github.com/JimmyHuang454/JLS-go@v0.0.0-20230831150107-90d536585ba0/internal/types/testdata/check/labels.go (about)

     1  // Copyright 2011 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // This file is a modified concatenation of the files
     6  // $GOROOT/test/label.go and $GOROOT/test/label1.go.
     7  
     8  package labels
     9  
    10  var x int
    11  
    12  func f0() {
    13  L1 /* ERROR "label L1 declared and not used" */ :
    14  	for {
    15  	}
    16  L2 /* ERROR "label L2 declared and not used" */ :
    17  	select {
    18  	}
    19  L3 /* ERROR "label L3 declared and not used" */ :
    20  	switch {
    21  	}
    22  L4 /* ERROR "label L4 declared and not used" */ :
    23  	if true {
    24  	}
    25  L5 /* ERROR "label L5 declared and not used" */ :
    26  	f0()
    27  L6:
    28  	f0()
    29  L6 /* ERROR "label L6 already declared" */ :
    30  	f0()
    31  	if x == 20 {
    32  		goto L6
    33  	}
    34  
    35  L7:
    36  	for {
    37  		break L7
    38  		break L8 /* ERROR "invalid break label L8" */
    39  	}
    40  
    41  // A label must be directly associated with a switch, select, or
    42  // for statement; it cannot be the label of a labeled statement.
    43  
    44  L7a /* ERROR "declared and not used" */ : L7b:
    45  	for {
    46  		break L7a /* ERROR "invalid break label L7a" */
    47  		continue L7a /* ERROR "invalid continue label L7a" */
    48  		continue L7b
    49  	}
    50  
    51  L8:
    52  	for {
    53  		if x == 21 {
    54  			continue L8
    55  			continue L7 /* ERROR "invalid continue label L7" */
    56  		}
    57  	}
    58  
    59  L9:
    60  	switch {
    61  	case true:
    62  		break L9
    63  	defalt /* ERROR "label defalt declared and not used" */ :
    64  	}
    65  
    66  L10:
    67  	select {
    68  	default:
    69  		break L10
    70  		break L9 /* ERROR "invalid break label L9" */
    71  	}
    72  
    73  	goto L10a
    74  L10a: L10b:
    75  	select {
    76  	default:
    77  		break L10a /* ERROR "invalid break label L10a" */
    78  		break L10b
    79  		continue L10b /* ERROR "invalid continue label L10b" */
    80  	}
    81  }
    82  
    83  func f1() {
    84  L1:
    85  	for {
    86  		if x == 0 {
    87  			break L1
    88  		}
    89  		if x == 1 {
    90  			continue L1
    91  		}
    92  		goto L1
    93  	}
    94  
    95  L2:
    96  	select {
    97  	default:
    98  		if x == 0 {
    99  			break L2
   100  		}
   101  		if x == 1 {
   102  			continue L2 /* ERROR "invalid continue label L2" */
   103  		}
   104  		goto L2
   105  	}
   106  
   107  L3:
   108  	switch {
   109  	case x > 10:
   110  		if x == 11 {
   111  			break L3
   112  		}
   113  		if x == 12 {
   114  			continue L3 /* ERROR "invalid continue label L3" */
   115  		}
   116  		goto L3
   117  	}
   118  
   119  L4:
   120  	if true {
   121  		if x == 13 {
   122  			break L4 /* ERROR "invalid break label L4" */
   123  		}
   124  		if x == 14 {
   125  			continue L4 /* ERROR "invalid continue label L4" */
   126  		}
   127  		if x == 15 {
   128  			goto L4
   129  		}
   130  	}
   131  
   132  L5:
   133  	f1()
   134  	if x == 16 {
   135  		break L5 /* ERROR "invalid break label L5" */
   136  	}
   137  	if x == 17 {
   138  		continue L5 /* ERROR "invalid continue label L5" */
   139  	}
   140  	if x == 18 {
   141  		goto L5
   142  	}
   143  
   144  	for {
   145  		if x == 19 {
   146  			break L1 /* ERROR "invalid break label L1" */
   147  		}
   148  		if x == 20 {
   149  			continue L1 /* ERROR "invalid continue label L1" */
   150  		}
   151  		if x == 21 {
   152  			goto L1
   153  		}
   154  	}
   155  }
   156  
   157  // Additional tests not in the original files.
   158  
   159  func f2() {
   160  L1 /* ERROR "label L1 declared and not used" */ :
   161  	if x == 0 {
   162  		for {
   163  			continue L1 /* ERROR "invalid continue label L1" */
   164  		}
   165  	}
   166  }
   167  
   168  func f3() {
   169  L1:
   170  L2:
   171  L3:
   172  	for {
   173  		break L1 /* ERROR "invalid break label L1" */
   174  		break L2 /* ERROR "invalid break label L2" */
   175  		break L3
   176  		continue L1 /* ERROR "invalid continue label L1" */
   177  		continue L2 /* ERROR "invalid continue label L2" */
   178  		continue L3
   179  		goto L1
   180  		goto L2
   181  		goto L3
   182  	}
   183  }
   184  
   185  // Blank labels are never declared.
   186  
   187  func f4() {
   188  _:
   189  _: // multiple blank labels are ok
   190  	goto _ /* ERROR "label _ not declared" */
   191  }
   192  
   193  func f5() {
   194  _:
   195  	for {
   196  		break _ /* ERROR "invalid break label _" */
   197  		continue _ /* ERROR "invalid continue label _" */
   198  	}
   199  }
   200  
   201  func f6() {
   202  _:
   203  	switch {
   204  	default:
   205  		break _ /* ERROR "invalid break label _" */
   206  	}
   207  }