make SVs_PADTMP and SVs_PADSTALE share a bit

SVs_PADSTALE is only meaningful with SVs_PADMY, while
SVs_PADTMP is only meaningful with !SVs_PADMY,
so let them share the same flag bit.

Note that this doesn't yet free a bit in SvFLAGS, as the two
bits are also used for SVpad_STATE, SVpad_TYPED.

(This is is follow-on to 62bb6514085e5eddc42b4fdaf3713ccdb7f1da85.)

6 files changed, 47 insertions, 30 deletions

diff --git a/dump.c b/dump.c
index 9990c8de87..3281031213 100644
--- a/dump.c
+++ b/dump.c
@@ -1527,10 +1527,12 @@ Perl_do_sv_dump(pTHX_ I32 level, PerlIO *file, SV *sv, I32 nest, I32 maxnest, bo
 
     if (!((flags & SVpad_NAME) == SVpad_NAME
 	  && (type == SVt_PVMG || type == SVt_PVNV))) {
-	if (flags & SVs_PADSTALE)	sv_catpv(d, "PADSTALE,");
+	if ((flags & SVs_PADMY) && (flags & SVs_PADSTALE))
+	    sv_catpv(d, "PADSTALE,");
     }
     if (!((flags & SVpad_NAME) == SVpad_NAME && type == SVt_PVMG)) {
-	if (flags & SVs_PADTMP)	sv_catpv(d, "PADTMP,");
+	if (!(flags & SVs_PADMY) && (flags & SVs_PADTMP))
+	    sv_catpv(d, "PADTMP,");
 	if (flags & SVs_PADMY)	sv_catpv(d, "PADMY,");
     }
     append_flags(d, flags, first_sv_flags_names);
diff --git a/pad.c b/pad.c
index 763e01bb63..c767b550c1 100644
--- a/pad.c
+++ b/pad.c
@@ -1720,7 +1720,7 @@ Perl_pad_free(pTHX_ PADOFFSET po)
     );
 
     if (PL_curpad[po] && PL_curpad[po] != &PL_sv_undef) {
-	SvPADTMP_off(PL_curpad[po]);
+	SvFLAGS(PL_curpad[po]) &= ~SVs_PADTMP; /* also clears SVs_PADSTALE */
     }
     if ((I32)po < PL_padix)
 	PL_padix = po - 1;
diff --git a/pp_ctl.c b/pp_ctl.c
index 692fdebd0d..24067618e3 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -2082,11 +2082,17 @@ PP(pp_dbstate)
 STATIC SV **
 S_adjust_stack_on_leave(pTHX_ SV **newsp, SV **sp, SV **mark, I32 gimme, U32 flags)
 {
+    bool padtmp = 0;
     PERL_ARGS_ASSERT_ADJUST_STACK_ON_LEAVE;
 
+    if (flags & SVs_PADTMP) {
+	flags &= ~SVs_PADTMP;
+	padtmp = 1;
+    }
     if (gimme == G_SCALAR) {
 	if (MARK < SP)
-	    *++newsp = (SvFLAGS(*SP) & flags) ? *SP : sv_mortalcopy(*SP);
+	    *++newsp = ((SvFLAGS(*SP) & flags) || (padtmp && SvPADTMP(*SP)))
+			    ? *SP : sv_mortalcopy(*SP);
 	else {
 	    /* MEXTEND() only updates MARK, so reuse it instead of newsp. */
 	    MARK = newsp;
@@ -2098,7 +2104,7 @@ S_adjust_stack_on_leave(pTHX_ SV **newsp, SV **sp, SV **mark, I32 gimme, U32 fla
     else if (gimme == G_ARRAY) {
 	/* in case LEAVE wipes old return values */
 	while (++MARK <= SP) {
-	    if (SvFLAGS(*MARK) & flags)
+	    if ((SvFLAGS(*MARK) & flags) || (padtmp && SvPADTMP(*MARK)))
 		*++newsp = *MARK;
 	    else {
 		*++newsp = sv_mortalcopy(*MARK);
diff --git a/scope.c b/scope.c
index 9ed6475d6c..14664a26c5 100644
--- a/scope.c
+++ b/scope.c
@@ -922,7 +922,8 @@ Perl_leave_scope(pTHX_ I32 base)
 		SvPADSTALE_on(sv); /* mark as no longer live */
 	    }
 	    else {	/* Someone has a claim on this, so abandon it. */
-		const U32 padflags = SvFLAGS(sv) & (SVs_PADMY|SVs_PADTMP);
+		assert(  SvFLAGS(sv) & SVs_PADMY);
+		assert(!(SvFLAGS(sv) & SVs_PADTMP));
 		switch (SvTYPE(sv)) {	/* Console ourselves with a new value */
 		case SVt_PVAV:	*(SV**)ptr = MUTABLE_SV(newAV());	break;
 		case SVt_PVHV:	*(SV**)ptr = MUTABLE_SV(newHV());	break;
@@ -931,7 +932,7 @@ Perl_leave_scope(pTHX_ I32 base)
 		SvREFCNT_dec(sv);	/* Cast current value to the winds. */
 		/* preserve pad nature, but also mark as not live
 		 * for any closure capturing */
-		SvFLAGS(*(SV**)ptr) |= padflags | SVs_PADSTALE;
+		SvFLAGS(*(SV**)ptr) |= (SVs_PADMY|SVs_PADSTALE);
 	    }
 	    break;
 	case SAVEt_DELETE:
diff --git a/sv.c b/sv.c
index 3360bf4f1b..e92ed2b525 100644
--- a/sv.c
+++ b/sv.c
@@ -2228,7 +2228,7 @@ S_sv_2iuv_common(pTHX_ SV *const sv)
 	if (isGV_with_GP(sv))
 	    return glob_2number(MUTABLE_GV(sv));
 
-	if (!(SvFLAGS(sv) & SVs_PADTMP)) {
+	if (!SvPADTMP(sv)) {
 	    if (!PL_localizing && ckWARN(WARN_UNINITIALIZED))
 		report_uninit(sv);
 	}
@@ -2613,7 +2613,7 @@ Perl_sv_2nv_flags(pTHX_ register SV *const sv, const I32 flags)
 	    return 0.0;
 	}
 
-	if (!PL_localizing && !(SvFLAGS(sv) & SVs_PADTMP) && ckWARN(WARN_UNINITIALIZED))
+	if (!PL_localizing && !SvPADTMP(sv) && ckWARN(WARN_UNINITIALIZED))
 	    report_uninit(sv);
 	assert (SvTYPE(sv) >= SVt_NV);
 	/* Typically the caller expects that sv_any is not NULL now.  */
@@ -2975,7 +2975,7 @@ Perl_sv_2pv_flags(pTHX_ register SV *const sv, STRLEN *const lp, const I32 flags
 	    *lp = 0;
 	if (flags & SV_UNDEF_RETURNS_NULL)
 	    return NULL;
-	if (!PL_localizing && !(SvFLAGS(sv) & SVs_PADTMP) && ckWARN(WARN_UNINITIALIZED))
+	if (!PL_localizing && !SvPADTMP(sv) && ckWARN(WARN_UNINITIALIZED))
 	    report_uninit(sv);
 	if (SvTYPE(sv) < SVt_PV)
 	    /* Typically the caller expects that sv_any is not NULL now.  */
diff --git a/sv.h b/sv.h
index bbf41c84f6..5324256d24 100644
--- a/sv.h
+++ b/sv.h
@@ -310,9 +310,10 @@ perform the upgrade if necessary.  See C<svtype>.
 				       CvIMPORTED_CV_ON() if it needs to be
 				       expanded to a real GV */
 
-#define SVs_PADSTALE	0x00010000  /* lexical has gone out of scope */
 #define SVpad_STATE	0x00010000  /* pad name is a "state" var */
-#define SVs_PADTMP	0x00020000  /* in use as tmp */
+#define SVs_PADTMP	0x00020000  /* in use as tmp; only if ! SVs_PADMY */
+#define SVs_PADSTALE	0x00020000  /* lexical has gone out of scope;
+					only valid for SVs_PADMY */
 #define SVpad_TYPED	0x00020000  /* pad name is a Typed Lexical */
 #define SVs_PADMY	0x00040000  /* in use a "my" variable */
 #define SVpad_OUR	0x00040000  /* pad name is "our" instead of "my" */
@@ -909,34 +910,41 @@ the scalar's value cannot change unless written to.
 
 #define SvTHINKFIRST(sv)	(SvFLAGS(sv) & SVf_THINKFIRST)
 
-#define SvPADSTALE(sv)		(SvFLAGS(sv) & SVs_PADSTALE)
-#define SvPADSTALE_off(sv)	(SvFLAGS(sv) &= ~SVs_PADSTALE)
+#define SvPADMY(sv)		(SvFLAGS(sv) & SVs_PADMY)
+#define SvPADMY_on(sv)		(SvFLAGS(sv) |= SVs_PADMY)
 
-#define SvPADTMP(sv)		(SvFLAGS(sv) & SVs_PADTMP)
-#define SvPADTMP_off(sv)	(SvFLAGS(sv) &= ~SVs_PADTMP)
+/* SVs_PADTMP and SVs_PADSTALE share the same bit, mediated by SVs_PADMY */
 
-#define SvPADMY(sv)		(SvFLAGS(sv) & SVs_PADMY)
+#define SvPADTMP(sv)	((SvFLAGS(sv) & (SVs_PADMY|SVs_PADTMP)) == SVs_PADTMP)
+#define SvPADSTALE(sv)	((SvFLAGS(sv) & (SVs_PADMY|SVs_PADSTALE)) \
+				    == (SVs_PADMY|SVs_PADSTALE))
 
 #if defined (DEBUGGING) && defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
-#  define SvPADTMP_on(sv)	({					\
-	    SV *const _svpad = MUTABLE_SV(sv);				\
-	    assert(!(SvFLAGS(_svpad) & (SVs_PADMY|SVs_PADSTALE)));	\
-	    (SvFLAGS(_svpad) |= SVs_PADTMP);		\
+#  define SvPADTMP_on(sv)	({			\
+	    SV *const _svpad = MUTABLE_SV(sv);		\
+	    assert(!(SvFLAGS(_svpad) & SVs_PADMY));	\
+	    SvFLAGS(_svpad) |= SVs_PADTMP;		\
 	})
-#  define SvPADMY_on(sv)	({					\
-	    SV *const _svpad = MUTABLE_SV(sv);				\
-	    assert(!(SvFLAGS(_svpad) & SVs_PADTMP));	\
-	    (SvFLAGS(_svpad) |= SVs_PADMY);		\
+#  define SvPADTMP_off(sv)	({			\
+	    SV *const _svpad = MUTABLE_SV(sv);		\
+	    assert(!(SvFLAGS(_svpad) & SVs_PADMY));	\
+	    SvFLAGS(_svpad) &= ~SVs_PADTMP;		\
 	})
-#  define SvPADSTALE_on(sv)	({					\
-	    SV *const _svpad = MUTABLE_SV(sv);				\
-	    assert(!(SvFLAGS(_svpad) & SVs_PADTMP));	\
-	    (SvFLAGS(_svpad) |= SVs_PADSTALE);		\
+#  define SvPADSTALE_on(sv)	({			\
+	    SV *const _svpad = MUTABLE_SV(sv);		\
+	    assert(SvFLAGS(_svpad) & SVs_PADMY);	\
+	    SvFLAGS(_svpad) |= SVs_PADSTALE;		\
+	})
+#  define SvPADSTALE_off(sv)	({			\
+	    SV *const _svpad = MUTABLE_SV(sv);		\
+	    assert(SvFLAGS(_svpad) & SVs_PADMY);	\
+	    SvFLAGS(_svpad) &= ~SVs_PADSTALE;		\
 	})
 #else
 #  define SvPADTMP_on(sv)	(SvFLAGS(sv) |= SVs_PADTMP)
-#  define SvPADMY_on(sv)	(SvFLAGS(sv) |= SVs_PADMY)
+#  define SvPADTMP_off(sv)	(SvFLAGS(sv) &= ~SVs_PADTMP)
 #  define SvPADSTALE_on(sv)	(SvFLAGS(sv) |= SVs_PADSTALE)
+#  define SvPADSTALE_off(sv)	(SvFLAGS(sv) &= ~SVs_PADSTALE)
 #endif
 
 #define SvTEMP(sv)		(SvFLAGS(sv) & SVs_TEMP)