|
If the argument was a function parameter, its type has already been
adjusted. So on x86_64, we can't just ignore the automatic
array-to-pointer conversion, since it was never a pointer to begin
with.
Instead, keep track of the adjusted va_list type, and check that
the arguments to varargs built-ins match that 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.
|
