On 26 January 2016 at 00:45, Prasad Ghangal <prasad.ghan...@gmail.com> wrote:
> Hi!
>
> I would like to solve "Bug 17896 - The expression (a>0 & b>0) should
> give clearer warning message (-Wparentheses)"
> (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=17896) but I am new to
> gcc internals.
>
> Can someone please guide me how to do it?
You would perhaps need to modify c-common.c:warn_about_parentheses ().
my untested patch gives:
f.c: In function ‘main’:
f.c:5:13: warning: suggest && instead of & [-Wparentheses]
if (a > b & a > c)
^
You will probably need to extend along similar lines.
Thanks,
Prathamesh
>
> --
> Thanks and Regards,
> Prasad Ghangal
diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 378afae..9444f29 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -11642,6 +11642,10 @@ warn_about_parentheses (location_t loc, enum tree_code
code,
else if (code_right == MINUS_EXPR)
warning_at (EXPR_LOC_OR_LOC (arg_right, loc), OPT_Wparentheses,
"suggest parentheses around %<-%> in operand of %<&%>");
+ else if (TREE_CODE_CLASS (code_left) == tcc_comparison
+ && TREE_CODE_CLASS (code_right) == tcc_comparison)
+ warning_at (loc, OPT_Wparentheses,
+ "suggest && instead of &");
/* Check cases like x&y==z */
else if (TREE_CODE_CLASS (code_left) == tcc_comparison)
warning_at (EXPR_LOC_OR_LOC (arg_left, loc), OPT_Wparentheses,
