bash-3.00$ cat z1.c
int foo(void);
void bar(void) { (unsigned int)foo(); }
bash-3.00$ vi z1.c
bash-3.00$ /usr/local/gcc-4.1-branch/bin/gcc -c z1.c -Wall -O2
z1.c: In function bar:
z1.c:1: warning: value computed is not used
bash-3.00$ /usr/local/gcc-4.1-branch/bin/gcc -v
Using built-in specs.
Target: i686-pc-linux-gnu
Configured with: ../gcc/configure --prefix=/usr/local/gcc-4.1-branch
--with-gnu-ld=/usr/local/binutils-2.16.1/bin/ld
--with-gnu-as=/usr/local/binutils-2.16.1/bin/as
Thread model: posix
gcc version 4.1.0 20060118 (prerelease)
Background:
Wine's windowsx.h defines:
#define ListBox_SetCurSel(hwndCtl, index) \
((int)SendMessage((hwndCtl), LB_SETCURSEL, (WPARAM)(int)(index), 0L))
Using this macro will give a warning in the gcc 4.1 branch, but not with gcc
4.0.2. Though the warning is technically correct, it doesn't really make much
sense, and I can't think of a real problem it's going to catch.
--
Summary: regression: value computed not used warning with cast
return value
Product: gcc
Version: 4.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: mike at codeweavers dot com
GCC build triplet: i686-pc-linux-gnu
GCC host triplet: i486-slackware-linux
GCC target triplet: i686-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25955
