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| author | Aaron Ballman <aaron@aaronballman.com> | 2023-01-18 08:49:45 -0500 |
|---|---|---|
| committer | Aaron Ballman <aaron@aaronballman.com> | 2023-01-18 08:51:21 -0500 |
| commit | e7300e75b51a7e7d4e81975b4be7a6c65f9a8286 (patch) | |
| tree | de4e2e3f1ceaca35ae0e37c4417c66b97d9af7d6 /clang/test/CodeGen/offsetof.c | |
| parent | 63ba34f3fb752e0a60a78c21ee694e1064a870ab (diff) | |
| download | llvm-e7300e75b51a7e7d4e81975b4be7a6c65f9a8286.zip llvm-e7300e75b51a7e7d4e81975b4be7a6c65f9a8286.tar.gz llvm-e7300e75b51a7e7d4e81975b4be7a6c65f9a8286.tar.bz2 | |
Diagnose extensions in 'offsetof'
https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2350.htm made very
clear that it is an UB having type definitions with in offsetof.
Clang supports defining a type as the first argument as a conforming
extension due to how many projects use the construct in C99 and earlier
to calculate the alignment of a type. GCC also supports defining a type
as the first argument.
This adds extension warnings and documentation for the functionality
Clang explicitly supports.
Fixes #57065
Reverts the revert of 39da55e8f548a11f7dadefa73ea73d809a5f1729
Co-authored-by: Yingchi Long <i@lyc.dev>
Co-authored-by: Aaron Ballman <aaron@aaronballman.com>
Differential Revision: https://reviews.llvm.org/D133574
Diffstat (limited to 'clang/test/CodeGen/offsetof.c')
| -rw-r--r-- | clang/test/CodeGen/offsetof.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/clang/test/CodeGen/offsetof.c b/clang/test/CodeGen/offsetof.c index c279e22..13b34ea 100644 --- a/clang/test/CodeGen/offsetof.c +++ b/clang/test/CodeGen/offsetof.c @@ -10,3 +10,7 @@ int test(int len) { return __builtin_offsetof(struct sockaddr_un, sun_path[len+1]); } +// Ensure we can form the offset to a structure defined in the first argument +// without crashing or asserting on an invalid declaration (because the +// declaration is actually valid). +void c() { __builtin_offsetof(struct {int b;}, b); } |