Commit 482b37f00467325e3389bab322525099860dd9aa
2017-09-18T12:44:08
Fix passing struct by value on aarch64 This fixes the ctypes test in the python testsuite.
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diff --git a/src/aarch64/ffi.c b/src/aarch64/ffi.c
index 4400b61..b64a6b9 100644
--- a/src/aarch64/ffi.c
+++ b/src/aarch64/ffi.c
@@ -238,13 +238,18 @@ is_vfp_type (const ffi_type *ty)
state.
The terse state variable names match the names used in the AARCH64
- PCS. */
+ PCS.
+
+ The struct area is allocated downwards from the top of the argument
+ area. It is used to hold copies of structures passed by value that are
+ bigger than 16 bytes. */
struct arg_state
{
unsigned ngrn; /* Next general-purpose register number. */
unsigned nsrn; /* Next vector register number. */
size_t nsaa; /* Next stack offset. */
+ size_t next_struct_area; /* Place to allocate big structs. */
#if defined (__APPLE__)
unsigned allocating_variadic;
@@ -253,11 +258,12 @@ struct arg_state
/* Initialize a procedure call argument marshalling state. */
static void
-arg_init (struct arg_state *state)
+arg_init (struct arg_state *state, size_t size)
{
state->ngrn = 0;
state->nsrn = 0;
state->nsaa = 0;
+ state->next_struct_area = size;
#if defined (__APPLE__)
state->allocating_variadic = 0;
#endif
@@ -286,6 +292,21 @@ allocate_to_stack (struct arg_state *state, void *stack,
return (char *)stack + nsaa;
}
+/* Allocate and copy a structure that is passed by value on the stack and
+ return a pointer to it. */
+static void *
+allocate_and_copy_struct_to_stack (struct arg_state *state, void *stack,
+ size_t alignment, size_t size, void *value)
+{
+ size_t dest = state->next_struct_area - size;
+
+ /* Round down to the natural alignment of the value. */
+ dest = ALIGN_DOWN (dest, alignment);
+ state->next_struct_area = dest;
+
+ return memcpy ((char *) stack + dest, value, size);
+}
+
static ffi_arg
extend_integer_type (void *source, int type)
{
@@ -591,13 +612,14 @@ ffi_call_int (ffi_cif *cif, void (*fn)(void), void *orig_rvalue,
frame = stack + stack_bytes;
rvalue = (rsize ? frame + 32 : orig_rvalue);
- arg_init (&state);
+ arg_init (&state, stack_bytes);
for (i = 0, nargs = cif->nargs; i < nargs; i++)
{
ffi_type *ty = cif->arg_types[i];
size_t s = ty->size;
void *a = avalue[i];
int h, t;
+ void *dest;
t = ty->type;
switch (t)
@@ -645,8 +667,6 @@ ffi_call_int (ffi_cif *cif, void (*fn)(void), void *orig_rvalue,
case FFI_TYPE_STRUCT:
case FFI_TYPE_COMPLEX:
{
- void *dest;
-
h = is_vfp_type (ty);
if (h)
{
@@ -664,9 +684,12 @@ ffi_call_int (ffi_cif *cif, void (*fn)(void), void *orig_rvalue,
else if (s > 16)
{
/* If the argument is a composite type that is larger than 16
- bytes, then the argument has been copied to memory, and
+ bytes, then the argument is copied to memory, and
the argument is replaced by a pointer to the copy. */
- a = &avalue[i];
+ dest = allocate_and_copy_struct_to_stack (&state, stack,
+ ty->alignment, s,
+ avalue[i]);
+ a = &dest;
t = FFI_TYPE_POINTER;
s = sizeof (void *);
goto do_pointer;
@@ -835,7 +858,7 @@ ffi_closure_SYSV_inner (ffi_cif *cif,
int i, h, nargs, flags;
struct arg_state state;
- arg_init (&state);
+ arg_init (&state, cif->bytes);
for (i = 0, nargs = cif->nargs; i < nargs; i++)
{