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.

1 files changed, 18 insertions, 0 deletions

diff --git a/targ.c b/targ.c
index 2859975..f2be127 100644
--- a/targ.c
+++ b/targ.c
@@ -9,14 +9,32 @@ static const struct target alltargs[] = {
 	{
 		.name = "x86_64",
 		.typewchar = &typeint,
+		.typevalist = &(struct type){
+			.kind = TYPEARRAY, .prop = PROPOBJECT|PROPDERIVED|PROPAGGR,
+			.align = 8, .size = 24,
+			.array = {1}, .base = &(struct type){
+				.kind = TYPESTRUCT, .prop = PROPOBJECT|PROPAGGR,
+				.align = 8, .size = 24,
+			},
+		},
 		.signedchar = 1,
 	},
 	{
 		.name = "aarch64",
+		.typevalist = &(struct type){
+			.kind = TYPESTRUCT, .prop = PROPOBJECT|PROPAGGR,
+			.align = 8, .size = 32,
+			.structunion.tag = "va_list",
+		},
 		.typewchar = &typeuint,
 	},
 	{
 		.name = "riscv64",
+		.typevalist = &(struct type){
+			.kind = TYPEPOINTER, .prop = PROPOBJECT|PROPDERIVED|PROPSCALAR,
+			.align = 8, .size = 8,
+			.base = &typevoid,
+		},
 		.typewchar = &typeint,
 	},
 };