71 lines
1.7 KiB
Go
71 lines
1.7 KiB
Go
// +build !gccgo
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package reflect2
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import (
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"reflect"
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"sync"
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"unsafe"
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)
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// typelinks2 for 1.7 ~
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//go:linkname typelinks2 reflect.typelinks
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func typelinks2() (sections []unsafe.Pointer, offset [][]int32)
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// initOnce guards initialization of types and packages
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var initOnce sync.Once
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var types map[string]reflect.Type
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var packages map[string]map[string]reflect.Type
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// discoverTypes initializes types and packages
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func discoverTypes() {
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types = make(map[string]reflect.Type)
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packages = make(map[string]map[string]reflect.Type)
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loadGoTypes()
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}
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func loadGoTypes() {
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var obj interface{} = reflect.TypeOf(0)
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sections, offset := typelinks2()
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for i, offs := range offset {
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rodata := sections[i]
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for _, off := range offs {
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(*emptyInterface)(unsafe.Pointer(&obj)).word = resolveTypeOff(unsafe.Pointer(rodata), off)
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typ := obj.(reflect.Type)
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if typ.Kind() == reflect.Ptr && typ.Elem().Kind() == reflect.Struct {
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loadedType := typ.Elem()
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pkgTypes := packages[loadedType.PkgPath()]
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if pkgTypes == nil {
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pkgTypes = map[string]reflect.Type{}
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packages[loadedType.PkgPath()] = pkgTypes
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}
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types[loadedType.String()] = loadedType
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pkgTypes[loadedType.Name()] = loadedType
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}
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}
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}
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}
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type emptyInterface struct {
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typ unsafe.Pointer
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word unsafe.Pointer
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}
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// TypeByName return the type by its name, just like Class.forName in java
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func TypeByName(typeName string) Type {
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initOnce.Do(discoverTypes)
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return Type2(types[typeName])
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}
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// TypeByPackageName return the type by its package and name
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func TypeByPackageName(pkgPath string, name string) Type {
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initOnce.Do(discoverTypes)
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pkgTypes := packages[pkgPath]
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if pkgTypes == nil {
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return nil
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}
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return Type2(pkgTypes[name])
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}
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