__attribute__((warn_unused_result)) does not work when applied to pointers to functions

[llvmbot]

Bugzilla Link	4010
Resolution	FIXED
Resolved on	Feb 22, 2010 12:49
Version	unspecified
OS	MacOS X
Attachments	Example demonstrating problem
Reporter	LLVM Bugzilla Contributor
CC	@nunoplopes,@sirainen

Extended Description

version used: checker-186

Clang does not allow attribute((warn_unused_result)) to be applied to pointers to functions. For example:

char *(*functionPointerTest)(void) attribute((warn_unused_result));

Clang gives the following warning:

warnbug.c:8:57: warning: 'warn_unused_result' attribute only applies to function types
char *(*functionPointerTest)(void) attribute((warn_unused_result));
^

Expected behavior: You should be able to apply warn_unused_result to pointers to functions just as you would a common function prototype.

Attached is an example that demonstrates the problem. When run with scan-build gcc -c -Wall -Wextra warnbug.c, gcc correctly handles the attribute and correctly warns for the line that does not check/use the result.

[nunoplopes]

fixed in r91803.