github.com/MangoDowner/go-gm@v0.0.0-20180818020936-8baa2bd4408c/misc/cgo/test/fpvar.go (about)

     1  // Copyright 2013 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  // This file contains test cases for cgo with function pointer variables.
     6  
     7  package cgotest
     8  
     9  /*
    10  typedef int (*intFunc) ();
    11  
    12  int
    13  bridge_int_func(intFunc f)
    14  {
    15  	return f();
    16  }
    17  
    18  int fortytwo()
    19  {
    20  	return 42;
    21  }
    22  
    23  */
    24  import "C"
    25  import "testing"
    26  
    27  func callBridge(f C.intFunc) int {
    28  	return int(C.bridge_int_func(f))
    29  }
    30  
    31  func callCBridge(f C.intFunc) C.int {
    32  	return C.bridge_int_func(f)
    33  }
    34  
    35  func testFpVar(t *testing.T) {
    36  	const expected = 42
    37  	f := C.intFunc(C.fortytwo)
    38  	res1 := C.bridge_int_func(f)
    39  	if r1 := int(res1); r1 != expected {
    40  		t.Errorf("got %d, want %d", r1, expected)
    41  	}
    42  	res2 := callCBridge(f)
    43  	if r2 := int(res2); r2 != expected {
    44  		t.Errorf("got %d, want %d", r2, expected)
    45  	}
    46  	r3 := callBridge(f)
    47  	if r3 != expected {
    48  		t.Errorf("got %d, want %d", r3, expected)
    49  	}
    50  }