github.com/xushiwei/go@v0.0.0-20130601165731-2b9d83f45bc9/test/fixedbugs/issue4518.go (about)

     1  // run
     2  
     3  // Copyright 2012 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  // Issue 4518. In some circumstances "return F(...)"
     8  // where F has multiple returns is miscompiled by 6g due to
     9  // bold assumptions in componentgen.
    10  
    11  package main
    12  
    13  func DontInline() {}
    14  
    15  func F(e interface{}) (int, int) {
    16  	DontInline()
    17  	return 3, 7
    18  }
    19  
    20  func G() (int, int) {
    21  	DontInline()
    22  	return 3, 7
    23  }
    24  
    25  func bogus1(d interface{}) (int, int) {
    26  	switch {
    27  	default:
    28  		return F(d)
    29  	}
    30  	return 0, 0
    31  }
    32  
    33  func bogus2() (int, int) {
    34  	switch {
    35  	default:
    36  		return F(3)
    37  	}
    38  	return 0, 0
    39  }
    40  
    41  func bogus3(d interface{}) (int, int) {
    42  	switch {
    43  	default:
    44  		return G()
    45  	}
    46  	return 0, 0
    47  }
    48  
    49  func bogus4() (int, int) {
    50  	switch {
    51  	default:
    52  		return G()
    53  	}
    54  	return 0, 0
    55  }
    56  
    57  func check(a, b int) {
    58  	if a != 3 || b != 7 {
    59  		println(a, b)
    60  		panic("a != 3 || b != 7")
    61  	}
    62  }
    63  
    64  func main() {
    65  	check(bogus1(42))
    66  	check(bogus2())
    67  }