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author | Bernhard Schommer <bschommer@users.noreply.github.com> | 2018-09-10 15:43:20 +0200 |
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committer | Xavier Leroy <xavierleroy@users.noreply.github.com> | 2018-09-10 15:43:20 +0200 |
commit | 45ca9fe8fcc6a67036369624f57576be22ac7bbd (patch) | |
tree | 7f4e1e79a1abd7fccfdf965f872e9ae6b4437c52 /test/regression/alignas.c | |
parent | 49ecf8a3e5b5a4449f4bcbc1d6d4f55c8b5888be (diff) | |
download | compcert-45ca9fe8fcc6a67036369624f57576be22ac7bbd.tar.gz compcert-45ca9fe8fcc6a67036369624f57576be22ac7bbd.zip |
Attach _Alignas to names and refactor _Alignas checks (#133)
* Refactor common code of alignas.
Instead of working on attributes the function now works directly
on the type since the check always performed an extraction of
attributes from a type.
Bug 23393
* Attach _Alignas to the name.
Bug 23393
* Attach "aligned" attributes to names
So that __attribute((aligned(N))) remains consistent with _Alignas(N).
gcc and clang apply "aligned" attributes to names, with a special case
for typedefs:
typedef __attribute((aligned(16))) int int_al_16;
int_al_16 * p;
__attribute((aligned(16))) int * q;
For gcc, p is naturally-aligned pointer to 16-aligned int and
q is 16-aligned pointer to naturally-aligned int.
For CompCert with this commit, both p and q are 16-aligned pointers
to naturally-aligned int.
* Resurrect the alignment test involving typedef
The test was removed because it involved an _Alignas in a typedef,
which is no longer supported. However the same effect can be achieved
with an "aligned" attribute, which is still supported in typedef.
Diffstat (limited to 'test/regression/alignas.c')
-rw-r--r-- | test/regression/alignas.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/test/regression/alignas.c b/test/regression/alignas.c index 23966b59..777c13a5 100644 --- a/test/regression/alignas.c +++ b/test/regression/alignas.c @@ -7,7 +7,7 @@ #endif #if __STDC_VERSION__ < 201100 && defined(__GNUC__) -#define _Alignas(x) __attribute__((aligned(x))) +#define _Alignas(x) __attribute((aligned(x))) #endif /* Base type */ @@ -20,10 +20,9 @@ _Alignas(16) int b[3]; typedef int int3[3]; _Alignas(16) int3 bb; -#if 0 -typedef _Alignas(16) int int16; +/* _Alignas is not allowed in typedefs but the "aligned" attribute is */ +typedef __attribute((aligned(16))) int int16; int16 bbb[3]; -#endif char filler2; @@ -74,10 +73,8 @@ int main() (unsigned) sizeof(b), ((unsigned) &b) & 0xF); printf("bb: size = %u, address mod 16 = %u\n", (unsigned) sizeof(bb), ((unsigned) &bb) & 0xF); -#if 0 printf("bbb: size = %u, address mod 16 = %u\n", (unsigned) sizeof(bbb), ((unsigned) &bbb) & 0xF); -#endif printf("c: size = %u, address mod 16 = %u\n", (unsigned) sizeof(c), ((unsigned) &c) & 0xF); printf("d: size = %u, address mod 64 = %u\n", |