libgo/misc/cgo/test/issue17537.go

   1 // Copyright 2016 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 // Issue 17537.  The void* cast introduced by cgo to avoid problems
   6 // with const/volatile qualifiers breaks C preprocessor macros that
   7 // emulate functions.
   8
   9 package cgotest
  10
  11 /*
  12 #include <stdlib.h>
  13
  14 typedef struct {
  15         int i;
  16 } S17537;
  17
  18 int I17537(S17537 *p);
  19
  20 #define I17537(p) ((p)->i)
  21
  22 // Calling this function used to fail without the cast.
  23 const int F17537(const char **p) {
  24         return **p;
  25 }
  26
  27 // Calling this function used to trigger an error from the C compiler
  28 // (issue 18298).
  29 void F18298(const void *const *p) {
  30 }
  31
  32 // Test that conversions between typedefs work as they used to.
  33 typedef const void *T18298_1;
  34 struct S18298 { int i; };
  35 typedef const struct S18298 *T18298_2;
  36 void G18298(T18298_1 t) {
  37 }
  38 */
  39 import "C"
  40
  41 import "testing"
  42
  43 func test17537(t *testing.T) {
  44         v := C.S17537{i: 17537}
  45         if got, want := C.I17537(&v), C.int(17537); got != want {
  46                 t.Errorf("got %d, want %d", got, want)
  47         }
  48
  49         p := (*C.char)(C.malloc(1))
  50         *p = 17
  51         if got, want := C.F17537(&p), C.int(17); got != want {
  52                 t.Errorf("got %d, want %d", got, want)
  53         }
  54
  55         C.F18298(nil)
  56         var v18298 C.T18298_2
  57         C.G18298(C.T18298_1(v18298))
  58 }