compiler,reflect: add reflect.Type.NumMethods()

compiler/interface.go

@@ -134,6 +134,7 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 			typeFieldTypes = append(typeFieldTypes,
 				types.NewVar(token.NoPos, nil, "ptrTo", types.Typ[types.UnsafePointer]),
 				types.NewVar(token.NoPos, nil, "underlying", types.Typ[types.UnsafePointer]),
+				types.NewVar(token.NoPos, nil, "numMethods", types.Typ[types.Uint16]),
 				types.NewVar(token.NoPos, nil, "pkgpath", types.Typ[types.UnsafePointer]),
 				types.NewVar(token.NoPos, nil, "name", types.NewArray(types.Typ[types.Int8], 1+int64(len(typ.Obj().Name())))),
 			)
@@ -145,6 +146,7 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 		case *types.Pointer:
 			typeFieldTypes = append(typeFieldTypes,
 				types.NewVar(token.NoPos, nil, "elementType", types.Typ[types.UnsafePointer]),
+				types.NewVar(token.NoPos, nil, "numMethods", types.Typ[types.Uint16]),
 			)
 		case *types.Array:
 			typeFieldTypes = append(typeFieldTypes,
@@ -161,6 +163,7 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 		case *types.Struct:
 			typeFieldTypes = append(typeFieldTypes,
 				types.NewVar(token.NoPos, nil, "numFields", types.Typ[types.Uint16]),
+				types.NewVar(token.NoPos, nil, "numMethods", types.Typ[types.Uint16]),
 				types.NewVar(token.NoPos, nil, "ptrTo", types.Typ[types.UnsafePointer]),
 				types.NewVar(token.NoPos, nil, "pkgpath", types.Typ[types.UnsafePointer]),
 				types.NewVar(token.NoPos, nil, "fields", types.NewArray(c.getRuntimeType("structField"), int64(typ.NumFields()))),
@@ -203,6 +206,7 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 			typeFields = []llvm.Value{
 				c.getTypeCode(types.NewPointer(typ)),                      // ptrTo
 				c.getTypeCode(typ.Underlying()),                           // underlying
+				llvm.ConstInt(c.ctx.Int16Type(), uint64(ms.Len()), false), // numMethods
 				pkgPathPtr,                            // pkgpath pointer
 				c.ctx.ConstString(name+"\x00", false), // name
 			}
@@ -218,7 +222,10 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 				c.getTypeCode(typ.Elem()),            // elementType
 			}
 		case *types.Pointer:
-			typeFields = []llvm.Value{c.getTypeCode(typ.Elem())}
+			typeFields = []llvm.Value{
+				c.getTypeCode(typ.Elem()),
+				llvm.ConstInt(c.ctx.Int16Type(), uint64(ms.Len()), false), // numMethods
+			}
 		case *types.Array:
 			typeFields = []llvm.Value{
 				c.getTypeCode(types.NewPointer(typ)),                   // ptrTo
@@ -242,6 +249,7 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 
 			typeFields = []llvm.Value{
 				llvm.ConstInt(c.ctx.Int16Type(), uint64(typ.NumFields()), false), // numFields
+				llvm.ConstInt(c.ctx.Int16Type(), uint64(ms.Len()), false),        // numMethods
 				c.getTypeCode(types.NewPointer(typ)),                             // ptrTo
 				pkgPathPtr,
 			}

compiler/testdata/gc.ll

@@ -22,7 +22,7 @@ target triple = "wasm32-unknown-wasi"
 @"runtime/gc.layout:62-2000000000000001" = linkonce_odr unnamed_addr constant { i32, [8 x i8] } { i32 62, [8 x i8] c"\01\00\00\00\00\00\00 " }
 @"runtime/gc.layout:62-0001" = linkonce_odr unnamed_addr constant { i32, [8 x i8] } { i32 62, [8 x i8] c"\01\00\00\00\00\00\00\00" }
 @"reflect/types.type:basic:complex128" = linkonce_odr constant { i8, ptr } { i8 16, ptr @"reflect/types.type:pointer:basic:complex128" }, align 4
-@"reflect/types.type:pointer:basic:complex128" = linkonce_odr constant { i8, ptr } { i8 21, ptr @"reflect/types.type:basic:complex128" }, align 4
+@"reflect/types.type:pointer:basic:complex128" = linkonce_odr constant { i8, ptr, i16 } { i8 21, ptr @"reflect/types.type:basic:complex128", i16 0 }, align 4
 
 declare noalias nonnull ptr @runtime.alloc(i32, ptr, ptr) #0
 

compiler/testdata/interface.ll

@@ -7,13 +7,13 @@ target triple = "wasm32-unknown-wasi"
 %runtime._string = type { ptr, i32 }
 
 @"reflect/types.type:basic:int" = linkonce_odr constant { i8, ptr } { i8 2, ptr @"reflect/types.type:pointer:basic:int" }, align 4
-@"reflect/types.type:pointer:basic:int" = linkonce_odr constant { i8, ptr } { i8 21, ptr @"reflect/types.type:basic:int" }, align 4
+@"reflect/types.type:pointer:basic:int" = linkonce_odr constant { i8, ptr, i16 } { i8 21, ptr @"reflect/types.type:basic:int", i16 0 }, align 4
-@"reflect/types.type:pointer:named:error" = linkonce_odr constant { i8, ptr } { i8 21, ptr @"reflect/types.type:named:error" }, align 4
+@"reflect/types.type:pointer:named:error" = linkonce_odr constant { i8, ptr, i16 } { i8 21, ptr @"reflect/types.type:named:error", i16 0 }, align 4
-@"reflect/types.type:named:error" = linkonce_odr constant { i8, ptr, ptr, ptr, [6 x i8] } { i8 52, ptr @"reflect/types.type:pointer:named:error", ptr @"reflect/types.type:interface:{Error:func:{}{basic:string}}", ptr @"reflect/types.type.pkgpath.empty", [6 x i8] c"error\00" }, align 4
+@"reflect/types.type:named:error" = linkonce_odr constant { i8, ptr, ptr, i16, ptr, [6 x i8] } { i8 52, ptr @"reflect/types.type:pointer:named:error", ptr @"reflect/types.type:interface:{Error:func:{}{basic:string}}", i16 1, ptr @"reflect/types.type.pkgpath.empty", [6 x i8] c"error\00" }, align 4
 @"reflect/types.type.pkgpath.empty" = linkonce_odr unnamed_addr constant [1 x i8] zeroinitializer, align 1
 @"reflect/types.type:interface:{Error:func:{}{basic:string}}" = linkonce_odr constant { i8, ptr } { i8 20, ptr @"reflect/types.type:pointer:interface:{Error:func:{}{basic:string}}" }, align 4
-@"reflect/types.type:pointer:interface:{Error:func:{}{basic:string}}" = linkonce_odr constant { i8, ptr } { i8 21, ptr @"reflect/types.type:interface:{Error:func:{}{basic:string}}" }, align 4
+@"reflect/types.type:pointer:interface:{Error:func:{}{basic:string}}" = linkonce_odr constant { i8, ptr, i16 } { i8 21, ptr @"reflect/types.type:interface:{Error:func:{}{basic:string}}", i16 0 }, align 4
-@"reflect/types.type:pointer:interface:{String:func:{}{basic:string}}" = linkonce_odr constant { i8, ptr } { i8 21, ptr @"reflect/types.type:interface:{String:func:{}{basic:string}}" }, align 4
+@"reflect/types.type:pointer:interface:{String:func:{}{basic:string}}" = linkonce_odr constant { i8, ptr, i16 } { i8 21, ptr @"reflect/types.type:interface:{String:func:{}{basic:string}}", i16 0 }, align 4
 @"reflect/types.type:interface:{String:func:{}{basic:string}}" = linkonce_odr constant { i8, ptr } { i8 20, ptr @"reflect/types.type:pointer:interface:{String:func:{}{basic:string}}" }, align 4
 @"reflect/types.typeid:basic:int" = external constant i8
 

src/reflect/type.go

@@ -25,6 +25,7 @@
 // - pointer types (see ptrType, this doesn't include chan, map, etc):
 //     meta         uint8
 //     elementType  *typeStruct
+//     nmethods     uint16
 // - array types (see arrayType)
 //     meta         uint8
 //     ptrTo        *typeStruct
@@ -38,6 +39,7 @@
 // - struct types (see structType):
 //     meta         uint8
 //     numField     uint16
+//     nmethods     uint16
 //     ptrTo        *typeStruct
 //     pkgpath      *byte
 //     fields       [...]structField // the remaining fields are all of type structField
@@ -51,6 +53,7 @@
 //     meta         uint8
 //     ptrTo        *typeStruct
 //     elem         *typeStruct // underlying type
+//     nmethods     uint16      // number of methods
 //     pkg          *byte       // pkgpath
 //     name         [1]byte     // actual name; length nlem
 //
@@ -410,6 +413,7 @@ type elemType struct {
 type ptrType struct {
 	rawType
 	elem      *rawType
+	numMethod uint16
 }
 
 type arrayType struct {
@@ -430,6 +434,7 @@ type namedType struct {
 	rawType
 	ptrTo     *rawType
 	elem      *rawType
+	numMethod uint16
 	pkg       *byte
 	name      [1]byte
 }
@@ -444,6 +449,7 @@ type namedType struct {
 type structType struct {
 	rawType
 	numField  uint16
+	numMethod uint16
 	ptrTo     *rawType
 	pkgpath   *byte
 	fields    [1]structField // the remaining fields are all of type structField
@@ -992,7 +998,20 @@ func (t *rawType) NumOut() int {
 }
 
 func (t *rawType) NumMethod() int {
-	panic("unimplemented: (reflect.Type).NumMethod()")
+
+	if t.isNamed() {
+		return int((*namedType)(unsafe.Pointer(t)).numMethod)
+	}
+
+	switch t.Kind() {
+	case Pointer:
+		return int((*ptrType)(unsafe.Pointer(t)).numMethod)
+	case Struct:
+		return int((*structType)(unsafe.Pointer(t)).numMethod)
+	}
+
+	// Other types have no methods attached.  Note we don't panic here.
+	return 0
 }
 
 // Read and return a null terminated string starting from data.