From d2f677201f78036f37e6a614b0bc4cfa46cf02d8 Mon Sep 17 00:00:00 2001
From: Nicholas Clark <nick@ccl4.org>
Date: Fri, 27 Jul 2012 13:16:29 +0200
Subject: [PATCH] Remove dSP from all filetest ops.

Following commit d2c4d2d1e22d3125, all filetest ops avoid manipulating the
stack pointer until the point of pushing a return value. As all the filetest
returns now go through either FT_RETURN_FALSE() or FT_RETURN_TRUE(), it's
viable to put the dSP inside those two macros and use *PL_stack_sp in place
of TOPs. This eliminates all uses of sp in the bodies of the functions
(explicit, or implicit via macros), and that makes it clear that the main
bodies of the functions are not manipulating the stack.
---
 pp_sys.c | 21 ++++++++-------------
 1 file changed, 8 insertions(+), 13 deletions(-)

diff --git a/pp_sys.c b/pp_sys.c
index 3368d5f..799ead3 100644
--- a/pp_sys.c
+++ b/pp_sys.c
@@ -2923,6 +2923,7 @@ S_ft_stacking_return_false(pTHX_ SV *ret) {
 
 #define FT_RETURN_FALSE(X)			     \
     STMT_START {				      \
+        dSP;                                           \
 	if (PL_op->op_private & OPpFT_STACKING)	       \
 	    return S_ft_stacking_return_false(aTHX_ X);	\
 	PL_op->op_flags & OPf_REF ? XPUSHs(X) : SETs(X); \
@@ -2931,6 +2932,7 @@ S_ft_stacking_return_false(pTHX_ SV *ret) {
     } STMT_END
 #define FT_RETURN_TRUE(X)                                               \
     STMT_START {                                                        \
+        dSP;                                                            \
         (void)(                                                         \
             PL_op->op_flags & OPf_REF                                   \
 	    ? (bool)XPUSHs(                                             \
@@ -2947,7 +2949,7 @@ S_ft_stacking_return_false(pTHX_ SV *ret) {
 #define FT_RETURNYES	FT_RETURN_TRUE(&PL_sv_yes)
 
 #define tryAMAGICftest_MG(chr) STMT_START { \
-	if ( (SvFLAGS(TOPs) & (SVf_ROK|SVs_GMG)) \
+	if ( (SvFLAGS(*PL_stack_sp) & (SVf_ROK|SVs_GMG)) \
 		&& PL_op->op_flags & OPf_KIDS) {     \
 	    OP *next = S_try_amagic_ftest(aTHX_ chr);	\
 	    if (next) return next;			  \
@@ -2957,13 +2959,12 @@ S_ft_stacking_return_false(pTHX_ SV *ret) {
 STATIC OP *
 S_try_amagic_ftest(pTHX_ char chr) {
     dVAR;
-    dSP;
-    SV* const arg = TOPs;
+    SV *const arg = *PL_stack_sp;
 
     assert(chr != '?');
     if (!(PL_op->op_private & OPpFT_STACKING)) SvGETMAGIC(arg);
 
-    if (SvAMAGIC(TOPs))
+    if (SvAMAGIC(arg))
     {
 	const char tmpchr = chr;
 	SV * const tmpsv = amagic_call(arg,
@@ -3003,7 +3004,6 @@ PP(pp_ftrread)
 
     bool effective = FALSE;
     char opchar = '?';
-    dSP;
 
     switch (PL_op->op_type) {
     case OP_FTRREAD:	opchar = 'R'; break;
@@ -3067,7 +3067,7 @@ PP(pp_ftrread)
 
     if (use_access) {
 #if defined(HAS_ACCESS) || defined (PERL_EFF_ACCESS)
-	const char *name = TOPpx;
+	const char *name = SvPV_nolen(*PL_stack_sp);
 	if (effective) {
 #  ifdef PERL_EFF_ACCESS
 	    result = PERL_EFF_ACCESS(name, access_mode);
@@ -3105,7 +3105,6 @@ PP(pp_ftis)
     I32 result;
     const int op_type = PL_op->op_type;
     char opchar = '?';
-    dSP;
 
     switch (op_type) {
     case OP_FTIS:	opchar = 'e'; break;
@@ -3157,7 +3156,6 @@ PP(pp_ftrowned)
     dVAR;
     I32 result;
     char opchar = '?';
-    dSP;
 
     switch (PL_op->op_type) {
     case OP_FTROWNED:	opchar = 'O'; break;
@@ -3258,7 +3256,6 @@ PP(pp_ftrowned)
 PP(pp_ftlink)
 {
     dVAR;
-    dSP;
     I32 result;
 
     tryAMAGICftest_MG('l');
@@ -3274,7 +3271,6 @@ PP(pp_ftlink)
 PP(pp_fttty)
 {
     dVAR;
-    dSP;
     int fd;
     GV *gv;
     char *name = NULL;
@@ -3285,7 +3281,7 @@ PP(pp_fttty)
     if (PL_op->op_flags & OPf_REF)
 	gv = cGVOP_gv;
     else {
-      SV *tmpsv = TOPs;
+      SV *tmpsv = *PL_stack_sp;
       if (!(gv = MAYBE_DEREF_GV_nomg(tmpsv))) {
 	name = SvPV_nomg(tmpsv, namelen);
 	gv = gv_fetchpvn_flags(name, namelen, SvUTF8(tmpsv), SVt_PVIO);
@@ -3314,7 +3310,6 @@ PP(pp_fttty)
 PP(pp_fttext)
 {
     dVAR;
-    dSP;
     I32 i;
     I32 len;
     I32 odd = 0;
@@ -3333,7 +3328,7 @@ PP(pp_fttext)
 	     == OPpFT_STACKED)
 	gv = PL_defgv;
     else {
-	sv = TOPs;
+	sv = *PL_stack_sp;
 	gv = MAYBE_DEREF_GV_nomg(sv);
     }
 
-- 
2.7.4