Retro68/gcc/libgo/go/reflect/makefunc_ffi_c.c
2015-08-28 17:33:40 +02:00

94 lines
2.4 KiB
C

// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include "runtime.h"
#include "go-type.h"
#include "go-panic.h"
#ifdef USE_LIBFFI
#include "go-ffi.h"
#if FFI_GO_CLOSURES
#define USE_LIBFFI_CLOSURES
#endif
#endif /* defined(USE_LIBFFI) */
/* Declare C functions with the names used to call from Go. */
void makeFuncFFI(const struct __go_func_type *ftyp, void *impl)
__asm__ (GOSYM_PREFIX "reflect.makeFuncFFI");
#ifdef USE_LIBFFI_CLOSURES
/* The function that we pass to ffi_prep_closure_loc. This calls the Go
function ffiCall with the pointer to the arguments, the results area,
and the closure structure. */
void FFICallbackGo(void *result, void **args, ffi_go_closure *closure)
__asm__ (GOSYM_PREFIX "reflect.FFICallbackGo");
static void ffi_callback (ffi_cif *, void *, void **, void *)
__asm__ ("reflect.ffi_callback");
static void
ffi_callback (ffi_cif* cif __attribute__ ((unused)), void *results,
void **args, void *closure)
{
Location locs[8];
int n;
int i;
/* This function is called from some series of FFI closure functions
called by a Go function. We want to see whether the caller of
the closure functions can recover. Look up the stack and skip
the FFI functions. */
n = runtime_callers (1, &locs[0], sizeof locs / sizeof locs[0], true);
for (i = 0; i < n; i++)
{
const byte *name;
if (locs[i].function.len == 0)
continue;
if (locs[i].function.len < 4)
break;
name = locs[i].function.str;
if (name[0] != 'f' || name[1] != 'f' || name[2] != 'i' || name[3] != '_')
break;
}
if (i < n)
__go_makefunc_ffi_can_recover (locs + i, n - i);
FFICallbackGo(results, args, closure);
if (i < n)
__go_makefunc_returning ();
}
/* Allocate an FFI closure and arrange to call ffi_callback. */
void
makeFuncFFI(const struct __go_func_type *ftyp, void *impl)
{
ffi_cif *cif;
cif = (ffi_cif *) __go_alloc (sizeof (ffi_cif));
__go_func_to_cif (ftyp, 0, 0, cif);
ffi_prep_go_closure(impl, cif, ffi_callback);
}
#else /* !defined(USE_LIBFFI_CLOSURES) */
void
makeFuncFFI(const struct __go_func_type *ftyp __attribute__ ((unused)),
void *impl __attribute__ ((unused)))
{
runtime_panicstring ("libgo built without FFI does not support "
"reflect.MakeFunc");
}
#endif