github.com/ccccaoqing/test@v0.0.0-20220510085219-3985d23445c0/misc/cgo/testso/cgoso_c.c (about)

     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  // +build ignore
     6  
     7  #ifdef WIN32
     8  // A Windows DLL is unable to call an arbitrary function in
     9  // the main executable. Work around that by making the main
    10  // executable pass the callback function pointer to us.
    11  void (*goCallback)(void);
    12  __declspec(dllexport) void setCallback(void *f)
    13  {
    14  	goCallback = (void (*)())f;
    15  }
    16  __declspec(dllexport) void sofunc(void);
    17  #else
    18  extern void goCallback(void);
    19  void setCallback(void *f) { (void)f; }
    20  #endif
    21  
    22  // OpenBSD and older Darwin lack TLS support
    23  #if !defined(__OpenBSD__) && !defined(__APPLE__)
    24  __thread int tlsvar = 12345;
    25  #endif
    26  
    27  void sofunc(void)
    28  {
    29  	goCallback();
    30  }