diff options
author | Ian Lance Taylor <iant@golang.org> | 2011-01-11 09:36:44 -0800 |
---|---|---|
committer | Ian Lance Taylor <iant@golang.org> | 2011-01-11 09:36:44 -0800 |
commit | 17d50d8664837c10a23560ed53a297b493dda26e (patch) | |
tree | ee5277581dec86f2140047667aed0e8f8abb256b | |
parent | 5b8bcf2324fab8a5b7c32886dda828b934645ecc (diff) | |
download | go-17d50d8664837c10a23560ed53a297b493dda26e.tar.gz go-17d50d8664837c10a23560ed53a297b493dda26e.zip |
runtime/cgo: Add callbacks to support SWIG.
R=rsc, iant2, r
CC=golang-dev
https://golang.org/cl/3886041
-rw-r--r-- | src/pkg/runtime/cgo/Makefile | 1 | ||||
-rw-r--r-- | src/pkg/runtime/cgo/callbacks.c | 73 | ||||
-rw-r--r-- | src/pkg/runtime/cgo/cgo.go | 7 |
3 files changed, 81 insertions, 0 deletions
diff --git a/src/pkg/runtime/cgo/Makefile b/src/pkg/runtime/cgo/Makefile index 3e6ca84a2c..55b6967d92 100644 --- a/src/pkg/runtime/cgo/Makefile +++ b/src/pkg/runtime/cgo/Makefile @@ -26,6 +26,7 @@ CGO_OFILES=\ OFILES=\ iscgo.$O\ + callbacks.$O\ _cgo_import.$O\ $(CGO_OFILES)\ diff --git a/src/pkg/runtime/cgo/callbacks.c b/src/pkg/runtime/cgo/callbacks.c new file mode 100644 index 0000000000..f36fb3fd7e --- /dev/null +++ b/src/pkg/runtime/cgo/callbacks.c @@ -0,0 +1,73 @@ +// 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); + FLUSH(&ret); +} + +#pragma dynexport _cgo_allocate _cgo_allocate +void +_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); + runtime·panic(err); +} + +#pragma dynexport _cgo_panic _cgo_panic +void +_cgo_panic(void *a, int32 n) +{ + runtime·cgocallback((void(*)(void))_cgo_panic_internal, a, n); +} diff --git a/src/pkg/runtime/cgo/cgo.go b/src/pkg/runtime/cgo/cgo.go index 249d1dd638..5dcced1e42 100644 --- a/src/pkg/runtime/cgo/cgo.go +++ b/src/pkg/runtime/cgo/cgo.go @@ -8,3 +8,10 @@ by the cgo tool. See the documentation for the cgo command for details on using cgo. */ package cgo + +// Supports _cgo_panic by converting a string constant to an empty +// interface. + +func cgoStringToEface(s string, ret *interface{}) { + *ret = s +} |