1 // Copyright 2014 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
9 //go:cgo_export_static main
11 // Filled in by runtime/cgo when linked into binary.
13 //go:linkname _cgo_init _cgo_init
14 //go:linkname _cgo_thread_start _cgo_thread_start
15 //go:linkname _cgo_sys_thread_create _cgo_sys_thread_create
16 //go:linkname _cgo_notify_runtime_init_done _cgo_notify_runtime_init_done
17 //go:linkname _cgo_callers _cgo_callers
18 //go:linkname _cgo_set_context_function _cgo_set_context_function
19 //go:linkname _cgo_yield _cgo_yield
20 //go:linkname _cgo_pthread_key_created _cgo_pthread_key_created
21 //go:linkname _cgo_bindm _cgo_bindm
22 //go:linkname _cgo_getstackbound _cgo_getstackbound
25 _cgo_init unsafe.Pointer
26 _cgo_thread_start unsafe.Pointer
27 _cgo_sys_thread_create unsafe.Pointer
28 _cgo_notify_runtime_init_done unsafe.Pointer
29 _cgo_callers unsafe.Pointer
30 _cgo_set_context_function unsafe.Pointer
31 _cgo_yield unsafe.Pointer
32 _cgo_pthread_key_created unsafe.Pointer
33 _cgo_bindm unsafe.Pointer
34 _cgo_getstackbound unsafe.Pointer
37 // iscgo is set to true by the runtime/cgo package
40 // set_crosscall2 is set by the runtime/cgo package
41 var set_crosscall2 func()
43 // cgoHasExtraM is set on startup when an extra M is created for cgo.
44 // The extra M must be created before any C/C++ code calls cgocallback.
47 // cgoUse is called by cgo-generated code (using go:linkname to get at
48 // an unexported name). The calls serve two purposes:
49 // 1) they are opaque to escape analysis, so the argument is considered to
50 // escape to the heap.
51 // 2) they keep the argument alive until the call site; the call is emitted after
52 // the end of the (presumed) use of the argument by C.
53 // cgoUse should not actually be called (see cgoAlwaysFalse).
54 func cgoUse(any) { throw("cgoUse should not be called") }
56 // cgoAlwaysFalse is a boolean value that is always false.
57 // The cgo-generated code says if cgoAlwaysFalse { cgoUse(p) }.
58 // The compiler cannot see that cgoAlwaysFalse is always false,
59 // so it emits the test and keeps the call, giving the desired
60 // escape analysis result. The test is cheaper than the call.
61 var cgoAlwaysFalse bool
63 var cgo_yield = &_cgo_yield
65 func cgoNoCallback(v bool) {
67 if g.nocgocallback && v {
68 panic("runtime: unexpected setting cgoNoCallback")