issue32288.go

     1  // run
     2  
     3  // Copyright 2019 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  type T struct {
    10  	s   [1]string
    11  	pad [16]uintptr
    12  }
    13  
    14  //go:noinline
    15  func f(t *int, p *int) []T {
    16  	var res []T
    17  	for {
    18  		var e *T
    19  		res = append(res, *e)
    20  	}
    21  }
    22  
    23  func main() {
    24  	defer func() {
    25  		useStack(100) // force a stack copy
    26  		// We're expecting a panic.
    27  		// The bug in this issue causes a throw, which this recover() will not squash.
    28  		recover()
    29  	}()
    30  	junk() // fill the stack with invalid pointers
    31  	f(nil, nil)
    32  }
    33  
    34  func useStack(n int) {
    35  	if n == 0 {
    36  		return
    37  	}
    38  	useStack(n - 1)
    39  }
    40  
    41  //go:noinline
    42  func junk() uintptr {
    43  	var a [128]uintptr // 1k of bad pointers on the stack
    44  	for i := range a {
    45  		a[i] = 0xaa
    46  	}
    47  	return a[12]
    48  }
    49
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