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 5 package cgo 6 7 import "unsafe" 8 9 // These utility functions are available to be called from code 10 // compiled with gcc via crosscall2. 11 12 // cgocallback is defined in runtime 13 //go:linkname _runtime_cgocallback runtime.cgocallback 14 func _runtime_cgocallback(unsafe.Pointer, unsafe.Pointer, uintptr, uintptr) 15 16 // The declaration of crosscall2 is: 17 // void crosscall2(void (*fn)(void *, int), void *, int); 18 // 19 // We need to export the symbol crosscall2 in order to support 20 // callbacks from shared libraries. This applies regardless of 21 // linking mode. 22 // 23 // Compatibility note: crosscall2 actually takes four arguments, but 24 // it works to call it with three arguments when calling _cgo_panic. 25 // That is supported for backward compatibility. 26 //go:cgo_export_static crosscall2 27 //go:cgo_export_dynamic crosscall2 28 29 // Panic. The argument is converted into a Go string. 30 31 // Call like this in code compiled with gcc: 32 // struct { const char *p; } a; 33 // a.p = /* string to pass to panic */; 34 // crosscall2(_cgo_panic, &a, sizeof a); 35 // /* The function call will not return. */ 36 37 //go:linkname _runtime_cgo_panic_internal runtime._cgo_panic_internal 38 func _runtime_cgo_panic_internal(p *byte) 39 40 //go:linkname _cgo_panic _cgo_panic 41 //go:cgo_export_static _cgo_panic 42 //go:cgo_export_dynamic _cgo_panic 43 //go:nosplit 44 //go:norace 45 func _cgo_panic(a unsafe.Pointer, n int32) { 46 f := _runtime_cgo_panic_internal 47 type funcval struct { 48 pc unsafe.Pointer 49 } 50 fv := *(**funcval)(unsafe.Pointer(&f)) 51 _runtime_cgocallback(fv.pc, a, uintptr(n), 0) 52 } 53 54 //go:cgo_import_static x_cgo_init 55 //go:linkname x_cgo_init x_cgo_init 56 //go:linkname _cgo_init _cgo_init 57 var x_cgo_init byte 58 var _cgo_init = &x_cgo_init 59 60 //go:cgo_import_static x_cgo_thread_start 61 //go:linkname x_cgo_thread_start x_cgo_thread_start 62 //go:linkname _cgo_thread_start _cgo_thread_start 63 var x_cgo_thread_start byte 64 var _cgo_thread_start = &x_cgo_thread_start 65 66 // Creates a new system thread without updating any Go state. 67 // 68 // This method is invoked during shared library loading to create a new OS 69 // thread to perform the runtime initialization. This method is similar to 70 // _cgo_sys_thread_start except that it doesn't update any Go state. 71 72 //go:cgo_import_static x_cgo_sys_thread_create 73 //go:linkname x_cgo_sys_thread_create x_cgo_sys_thread_create 74 //go:linkname _cgo_sys_thread_create _cgo_sys_thread_create 75 var x_cgo_sys_thread_create byte 76 var _cgo_sys_thread_create = &x_cgo_sys_thread_create 77 78 // Notifies that the runtime has been initialized. 79 // 80 // We currently block at every CGO entry point (via _cgo_wait_runtime_init_done) 81 // to ensure that the runtime has been initialized before the CGO call is 82 // executed. This is necessary for shared libraries where we kickoff runtime 83 // initialization in a separate thread and return without waiting for this 84 // thread to complete the init. 85 86 //go:cgo_import_static x_cgo_notify_runtime_init_done 87 //go:linkname x_cgo_notify_runtime_init_done x_cgo_notify_runtime_init_done 88 //go:linkname _cgo_notify_runtime_init_done _cgo_notify_runtime_init_done 89 var x_cgo_notify_runtime_init_done byte 90 var _cgo_notify_runtime_init_done = &x_cgo_notify_runtime_init_done 91 92 // Sets the traceback context function. See runtime.SetCgoTraceback. 93 94 //go:cgo_import_static x_cgo_set_context_function 95 //go:linkname x_cgo_set_context_function x_cgo_set_context_function 96 //go:linkname _cgo_set_context_function _cgo_set_context_function 97 var x_cgo_set_context_function byte 98 var _cgo_set_context_function = &x_cgo_set_context_function 99 100 // Calls a libc function to execute background work injected via libc 101 // interceptors, such as processing pending signals under the thread 102 // sanitizer. 103 // 104 // Left as a nil pointer if no libc interceptors are expected. 105 106 //go:cgo_import_static _cgo_yield 107 //go:linkname _cgo_yield _cgo_yield 108 var _cgo_yield unsafe.Pointer 109 110 //go:cgo_export_static _cgo_topofstack 111 //go:cgo_export_dynamic _cgo_topofstack 112