Viewing file:  makefunc_ffi_c.c (2.57 KB) -rw-r--r--
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// 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"
#ifdef USE_LIBFFI
#include "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(void *cif, 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. */
extern void ffiCallbackGo(void *result, void **args, ffi_go_closure *closure,
int32 wordsize, _Bool big_endian)
__asm__ (GOSYM_PREFIX "reflect.ffiCallbackGo");
extern void makefuncfficanrecover(Slice)
__asm__ (GOSYM_PREFIX "runtime.makefuncfficanrecover");
extern void makefuncreturning(void)
__asm__ (GOSYM_PREFIX "runtime.makefuncreturning");
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)
{
Slice s;
s.__values = (void *) &locs[i];
s.__count = n - i;
s.__capacity = n - i;
makefuncfficanrecover (s);
}
ffiCallbackGo(results, args, closure, sizeof(ffi_arg),
__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__);
if (i < n)
makefuncreturning ();
}
/* Allocate an FFI closure and arrange to call ffi_callback. */
void
makeFuncFFI(void *cif, void *impl)
{
ffi_prep_go_closure(impl, (ffi_cif*)cif, ffi_callback);
}
#else /* !defined(USE_LIBFFI_CLOSURES) */
void
makeFuncFFI(void *cif __attribute__ ((unused)),
void *impl __attribute__ ((unused)))
{
runtime_panicstring ("libgo built without FFI does not support "
"reflect.MakeFunc");
}
#endif
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