1// Copyright 2011 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.
4
5package cgo
6
7import "unsafe"
8
9// These utility functions are available to be called from code
10// compiled with gcc via crosscall2.
11
12// The declaration of crosscall2 is:
13//   void crosscall2(void (*fn)(void *), void *, int);
14//
15// We need to export the symbol crosscall2 in order to support
16// callbacks from shared libraries. This applies regardless of
17// linking mode.
18//
19// Compatibility note: SWIG uses crosscall2 in exactly one situation:
20// to call _cgo_panic using the pattern shown below. We need to keep
21// that pattern working. In particular, crosscall2 actually takes four
22// arguments, but it works to call it with three arguments when
23// calling _cgo_panic.
24//
25//go:cgo_export_static crosscall2
26//go:cgo_export_dynamic crosscall2
27
28// Panic. The argument is converted into a Go string.
29
30// Call like this in code compiled with gcc:
31//   struct { const char *p; } a;
32//   a.p = /* string to pass to panic */;
33//   crosscall2(_cgo_panic, &a, sizeof a);
34//   /* The function call will not return.  */
35
36// TODO: We should export a regular C function to panic, change SWIG
37// to use that instead of the above pattern, and then we can drop
38// backwards-compatibility from crosscall2 and stop exporting it.
39
40//go:linkname _runtime_cgo_panic_internal runtime._cgo_panic_internal
41func _runtime_cgo_panic_internal(p *byte)
42
43//go:linkname _cgo_panic _cgo_panic
44//go:cgo_export_static _cgo_panic
45//go:cgo_export_dynamic _cgo_panic
46func _cgo_panic(a *struct{ cstr *byte }) {
47	_runtime_cgo_panic_internal(a.cstr)
48}
49
50//go:cgo_import_static x_cgo_init
51//go:linkname x_cgo_init x_cgo_init
52//go:linkname _cgo_init _cgo_init
53var x_cgo_init byte
54var _cgo_init = &x_cgo_init
55
56//go:cgo_import_static x_cgo_thread_start
57//go:linkname x_cgo_thread_start x_cgo_thread_start
58//go:linkname _cgo_thread_start _cgo_thread_start
59var x_cgo_thread_start byte
60var _cgo_thread_start = &x_cgo_thread_start
61
62// Creates a new system thread without updating any Go state.
63//
64// This method is invoked during shared library loading to create a new OS
65// thread to perform the runtime initialization. This method is similar to
66// _cgo_sys_thread_start except that it doesn't update any Go state.
67
68//go:cgo_import_static x_cgo_sys_thread_create
69//go:linkname x_cgo_sys_thread_create x_cgo_sys_thread_create
70//go:linkname _cgo_sys_thread_create _cgo_sys_thread_create
71var x_cgo_sys_thread_create byte
72var _cgo_sys_thread_create = &x_cgo_sys_thread_create
73
74// Indicates whether a dummy thread key has been created or not.
75//
76// When calling go exported function from C, we register a destructor
77// callback, for a dummy thread key, by using pthread_key_create.
78
79//go:cgo_import_static x_cgo_pthread_key_created
80//go:linkname x_cgo_pthread_key_created x_cgo_pthread_key_created
81//go:linkname _cgo_pthread_key_created _cgo_pthread_key_created
82var x_cgo_pthread_key_created byte
83var _cgo_pthread_key_created = &x_cgo_pthread_key_created
84
85// Export crosscall2 to a c function pointer variable.
86// Used to dropm in pthread key destructor, while C thread is exiting.
87
88//go:cgo_import_static x_crosscall2_ptr
89//go:linkname x_crosscall2_ptr x_crosscall2_ptr
90//go:linkname _crosscall2_ptr _crosscall2_ptr
91var x_crosscall2_ptr byte
92var _crosscall2_ptr = &x_crosscall2_ptr
93
94// Set the x_crosscall2_ptr C function pointer variable point to crosscall2.
95// It's for the runtime package to call at init time.
96func set_crosscall2()
97
98//go:linkname _set_crosscall2 runtime.set_crosscall2
99var _set_crosscall2 = set_crosscall2
100
101// Store the g into the thread-specific value.
102// So that pthread_key_destructor will dropm when the thread is exiting.
103
104//go:cgo_import_static x_cgo_bindm
105//go:linkname x_cgo_bindm x_cgo_bindm
106//go:linkname _cgo_bindm _cgo_bindm
107var x_cgo_bindm byte
108var _cgo_bindm = &x_cgo_bindm
109
110// Notifies that the runtime has been initialized.
111//
112// We currently block at every CGO entry point (via _cgo_wait_runtime_init_done)
113// to ensure that the runtime has been initialized before the CGO call is
114// executed. This is necessary for shared libraries where we kickoff runtime
115// initialization in a separate thread and return without waiting for this
116// thread to complete the init.
117
118//go:cgo_import_static x_cgo_notify_runtime_init_done
119//go:linkname x_cgo_notify_runtime_init_done x_cgo_notify_runtime_init_done
120//go:linkname _cgo_notify_runtime_init_done _cgo_notify_runtime_init_done
121var x_cgo_notify_runtime_init_done byte
122var _cgo_notify_runtime_init_done = &x_cgo_notify_runtime_init_done
123
124// Sets the traceback context function. See runtime.SetCgoTraceback.
125
126//go:cgo_import_static x_cgo_set_context_function
127//go:linkname x_cgo_set_context_function x_cgo_set_context_function
128//go:linkname _cgo_set_context_function _cgo_set_context_function
129var x_cgo_set_context_function byte
130var _cgo_set_context_function = &x_cgo_set_context_function
131
132// Calls a libc function to execute background work injected via libc
133// interceptors, such as processing pending signals under the thread
134// sanitizer.
135//
136// Left as a nil pointer if no libc interceptors are expected.
137
138//go:cgo_import_static _cgo_yield
139//go:linkname _cgo_yield _cgo_yield
140var _cgo_yield unsafe.Pointer
141
142//go:cgo_export_static _cgo_topofstack
143//go:cgo_export_dynamic _cgo_topofstack
144
145// x_cgo_getstackbound gets the thread's C stack size and
146// set the G's stack bound based on the stack size.
147
148//go:cgo_import_static x_cgo_getstackbound
149//go:linkname x_cgo_getstackbound x_cgo_getstackbound
150//go:linkname _cgo_getstackbound _cgo_getstackbound
151var x_cgo_getstackbound byte
152var _cgo_getstackbound = &x_cgo_getstackbound
153