mirror of
https://github.com/golang/go
synced 2024-11-19 06:34:42 -07:00
94c387c610
The implementation follows the basic pattern of an indirect
function call (genDynamicCall).
We use the same trick as SetFinalizer so that direct calls to
(r.V).Call, which are overwhelmingly the norm, are inlined.
Bug fix (and simplification): calling untag() to unbox a
reflect.Value is wrong for reflect.Values containing interfaces
(rare). Now, we call untag for concrete types and typeFilter
for interface types, and we can use this pattern in all cases.
It corresponds to the ssa.TypeAssert operator, so we call
it typeAssert. Added tests to cover this.
We also specialize reflect.{In,Out} when the operand is an int
literal.
+ Tests.
Also:
- make taggedValue() panic, not return nil, eliminating many checks.
We call isTaggedValue for the one place that cares.
- pointer_test: recover from panics in Analyze() and dump the log.
R=crawshaw
CC=golang-dev
https://golang.org/cl/14426050
119 lines
3.2 KiB
Go
119 lines
3.2 KiB
Go
// +build ignore
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package main
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import "reflect"
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var zero, a, b int
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var false2 bool
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func f(p *int, q hasF) *int {
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print(p) // @pointsto main.a
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print(q) // @types *T
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print(q.(*T)) // @pointsto new@newT1:22
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return &b
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}
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func g(p *bool) (*int, *bool, hasF) {
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return &b, p, new(T) // @line newT2
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}
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func reflectValueCall() {
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rvf := reflect.ValueOf(f)
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res := rvf.Call([]reflect.Value{
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// argument order is not significant:
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reflect.ValueOf(new(T)), // @line newT1
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reflect.ValueOf(&a),
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})
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print(res[0].Interface()) // @types *int
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print(res[0].Interface().(*int)) // @pointsto main.b
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}
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// @calls main.reflectValueCall -> main.f
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func reflectValueCallIndirect() {
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rvf := reflect.ValueOf(g)
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call := rvf.Call // kids, don't try this at home
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// Indirect call uses shared contour.
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//
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// Also notice that argument position doesn't matter, and args
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// of inappropriate type (e.g. 'a') are ignored.
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res := call([]reflect.Value{
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reflect.ValueOf(&a),
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reflect.ValueOf(&false2),
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})
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res0 := res[0].Interface()
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print(res0) // @types *int | *bool | *T
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print(res0.(*int)) // @pointsto main.b
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print(res0.(*bool)) // @pointsto main.false2
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print(res0.(hasF)) // @types *T
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print(res0.(*T)) // @pointsto new@newT2:19
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}
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// @calls main.reflectValueCallIndirect -> bound$(reflect.Value).Call
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// @calls bound$(reflect.Value).Call -> main.g
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func reflectTypeInOut() {
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var f func(float64, bool) (string, int)
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print(reflect.Zero(reflect.TypeOf(f).In(0)).Interface()) // @types float64
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print(reflect.Zero(reflect.TypeOf(f).In(1)).Interface()) // @types bool
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print(reflect.Zero(reflect.TypeOf(f).In(-1)).Interface()) // @types float64 | bool
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print(reflect.Zero(reflect.TypeOf(f).In(zero)).Interface()) // @types float64 | bool
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print(reflect.Zero(reflect.TypeOf(f).Out(0)).Interface()) // @types string
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print(reflect.Zero(reflect.TypeOf(f).Out(1)).Interface()) // @types int
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print(reflect.Zero(reflect.TypeOf(f).Out(2)).Interface()) // @types
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print(reflect.Zero(reflect.TypeOf(3).Out(0)).Interface()) // @types
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}
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type hasF interface {
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F()
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}
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type T struct{}
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func (T) F() {}
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func (T) g(int) {}
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type U struct{}
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func (U) F(int) {}
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func (U) g(string) {}
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var nonconst string
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func reflectTypeMethodByName() {
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TU := reflect.TypeOf([]interface{}{T{}, U{}}[0])
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print(reflect.Zero(TU)) // @types T | U
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F, _ := TU.MethodByName("F")
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print(reflect.Zero(F.Type)) // @types func(T) | func(U, int)
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print(F.Func) // @pointsto (main.T).F | (main.U).F
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g, _ := TU.MethodByName("g")
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print(reflect.Zero(g.Type)) // @types func(T, int) | func(U, string)
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print(g.Func) // @pointsto (main.T).g | (main.U).g
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// Non-literal method names are treated less precisely.
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U := reflect.TypeOf(U{})
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X, _ := U.MethodByName(nonconst)
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print(reflect.Zero(X.Type)) // @types func(U, int) | func(U, string)
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print(X.Func) // @pointsto (main.U).F | (main.U).g
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}
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func reflectTypeMethod() {
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m := reflect.TypeOf(T{}).Method(0)
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print(reflect.Zero(m.Type)) // @types func(T) | func(T, int)
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print(m.Func) // @pointsto (main.T).F | (main.T).g
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}
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func main() {
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reflectValueCall()
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reflectValueCallIndirect()
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reflectTypeInOut()
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reflectTypeMethodByName()
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reflectTypeMethod()
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}
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