8f0dd9478e
Future releases of GCC are planning to remove[0] default support for
some old features that were removed from C99 but GCC still accepts.
We can test for these changes by using the following -Werror=
directives
-Werror=implicit-int
-Werror=implicit-function-declaration
-Werror=int-conversion
-Werror=strict-prototypes
-Werror=old-style-definition
Doing so revealed an issue with the auto/ tests in that the test
programs always define main as
int main()
rather than
int main(void)
which results in a bunch of errors like
build/autotest.c:3:23: error: function declaration isn't a prototype [-Werror=strict-prototypes]
3 | int main() {
| ^~~~
build/autotest.c: In function 'main':
build/autotest.c:3:23: error: old-style function definition [-Werror=old-style-definition]
The fix was easy, it only required fixing the main prototype with
find -type f -exec sed -i 's/int main() {/int main(void) {/g' {} \;
Regardless of these upcoming GCC changes, this is probably a good thing
to do anyway for correctness.
[0]: https://fedoraproject.org/wiki/Changes/PortingToModernC
Link: <https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/CJXKTLXJUPZ4F2C2VQOTNMEA5JAUPMBD/>
Link: <https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/6SGHPHPAXKCVJ6PUZ57WVDQ5TDBVIRMF/>
Reviewed-by: Alejandro Colomar <alx@nginx.com>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
196 lines
4.7 KiB
Text
196 lines
4.7 KiB
Text
|
|
# Copyright (C) Igor Sysoev
|
|
# Copyright (C) NGINX, Inc.
|
|
|
|
|
|
# C language features.
|
|
|
|
|
|
nxt_feature="C99 variadic macro"
|
|
nxt_feature_name=NXT_HAVE_C99_VARIADIC_MACRO
|
|
nxt_feature_run=yes
|
|
nxt_feature_incs=
|
|
nxt_feature_libs=
|
|
nxt_feature_test="#include <stdio.h>
|
|
#define set(dummy, ...) sprintf(__VA_ARGS__)
|
|
|
|
int main(void) {
|
|
char buf[4];
|
|
|
|
buf[0] = '0';
|
|
set(0, buf, \"%d\", 1);
|
|
|
|
if (buf[0] == '1')
|
|
return 0;
|
|
return 1;
|
|
}"
|
|
. auto/feature
|
|
|
|
|
|
if [ $nxt_found = no ]; then
|
|
|
|
nxt_feature="GCC variadic macro"
|
|
nxt_feature_name=NXT_HAVE_GCC_VARIADIC_MACRO
|
|
nxt_feature_run=yes
|
|
nxt_feature_incs=
|
|
nxt_feature_libs=
|
|
nxt_feature_test="#include <stdio.h>
|
|
#define set(dummy, args...) sprintf(args)
|
|
|
|
int main(void) {
|
|
char buf[4];
|
|
|
|
buf[0] = '0';
|
|
set(0, buf, \"%d\", 1);
|
|
|
|
if (buf[0] == '1')
|
|
return 0;
|
|
return 1;
|
|
}"
|
|
. auto/feature
|
|
fi
|
|
|
|
|
|
nxt_feature="GCC __builtin_expect()"
|
|
nxt_feature_name=NXT_HAVE_BUILTIN_EXPECT
|
|
nxt_feature_run=no
|
|
nxt_feature_incs=
|
|
nxt_feature_libs=
|
|
nxt_feature_test="int main(int argc, char *const *argv) {
|
|
if ((__typeof__(argc == 0))
|
|
__builtin_expect((argc == 0), 0))
|
|
return 0;
|
|
return 1;
|
|
}"
|
|
. auto/feature
|
|
|
|
|
|
nxt_feature="GCC __builtin_unreachable()"
|
|
nxt_feature_name=NXT_HAVE_BUILTIN_UNREACHABLE
|
|
nxt_feature_run=no
|
|
nxt_feature_incs=
|
|
nxt_feature_libs=
|
|
nxt_feature_test="int main(void) {
|
|
__builtin_unreachable();
|
|
}"
|
|
. auto/feature
|
|
|
|
|
|
nxt_feature="GCC __builtin_prefetch()"
|
|
nxt_feature_name=NXT_HAVE_BUILTIN_PREFETCH
|
|
nxt_feature_run=no
|
|
nxt_feature_incs=
|
|
nxt_feature_libs=
|
|
nxt_feature_test="int main(void) {
|
|
__builtin_prefetch(0);
|
|
return 0;
|
|
}"
|
|
. auto/feature
|
|
|
|
|
|
nxt_feature="GCC __builtin_clz()"
|
|
nxt_feature_name=NXT_HAVE_BUILTIN_CLZ
|
|
nxt_feature_run=
|
|
nxt_feature_incs=
|
|
nxt_feature_libs=
|
|
nxt_feature_test="int main(void) {
|
|
if (__builtin_clz(1) == 31)
|
|
return 0;
|
|
return 1;
|
|
}"
|
|
. auto/feature
|
|
|
|
|
|
nxt_feature="GCC __builtin_popcount()"
|
|
nxt_feature_name=NXT_HAVE_BUILTIN_POPCOUNT
|
|
nxt_feature_run=
|
|
nxt_feature_incs=
|
|
nxt_feature_libs=
|
|
nxt_feature_test="int main(void) {
|
|
if (__builtin_popcount(5) == 2)
|
|
return 0;
|
|
return 1;
|
|
}"
|
|
. auto/feature
|
|
|
|
|
|
nxt_feature="GCC __attribute__ visibility"
|
|
nxt_feature_name=NXT_HAVE_GCC_ATTRIBUTE_VISIBILITY
|
|
nxt_feature_run=
|
|
nxt_feature_incs=
|
|
nxt_feature_libs=
|
|
nxt_feature_test="int n __attribute__ ((visibility(\"default\")));
|
|
|
|
int main(void) {
|
|
return 1;
|
|
}"
|
|
. auto/feature
|
|
|
|
|
|
nxt_feature="GCC __attribute__ aligned"
|
|
nxt_feature_name=NXT_HAVE_GCC_ATTRIBUTE_ALIGNED
|
|
nxt_feature_run=
|
|
nxt_feature_incs=
|
|
nxt_feature_libs=
|
|
nxt_feature_test="int n __attribute__ ((aligned(64)));
|
|
|
|
int main(void) {
|
|
return 1;
|
|
}"
|
|
. auto/feature
|
|
|
|
|
|
nxt_feature="GCC __attribute__ malloc"
|
|
nxt_feature_name=NXT_HAVE_GCC_ATTRIBUTE_MALLOC
|
|
nxt_feature_run=
|
|
nxt_feature_incs=
|
|
nxt_feature_libs=
|
|
nxt_feature_test="#include <stdlib.h>
|
|
|
|
void *f(void) __attribute__ ((__malloc__));
|
|
|
|
void *f(void) {
|
|
return malloc(1);
|
|
}
|
|
|
|
int main(void) {
|
|
if (f() != NULL) {
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}"
|
|
. auto/feature
|
|
|
|
|
|
nxt_feature="GCC __attribute__ packed"
|
|
nxt_feature_name=NXT_HAVE_GCC_ATTRIBUTE_PACKED
|
|
nxt_feature_run=
|
|
nxt_feature_incs=
|
|
nxt_feature_libs=
|
|
nxt_feature_test="struct s {
|
|
char c;
|
|
int i;
|
|
} __attribute__ ((__packed__));
|
|
|
|
int main(void) {
|
|
return 1;
|
|
}"
|
|
. auto/feature
|
|
|
|
|
|
nxt_feature="GCC __attribute__ unused"
|
|
nxt_feature_name=NXT_HAVE_GCC_ATTRIBUTE_UNUSED
|
|
nxt_feature_run=
|
|
nxt_feature_incs=
|
|
nxt_feature_libs=
|
|
nxt_feature_test="static void f(void) __attribute__ ((__unused__));
|
|
|
|
static void f(void)
|
|
{
|
|
return;
|
|
}
|
|
|
|
int main(void) {
|
|
return 0;
|
|
}"
|
|
. auto/feature
|