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// Copyright 2011 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 "../cgocall.h"
// These utility functions are available to be called from code
// compiled with gcc via crosscall2.
// The declaration of crosscall2 is:
// void crosscall2(void (*fn)(void *, int), void *, int);
// We need to export the symbol crosscall2 in order to support
// callbacks from shared libraries.
#pragma dynexport crosscall2 crosscall2
// Allocate memory. This allocates the requested number of bytes in
// memory controlled by the Go runtime. The allocated memory will be
// zeroed. You are responsible for ensuring that the Go garbage
// collector can see a pointer to the allocated memory for as long as
// it is valid, e.g., by storing a pointer in a local variable in your
// C function, or in memory allocated by the Go runtime. If the only
// pointers are in a C global variable or in memory allocated via
// malloc, then the Go garbage collector may collect the memory.
// Call like this in code compiled with gcc:
// struct { size_t len; void *ret; } a;
// a.len = /* number of bytes to allocate */;
// crosscall2(_cgo_allocate, &a, sizeof a);
// /* Here a.ret is a pointer to the allocated memory. */
static void
_cgo_allocate_internal(uintptr len, byte *ret)
ret = runtime·mal(len);
#pragma dynexport _cgo_allocate _cgo_allocate
_cgo_allocate(void *a, int32 n)
runtime·cgocallback((void(*)(void))_cgo_allocate_internal, a, n);
// Panic. The argument is converted into a Go string.
// Call like this in code compiled with gcc:
// struct { const char *p; } a;
// a.p = /* string to pass to panic */;
// crosscall2(_cgo_panic, &a, sizeof a);
// /* The function call will not return. */
extern void ·cgoStringToEface(String, Eface*);
static void
_cgo_panic_internal(byte *p)
String s;
Eface err;
s = runtime·gostring(p);
·cgoStringToEface(s, &err);
#pragma dynexport _cgo_panic _cgo_panic
_cgo_panic(void *a, int32 n)
runtime·cgocallback((void(*)(void))_cgo_panic_internal, a, n);