1 files changed, 83 insertions, 0 deletions
diff --git a/src/runtime/cgo/callbacks.c b/src/runtime/cgo/callbacks.c
new file mode 100644
index 000000000..282beeea8
--- /dev/null
+++ b/src/runtime/cgo/callbacks.c
@@ -0,0 +1,83 @@
+// 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"
+#include "textflag.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. This applies regardless of
+// linking mode.
+#pragma cgo_export_static crosscall2
+#pragma cgo_export_dynamic 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.  */
+
+void runtime·_cgo_allocate_internal(void);
+
+#pragma cgo_export_static _cgo_allocate
+#pragma cgo_export_dynamic _cgo_allocate
+#pragma textflag NOSPLIT
+void
+_cgo_allocate(void *a, int32 n)
+{
+	runtime·cgocallback((void(*)(void))runtime·_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.  */
+
+void runtime·_cgo_panic_internal(void);
+
+#pragma cgo_export_static _cgo_panic
+#pragma cgo_export_dynamic _cgo_panic
+#pragma textflag NOSPLIT
+void
+_cgo_panic(void *a, int32 n)
+{
+	runtime·cgocallback((void(*)(void))runtime·_cgo_panic_internal, a, n);
+}
+
+#pragma cgo_import_static x_cgo_init
+extern void x_cgo_init(G*);
+void (*_cgo_init)(G*) = x_cgo_init;
+
+#pragma cgo_import_static x_cgo_malloc
+extern void x_cgo_malloc(void*);
+void (*_cgo_malloc)(void*) = x_cgo_malloc;
+
+#pragma cgo_import_static x_cgo_free
+extern void x_cgo_free(void*);
+void (*_cgo_free)(void*) = x_cgo_free;
+
+#pragma cgo_import_static x_cgo_thread_start
+extern void x_cgo_thread_start(void*);
+void (*_cgo_thread_start)(void*) = x_cgo_thread_start;
+
+#pragma cgo_export_static _cgo_topofstack
+#pragma cgo_export_dynamic _cgo_topofstack