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[Bug c/17896] The expression (a>0 & b>0) should give clearer warning message (-Wparentheses)
- From: "manu at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Thu, 26 Apr 2012 22:23:59 +0000
- Subject: [Bug c/17896] The expression (a>0 & b>0) should give clearer warning message (-Wparentheses)
- Auto-submitted: auto-generated
- References: <bug-17896-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17896
Manuel LÃpez-IbÃÃez <manu at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |manu at gcc dot gnu.org
--- Comment #5 from Manuel LÃpez-IbÃÃez <manu at gcc dot gnu.org> 2012-04-26 22:23:59 UTC ---
manuel@gcc12:~$ clang -Wextra -Wall -Weverything -fsyntax-only pr17896.c
pr17896.c:4:1: warning: no previous prototype for function 'bar'
[-Wmissing-prototypes]
bar (int a, int b, int c)
^
pr17896.c:7:17: warning: & has lower precedence than ==; == will be evaluated
first [-Wparentheses]
foo (a == b & (b == c)); /* { dg-warning "boolean" "correct warning" } */
~~~~~~~^
pr17896.c:7:17: note: place parentheses around the == expression to silence
this warning
foo (a == b & (b == c)); /* { dg-warning "boolean" "correct warning" } */
^
( )
pr17896.c:7:17: note: place parentheses around the & expression to evaluate it
first
foo (a == b & (b == c)); /* { dg-warning "boolean" "correct warning" } */
^
( )
pr17896.c:8:19: warning: & has lower precedence than ==; == will be evaluated
first [-Wparentheses]
foo ((a == b) & b == c); /* { dg-warning "boolean" "correct warning" } */
^~~~~~~~
pr17896.c:8:19: note: place parentheses around the == expression to silence
this warning
foo ((a == b) & b == c); /* { dg-warning "boolean" "correct warning" } */
^
( )
pr17896.c:8:19: note: place parentheses around the & expression to evaluate it
first
foo ((a == b) & b == c); /* { dg-warning "boolean" "correct warning" } */
^
( )
pr17896.c:13:16: warning: | has lower precedence than ==; == will be evaluated
first [-Wparentheses]
foo (a == b | (b == c)); /* { dg-warning "boolean" "correct warning" } */
~~~~~~~^
pr17896.c:13:16: note: place parentheses around the == expression to silence
this warning
foo (a == b | (b == c)); /* { dg-warning "boolean" "correct warning" } */
^
( )
pr17896.c:13:16: note: place parentheses around the | expression to evaluate it
first
foo (a == b | (b == c)); /* { dg-warning "boolean" "correct warning" } */
^
( )
pr17896.c:14:18: warning: | has lower precedence than ==; == will be evaluated
first [-Wparentheses]
foo ((a == b) | b == c); /* { dg-warning "boolean" "correct warning" } */
^~~~~~~~
pr17896.c:14:18: note: place parentheses around the == expression to silence
this warning
foo ((a == b) | b == c); /* { dg-warning "boolean" "correct warning" } */
^
( )
pr17896.c:14:18: note: place parentheses around the | expression to evaluate it
first
foo ((a == b) | b == c); /* { dg-warning "boolean" "correct warning" } */
^
( )
5 warnings generated.
manuel@gcc12:~$ ~/trunk/186353/build/gcc/cc1 -Wextra -Wall -Wlogical-op
-fsyntax-only pr17896.c
bar
pr17896.c: In function âbarâ:
pr17896.c:6:5: warning: suggest parentheses around comparison in operand of â&â
[-Wparentheses]
foo (a == b & b == c); /* { dg-warning "boolean" "correct warning" }
*/
^
pr17896.c:7:5: warning: suggest parentheses around comparison in operand of â&â
[-Wparentheses]
foo (a == b & (b == c)); /* { dg-warning "boolean" "correct warning" }
*/
^
pr17896.c:8:5: warning: suggest parentheses around comparison in operand of â&â
[-Wparentheses]
foo ((a == b) & b == c); /* { dg-warning "boolean" "correct warning" }
*/
^
pr17896.c:9:5: warning: suggest parentheses around comparison in operand of â&â
[-Wparentheses]
foo (++a == b & b == c); /* { dg-warning "comparison" "correct warning"
} */
^
pr17896.c:12:5: warning: suggest parentheses around comparison in operand of
â|â [-Wparentheses]
foo (a == b | b == c); /* { dg-warning "boolean" "correct warning" }
*/
^
pr17896.c:13:4: warning: suggest parentheses around comparison in operand of
â|â [-Wparentheses]
foo (a == b | (b == c)); /* { dg-warning "boolean" "correct warning" } */
^
pr17896.c:14:4: warning: suggest parentheses around comparison in operand of
â|â [-Wparentheses]
foo ((a == b) | b == c); /* { dg-warning "boolean" "correct warning" } */
^
pr17896.c:15:4: warning: suggest parentheses around comparison in operand of
â|â [-Wparentheses]
foo (++a == b | b == c); /* { dg-warning "comparison" "correct warning" }
*/
^