diff options
| -rw-r--r-- | contrib/gcc/unwind-dw2.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/contrib/gcc/unwind-dw2.c b/contrib/gcc/unwind-dw2.c index 62c9d09..3306e06 100644 --- a/contrib/gcc/unwind-dw2.c +++ b/contrib/gcc/unwind-dw2.c @@ -1438,6 +1438,17 @@ uw_init_context_1 (struct _Unwind_Context *context, context->ra = __builtin_extract_return_addr (outer_ra); } +#if defined(__clang__) && defined(__amd64__) +/* Some versions of clang don't save and restore all callee registers, if a + __builtin_eh_return() intrinsic is used in a function. This is particularly + bad on amd64. For now, use the following ugly hack to force it to assume + those registers are clobbered, when invoking __builtin_eh_return(), so it + will emit code to save and restore them. */ +#define CLOBBER_REGS_HACK \ + __asm __volatile(" " : : : "r15", "r14", "r13", "r12", "rbx", "rdx", "rax"); +#else +#define CLOBBER_REGS_HACK +#endif /* __clang__ */ /* Install TARGET into CURRENT so that we can return to it. This is a macro because __builtin_eh_return must be invoked in the context of @@ -1448,6 +1459,7 @@ uw_init_context_1 (struct _Unwind_Context *context, { \ long offset = uw_install_context_1 ((CURRENT), (TARGET)); \ void *handler = __builtin_frob_return_addr ((TARGET)->ra); \ + CLOBBER_REGS_HACK \ __builtin_eh_return (offset, handler); \ } \ while (0) |
