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Diffstat (limited to 'src/runtime/cgo/callbacks.go')
-rw-r--r-- | src/runtime/cgo/callbacks.go | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/src/runtime/cgo/callbacks.go b/src/runtime/cgo/callbacks.go new file mode 100644 index 000000000..1e8b59054 --- /dev/null +++ b/src/runtime/cgo/callbacks.go @@ -0,0 +1,95 @@ +// 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. + +package cgo + +import "unsafe" + +// These utility functions are available to be called from code +// compiled with gcc via crosscall2. + +// cgocallback is defined in runtime +//go:linkname _runtime_cgocallback runtime.cgocallback +func _runtime_cgocallback(unsafe.Pointer, unsafe.Pointer, uintptr) + +// 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. +//go:cgo_export_static crosscall2 +//go: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. */ + +//go:linkname _runtime_cgo_allocate_internal runtime._cgo_allocate_internal +var _runtime_cgo_allocate_internal byte + +//go:linkname _cgo_allocate _cgo_allocate +//go:cgo_export_static _cgo_allocate +//go:cgo_export_dynamic _cgo_allocate +//go:nosplit +func _cgo_allocate(a unsafe.Pointer, n int32) { + _runtime_cgocallback(unsafe.Pointer(&_runtime_cgo_allocate_internal), a, uintptr(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. */ + +//go:linkname _runtime_cgo_panic_internal runtime._cgo_panic_internal +var _runtime_cgo_panic_internal byte + +//go:linkname _cgo_panic _cgo_panic +//go:cgo_export_static _cgo_panic +//go:cgo_export_dynamic _cgo_panic +//go:nosplit +func _cgo_panic(a unsafe.Pointer, n int32) { + _runtime_cgocallback(unsafe.Pointer(&_runtime_cgo_panic_internal), a, uintptr(n)) +} + +//go:cgo_import_static x_cgo_init +//go:linkname x_cgo_init x_cgo_init +//go:linkname _cgo_init _cgo_init +var x_cgo_init byte +var _cgo_init = &x_cgo_init + +//go:cgo_import_static x_cgo_malloc +//go:linkname x_cgo_malloc x_cgo_malloc +//go:linkname _cgo_malloc _cgo_malloc +var x_cgo_malloc byte +var _cgo_malloc = &x_cgo_malloc + +//go:cgo_import_static x_cgo_free +//go:linkname x_cgo_free x_cgo_free +//go:linkname _cgo_free _cgo_free +var x_cgo_free byte +var _cgo_free = &x_cgo_free + +//go:cgo_import_static x_cgo_thread_start +//go:linkname x_cgo_thread_start x_cgo_thread_start +//go:linkname _cgo_thread_start _cgo_thread_start +var x_cgo_thread_start byte +var _cgo_thread_start = &x_cgo_thread_start + +//go:cgo_export_static _cgo_topofstack +//go:cgo_export_dynamic _cgo_topofstack |