https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101601
Bug ID: 101601
Summary: [12 Regression] -Wall is reported as a build error
(not warning): error: arrays of functions are not
meaningful
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: slyfox at gcc dot gnu.org
Target Milestone: ---
The example is extracted from wine-6.13 build failure against gcc-master.
Here is the smaller example:
$ cat a.c
// x86_64-pc-linux-gnu-gcc -m32 -c -o a.o a.c -Wall -pipe -O2
typedef void f(void);
void args(void*);
f *SSCall_fun;
void SSCall(void) { args(&SSCall_fun + 1); }
$ ./xgcc -B. -m32 -c -o a.o a.c -Wall -pipe -O2
a.c: In function 'SSCall':
a.c:5:6: error: arrays of functions are not meaningful
5 | void SSCall(void) { args(&SSCall_fun + 1); }
| ^~~~~~
Note1: -Wall turns successful build into build failure.
I think it's not expected: it should still be a warning (or an unconditional
error).
$ ./xgcc -B. -m32 -c -o a.o a.c -Wall -pipe
$ ./xgcc -B. -m32 -c -o a.o a.c -pipe -O2
$ gcc-11.1.0 -m32 -c -o a.o a.c -Wall -pipe -O2
Note2: -O2 vs. -O0 causes warning to go away (maybe it's ok).
$ ./xgcc -B. -v
Reading specs from ./specs
COLLECT_GCC=./xgcc
COLLECT_LTO_WRAPPER=./lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /home/slyfox/dev/git/gcc/configure --build=x86_64-pc-linux-gnu
--host=x86_64-pc-linux-gnu --target=x86_64-pc-linux-gnu
--enable-languages=c,c++ --disable-bootstrap --with-multilib-list=m64
--prefix=/tmp/gcc-build/../gcc-native-quick-installed --disable-nls
--without-isl --disable-libsanitizer --disable-libvtv --disable-libgomp
--disable-libstdcxx-pch --disable-libunwind-exceptions CFLAGS='-O1 '
CXXFLAGS='-O1 '
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 12.0.0 20210723 (experimental) (GCC)
