libgo/misc/cgo/test/issue7560.go

   1 // Copyright 2014 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 cgotest
   6
   7 /*
   8 #include <stdint.h>
   9
  10 typedef struct {
  11         char x;
  12         long y;
  13 } __attribute__((__packed__)) misaligned;
  14
  15 int
  16 offset7560(void)
  17 {
  18         return (uintptr_t)&((misaligned*)0)->y;
  19 }
  20 */
  21 import "C"
  22
  23 import (
  24         "reflect"
  25         "testing"
  26 )
  27
  28 func test7560(t *testing.T) {
  29         // some mingw don't implement __packed__ correctly.
  30         if C.offset7560() != 1 {
  31                 t.Skip("C compiler did not pack struct")
  32         }
  33
  34         // C.misaligned should have x but then a padding field to get to the end of the struct.
  35         // There should not be a field named 'y'.
  36         var v C.misaligned
  37         rt := reflect.TypeOf(&v).Elem()
  38         if rt.NumField() != 2 || rt.Field(0).Name != "x" || rt.Field(1).Name != "_" {
  39                 t.Errorf("unexpected fields in C.misaligned:\n")
  40                 for i := 0; i < rt.NumField(); i++ {
  41                         t.Logf("%+v\n", rt.Field(i))
  42                 }
  43         }
  44 }