reflect: add support for non-named basic types

compiler/interface-lowering.go

@@ -104,15 +104,6 @@ func (t *typeInfo) getMethod(signature *signatureInfo) *methodInfo {
 	panic("could not find method")
 }
 
-// id returns the fully-qualified type name including import path, removing the
-// $type suffix.
-func (t *typeInfo) id() string {
-	if !strings.HasSuffix(t.name, "$type") {
-		panic("concrete type does not have $type suffix: " + t.name)
-	}
-	return t.name[:len(t.name)-len("$type")]
-}
-
 // typeInfoSlice implements sort.Slice, sorting the most commonly used types
 // first.
 type typeInfoSlice []*typeInfo
@@ -423,9 +414,7 @@ func (p *lowerInterfacesPass) run() {
 	}
 
 	// Assign a type code for each type.
-	for i, t := range typeSlice {
+	p.assignTypeCodes(typeSlice)
-		t.num = uint64(i + 1)
-	}
 
 	// Replace each call to runtime.makeInterface with the constant type code.
 	for _, use := range makeInterfaceUses {
@@ -691,7 +680,7 @@ func (p *lowerInterfacesPass) createInterfaceMethodFunc(itf *interfaceInfo, sign
 
 	// Define all possible functions that can be called.
 	for _, typ := range itf.types {
-		bb := llvm.AddBasicBlock(fn, typ.id())
+		bb := llvm.AddBasicBlock(fn, typ.name)
 		sw.AddCase(llvm.ConstInt(p.uintptrType, typ.num, false), bb)
 
 		// The function we will redirect to when the interface has this type.

compiler/interface.go

@@ -79,9 +79,58 @@ func (c *Compiler) parseMakeInterface(val llvm.Value, typ types.Type, global str
 // It returns a pointer to an external global which should be replaced with the
 // real type in the interface lowering pass.
 func (c *Compiler) getTypeCode(typ types.Type) llvm.Value {
-	global := c.mod.NamedGlobal(typ.String() + "$type")
+	var globalName string
+	switch typ := typ.(type) {
+	case *types.Basic:
+		var name string
+		switch typ.Kind() {
+		case types.Bool:
+			name = "bool"
+		case types.Int:
+			name = "int"
+		case types.Int8:
+			name = "int8"
+		case types.Int16:
+			name = "int16"
+		case types.Int32:
+			name = "int32"
+		case types.Int64:
+			name = "int64"
+		case types.Uint:
+			name = "uint"
+		case types.Uint8:
+			name = "uint8"
+		case types.Uint16:
+			name = "uint16"
+		case types.Uint32:
+			name = "uint32"
+		case types.Uint64:
+			name = "uint64"
+		case types.Uintptr:
+			name = "uintptr"
+		case types.Float32:
+			name = "float32"
+		case types.Float64:
+			name = "float64"
+		case types.Complex64:
+			name = "complex64"
+		case types.Complex128:
+			name = "complex128"
+		case types.String:
+			name = "string"
+		case types.UnsafePointer:
+			name = "unsafeptr"
+		default:
+			panic("unknown basic type: " + typ.Name())
+		}
+		globalName = "type:basic:" + name
+	default:
+		// Unknown type, fall back to the .String() method for identification.
+		globalName = "type:other:" + typ.String()
+	}
+	global := c.mod.NamedGlobal(globalName)
 	if global.IsNil() {
-		global = llvm.AddGlobal(c.mod, c.ctx.Int8Type(), typ.String()+"$type")
+		global = llvm.AddGlobal(c.mod, c.ctx.Int8Type(), globalName)
 		global.SetGlobalConstant(true)
 	}
 	return global

compiler/reflect.go

@@ -0,0 +1,55 @@
+package compiler
+
+import (
+	"strings"
+)
+
+var basicTypes = map[string]uint64{
+	"bool":       1,
+	"int":        2,
+	"int8":       3,
+	"int16":      4,
+	"int32":      5,
+	"int64":      6,
+	"uint":       7,
+	"uint8":      8,
+	"uint16":     9,
+	"uint32":     10,
+	"uint64":     11,
+	"uintptr":    12,
+	"float32":    13,
+	"float64":    14,
+	"complex64":  15,
+	"complex128": 16,
+	"string":     17,
+	"unsafeptr":  18,
+}
+
+func (c *Compiler) assignTypeCodes(typeSlice typeInfoSlice) {
+	fn := c.mod.NamedFunction("reflect.ValueOf")
+	if fn.IsNil() {
+		// reflect.ValueOf is never used, so we can use the most efficient
+		// encoding possible.
+		for i, t := range typeSlice {
+			t.num = uint64(i + 1)
+		}
+		return
+	}
+
+	// Assign typecodes the way the reflect package expects.
+	fallbackIndex := 1
+	for _, t := range typeSlice {
+		if strings.HasPrefix(t.name, "type:basic:") {
+			// Basic types have a typecode with the lowest bit set to 0.
+			num, ok := basicTypes[t.name[len("type:basic:"):]]
+			if !ok {
+				panic("invalid basic type: " + t.name)
+			}
+			t.num = num<<1 | 0
+		} else {
+			// Fallback types have a typecode with the lowest bit set to 1.
+			t.num = uint64(fallbackIndex<<1 | 1)
+			fallbackIndex++
+		}
+	}
+}

src/reflect/type.go

@@ -26,6 +26,8 @@ const (
 	Float64
 	Complex64
 	Complex128
+	String
+	UnsafePointer
 	Array
 	Chan
 	Func
@@ -33,11 +35,52 @@ const (
 	Map
 	Ptr
 	Slice
-	String
 	Struct
-	UnsafePointer
 )
 
+func (k Kind) String() string {
+	switch k {
+	case Bool:
+		return "bool"
+	case Int:
+		return "int"
+	case Int8:
+		return "int8"
+	case Int16:
+		return "int16"
+	case Int32:
+		return "int32"
+	case Int64:
+		return "int64"
+	case Uint:
+		return "uint"
+	case Uint8:
+		return "uint8"
+	case Uint16:
+		return "uint16"
+	case Uint32:
+		return "uint32"
+	case Uint64:
+		return "uint64"
+	case Uintptr:
+		return "uintptr"
+	case Float32:
+		return "float32"
+	case Float64:
+		return "float64"
+	case Complex64:
+		return "complex64"
+	case Complex128:
+		return "complex128"
+	case String:
+		return "string"
+	case UnsafePointer:
+		return "unsafe.Pointer"
+	default:
+		return "T"
+	}
+}
+
 // The typecode as used in an interface{}.
 type Type uintptr
 
@@ -50,8 +93,13 @@ func (t Type) String() string {
 }
 
 func (t Type) Kind() Kind {
+	if t & 1 == 0 {
+		// Basic type
+		return Kind(t >> 1)
+	} else {
 		return Invalid // TODO
 	}
+}
 
 func (t Type) Elem() Type {
 	panic("unimplemented: (reflect.Type).Elem()")

src/reflect/value.go

@@ -33,7 +33,14 @@ func (v Value) IsNil() bool {
 }
 
 func (v Value) Pointer() uintptr {
+	switch v.Type().Kind() {
+	case UnsafePointer:
+		return uintptr(v.value)
+	case Chan, Func, Map, Ptr, Slice:
 		panic("unimplemented: (reflect.Value).Pointer()")
+	default:
+		panic(&ValueError{"Pointer"})
+	}
 }
 
 func (v Value) IsValid() bool {
@@ -57,27 +64,132 @@ func (v Value) CanSet() bool {
 }
 
 func (v Value) Bool() bool {
-	panic("unimplemented: (reflect.Value).Bool()")
+	switch v.Type().Kind() {
+	case Bool:
+		return uintptr(v.value) != 0
+	default:
+		panic(&ValueError{"Bool"})
+	}
 }
 
 func (v Value) Int() int64 {
-	panic("unimplemented: (reflect.Value).Int()")
+	switch v.Type().Kind() {
+	case Int:
+		if unsafe.Sizeof(int(0)) <= unsafe.Sizeof(uintptr(0)) {
+			return int64(int(uintptr(v.value)))
+		} else {
+			return int64(*(*int)(v.value))
+		}
+	case Int8:
+		return int64(int8(uintptr(v.value)))
+	case Int16:
+		return int64(int16(uintptr(v.value)))
+	case Int32:
+		if unsafe.Sizeof(int32(0)) <= unsafe.Sizeof(uintptr(0)) {
+			return int64(int32(uintptr(v.value)))
+		} else {
+			return int64(*(*int32)(v.value))
+		}
+		return int64(uintptr(v.value))
+	case Int64:
+		if unsafe.Sizeof(int64(0)) <= unsafe.Sizeof(uintptr(0)) {
+			return int64(uintptr(v.value))
+		} else {
+			return *(*int64)(v.value)
+		}
+	default:
+		panic(&ValueError{"Int"})
+	}
 }
 
 func (v Value) Uint() uint64 {
-	panic("unimplemented: (reflect.Value).Uint()")
+	switch v.Type().Kind() {
+	case Uintptr, Uint8, Uint16:
+		return uint64(uintptr(v.value))
+	case Uint:
+		if unsafe.Sizeof(uint(0)) <= unsafe.Sizeof(uintptr(0)) {
+			return uint64(uintptr(v.value))
+		} else {
+			// For systems with 16-bit pointers.
+			return uint64(*(*uint)(v.value))
+		}
+	case Uint32:
+		if unsafe.Sizeof(uint32(0)) <= unsafe.Sizeof(uintptr(0)) {
+			return uint64(uintptr(v.value))
+		} else {
+			// For systems with 16-bit pointers.
+			return uint64(*(*uint32)(v.value))
+		}
+	case Uint64:
+		if unsafe.Sizeof(uint64(0)) <= unsafe.Sizeof(uintptr(0)) {
+			return uint64(uintptr(v.value))
+		} else {
+			// For systems with 16-bit or 32-bit pointers.
+			return *(*uint64)(v.value)
+		}
+	default:
+		panic(&ValueError{"Uint"})
+	}
 }
 
 func (v Value) Float() float64 {
-	panic("unimplemented: (reflect.Value).Float()")
+	switch v.Type().Kind() {
+	case Float32:
+		if unsafe.Sizeof(float32(0)) <= unsafe.Sizeof(uintptr(0)) {
+			// The float is directly stored in the interface value on systems
+			// with 32-bit and 64-bit pointers.
+			return float64(*(*float32)(unsafe.Pointer(&v.value)))
+		} else {
+			// The float is stored as an external value on systems with 16-bit
+			// pointers.
+			return float64(*(*float32)(v.value))
+		}
+	case Float64:
+		if unsafe.Sizeof(float64(0)) <= unsafe.Sizeof(uintptr(0)) {
+			// The float is directly stored in the interface value on systems
+			// with 64-bit pointers.
+			return *(*float64)(unsafe.Pointer(&v.value))
+		} else {
+			// For systems with 16-bit and 32-bit pointers.
+			return *(*float64)(v.value)
+		}
+	default:
+		panic(&ValueError{"Float"})
+	}
 }
 
 func (v Value) Complex() complex128 {
-	panic("unimplemented: (reflect.Value).Complex()")
+	switch v.Type().Kind() {
+	case Complex64:
+		if unsafe.Sizeof(complex64(0)) <= unsafe.Sizeof(uintptr(0)) {
+			// The complex number is directly stored in the interface value on
+			// systems with 64-bit pointers.
+			return complex128(*(*complex64)(unsafe.Pointer(&v.value)))
+		} else {
+			// The complex number is stored as an external value on systems with
+			// 16-bit and 32-bit pointers.
+			return complex128(*(*complex64)(v.value))
+		}
+	case Complex128:
+		// This is a 128-bit value, which is always stored as an external value.
+		// It may be stored in the pointer directly on very uncommon
+		// architectures with 128-bit pointers, however.
+		return *(*complex128)(v.value)
+	default:
+		panic(&ValueError{"Complex"})
+	}
 }
 
 func (v Value) String() string {
-	panic("unimplemented: (reflect.Value).String()")
+	switch v.Type().Kind() {
+	case String:
+		// A string value is always bigger than a pointer as it is made of a
+		// pointer and a length.
+		return *(*string)(v.value)
+	default:
+		// Special case because of the special treatment of .String() in Go.
+		return "<T>"
+	}
 }
 
 func (v Value) Bytes() []byte {
@@ -147,3 +259,11 @@ func (v Value) SetString(x string) {
 func MakeSlice(typ Type, len, cap int) Value {
 	panic("unimplemented: reflect.MakeSlice()")
 }
+
+type ValueError struct {
+	Method string
+}
+
+func (e *ValueError) Error() string {
+	return "reflect: call of reflect.Value." + e.Method + " on invalid type"
+}

testdata/reflect.go

@@ -1,6 +1,9 @@
 package main
 
-import "reflect"
+import (
+	"reflect"
+	"unsafe"
+)
 
 type myint int
 
@@ -9,4 +12,61 @@ func main() {
 	println(reflect.TypeOf(int(3)) == reflect.TypeOf(int(5)))
 	println(reflect.TypeOf(int(3)) == reflect.TypeOf(uint(5)))
 	println(reflect.TypeOf(myint(3)) == reflect.TypeOf(int(5)))
+
+	println("\nvalues of interfaces")
+	for _, v := range []interface{}{
+		true,
+		false,
+		int(2000),
+		int(-2000),
+		uint(2000),
+		int8(-3),
+		int8(3),
+		uint8(200),
+		int16(-300),
+		int16(300),
+		uint16(50000),
+		int32(7 << 20),
+		int32(-7 << 20),
+		uint32(7 << 20),
+		int64(9 << 40),
+		int64(-9 << 40),
+		uint64(9 << 40),
+		uintptr(12345),
+		float32(3.14),
+		float64(3.14),
+		complex64(1.2 + 0.3i),
+		complex128(1.3 + 0.4i),
+		"foo",
+		unsafe.Pointer(new(int)),
+	} {
+		showValue(v)
+	}
+}
+
+func showValue(v interface{}) {
+	rv := reflect.ValueOf(v)
+	rt := rv.Type()
+	if reflect.TypeOf(v) != rt {
+		panic("direct TypeOf() is different from ValueOf().Type()")
+	}
+	println("reflect type:", rt.Kind().String())
+	switch rt.Kind() {
+	case reflect.Bool:
+		println("  bool:", rv.Bool())
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		println("  int:", rv.Int())
+	case reflect.Uint, reflect.Uintptr, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		println("  uint:", rv.Uint())
+	case reflect.Float32, reflect.Float64:
+		println("  float:", rv.Float())
+	case reflect.Complex64, reflect.Complex128:
+		println("  complex:", rv.Complex())
+	case reflect.String:
+		println("  string:", rv.String())
+	case reflect.UnsafePointer:
+		println("  pointer:", rv.Pointer() != 0)
+	default:
+		println("  unknown type kind!")
+	}
 }

testdata/reflect.txt

@@ -2,3 +2,53 @@ matching types
 true
 false
 false
+
+values of interfaces
+reflect type: bool
+  bool: true
+reflect type: bool
+  bool: false
+reflect type: int
+  int: 2000
+reflect type: int
+  int: -2000
+reflect type: uint
+  uint: 2000
+reflect type: int8
+  int: -3
+reflect type: int8
+  int: 3
+reflect type: uint8
+  uint: 200
+reflect type: int16
+  int: -300
+reflect type: int16
+  int: 300
+reflect type: uint16
+  uint: 50000
+reflect type: int32
+  int: 7340032
+reflect type: int32
+  int: -7340032
+reflect type: uint32
+  uint: 7340032
+reflect type: int64
+  int: 9895604649984
+reflect type: int64
+  int: -9895604649984
+reflect type: uint64
+  uint: 9895604649984
+reflect type: uintptr
+  uint: 12345
+reflect type: float32
+  float: +3.140000e+000
+reflect type: float64
+  float: +3.140000e+000
+reflect type: complex64
+  complex: (+1.200000e+000+3.000000e-001i)
+reflect type: complex128
+  complex: (+1.300000e+000+4.000000e-001i)
+reflect type: string
+  string: foo
+reflect type: unsafe.Pointer
+  pointer: true