https://gcc.gnu.org/g:758a95db8a9ee0048a5de5334b59027535e2ecbc
commit r15-4903-g758a95db8a9ee0048a5de5334b59027535e2ecbc
Author: Daniel King <dmk...@adacore.com>
Date: Fri Sep 13 16:16:52 2024 +0100
ada: Fix alignment of pthread_mutex_t
On most targets the alignment of unsigned long is the same as pointer
alignment, but on CHERI targets pointers have larger alignment (16 bytes
compared to 8 bytes). pthread_mutex_t needs the same alignment as
System.Address to account for CHERI targets.
gcc/ada/ChangeLog:
* libgnat/s-oslock__posix.ads: Fix alignment of pthread_mutex_t
for CHERI targets.
Diff:
---
gcc/ada/libgnat/s-oslock__posix.ads | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/gcc/ada/libgnat/s-oslock__posix.ads
b/gcc/ada/libgnat/s-oslock__posix.ads
index e2c237f26981..cde92e5f23a3 100644
--- a/gcc/ada/libgnat/s-oslock__posix.ads
+++ b/gcc/ada/libgnat/s-oslock__posix.ads
@@ -52,6 +52,11 @@ private
Data : char_array (1 .. OS_Constants.PTHREAD_MUTEX_SIZE);
end record;
pragma Convention (C, pthread_mutex_t);
- for pthread_mutex_t'Alignment use Interfaces.C.unsigned_long'Alignment;
+ for pthread_mutex_t'Alignment use
+ Integer'Max (Interfaces.C.unsigned_long'Alignment,
+ System.Address'Alignment);
+ -- On some targets (e.g. CHERI), pointers have larger alignment than
+ -- unsigned_long. On other targets (e.g. some 16-bit targets) long is
+ -- larger than a pointer. Choose the largest to err on the side of caution.
end System.OS_Locks;
