diff mbox

do not ignore attribute 'noreturn'...

Message ID 200908282330.08332.kdudka@redhat.com (mailing list archive)
State Mainlined, archived
Headers show

Commit Message

Kamil Dudka Aug. 28, 2009, 9:30 p.m. UTC 
Hello,

enclosed is a simple patch adding support for attribute 'noreturn' to the 
parser. The enhancement makes it possible to optimize walk through CFG and 
thus help us to fight with the state explosion. The benefit is demonstrated 
on a simple real-world example.

Generated CFG before patch:
http://dudka.cz/devel/html/slsparse-before/slplug.c-handle_stmt_assign.svg

Generated CFG after patch:
http://dudka.cz/devel/html/slsparse-after/slplug.c-handle_stmt_assign.svg

It's one of the key features I am currently missing in SPARSE in contrast
to gcc used as parser. Thanks in advance for considering it!

Kamil

Comments

Christopher Li Aug. 28, 2009, 9:44 p.m. UTC | #1 
On Fri, Aug 28, 2009 at 2:30 PM, Kamil Dudka<kdudka@redhat.com> wrote:
> enclosed is a simple patch adding support for attribute 'noreturn' to the
> parser. The enhancement makes it possible to optimize walk through CFG and
> thus help us to fight with the state explosion. The benefit is demonstrated
> on a simple real-world example.
>
> Generated CFG before patch:
> http://dudka.cz/devel/html/slsparse-before/slplug.c-handle_stmt_assign.svg
>
> Generated CFG after patch:
> http://dudka.cz/devel/html/slsparse-after/slplug.c-handle_stmt_assign.svg
>
> It's one of the key features I am currently missing in SPARSE in contrast
> to gcc used as parser. Thanks in advance for considering it!

Yes, no return is kind of useful. I think we need to do some thing about the
MOD_XXX eventually. It is very easy to run out of bits there.

Thanks for the patch. Applied.

Chris
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diff mbox

Patch

From 892f19915cbcbe26b3a7ad2c3baf1a1420f3c954 Mon Sep 17 00:00:00 2001
From: Kamil Dudka <kdudka@redhat.com>
Date: Fri, 28 Aug 2009 21:49:16 +0200
Subject: [PATCH] do not ignore attribute 'noreturn'...

... and thus make it possible to optimize walk through CFG.

Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
 parse.c  |    4 ++--
 symbol.h |    4 +++-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/parse.c b/parse.c
index e5ad867..215c4da 100644
--- a/parse.c
+++ b/parse.c
@@ -480,8 +480,8 @@  static struct init_keyword {
 	{ "const",	NS_KEYWORD,	.op = &ignore_attr_op },
 	{ "__const",	NS_KEYWORD,	.op = &ignore_attr_op },
 	{ "__const__",	NS_KEYWORD,	.op = &ignore_attr_op },
-	{ "noreturn",	NS_KEYWORD,	.op = &ignore_attr_op },
-	{ "__noreturn__",	NS_KEYWORD,	.op = &ignore_attr_op },
+	{ "noreturn",	NS_KEYWORD,	MOD_NORETURN,	.op = &attr_mod_op },
+	{ "__noreturn__",	NS_KEYWORD,	MOD_NORETURN,	.op = &attr_mod_op },
 	{ "no_instrument_function",	NS_KEYWORD,	.op = &ignore_attr_op },
 	{ "__no_instrument_function__",	NS_KEYWORD,	.op = &ignore_attr_op },
 	{ "sentinel",	NS_KEYWORD,	.op = &ignore_attr_op },
diff --git a/symbol.h b/symbol.h
index 42d69d6..d8d1793 100644
--- a/symbol.h
+++ b/symbol.h
@@ -216,6 +216,8 @@  struct symbol {
 #define MOD_EXPLICITLY_SIGNED	0x40000000
 #define MOD_BITWISE	0x80000000
 
+#define MOD_NORETURN	0x100000000
+
 #define MOD_NONLOCAL	(MOD_EXTERN | MOD_TOPLEVEL)
 #define MOD_STORAGE	(MOD_AUTO | MOD_REGISTER | MOD_STATIC | MOD_EXTERN | MOD_INLINE | MOD_TOPLEVEL)
 #define MOD_SIGNEDNESS	(MOD_SIGNED | MOD_UNSIGNED | MOD_EXPLICITLY_SIGNED)
@@ -223,7 +225,7 @@  struct symbol {
 #define MOD_SIZE	(MOD_CHAR | MOD_SHORT | MOD_LONG | MOD_LONGLONG)
 #define MOD_IGNORE (MOD_TOPLEVEL | MOD_STORAGE | MOD_ADDRESSABLE |	\
 	MOD_ASSIGNED | MOD_USERTYPE | MOD_ACCESSED | MOD_EXPLICITLY_SIGNED)
-#define MOD_PTRINHERIT (MOD_VOLATILE | MOD_CONST | MOD_NODEREF | MOD_STORAGE)
+#define MOD_PTRINHERIT (MOD_VOLATILE | MOD_CONST | MOD_NODEREF | MOD_STORAGE | MOD_NORETURN)
 
 
 /* Current parsing/evaluation function */
-- 
1.6.4.1