From e07ea69d611991a24d67076df906866c198252c0 Mon Sep 17 00:00:00 2001 From: Michael Forney Date: Sat, 4 Sep 2021 13:53:09 -0700 Subject: Use architecture-specific va_list type Previously, cproc effectively used used typedef struct { /* 32 bytes, 8-byte aligned */ } __builtin_va_list[1]; However, this is not quite correct for x86_64 nor aarch64, though it was close enough for both to work in most cases. In actuality, for x86_64 we want typedef struct { /* 24 bytes, 8-byte aligned */ } __builtin_va_list[1]; and for aarch64 we want typedef struct { /* 32 bytes, 8-byte aligned */ } __builtin_va_list; The difference only appears when the size of va_list matters, or when va_list is passed as a parameter. However, the former is not often the case, and the aarch64 ABI replaces aggregate arguments with pointers to caller-allocated memory, which is quite similar to arrays decaying to pointers in C except that the struct is not copied. Additionally, riscv64 simply uses typedef void *__builtin_va_list; which again has a different size and calling convention. To fix this, make the __builtin_va_list type architecture-specific and use architecture-specific tests for varargs-related functionality. --- test/varargs-pass-valist+riscv64.c | 5 +++++ 1 file changed, 5 insertions(+) create mode 100644 test/varargs-pass-valist+riscv64.c (limited to 'test/varargs-pass-valist+riscv64.c') diff --git a/test/varargs-pass-valist+riscv64.c b/test/varargs-pass-valist+riscv64.c new file mode 100644 index 0000000..c1ede84 --- /dev/null +++ b/test/varargs-pass-valist+riscv64.c @@ -0,0 +1,5 @@ +void f(__builtin_va_list ap); +void g(void) { + static __builtin_va_list ap; + f(ap); +} -- cgit v1.2.3