diff options
| author | Ulf Hermann <ulf.hermann@qt.io> | 2017-08-18 14:05:10 +0200 |
|---|---|---|
| committer | Mark Wielaard <mark@klomp.org> | 2017-09-20 21:40:31 +0200 |
| commit | 17d7194d291bf91d130b78e06cbe27b290e0376d (patch) | |
| tree | 6197e445e38169e4672b80072dccabcca8d54dde /libcpu | |
| parent | b10d7eb74064c5906f031cd17c0f82041c6a4ca1 (diff) | |
Make sure packed structs follow the gcc memory layout
gcc defaults to using struct layouts that follow the native conventions,
even if __attribute__((packed)) is given. In order to get the layout we
expect, we need to tell gcc to always use the gcc struct layout, at
least for packed structs. To do this, we can use the gcc_struct
attribute.
This is important, not only for porting to windows, but also potentially
for other platforms, as the bugs resulting from struct layout
differences are rather subtle and hard to find.
Signed-off-by: Ulf Hermann <ulf.hermann@qt.io>
Diffstat (limited to 'libcpu')
| -rw-r--r-- | libcpu/ChangeLog | 4 | ||||
| -rw-r--r-- | libcpu/memory-access.h | 2 |
2 files changed, 5 insertions, 1 deletions
diff --git a/libcpu/ChangeLog b/libcpu/ChangeLog index 173defe6..c710e5af 100644 --- a/libcpu/ChangeLog +++ b/libcpu/ChangeLog @@ -1,3 +1,7 @@ +2017-08-18 Ulf Hermann <ulf.hermann@qt.io> + + * memory-access.h: Use attribute_packed. + 2017-02-27 Ulf Hermann <ulf.hermann@qt.io> * Makefile.am: Use fpic_CFLAGS. diff --git a/libcpu/memory-access.h b/libcpu/memory-access.h index 44210e2f..779825fa 100644 --- a/libcpu/memory-access.h +++ b/libcpu/memory-access.h @@ -90,7 +90,7 @@ union unaligned int16_t s2; int32_t s4; int64_t s8; - } __attribute__ ((packed)); + } attribute_packed; static inline uint16_t read_2ubyte_unaligned (const void *p) |