Golang Struct.NumFields方法代码示例

func (c *funcContext) loadStruct(array, target string, s *types.Struct) string {
	view := c.newVariable("_view")
	code := fmt.Sprintf("%s = new DataView(%s.buffer, %s.byteOffset)", view, array, array)
	var fields []*types.Var
	var collectFields func(s *types.Struct, path string)
	collectFields = func(s *types.Struct, path string) {
		for i := 0; i < s.NumFields(); i++ {
			field := s.Field(i)
			if fs, isStruct := field.Type().Underlying().(*types.Struct); isStruct {
				collectFields(fs, path+"."+fieldName(s, i))
				continue
			}
			fields = append(fields, types.NewVar(0, nil, path+"."+fieldName(s, i), field.Type()))
		}
	}
	collectFields(s, target)
	offsets := sizes32.Offsetsof(fields)
	for i, field := range fields {
		switch t := field.Type().Underlying().(type) {
		case *types.Basic:
			if t.Info()&types.IsNumeric != 0 {
				if is64Bit(t) {
					code += fmt.Sprintf(", %s = new %s(%s.getUint32(%d, true), %s.getUint32(%d, true))", field.Name(), c.typeName(field.Type()), view, offsets[i]+4, view, offsets[i])
					break
				}
				code += fmt.Sprintf(", %s = %s.get%s(%d, true)", field.Name(), view, toJavaScriptType(t), offsets[i])
			}
		case *types.Array:
			code += fmt.Sprintf(`, %s = new ($nativeArray("%s"))(%s.buffer, $min(%s.byteOffset + %d, %s.buffer.byteLength))`, field.Name(), typeKind(t.Elem()), array, array, offsets[i], array)
		}
	}
	return code
}

func (c *PkgContext) loadStruct(array, target string, s *types.Struct) {
	view := c.newVariable("_view")
	c.Printf("%s = new DataView(%s.buffer, %s.byteOffset);", view, array, array)
	var fields []*types.Var
	var collectFields func(s *types.Struct, path string)
	collectFields = func(s *types.Struct, path string) {
		for i := 0; i < s.NumFields(); i++ {
			field := s.Field(i)
			if fs, isStruct := field.Type().Underlying().(*types.Struct); isStruct {
				collectFields(fs, path+"."+field.Name())
				continue
			}
			fields = append(fields, types.NewVar(0, nil, path+"."+field.Name(), field.Type()))
		}
	}
	collectFields(s, target)
	offsets := sizes32.Offsetsof(fields)
	for i, field := range fields {
		switch t := field.Type().Underlying().(type) {
		case *types.Basic:
			if t.Info()&types.IsNumeric != 0 {
				if is64Bit(t) {
					c.Printf("%s = new %s(%s.getUint32(%d, true), %s.getUint32(%d, true));", field.Name(), c.typeName(field.Type()), view, offsets[i]+4, view, offsets[i])
					continue
				}
				c.Printf("%s = %s.get%s(%d, true);", field.Name(), view, toJavaScriptType(t), offsets[i])
			}
			continue
		case *types.Array:
			c.Printf("%s = new %s(%s.buffer, Go$min(%s.byteOffset + %d, %s.buffer.byteLength));", field.Name(), toArrayType(t.Elem()), array, array, offsets[i], array)
			continue
		}
		c.Printf("// skipped: %s %s", field.Name(), field.Type().String())
	}
}

// matchStructArgType reports whether all the elements of the struct match the expected
// type. For instance, with "%d" all the elements must be printable with the "%d" format.
func (f *File) matchStructArgType(t printfArgType, typ *types.Struct, arg ast.Expr, inProgress map[types.Type]bool) bool {
	for i := 0; i < typ.NumFields(); i++ {
		if !f.matchArgTypeInternal(t, typ.Field(i).Type(), arg, inProgress) {
			return false
		}
	}
	return true
}

func fieldIndex(s *types.Struct, name string) int {
	for i := 0; i < s.NumFields(); i++ {
		f := s.Field(i)
		if f.Name() == name {
			return i
		}
	}
	return -1
}

func (m *TypeMap) descriptorStruct(t *types.Struct, name string) TypeDebugDescriptor {
	members := make([]DebugDescriptor, t.NumFields())
	for i := range members {
		f := t.Field(i)
		member := NewMemberDerivedType(m.TypeDebugDescriptor(f.Type()))
		member.Name = f.Name()
		members[i] = member
	}
	dt := NewStructCompositeType(members)
	dt.Name = name
	return dt
}

func (tm *llvmTypeMap) structLLVMType(s *types.Struct, name string) llvm.Type {
	typ, ok := tm.types.At(s).(llvm.Type)
	if !ok {
		typ = llvm.GlobalContext().StructCreateNamed(name)
		tm.types.Set(s, typ)
		elements := make([]llvm.Type, s.NumFields())
		for i := range elements {
			f := s.Field(i)
			ft := f.Type()
			elements[i] = tm.ToLLVM(ft)
		}
		typ.StructSetBody(elements, false)
	}
	return typ
}

func (tm *LLVMTypeMap) structLLVMType(tstr string, s *types.Struct) llvm.Type {
	typ, ok := tm.types[tstr]
	if !ok {
		typ = llvm.GlobalContext().StructCreateNamed("")
		tm.types[tstr] = typ
		elements := make([]llvm.Type, s.NumFields())
		for i := range elements {
			f := s.Field(i)
			ft := f.Type
			elements[i] = tm.ToLLVM(ft)
		}
		typ.StructSetBody(elements, false)
	}
	return typ
}

func (w *Walker) emitStructType(name string, typ *types.Struct) {
	typeStruct := fmt.Sprintf("type %s struct", name)
	w.emitf(typeStruct)
	defer w.pushScope(typeStruct)()

	for i := 0; i < typ.NumFields(); i++ {
		f := typ.Field(i)
		if !f.IsExported() {
			continue
		}
		typ := f.Type()
		if f.Anonymous() {
			w.emitf("embedded %s", w.typeString(typ))
			continue
		}
		w.emitf("%s %s", f.Name(), w.typeString(typ))
	}
}

func (tm *TypeMap) structRuntimeType(s *types.Struct) (global, ptr llvm.Value) {
	rtype := tm.makeRtype(s, reflect.Struct)
	structType := llvm.ConstNull(tm.runtime.structType.llvm)
	structType = llvm.ConstInsertValue(structType, rtype, []uint32{0})
	global, ptr = tm.makeRuntimeTypeGlobal(structType, typeString(s))
	tm.types.Set(s, runtimeTypeInfo{global, ptr})
	fieldVars := make([]*types.Var, s.NumFields())
	for i := range fieldVars {
		fieldVars[i] = s.Field(i)
	}
	offsets := tm.Offsetsof(fieldVars)
	structFields := make([]llvm.Value, len(fieldVars))
	for i := range structFields {
		field := fieldVars[i]
		structField := llvm.ConstNull(tm.runtime.structField.llvm)
		if !field.Anonymous() {
			name := tm.globalStringPtr(field.Name())
			name = llvm.ConstBitCast(name, tm.runtime.structField.llvm.StructElementTypes()[0])
			structField = llvm.ConstInsertValue(structField, name, []uint32{0})
		}
		if !ast.IsExported(field.Name()) {
			pkgpath := tm.globalStringPtr(field.Pkg().Path())
			pkgpath = llvm.ConstBitCast(pkgpath, tm.runtime.structField.llvm.StructElementTypes()[1])
			structField = llvm.ConstInsertValue(structField, pkgpath, []uint32{1})
		}
		fieldType := tm.ToRuntime(field.Type())
		structField = llvm.ConstInsertValue(structField, fieldType, []uint32{2})
		if tag := s.Tag(i); tag != "" {
			tag := tm.globalStringPtr(tag)
			tag = llvm.ConstBitCast(tag, tm.runtime.structField.llvm.StructElementTypes()[3])
			structField = llvm.ConstInsertValue(structField, tag, []uint32{3})
		}
		offset := llvm.ConstInt(tm.runtime.structField.llvm.StructElementTypes()[4], uint64(offsets[i]), false)
		structField = llvm.ConstInsertValue(structField, offset, []uint32{4})
		structFields[i] = structField
	}
	structFieldsSliceType := tm.runtime.structType.llvm.StructElementTypes()[1]
	structFieldsSlice := tm.makeSlice(structFields, structFieldsSliceType)
	structType = llvm.ConstInsertValue(structType, structFieldsSlice, []uint32{1})
	global.SetInitializer(structType)
	return global, ptr
}