[PATCH] asm: Use SEH assembly when building with clang in MSVC mode

[Martin Storsjo]

In MSVC mode, the __SEH__ macro isn't defined, but the .seh directives
are supported in assembly. In these cases, we have to hardcode which
architectures we know clang supports SEH directives in as it's not
exposed otherwise.

Signed-off-by: Martin Storsjo <martin(a)martin.st>

---
This is admittedly rather ugly, but fixes a few unwinding cases with
a wine in PE mode, built with clang in MSVC mode.
---
 include/wine/asm.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/wine/asm.h b/include/wine/asm.h
index ed44a7dd6dd..236b35cf8fe 100644
--- a/include/wine/asm.h
+++ b/include/wine/asm.h
@@ -41,7 +41,7 @@
 # define __ASM_CFI(str)
 #endif
 
-#ifdef __SEH__
+#if defined(__SEH__) || (defined(_MSC_VER) && defined(__clang__) && (defined(__x86_64__) || defined(__aarch64__)))
 # if defined(__aarch64__) && defined(__clang_major__) && (__clang_major__ < 12 || defined(__apple_build_version__))
    /* Clang got support for aarch64 SEH assembly directives in Clang 12,
     * before that, only .seh_startproc/.seh_endproc but nothing else was
-- 
2.17.1

[Jacek Caban]

Signed-off-by: Jacek Caban <jacek(a)codeweavers.com>

On 18.12.2020 23:37, Martin Storsjo wrote:
> In MSVC mode, the __SEH__ macro isn't defined, but the .seh directives
> are supported in assembly. In these cases, we have to hardcode which
> architectures we know clang supports SEH directives in as it's not
> exposed otherwise.
>
> Signed-off-by: Martin Storsjo<martin(a)martin.st>

Nice. I recall having build problems with something like that, but your 
patch works fine now. Maybe it was only about x86.


Thanks,

Jacek