issue16760.go

     1  // run
     2  
     3  // Copyright 2016 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  // Make sure we don't start marshaling (writing to the stack)
     8  // arguments until those arguments are evaluated and known
     9  // not to unconditionally panic. If they unconditionally panic,
    10  // we write some args but never do the call. That messes up
    11  // the logic which decides how big the argout section needs to be.
    12  
    13  package main
    14  
    15  type W interface {
    16  	Write([]byte)
    17  }
    18  
    19  type F func(W)
    20  
    21  func foo(f F) {
    22  	defer func() {
    23  		if r := recover(); r != nil {
    24  			usestack(1000)
    25  		}
    26  	}()
    27  	f(nil)
    28  }
    29  
    30  func main() {
    31  	foo(func(w W) {
    32  		var x []string
    33  		w.Write([]byte(x[5]))
    34  	})
    35  }
    36  
    37  func usestack(n int) {
    38  	if n == 0 {
    39  		return
    40  	}
    41  	usestack(n - 1)
    42  }
    43
View as plain text