gcc/testsuite/go.test/test/stack.go

   1 // run
   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 // Test stack splitting code.
   8 // Try to tickle stack splitting bugs by doing
   9 // go, defer, and closure calls at different stack depths.
  10
  11 package main
  12
  13 type T [20]int
  14
  15 func g(c chan int, t T) {
  16         s := 0
  17         for i := 0; i < len(t); i++ {
  18                 s += t[i]
  19         }
  20         c <- s
  21 }
  22
  23 func d(t T) {
  24         s := 0
  25         for i := 0; i < len(t); i++ {
  26                 s += t[i]
  27         }
  28         if s != len(t) {
  29                 println("bad defer", s)
  30                 panic("fail")
  31         }
  32 }
  33
  34 func f0() {
  35         // likely to make a new stack for f0,
  36         // because the call to f1 puts 3000 bytes
  37         // in our frame.
  38         f1()
  39 }
  40
  41 func f1() [3000]byte {
  42         // likely to make a new stack for f1,
  43         // because 3000 bytes were used by f0
  44         // and we need 3000 more for the call
  45         // to f2.  if the call to morestack in f1
  46         // does not pass the frame size, the new
  47         // stack (default size 5k) will not be big
  48         // enough for the frame, and the morestack
  49         // check in f2 will die, if we get that far
  50         // without faulting.
  51         f2()
  52         return [3000]byte{}
  53 }
  54
  55 func f2() [3000]byte {
  56         // just take up space
  57         return [3000]byte{}
  58 }
  59
  60 var c = make(chan int)
  61 var t T
  62 var b = []byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
  63
  64 func recur(n int) {
  65         ss := string(b)
  66         if len(ss) != len(b) {
  67                 panic("bad []byte -> string")
  68         }
  69         go g(c, t)
  70         f0()
  71         s := <-c
  72         if s != len(t) {
  73                 println("bad go", s)
  74                 panic("fail")
  75         }
  76         f := func(t T) int {
  77                 s := 0
  78                 for i := 0; i < len(t); i++ {
  79                         s += t[i]
  80                 }
  81                 s += n
  82                 return s
  83         }
  84         s = f(t)
  85         if s != len(t)+n {
  86                 println("bad func", s, "at level", n)
  87                 panic("fail")
  88         }
  89         if n > 0 {
  90                 recur(n - 1)
  91         }
  92         defer d(t)
  93 }
  94
  95 func main() {
  96         for i := 0; i < len(t); i++ {
  97                 t[i] = 1
  98         }
  99         recur(8000)
 100 }