modernc.org/gc@v1.0.1-0.20240304020402-f0dba7c97c2b/testdata/errchk/test/escape_closure.go (about)

     1  // errorcheck -0 -m -l
     2  
     3  // Copyright 2015 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 escape analysis for closure arguments.
     8  
     9  package escape
    10  
    11  var sink interface{}
    12  
    13  func ClosureCallArgs0() {
    14  	x := 0         // ERROR "moved to heap: x"
    15  	func(p *int) { // ERROR "p does not escape" "func literal does not escape"
    16  		*p = 1
    17  		// BAD: x should not escape to heap here
    18  	}(&x) // ERROR "&x escapes to heap"
    19  }
    20  
    21  func ClosureCallArgs1() {
    22  	x := 0 // ERROR "moved to heap: x"
    23  	for {
    24  		func(p *int) { // ERROR "p does not escape" "func literal does not escape"
    25  			*p = 1
    26  			// BAD: x should not escape to heap here
    27  		}(&x) // ERROR "&x escapes to heap"
    28  	}
    29  }
    30  
    31  func ClosureCallArgs2() {
    32  	for {
    33  		// BAD: x should not escape here
    34  		x := 0         // ERROR "moved to heap: x"
    35  		func(p *int) { // ERROR "p does not escape" "func literal does not escape"
    36  			*p = 1
    37  		}(&x) // ERROR "&x escapes to heap"
    38  	}
    39  }
    40  
    41  func ClosureCallArgs3() {
    42  	x := 0         // ERROR "moved to heap: x"
    43  	func(p *int) { // ERROR "leaking param: p" "func literal does not escape"
    44  		sink = p // ERROR "p escapes to heap"
    45  	}(&x) // ERROR "&x escapes to heap"
    46  }
    47  
    48  func ClosureCallArgs4() {
    49  	// BAD: x should not leak here
    50  	x := 0                  // ERROR "moved to heap: x"
    51  	_ = func(p *int) *int { // ERROR "leaking param: p to result ~r1" "func literal does not escape"
    52  		return p
    53  	}(&x) // ERROR "&x escapes to heap"
    54  }
    55  
    56  func ClosureCallArgs5() {
    57  	x := 0                     // ERROR "moved to heap: x"
    58  	sink = func(p *int) *int { // ERROR "leaking param: p to result ~r1" "func literal does not escape" "\(func literal\)\(&x\) escapes to heap"
    59  		return p
    60  	}(&x) // ERROR "&x escapes to heap"
    61  }
    62  
    63  func ClosureCallArgs6() {
    64  	x := 0         // ERROR "moved to heap: x"
    65  	func(p *int) { // ERROR "moved to heap: p" "func literal does not escape"
    66  		sink = &p // ERROR "&p escapes to heap"
    67  	}(&x) // ERROR "&x escapes to heap"
    68  }
    69  
    70  func ClosureCallArgs7() {
    71  	var pp *int
    72  	for {
    73  		x := 0         // ERROR "moved to heap: x"
    74  		func(p *int) { // ERROR "leaking param: p" "func literal does not escape"
    75  			pp = p
    76  		}(&x) // ERROR "&x escapes to heap"
    77  	}
    78  	_ = pp
    79  }
    80  
    81  func ClosureCallArgs8() {
    82  	x := 0               // ERROR "moved to heap: x"
    83  	defer func(p *int) { // ERROR "p does not escape" "func literal does not escape"
    84  		*p = 1
    85  		// BAD: x should not escape to heap here
    86  	}(&x) // ERROR "&x escapes to heap"
    87  }
    88  
    89  func ClosureCallArgs9() {
    90  	// BAD: x should not leak
    91  	x := 0 // ERROR "moved to heap: x"
    92  	for {
    93  		defer func(p *int) { // ERROR "func literal escapes to heap" "p does not escape"
    94  			*p = 1
    95  		}(&x) // ERROR "&x escapes to heap"
    96  	}
    97  }
    98  
    99  func ClosureCallArgs10() {
   100  	for {
   101  		x := 0               // ERROR "moved to heap: x"
   102  		defer func(p *int) { // ERROR "func literal escapes to heap" "p does not escape"
   103  			*p = 1
   104  		}(&x) // ERROR "&x escapes to heap"
   105  	}
   106  }
   107  
   108  func ClosureCallArgs11() {
   109  	x := 0               // ERROR "moved to heap: x"
   110  	defer func(p *int) { // ERROR "leaking param: p" "func literal does not escape"
   111  		sink = p // ERROR "p escapes to heap"
   112  	}(&x) // ERROR "&x escapes to heap"
   113  }
   114  
   115  func ClosureCallArgs12() {
   116  	// BAD: x should not leak
   117  	x := 0                    // ERROR "moved to heap: x"
   118  	defer func(p *int) *int { // ERROR "leaking param: p to result ~r1" "func literal does not escape"
   119  		return p
   120  	}(&x) // ERROR "&x escapes to heap"
   121  }
   122  
   123  func ClosureCallArgs13() {
   124  	x := 0               // ERROR "moved to heap: x"
   125  	defer func(p *int) { // ERROR "moved to heap: p" "func literal does not escape"
   126  		sink = &p // ERROR "&p escapes to heap"
   127  	}(&x) // ERROR "&x escapes to heap"
   128  }
   129  
   130  func ClosureCallArgs14() {
   131  	x := 0 // ERROR "moved to heap: x"
   132  	// BAD: &x should not escape here
   133  	p := &x                  // ERROR "moved to heap: p" "&x escapes to heap"
   134  	_ = func(p **int) *int { // ERROR "leaking param: p to result ~r1 level=1" "func literal does not escape"
   135  		return *p
   136  		// BAD: p should not escape here
   137  	}(&p) // ERROR "&p escapes to heap"
   138  }
   139  
   140  func ClosureCallArgs15() {
   141  	x := 0                      // ERROR "moved to heap: x"
   142  	p := &x                     // ERROR "moved to heap: p" "&x escapes to heap"
   143  	sink = func(p **int) *int { // ERROR "leaking param: p to result ~r1 level=1" "func literal does not escape" "\(func literal\)\(&p\) escapes to heap"
   144  		return *p
   145  		// BAD: p should not escape here
   146  	}(&p) // ERROR "&p escapes to heap"
   147  }
   148  
   149  func ClosureLeak1(s string) string { // ERROR "ClosureLeak1 s does not escape"
   150  	t := s + "YYYY"         // ERROR "escapes to heap"
   151  	return ClosureLeak1a(t) // ERROR "ClosureLeak1 ... argument does not escape"
   152  }
   153  
   154  // See #14409 -- returning part of captured var leaks it.
   155  func ClosureLeak1a(a ...string) string { // ERROR "leaking param: a to result ~r1 level=1"
   156  	return func() string { // ERROR "ClosureLeak1a func literal does not escape"
   157  		return a[0]
   158  	}()
   159  }
   160  
   161  func ClosureLeak2(s string) string { // ERROR "ClosureLeak2 s does not escape"
   162  	t := s + "YYYY"       // ERROR "escapes to heap"
   163  	c := ClosureLeak2a(t) // ERROR "ClosureLeak2 ... argument does not escape"
   164  	return c
   165  }
   166  func ClosureLeak2a(a ...string) string { // ERROR "leaking param: a to result ~r1 level=1"
   167  	return ClosureLeak2b(func() string { // ERROR "ClosureLeak2a func literal does not escape"
   168  		return a[0]
   169  	})
   170  }
   171  func ClosureLeak2b(f func() string) string { // ERROR "leaking param: f to result ~r1 level=1"
   172  	return f()
   173  }