aTHX_ hv_tie, STR_WITH_LEN("all"), newSViv(1), 0);
-
-            SvREADONLY_on(hv);
-            SvREADONLY_on(tie);
             SvREADONLY_on(av);
 
-	    require_tie_mod(gv, name, stashname, "FETCH", 0);
+            if (sv_type == SVt_PVHV || sv_type == SVt_PVGV)
+                require_tie_mod(gv, name, newSVpvs("Tie::Hash::NamedCapture"), "TIEHASH", 0);
 
-	    break;
+            break;
 	}
 	case '*':
 	case '#':
-	    if (sv_type == SVt_PV && ckWARN2(WARN_DEPRECATED, WARN_SYNTAX))
+	    if (sv_type == SVt_PV && ckWARN2_d(WARN_DEPRECATED, WARN_SYNTAX))
 		Perl_warner(aTHX_ packWARN2(WARN_DEPRECATED, WARN_SYNTAX),
 			    "$%c is no longer supported", *name);
 	    break;
@@ -1246,6 +1384,9 @@ Perl_gv_fetchpvn_flags(pTHX_ const char *nambeg, STRLEN full_len, I32 flags,
 	    }
 	    goto magicalize;
 	case '\023':	/* $^S */
+	ro_magicalize:
+	    SvREADONLY_on(GvSVn(gv));
+	    /* FALL THROUGH */
 	case '1':
 	case '2':
 	case '3':
@@ -1255,9 +1396,6 @@ Perl_gv_fetchpvn_flags(pTHX_ const char *nambeg, STRLEN full_len, I32 flags,
 	case '7':
 	case '8':
 	case '9':
-	ro_magicalize:
-	    SvREADONLY_on(GvSVn(gv));
-	    /* FALL THROUGH */
 	case '[':
 	case '^':
 	case '~':
@@ -1297,7 +1435,7 @@ Perl_gv_fetchpvn_flags(pTHX_ const char *nambeg, STRLEN full_len, I32 flags,
 	{
 	    SV * const sv = GvSVn(gv);
 	    if (!sv_derived_from(PL_patchlevel, "version"))
-		upg_version(PL_patchlevel);
+		upg_version(PL_patchlevel, TRUE);
 	    GvSV(gv) = vnumify(PL_patchlevel);
 	    SvREADONLY_on(GvSV(gv));
 	    SvREFCNT_dec(sv);
@@ -1322,6 +1460,9 @@ Perl_gv_fullname4(pTHX_ SV *sv, const GV *gv, const char *prefix, bool keepmain)
     const char *name;
     STRLEN namelen;
     const HV * const hv = GvSTASH(gv);
+
+    PERL_ARGS_ASSERT_GV_FULLNAME4;
+
     if (!hv) {
 	SvOK_off(sv);
 	return;
@@ -1347,6 +1488,9 @@ void
 Perl_gv_efullname4(pTHX_ SV *sv, const GV *gv, const char *prefix, bool keepmain)
 {
     const GV * const egv = GvEGV(gv);
+
+    PERL_ARGS_ASSERT_GV_EFULLNAME4;
+
     gv_fullname4(sv, egv ? egv : gv, prefix, keepmain);
 }
 
@@ -1377,6 +1521,8 @@ Perl_gv_check(pTHX_ const HV *stash)
     dVAR;
     register I32 i;
 
+    PERL_ARGS_ASSERT_GV_CHECK;
+
     if (!HvARRAY(stash))
 	return;
     for (i = 0; i <= (I32) HvMAX(stash); i++) {
@@ -1396,24 +1542,12 @@ Perl_gv_check(pTHX_ const HV *stash)
 		if (SvTYPE(gv) != SVt_PVGV || GvMULTI(gv))
 		    continue;
 		file = GvFILE(gv);
-		/* performance hack: if filename is absolute and it's a standard
-		 * module, don't bother warning */
-#ifdef MACOS_TRADITIONAL
-#   define LIB_COMPONENT ":lib:"
-#else
-#   define LIB_COMPONENT "/lib/"
-#endif
-		if (file
-		    && PERL_FILE_IS_ABSOLUTE(file)
-		    && (instr(file, LIB_COMPONENT) || instr(file, ".pm")))
-		{
-		    continue;
-		}
 		CopLINE_set(PL_curcop, GvLINE(gv));
 #ifdef USE_ITHREADS
 		CopFILE(PL_curcop) = (char *)file;	/* set for warning */
 #else
-		CopFILEGV(PL_curcop) = gv_fetchfile(file);
+		CopFILEGV(PL_curcop)
+		    = gv_fetchfile_flags(file, HEK_LEN(GvFILE_HEK(gv)), 0);
 #endif
 		Perl_warner(aTHX_ packWARN(WARN_ONCE),
 			"Name \"%s::%s\" used only once: possible typo",
@@ -1427,6 +1561,9 @@ GV *
 Perl_newGVgen(pTHX_ const char *pack)
 {
     dVAR;
+
+    PERL_ARGS_ASSERT_NEWGVGEN;
+
     return gv_fetchpv(Perl_form(aTHX_ "%s::_GEN_%ld", pack, (long)PL_gensym++),
 		      GV_ADD, SVt_PVGV);
 }
@@ -1442,15 +1579,13 @@ Perl_gp_ref(pTHX_ GP *gp)
     gp->gp_refcnt++;
     if (gp->gp_cv) {
 	if (gp->gp_cvgen) {
-	    /* multi-named GPs cannot be used for method cache */
+	    /* If the GP they asked for a reference to contains
+               a method cache entry, clear it first, so that we
+               don't infect them with our cached entry */
 	    SvREFCNT_dec(gp->gp_cv);
 	    gp->gp_cv = NULL;
 	    gp->gp_cvgen = 0;
 	}
-	else {
-	    /* Adding a new name to a subroutine invalidates method cache */
-	    PL_sub_generation++;
-	}
     }
     return gp;
 }
@@ -1470,10 +1605,6 @@ Perl_gp_free(pTHX_ GV *gv)
                         pTHX__FORMAT pTHX__VALUE);
         return;
     }
-    if (gp->gp_cv) {
-	/* Deleting the name of a subroutine invalidates method cache */
-	PL_sub_generation++;
-    }
     if (--gp->gp_refcnt > 0) {
 	if (gp->gp_egv == gv)
 	    gp->gp_egv = 0;
@@ -1490,7 +1621,7 @@ Perl_gp_free(pTHX_ GV *gv)
     if (gp->gp_hv && SvTYPE(gp->gp_hv) == SVt_PVHV) {
 	const char *hvname = HvNAME_get(gp->gp_hv);
 	if (PL_stashcache && hvname)
-	    hv_delete(PL_stashcache, hvname, HvNAMELEN_get(gp->gp_hv),
+	    (void)hv_delete(PL_stashcache, hvname, HvNAMELEN_get(gp->gp_hv),
 		      G_DISCARD);
 	SvREFCNT_dec(gp->gp_hv);
     }
@@ -1508,6 +1639,8 @@ Perl_magic_freeovrld(pTHX_ SV *sv, MAGIC *mg)
     AMT * const amtp = (AMT*)mg->mg_ptr;
     PERL_UNUSED_ARG(sv);
 
+    PERL_ARGS_ASSERT_MAGIC_FREEOVRLD;
+
     if (amtp && AMT_AMAGIC(amtp)) {
 	int i;
 	for (i = 1; i < NofAMmeth; i++) {
@@ -1529,11 +1662,16 @@ Perl_Gv_AMupdate(pTHX_ HV *stash)
   dVAR;
   MAGIC* const mg = mg_find((SV*)stash, PERL_MAGIC_overload_table);
   AMT amt;
+  const struct mro_meta* stash_meta = HvMROMETA(stash);
+  U32 newgen;
 
+  PERL_ARGS_ASSERT_GV_AMUPDATE;
+
+  newgen = PL_sub_generation + stash_meta->pkg_gen + stash_meta->cache_gen;
   if (mg) {
       const AMT * const amtp = (AMT*)mg->mg_ptr;
       if (amtp->was_ok_am == PL_amagic_generation
-	  && amtp->was_ok_sub == PL_sub_generation) {
+	  && amtp->was_ok_sub == newgen) {
 	  return (bool)AMT_OVERLOADED(amtp);
       }
       sv_unmagic((SV*)stash, PERL_MAGIC_overload_table);
@@ -1543,7 +1681,7 @@ Perl_Gv_AMupdate(pTHX_ HV *stash)
 
   Zero(&amt,1,AMT);
   amt.was_ok_am = PL_amagic_generation;
-  amt.was_ok_sub = PL_sub_generation;
+  amt.was_ok_sub = newgen;
   amt.fallback = AMGfallNO;
   amt.flags = 0;
 
@@ -1576,7 +1714,7 @@ Perl_Gv_AMupdate(pTHX_ HV *stash)
 	const char * const cooky = PL_AMG_names[i];
 	/* Human-readable form, for debugging: */
 	const char * const cp = (i >= DESTROY_amg ? cooky : AMG_id2name(i));
-	const STRLEN l = strlen(cooky);
+	const STRLEN l = PL_AMG_namelens[i];
 
 	DEBUG_o( Perl_deb(aTHX_ "Checking overloading of \"%s\" in package \"%.256s\"\n",
 		     cp, HvNAME_get(stash)) );
@@ -1655,9 +1793,15 @@ Perl_gv_handler(pTHX_ HV *stash, I32 id)
     dVAR;
     MAGIC *mg;
     AMT *amtp;
+    U32 newgen;
+    struct mro_meta* stash_meta;
 
     if (!stash || !HvNAME_get(stash))
         return NULL;
+
+    stash_meta = HvMROMETA(stash);
+    newgen = PL_sub_generation + stash_meta->pkg_gen + stash_meta->cache_gen;
+
     mg = mg_find((SV*)stash, PERL_MAGIC_overload_table);
     if (!mg) {
       do_update:
@@ -1667,7 +1811,7 @@ Perl_gv_handler(pTHX_ HV *stash, I32 id)
     assert(mg);
     amtp = (AMT*)mg->mg_ptr;
     if ( amtp->was_ok_am != PL_amagic_generation
-	 || amtp->was_ok_sub != PL_sub_generation )
+	 || amtp->was_ok_sub != newgen )
 	goto do_update;
     if (AMT_AMAGIC(amtp)) {
 	CV * const ret = amtp->table[id];
@@ -1704,6 +1848,9 @@ Perl_amagic_call(pTHX_ SV *left, SV *right, int method, int flags)
   int fl=0;
 #endif
   HV* stash=NULL;
+
+  PERL_ARGS_ASSERT_AMAGIC_CALL;
+
   if (!(AMGf_noleft & flags) && SvAMAGIC(left)
       && (stash = SvSTASH(SvRV(left)))
       && (mg = mg_find((SV*)stash, PERL_MAGIC_overload_table))
@@ -2001,7 +2148,8 @@ Perl_amagic_call(pTHX_ SV *left, SV *right, int method, int flags)
     PUSHs(lr>0? left: right);
     PUSHs( lr > 0 ? &PL_sv_yes : ( assign ? &PL_sv_undef : &PL_sv_no ));
     if (notfound) {
-      PUSHs( sv_2mortal(newSVpv(AMG_id2name(method + assignshift),0)));
+      PUSHs(newSVpvn_flags(AMG_id2name(method + assignshift),
+			   AMG_id2namelen(method + assignshift), SVs_TEMP));
     }
     PUSHs((SV*)cv);
     PUTBACK;
@@ -2070,6 +2218,9 @@ Perl_is_gv_magical_sv(pTHX_ SV *name, U32 flags)
 {
     STRLEN len;
     const char * const temp = SvPV_const(name, len);
+
+    PERL_ARGS_ASSERT_IS_GV_MAGICAL_SV;
+
     return is_gv_magical(temp, len, flags);
 }
 
@@ -2096,11 +2247,13 @@ Perl_is_gv_magical(pTHX_ const char *name, STRLEN len, U32 flags)
     PERL_UNUSED_CONTEXT;
     PERL_UNUSED_ARG(flags);
 
+    PERL_ARGS_ASSERT_IS_GV_MAGICAL;
+
     if (len > 1) {
 	const char * const name1 = name + 1;
 	switch (*name) {
 	case 'I':
-	    if (len == 3 && name1[1] == 'S' && name[2] == 'A')
+	    if (len == 3 && name[1] == 'S' && name[2] == 'A')
 		goto yes;
 	    break;
 	case 'O':
@@ -2218,7 +2371,7 @@ Perl_gv_name_set(pTHX_ GV *gv, const char *name, U32 len, U32 flags)
     dVAR;
     U32 hash;
 
-    assert(name);
+    PERL_ARGS_ASSERT_GV_NAME_SET;
     PERL_UNUSED_ARG(flags);
 
     if (len > I32_MAX)