Re: [PATCH V2] sparse: Allow override of sizeof(bool) warning

Christopher Li
2014-02-27T20:44:42Z

On Thu, Feb 27, 2014 at 12:26 PM, H. Peter Anvin <hpa@zytor.com> wrote:
> I would.
>

Joe, I assume you are OK with this patch, the default is now off.

Chris

Allow an override to emit or not the sizeof(bool) warning.
Add a "-Wsizeof-bool" description to the manpage.

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Christopher Li <sparse@chrisli.org>
---
evaluate.c | 3 ++-
lib.c | 2 ++
lib.h | 1 +
sparse.1 | 8 ++++++++
4 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/evaluate.c b/evaluate.c
index 6655615..a45f59b 100644
--- a/evaluate.c
+++ b/evaluate.c
@@ -2057,7 +2057,8 @@ static struct symbol *evaluate_sizeof(struct
expression *expr)
}

if (size == 1 && is_bool_type(type)) {
- warning(expr->pos, "expression using sizeof bool");
+ if (Wsizeof_bool)
+ warning(expr->pos, "expression using sizeof bool");
size = bits_in_char;
}

diff --git a/lib.c b/lib.c
index 51b97fd..844797d 100644
--- a/lib.c
+++ b/lib.c
@@ -226,6 +226,7 @@ int Wparen_string = 0;
int Wptr_subtraction_blows = 0;
int Wreturn_void = 0;
int Wshadow = 0;
+int Wsizeof_bool = 0;
int Wtransparent_union = 0;
int Wtypesign = 0;
int Wundef = 0;
@@ -438,6 +439,7 @@ static const struct warning {
{ "ptr-subtraction-blows", &Wptr_subtraction_blows },
{ "return-void", &Wreturn_void },
{ "shadow", &Wshadow },
+ { "sizeof-bool", &Wsizeof_bool },
{ "transparent-union", &Wtransparent_union },
{ "typesign", &Wtypesign },
{ "undef", &Wundef },
diff --git a/lib.h b/lib.h
index f09b338..f6cd9b4 100644
--- a/lib.h
+++ b/lib.h
@@ -120,6 +120,7 @@ extern int Wparen_string;
extern int Wptr_subtraction_blows;
extern int Wreturn_void;
extern int Wshadow;
+extern int Wsizeof_bool;
extern int Wtransparent_union;
extern int Wtypesign;
extern int Wundef;
diff --git a/sparse.1 b/sparse.1
index cd6be26..54da09b 100644
--- a/sparse.1
+++ b/sparse.1
@@ -297,6 +297,14 @@ Such declarations can lead to error-prone code.
Sparse does not issue these warnings by default.
.
.TP
+.B \-Wsizeof-bool
+Warn when checking the sizeof a _Bool.
+
+C99 does not specify the sizeof a _Bool. gcc uses 1.
+
+Sparse does not issue these warnings by default.
+.
+.TP
.B \-Wtransparent\-union
Warn about any declaration using the GCC extension
\fB__attribute__((transparent_union))\fR.
--
1.8.5.3