diff options
| author | Filipe Brandenburger <filbranden@google.com> | 2015-09-05 16:52:51 -0700 |
|---|---|---|
| committer | Filipe Brandenburger <filbranden@google.com> | 2015-09-22 09:54:33 -0700 |
| commit | a01a4517e16c532fbd5203fbfe2571255e2cd312 (patch) | |
| tree | 8dd5d51839ebd7b5fb173a13ac65ba8f85f045ec /configure.ac | |
| parent | 6a937f0645ab335ef13a79951c3e94d6d8becea9 (diff) | |
build-sys: Check behavior of -Werror=shadow before deciding to use it
gcc versions 4.6 and earlier used to complain when a local variable
shadows a global function, 4.7 and above only complain if a local
variable shadows a global variable.
Fix this by checking whether gcc 4.7+ behavior is in place before
deciding to use -Werror=shadow in $(CFLAGS), by using a custom test
program source that shadows a global function with a local variable and
confirming that -Werror=shadow does not make the compile to break.
Tested:
- On gcc 4.7 and 4.8, confirmed nothing changed (other than the order of
the -Werror=shadow argument, going to the end of CFLAGS.)
- On gcc 4.6, confirmed by looking at the config.log output that the
check for -Werror=shadow failed and it was not included in CFLAGS.
- Ran `make V=1` to confirm -Werror=shadow was still in use, introduced
a bogus shadowing issue and confirmed it was caught when building with
a recent gcc.
Diffstat (limited to 'configure.ac')
| -rw-r--r-- | configure.ac | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/configure.ac b/configure.ac index d71cb07366..5cdd1d1462 100644 --- a/configure.ac +++ b/configure.ac @@ -171,7 +171,6 @@ CC_CHECK_FLAGS_APPEND([with_cflags], [CFLAGS], [\ -Werror=implicit-function-declaration \ -Werror=missing-declarations \ -Werror=return-type \ - -Werror=shadow \ -Wstrict-prototypes \ -Wredundant-decls \ -Wmissing-noreturn \ @@ -196,6 +195,17 @@ CC_CHECK_FLAGS_APPEND([with_cflags], [CFLAGS], [\ -fPIE \ --param=ssp-buffer-size=4]) +CC_CHECK_FLAG_APPEND([with_cflags], [CFLAGS], [-Werror=shadow], [ +#include <time.h> +#include <inttypes.h> +typedef uint64_t usec_t; +usec_t now(clockid_t clock); +int main(void) { + struct timespec now; + return 0; +} +]) + AS_CASE([$CC], [*clang*], [CC_CHECK_FLAGS_APPEND([with_cppflags], [CPPFLAGS], [\ -Wno-typedef-redefinition \ |