From 21f5b33c2ff83250a8b108970fbdc5a1d14c7523 Mon Sep 17 00:00:00 2001
From: Gurusamy Sarathy <gsar@cpan.org>
Date: Wed, 20 Oct 1999 00:52:34 +0000
Subject: [PATCH] disable optimizing troublesome ops in change#3612 (from Ilya
 Zakharevich)

p4raw-link: @3612 on //depot/perl: b162f9ead0a98db35cdcfc8c889e344c040c8d8e

p4raw-id: //depot/perl@4415
---
 Makefile.SH |  2 +-
 opcode.h    | 18 +++++++++---------
 opcode.pl   | 34 +++++++++++++++++++++++++---------
 3 files changed, 35 insertions(+), 19 deletions(-)

diff --git a/Makefile.SH b/Makefile.SH
index 2e88cdd..7c542a6 100644
--- a/Makefile.SH
+++ b/Makefile.SH
@@ -563,7 +563,7 @@ CHMOD_W = chmod +w
 # To force them to run, type
 #	make regen_headers
 regen_headers:	FORCE
-	$(CHMOD_W) proto.h warning.h lib/warning.pm 
+	$(CHMOD_W) proto.h warnings.h lib/warnings.pm 
 	perl keywords.pl
 	perl opcode.pl
 	perl embed.pl
diff --git a/opcode.h b/opcode.h
index e0bf4ff..81d9f36 100644
--- a/opcode.h
+++ b/opcode.h
@@ -1490,8 +1490,8 @@ EXT U32 PL_opargs[] = {
 	0x00003014,	/* trans */
 	0x00000004,	/* sassign */
 	0x00044408,	/* aassign */
-	0x0000570d,	/* chop */
-	0x0001378c,	/* schop */
+	0x0000560d,	/* chop */
+	0x0001368c,	/* schop */
 	0x0000570d,	/* chomp */
 	0x0001378c,	/* schomp */
 	0x00013694,	/* defined */
@@ -1502,9 +1502,9 @@ EXT U32 PL_opargs[] = {
 	0x00002254,	/* i_preinc */
 	0x00002264,	/* predec */
 	0x00002254,	/* i_predec */
-	0x0000236c,	/* postinc */
+	0x0000226c,	/* postinc */
 	0x0000235c,	/* i_postinc */
-	0x0000236c,	/* postdec */
+	0x0000226c,	/* postdec */
 	0x0000235c,	/* i_postdec */
 	0x0002250e,	/* pow */
 	0x0002252e,	/* multiply */
@@ -1543,13 +1543,13 @@ EXT U32 PL_opargs[] = {
 	0x00022416,	/* seq */
 	0x00022416,	/* sne */
 	0x0002241e,	/* scmp */
-	0x0002250e,	/* bit_and */
-	0x0002250e,	/* bit_xor */
-	0x0002250e,	/* bit_or */
-	0x0000232e,	/* negate */
+	0x0002240e,	/* bit_and */
+	0x0002240e,	/* bit_xor */
+	0x0002240e,	/* bit_or */
+	0x0000222e,	/* negate */
 	0x0000231e,	/* i_negate */
 	0x00002216,	/* not */
-	0x0000230e,	/* complement */
+	0x0000220e,	/* complement */
 	0x0002290e,	/* atan2 */
 	0x0001378e,	/* sin */
 	0x0001378e,	/* cos */
diff --git a/opcode.pl b/opcode.pl
index a41ef8b..53acd4d 100755
--- a/opcode.pl
+++ b/opcode.pl
@@ -289,6 +289,10 @@ sub tab {
 
 # lt and friends do SETs (including ncmp, but not scmp)
 
+# Additional mode of failure: the opcode can modify TARG before it "used"
+# all the arguments (or may call an external function which does the same).
+# If the target coincides with one of the arguments ==> kaboom.
+
 # pp.c	pos substr each not OK (RETPUSHUNDEF)
 #	substr vec also not OK due to LV to target (are they???)
 #	ref not OK (RETPUSHNO)
@@ -299,11 +303,21 @@ sub tab {
 #	sprintf: is calling do_sprintf(TARG,...) which can act on TARG
 #	  before other args are processed.
 
+#	Suspicious wrt "additional mode of failure" (and only it):
+#	schop, chop, postinc/dec, bit_and etc, negate, complement.
+
+#	Also suspicious: 4-arg substr, sprintf, uc/lc (POK_only), reverse, pack.
+
+#	substr/vec: doing TAINT_off()???
+
 # pp_hot.c
 #	readline - unknown whether it is safe
 #	match subst not OK (dTARG)
 #	grepwhile not OK (not always setting)
 
+#	Suspicious wrt "additional mode of failure": concat (dealt with
+#	in ck_sassign()), join (same).
+
 # pp_ctl.c
 #	mapwhile flip caller not OK (not always setting)
 
@@ -317,6 +331,8 @@ sub tab {
 #	sselect shm* sem* msg* syscall - unknown whether they are safe
 #	gmtime not OK (list context)
 
+#	Suspicious wrt "additional mode of failure": warn, die, select.
+
 __END__
 
 # New ops always go at the very end
@@ -382,8 +398,8 @@ trans		transliteration (tr///)	ck_null		is"	S
 sassign		scalar assignment	ck_sassign	s0
 aassign		list assignment		ck_null		t2	L L
 
-chop		chop			ck_spair	mTs%	L
-schop		scalar chop		ck_null		sTu%	S?
+chop		chop			ck_spair	mts%	L
+schop		scalar chop		ck_null		stu%	S?
 chomp		chomp			ck_spair	mTs%	L
 schomp		scalar chomp		ck_null		sTu%	S?
 defined		defined operator	ck_defined	isu%	S?
@@ -395,9 +411,9 @@ preinc		preincrement (++)		ck_lfun		dIs1	S
 i_preinc	integer preincrement (++)	ck_lfun		dis1	S
 predec		predecrement (--)		ck_lfun		dIs1	S
 i_predec	integer predecrement (--)	ck_lfun		dis1	S
-postinc		postincrement (++)		ck_lfun		dIsT1	S
+postinc		postincrement (++)		ck_lfun		dIst1	S
 i_postinc	integer postincrement (++)	ck_lfun		disT1	S
-postdec		postdecrement (--)		ck_lfun		dIsT1	S
+postdec		postdecrement (--)		ck_lfun		dIst1	S
 i_postdec	integer postdecrement (--)	ck_lfun		disT1	S
 
 # Ordinary operators.
@@ -445,14 +461,14 @@ seq		string eq		ck_null		ifs2	S S
 sne		string ne		ck_null		ifs2	S S
 scmp		string comparison (cmp)	ck_scmp		ifst2	S S
 
-bit_and		bitwise and (&)		ck_bitop	fsT2	S S
-bit_xor		bitwise xor (^)		ck_bitop	fsT2	S S
-bit_or		bitwise or (|)		ck_bitop	fsT2	S S
+bit_and		bitwise and (&)		ck_bitop	fst2	S S
+bit_xor		bitwise xor (^)		ck_bitop	fst2	S S
+bit_or		bitwise or (|)		ck_bitop	fst2	S S
 
-negate		negation (-)		ck_null		IfsT1	S
+negate		negation (-)		ck_null		Ifst1	S
 i_negate	integer negation (-)	ck_null		ifsT1	S
 not		not			ck_null		ifs1	S
-complement	1's complement (~)	ck_bitop	fsT1	S
+complement	1's complement (~)	ck_bitop	fst1	S
 
 # High falutin' math.
 
-- 
2.7.4