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

     1  // +build ignore
     2  
     3  package main
     4  
     5  import "reflect"
     6  
     7  var zero, a, b int
     8  var false2 bool
     9  
    10  func f(p *int, q hasF) *int {
    11  	print(p)      // @pointsto main.a
    12  	print(q)      // @types *T
    13  	print(q.(*T)) // @pointsto new@newT1:22
    14  	return &b
    15  }
    16  
    17  func g(p *bool) (*int, *bool, hasF) {
    18  	return &b, p, new(T) // @line newT2
    19  }
    20  
    21  func reflectValueCall() {
    22  	rvf := reflect.ValueOf(f)
    23  	res := rvf.Call([]reflect.Value{
    24  		// argument order is not significant:
    25  		reflect.ValueOf(new(T)), // @line newT1
    26  		reflect.ValueOf(&a),
    27  	})
    28  	print(res[0].Interface())        // @types *int
    29  	print(res[0].Interface().(*int)) // @pointsto main.b
    30  }
    31  
    32  // @calls main.reflectValueCall -> main.f
    33  
    34  func reflectValueCallIndirect() {
    35  	rvf := reflect.ValueOf(g)
    36  	call := rvf.Call // kids, don't try this at home
    37  
    38  	// Indirect call uses shared contour.
    39  	//
    40  	// Also notice that argument position doesn't matter, and args
    41  	// of inappropriate type (e.g. 'a') are ignored.
    42  	res := call([]reflect.Value{
    43  		reflect.ValueOf(&a),
    44  		reflect.ValueOf(&false2),
    45  	})
    46  	res0 := res[0].Interface()
    47  	print(res0)         // @types *int | *bool | *T
    48  	print(res0.(*int))  // @pointsto main.b
    49  	print(res0.(*bool)) // @pointsto main.false2
    50  	print(res0.(hasF))  // @types *T
    51  	print(res0.(*T))    // @pointsto new@newT2:19
    52  }
    53  
    54  // @calls main.reflectValueCallIndirect -> (reflect.Value).Call$bound
    55  // @calls (reflect.Value).Call$bound -> main.g
    56  
    57  func reflectTypeInOut() {
    58  	var f func(float64, bool) (string, int)
    59  	print(reflect.Zero(reflect.TypeOf(f).In(0)).Interface())    // @types float64
    60  	print(reflect.Zero(reflect.TypeOf(f).In(1)).Interface())    // @types bool
    61  	print(reflect.Zero(reflect.TypeOf(f).In(-1)).Interface())   // @types float64 | bool
    62  	print(reflect.Zero(reflect.TypeOf(f).In(zero)).Interface()) // @types float64 | bool
    63  
    64  	print(reflect.Zero(reflect.TypeOf(f).Out(0)).Interface()) // @types string
    65  	print(reflect.Zero(reflect.TypeOf(f).Out(1)).Interface()) // @types int
    66  	print(reflect.Zero(reflect.TypeOf(f).Out(2)).Interface()) // @types
    67  
    68  	print(reflect.Zero(reflect.TypeOf(3).Out(0)).Interface()) // @types
    69  }
    70  
    71  type hasF interface {
    72  	F()
    73  }
    74  
    75  type T struct{}
    76  
    77  func (T) F()    {}
    78  func (T) g(int) {}
    79  
    80  type U struct{}
    81  
    82  func (U) F(int)    {}
    83  func (U) g(string) {}
    84  
    85  type I interface {
    86  	f()
    87  }
    88  
    89  var nonconst string
    90  
    91  func reflectTypeMethodByName() {
    92  	TU := reflect.TypeOf([]interface{}{T{}, U{}}[0])
    93  	print(reflect.Zero(TU)) // @types T | U
    94  
    95  	F, _ := TU.MethodByName("F")
    96  	print(reflect.Zero(F.Type)) // @types func(T) | func(U, int)
    97  	print(F.Func)               // @pointsto (main.T).F | (main.U).F
    98  
    99  	g, _ := TU.MethodByName("g")
   100  	print(reflect.Zero(g.Type)) // @types func(T, int) | func(U, string)
   101  	print(g.Func)               // @pointsto (main.T).g | (main.U).g
   102  
   103  	// Non-literal method names are treated less precisely.
   104  	U := reflect.TypeOf(U{})
   105  	X, _ := U.MethodByName(nonconst)
   106  	print(reflect.Zero(X.Type)) // @types func(U, int) | func(U, string)
   107  	print(X.Func)               // @pointsto (main.U).F | (main.U).g
   108  
   109  	// Interface methods.
   110  	rThasF := reflect.TypeOf(new(hasF)).Elem()
   111  	print(reflect.Zero(rThasF)) // @types hasF
   112  	F2, _ := rThasF.MethodByName("F")
   113  	print(reflect.Zero(F2.Type)) // @types func()
   114  	print(F2.Func)               // @pointsto
   115  
   116  }
   117  
   118  func reflectTypeMethod() {
   119  	m := reflect.TypeOf(T{}).Method(0)
   120  	print(reflect.Zero(m.Type)) // @types func(T) | func(T, int)
   121  	print(m.Func)               // @pointsto (main.T).F | (main.T).g
   122  }
   123  
   124  func main() {
   125  	reflectValueCall()
   126  	reflectValueCallIndirect()
   127  	reflectTypeInOut()
   128  	reflectTypeMethodByName()
   129  	reflectTypeMethod()
   130  }