github.com/v2fly/tools@v0.100.0/go/pointer/testdata/maps.go (about)

     1  // +build ignore
     2  
     3  package main
     4  
     5  // Test of maps.
     6  
     7  var a, b, c int
     8  
     9  func maps1() {
    10  	m1 := map[*int]*int{&a: &b} // @line m1m1
    11  	m2 := make(map[*int]*int)   // @line m1m2
    12  	m2[&b] = &a
    13  
    14  	print(m1[nil]) // @pointsto main.b | main.c
    15  	print(m2[nil]) // @pointsto main.a
    16  
    17  	print(m1) // @pointsto makemap@m1m1:21
    18  	print(m2) // @pointsto makemap@m1m2:12
    19  
    20  	m1[&b] = &c
    21  
    22  	for k, v := range m1 {
    23  		print(k) // @pointsto main.a | main.b
    24  		print(v) // @pointsto main.b | main.c
    25  	}
    26  
    27  	for k, v := range m2 {
    28  		print(k) // @pointsto main.b
    29  		print(v) // @pointsto main.a
    30  	}
    31  
    32  	// Lookup doesn't create any aliases.
    33  	print(m2[&c]) // @pointsto main.a
    34  	if _, ok := m2[&a]; ok {
    35  		print(m2[&c]) // @pointsto main.a
    36  	}
    37  }
    38  
    39  func maps2() {
    40  	m1 := map[*int]*int{&a: &b}
    41  	m2 := map[*int]*int{&b: &c}
    42  	_ = []map[*int]*int{m1, m2} // (no spurious merging of m1, m2)
    43  
    44  	print(m1[nil]) // @pointsto main.b
    45  	print(m2[nil]) // @pointsto main.c
    46  }
    47  
    48  var g int
    49  
    50  func maps3() {
    51  	// Regression test for a constraint generation bug for map range
    52  	// loops in which the key is unused: the (ok, k, v) tuple
    53  	// returned by ssa.Next may have type 'invalid' for the k and/or
    54  	// v components, so copying the map key or value may cause
    55  	// miswiring if the key has >1 components.  In the worst case,
    56  	// this causes a crash.  The test below used to report that
    57  	// pts(v) includes not just main.g but new(float64) too, which
    58  	// is ill-typed.
    59  
    60  	// sizeof(K) > 1, abstractly
    61  	type K struct{ a, b *float64 }
    62  	k := K{new(float64), nil}
    63  	m := map[K]*int{k: &g}
    64  
    65  	for _, v := range m {
    66  		print(v) // @pointsto main.g
    67  	}
    68  }
    69  
    70  func main() {
    71  	maps1()
    72  	maps2()
    73  	maps3()
    74  }