gcc/testsuite/go.test/test/cmp1.go

   1 // $G $D/$F.go && $L $F.$A && ./$A.out
   2
   3 // Copyright 2009 The Go Authors. All rights reserved.
   4 // Use of this source code is governed by a BSD-style
   5 // license that can be found in the LICENSE file.
   6
   7 package main
   8
   9 import "unsafe"
  10
  11 func use(bool) {}
  12
  13 func stringptr(s string) uintptr { return *(*uintptr)(unsafe.Pointer(&s)) }
  14
  15 func isfalse(b bool) {
  16         if b {
  17                 // stack will explain where
  18                 panic("wanted false, got true")
  19         }
  20 }
  21
  22 func istrue(b bool) {
  23         if !b {
  24                 // stack will explain where
  25                 panic("wanted true, got false")
  26         }
  27 }
  28
  29 func main() {
  30         var a []int
  31         var b map[string]int
  32
  33         var c string = "hello"
  34         var d string = "hel" // try to get different pointer
  35         d = d + "lo"
  36         if stringptr(c) == stringptr(d) {
  37                 panic("compiler too smart -- got same string")
  38         }
  39
  40         var e = make(chan int)
  41
  42         var ia interface{} = a
  43         var ib interface{} = b
  44         var ic interface{} = c
  45         var id interface{} = d
  46         var ie interface{} = e
  47
  48         // these comparisons are okay because
  49         // string compare is okay and the others
  50         // are comparisons where the types differ.
  51         isfalse(ia == ib)
  52         isfalse(ia == ic)
  53         isfalse(ia == id)
  54         isfalse(ib == ic)
  55         isfalse(ib == id)
  56         istrue(ic == id)
  57         istrue(ie == ie)
  58
  59         // 6g used to let this go through as true.
  60         var g uint64 = 123
  61         var h int64 = 123
  62         var ig interface{} = g
  63         var ih interface{} = h
  64         isfalse(ig == ih)
  65
  66         // map of interface should use == on interface values,
  67         // not memory.
  68         // TODO: should m[c], m[d] be valid here?
  69         var m = make(map[interface{}]int)
  70         m[ic] = 1
  71         m[id] = 2
  72         if m[ic] != 2 {
  73                 println("m[ic] = ", m[ic])
  74                 panic("bad m[ic]")
  75         }
  76 }