Beispiel #1
0
func (p *exporter) value(x exact.Value) {
	if trace {
		p.tracef("value { ")
		defer p.tracef("} ")
	}

	switch kind := x.Kind(); kind {
	case exact.Bool:
		tag := falseTag
		if exact.BoolVal(x) {
			tag = trueTag
		}
		p.int(tag)
	case exact.Int:
		if i, ok := exact.Int64Val(x); ok {
			p.int(int64Tag)
			p.int64(i)
			return
		}
		p.int(floatTag)
		p.float(x)
	case exact.Float:
		p.int(fractionTag)
		p.fraction(x)
	case exact.Complex:
		p.int(complexTag)
		p.fraction(exact.Real(x))
		p.fraction(exact.Imag(x))
	case exact.String:
		p.int(stringTag)
		p.string(exact.StringVal(x))
	default:
		panic(fmt.Sprintf("unexpected value kind %d", kind))
	}
}
Beispiel #2
0
// checkPrintf checks a call to a formatted print routine such as Printf.
// call.Args[formatIndex] is (well, should be) the format argument.
func (f *File) checkPrintf(call *ast.CallExpr, name string, formatIndex int) {
	if formatIndex >= len(call.Args) {
		f.Bad(call.Pos(), "too few arguments in call to", name)
		return
	}
	lit := f.pkg.types[call.Args[formatIndex]].Value
	if lit == nil {
		if *verbose {
			f.Warn(call.Pos(), "can't check non-constant format in call to", name)
		}
		return
	}
	if lit.Kind() != exact.String {
		f.Badf(call.Pos(), "constant %v not a string in call to %s", lit, name)
		return
	}
	format := exact.StringVal(lit)
	firstArg := formatIndex + 1 // Arguments are immediately after format string.
	if !strings.Contains(format, "%") {
		if len(call.Args) > firstArg {
			f.Badf(call.Pos(), "no formatting directive in %s call", name)
		}
		return
	}
	// Hard part: check formats against args.
	argNum := firstArg
	indexed := false
	for i, w := 0, 0; i < len(format); i += w {
		w = 1
		if format[i] == '%' {
			state := f.parsePrintfVerb(call, name, format[i:], firstArg, argNum)
			if state == nil {
				return
			}
			w = len(state.format)
			if state.indexed {
				indexed = true
			}
			if !f.okPrintfArg(call, state) { // One error per format is enough.
				return
			}
			if len(state.argNums) > 0 {
				// Continue with the next sequential argument.
				argNum = state.argNums[len(state.argNums)-1] + 1
			}
		}
	}
	// Dotdotdot is hard.
	if call.Ellipsis.IsValid() && argNum >= len(call.Args)-1 {
		return
	}
	// If the arguments were direct indexed, we assume the programmer knows what's up.
	// Otherwise, there should be no leftover arguments.
	if !indexed && argNum != len(call.Args) {
		expect := argNum - firstArg
		numArgs := len(call.Args) - firstArg
		f.Badf(call.Pos(), "wrong number of args for format in %s call: %d needed but %d args", name, expect, numArgs)
	}
}
Beispiel #3
0
// constValue returns the value of the constant with the
// dynamic type tag appropriate for c.Type().
func constValue(c *ssa.Const) value {
	if c.IsNil() {
		return zero(c.Type()) // typed nil
	}

	if t, ok := c.Type().Underlying().(*types.Basic); ok {
		// TODO(adonovan): eliminate untyped constants from SSA form.
		switch t.Kind() {
		case types.Bool, types.UntypedBool:
			return exact.BoolVal(c.Value)
		case types.Int, types.UntypedInt:
			// Assume sizeof(int) is same on host and target.
			return int(c.Int64())
		case types.Int8:
			return int8(c.Int64())
		case types.Int16:
			return int16(c.Int64())
		case types.Int32, types.UntypedRune:
			return int32(c.Int64())
		case types.Int64:
			return c.Int64()
		case types.Uint:
			// Assume sizeof(uint) is same on host and target.
			return uint(c.Uint64())
		case types.Uint8:
			return uint8(c.Uint64())
		case types.Uint16:
			return uint16(c.Uint64())
		case types.Uint32:
			return uint32(c.Uint64())
		case types.Uint64:
			return c.Uint64()
		case types.Uintptr:
			// Assume sizeof(uintptr) is same on host and target.
			return uintptr(c.Uint64())
		case types.Float32:
			return float32(c.Float64())
		case types.Float64, types.UntypedFloat:
			return c.Float64()
		case types.Complex64:
			return complex64(c.Complex128())
		case types.Complex128, types.UntypedComplex:
			return c.Complex128()
		case types.String, types.UntypedString:
			if c.Value.Kind() == exact.String {
				return exact.StringVal(c.Value)
			}
			return string(rune(c.Int64()))
		}
	}

	panic(fmt.Sprintf("constValue: %s", c))
}
Beispiel #4
0
func (c *funcContext) identifierConstant(expr ast.Expr) (string, bool) {
	val := c.p.Types[expr].Value
	if val == nil {
		return "", false
	}
	s := exact.StringVal(val)
	if len(s) == 0 {
		return "", false
	}
	for i, c := range s {
		if !((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (i > 0 && c >= '0' && c <= '9') || c == '_' || c == '$') {
			return "", false
		}
	}
	return s, true
}
Beispiel #5
0
func (c *Const) RelString(from *types.Package) string {
	var s string
	if c.Value == nil {
		s = "nil"
	} else if c.Value.Kind() == exact.String {
		s = exact.StringVal(c.Value)
		const max = 20
		// TODO(adonovan): don't cut a rune in half.
		if len(s) > max {
			s = s[:max-3] + "..." // abbreviate
		}
		s = strconv.Quote(s)
	} else {
		s = c.Value.String()
	}
	return s + ":" + relType(c.Type(), from)
}
Beispiel #6
0
func Test(t *testing.T) {
	switch runtime.GOOS {
	case "windows":
		t.Skipf("skipping test on %q (no /usr/bin/diff)", runtime.GOOS)
	}

	conf := loader.Config{
		Fset:       token.NewFileSet(),
		ParserMode: parser.ParseComments,
	}

	// Each entry is a single-file package.
	// (Multi-file packages aren't interesting for this test.)
	// Order matters: each non-template package is processed using
	// the preceding template package.
	for _, filename := range []string{
		"testdata/A.template",
		"testdata/A1.go",
		"testdata/A2.go",

		"testdata/B.template",
		"testdata/B1.go",

		"testdata/C.template",
		"testdata/C1.go",

		"testdata/D.template",
		"testdata/D1.go",

		"testdata/E.template",
		"testdata/E1.go",

		"testdata/F.template",
		"testdata/F1.go",

		"testdata/G.template",
		"testdata/G1.go",

		"testdata/H.template",
		"testdata/H1.go",

		"testdata/bad_type.template",
		"testdata/no_before.template",
		"testdata/no_after_return.template",
		"testdata/type_mismatch.template",
		"testdata/expr_type_mismatch.template",
	} {
		pkgname := strings.TrimSuffix(filepath.Base(filename), ".go")
		conf.CreateFromFilenames(pkgname, filename)
	}
	iprog, err := conf.Load()
	if err != nil {
		t.Fatal(err)
	}

	var xform *eg.Transformer
	for _, info := range iprog.Created {
		file := info.Files[0]
		filename := iprog.Fset.File(file.Pos()).Name() // foo.go

		if strings.HasSuffix(filename, "template") {
			// a new template
			shouldFail, _ := info.Pkg.Scope().Lookup("shouldFail").(*types.Const)
			xform, err = eg.NewTransformer(iprog.Fset, info, *verboseFlag)
			if err != nil {
				if shouldFail == nil {
					t.Errorf("NewTransformer(%s): %s", filename, err)
				} else if want := exact.StringVal(shouldFail.Val()); !strings.Contains(err.Error(), want) {
					t.Errorf("NewTransformer(%s): got error %q, want error %q", filename, err, want)
				}
			} else if shouldFail != nil {
				t.Errorf("NewTransformer(%s) succeeded unexpectedly; want error %q",
					filename, shouldFail.Val())
			}
			continue
		}

		if xform == nil {
			t.Errorf("%s: no previous template", filename)
			continue
		}

		// apply previous template to this package
		n := xform.Transform(&info.Info, info.Pkg, file)
		if n == 0 {
			t.Errorf("%s: no matches", filename)
			continue
		}

		got := filename + "t"       // foo.got
		golden := filename + "lden" // foo.golden

		// Write actual output to foo.got.
		if err := eg.WriteAST(iprog.Fset, got, file); err != nil {
			t.Error(err)
		}
		defer os.Remove(got)

		// Compare foo.got with foo.golden.
		var cmd *exec.Cmd
		switch runtime.GOOS {
		case "plan9":
			cmd = exec.Command("/bin/diff", "-c", golden, got)
		default:
			cmd = exec.Command("/usr/bin/diff", "-u", golden, got)
		}
		buf := new(bytes.Buffer)
		cmd.Stdout = buf
		cmd.Stderr = os.Stderr
		if err := cmd.Run(); err != nil {
			t.Errorf("eg tests for %s failed: %s.\n%s\n", filename, err, buf)

			if *updateFlag {
				t.Logf("Updating %s...", golden)
				if err := exec.Command("/bin/cp", got, golden).Run(); err != nil {
					t.Errorf("Update failed: %s", err)
				}
			}
		}
	}
}
Beispiel #7
0
func (c *funcContext) translateExpr(expr ast.Expr) *expression {
	exprType := c.p.TypeOf(expr)
	if value := c.p.Types[expr].Value; value != nil {
		basic := exprType.Underlying().(*types.Basic)
		switch {
		case isBoolean(basic):
			return c.formatExpr("%s", strconv.FormatBool(exact.BoolVal(value)))
		case isInteger(basic):
			if is64Bit(basic) {
				if basic.Kind() == types.Int64 {
					d, ok := exact.Int64Val(value)
					if !ok {
						panic("could not get exact uint")
					}
					return c.formatExpr("new %s(%s, %s)", c.typeName(exprType), strconv.FormatInt(d>>32, 10), strconv.FormatUint(uint64(d)&(1<<32-1), 10))
				}
				d, ok := exact.Uint64Val(value)
				if !ok {
					panic("could not get exact uint")
				}
				return c.formatExpr("new %s(%s, %s)", c.typeName(exprType), strconv.FormatUint(d>>32, 10), strconv.FormatUint(d&(1<<32-1), 10))
			}
			d, ok := exact.Int64Val(value)
			if !ok {
				panic("could not get exact int")
			}
			return c.formatExpr("%s", strconv.FormatInt(d, 10))
		case isFloat(basic):
			f, _ := exact.Float64Val(value)
			return c.formatExpr("%s", strconv.FormatFloat(f, 'g', -1, 64))
		case isComplex(basic):
			r, _ := exact.Float64Val(exact.Real(value))
			i, _ := exact.Float64Val(exact.Imag(value))
			if basic.Kind() == types.UntypedComplex {
				exprType = types.Typ[types.Complex128]
			}
			return c.formatExpr("new %s(%s, %s)", c.typeName(exprType), strconv.FormatFloat(r, 'g', -1, 64), strconv.FormatFloat(i, 'g', -1, 64))
		case isString(basic):
			return c.formatExpr("%s", encodeString(exact.StringVal(value)))
		default:
			panic("Unhandled constant type: " + basic.String())
		}
	}

	var obj types.Object
	switch e := expr.(type) {
	case *ast.SelectorExpr:
		obj = c.p.Uses[e.Sel]
	case *ast.Ident:
		obj = c.p.Defs[e]
		if obj == nil {
			obj = c.p.Uses[e]
		}
	}

	if obj != nil && typesutil.IsJsPackage(obj.Pkg()) {
		switch obj.Name() {
		case "Global":
			return c.formatExpr("$global")
		case "Module":
			return c.formatExpr("$module")
		case "Undefined":
			return c.formatExpr("undefined")
		}
	}

	switch e := expr.(type) {
	case *ast.CompositeLit:
		if ptrType, isPointer := exprType.(*types.Pointer); isPointer {
			exprType = ptrType.Elem()
		}

		collectIndexedElements := func(elementType types.Type) []string {
			var elements []string
			i := 0
			zero := c.translateExpr(c.zeroValue(elementType)).String()
			for _, element := range e.Elts {
				if kve, isKve := element.(*ast.KeyValueExpr); isKve {
					key, ok := exact.Int64Val(c.p.Types[kve.Key].Value)
					if !ok {
						panic("could not get exact int")
					}
					i = int(key)
					element = kve.Value
				}
				for len(elements) <= i {
					elements = append(elements, zero)
				}
				elements[i] = c.translateImplicitConversionWithCloning(element, elementType).String()
				i++
			}
			return elements
		}

		switch t := exprType.Underlying().(type) {
		case *types.Array:
			elements := collectIndexedElements(t.Elem())
			if len(elements) == 0 {
				return c.formatExpr("%s.zero()", c.typeName(t))
			}
			zero := c.translateExpr(c.zeroValue(t.Elem())).String()
			for len(elements) < int(t.Len()) {
				elements = append(elements, zero)
			}
			return c.formatExpr(`$toNativeArray(%s, [%s])`, typeKind(t.Elem()), strings.Join(elements, ", "))
		case *types.Slice:
			return c.formatExpr("new %s([%s])", c.typeName(exprType), strings.Join(collectIndexedElements(t.Elem()), ", "))
		case *types.Map:
			entries := make([]string, len(e.Elts))
			for i, element := range e.Elts {
				kve := element.(*ast.KeyValueExpr)
				entries[i] = fmt.Sprintf("{ k: %s, v: %s }", c.translateImplicitConversionWithCloning(kve.Key, t.Key()), c.translateImplicitConversionWithCloning(kve.Value, t.Elem()))
			}
			return c.formatExpr("$makeMap(%s.keyFor, [%s])", c.typeName(t.Key()), strings.Join(entries, ", "))
		case *types.Struct:
			elements := make([]string, t.NumFields())
			isKeyValue := true
			if len(e.Elts) != 0 {
				_, isKeyValue = e.Elts[0].(*ast.KeyValueExpr)
			}
			if !isKeyValue {
				for i, element := range e.Elts {
					elements[i] = c.translateImplicitConversionWithCloning(element, t.Field(i).Type()).String()
				}
			}
			if isKeyValue {
				for i := range elements {
					elements[i] = c.translateExpr(c.zeroValue(t.Field(i).Type())).String()
				}
				for _, element := range e.Elts {
					kve := element.(*ast.KeyValueExpr)
					for j := range elements {
						if kve.Key.(*ast.Ident).Name == t.Field(j).Name() {
							elements[j] = c.translateImplicitConversionWithCloning(kve.Value, t.Field(j).Type()).String()
							break
						}
					}
				}
			}
			return c.formatExpr("new %s.ptr(%s)", c.typeName(exprType), strings.Join(elements, ", "))
		default:
			panic(fmt.Sprintf("Unhandled CompositeLit type: %T\n", t))
		}

	case *ast.FuncLit:
		_, fun := translateFunction(e.Type, nil, e.Body, c, exprType.(*types.Signature), c.p.FuncLitInfos[e], "")
		if len(c.p.escapingVars) != 0 {
			names := make([]string, 0, len(c.p.escapingVars))
			for obj := range c.p.escapingVars {
				names = append(names, c.p.objectNames[obj])
			}
			sort.Strings(names)
			list := strings.Join(names, ", ")
			return c.formatExpr("(function(%s) { return %s; })(%s)", list, fun, list)
		}
		return c.formatExpr("(%s)", fun)

	case *ast.UnaryExpr:
		t := c.p.TypeOf(e.X)
		switch e.Op {
		case token.AND:
			if typesutil.IsJsObject(exprType) {
				return c.formatExpr("%e.object", e.X)
			}

			switch t.Underlying().(type) {
			case *types.Struct, *types.Array:
				return c.translateExpr(e.X)
			}

			switch x := astutil.RemoveParens(e.X).(type) {
			case *ast.CompositeLit:
				return c.formatExpr("$newDataPointer(%e, %s)", x, c.typeName(c.p.TypeOf(e)))
			case *ast.Ident:
				obj := c.p.Uses[x].(*types.Var)
				if c.p.escapingVars[obj] {
					return c.formatExpr("(%1s.$ptr || (%1s.$ptr = new %2s(function() { return this.$target[0]; }, function($v) { this.$target[0] = $v; }, %1s)))", c.p.objectNames[obj], c.typeName(exprType))
				}
				return c.formatExpr(`(%1s || (%1s = new %2s(function() { return %3s; }, function($v) { %4s })))`, c.varPtrName(obj), c.typeName(exprType), c.objectName(obj), c.translateAssign(x, c.newIdent("$v", exprType), false))
			case *ast.SelectorExpr:
				sel, ok := c.p.Selections[x]
				if !ok {
					// qualified identifier
					obj := c.p.Uses[x.Sel].(*types.Var)
					return c.formatExpr(`(%1s || (%1s = new %2s(function() { return %3s; }, function($v) { %4s })))`, c.varPtrName(obj), c.typeName(exprType), c.objectName(obj), c.translateAssign(x, c.newIdent("$v", exprType), false))
				}
				newSel := &ast.SelectorExpr{X: c.newIdent("this.$target", c.p.TypeOf(x.X)), Sel: x.Sel}
				c.setType(newSel, exprType)
				c.p.Selections[newSel] = sel
				return c.formatExpr("(%1e.$ptr_%2s || (%1e.$ptr_%2s = new %3s(function() { return %4e; }, function($v) { %5s }, %1e)))", x.X, x.Sel.Name, c.typeName(exprType), newSel, c.translateAssign(newSel, c.newIdent("$v", exprType), false))
			case *ast.IndexExpr:
				if _, ok := c.p.TypeOf(x.X).Underlying().(*types.Slice); ok {
					return c.formatExpr("$indexPtr(%1e.$array, %1e.$offset + %2e, %3s)", x.X, x.Index, c.typeName(exprType))
				}
				return c.formatExpr("$indexPtr(%e, %e, %s)", x.X, x.Index, c.typeName(exprType))
			case *ast.StarExpr:
				return c.translateExpr(x.X)
			default:
				panic(fmt.Sprintf("Unhandled: %T\n", x))
			}

		case token.ARROW:
			call := &ast.CallExpr{
				Fun:  c.newIdent("$recv", types.NewSignature(nil, types.NewTuple(types.NewVar(0, nil, "", t)), types.NewTuple(types.NewVar(0, nil, "", exprType), types.NewVar(0, nil, "", types.Typ[types.Bool])), false)),
				Args: []ast.Expr{e.X},
			}
			c.Blocking[call] = true
			if _, isTuple := exprType.(*types.Tuple); isTuple {
				return c.formatExpr("%e", call)
			}
			return c.formatExpr("%e[0]", call)
		}

		basic := t.Underlying().(*types.Basic)
		switch e.Op {
		case token.ADD:
			return c.translateExpr(e.X)
		case token.SUB:
			switch {
			case is64Bit(basic):
				return c.formatExpr("new %1s(-%2h, -%2l)", c.typeName(t), e.X)
			case isComplex(basic):
				return c.formatExpr("new %1s(-%2r, -%2i)", c.typeName(t), e.X)
			case isUnsigned(basic):
				return c.fixNumber(c.formatExpr("-%e", e.X), basic)
			default:
				return c.formatExpr("-%e", e.X)
			}
		case token.XOR:
			if is64Bit(basic) {
				return c.formatExpr("new %1s(~%2h, ~%2l >>> 0)", c.typeName(t), e.X)
			}
			return c.fixNumber(c.formatExpr("~%e", e.X), basic)
		case token.NOT:
			return c.formatExpr("!%e", e.X)
		default:
			panic(e.Op)
		}

	case *ast.BinaryExpr:
		if e.Op == token.NEQ {
			return c.formatExpr("!(%s)", c.translateExpr(&ast.BinaryExpr{
				X:  e.X,
				Op: token.EQL,
				Y:  e.Y,
			}))
		}

		t := c.p.TypeOf(e.X)
		t2 := c.p.TypeOf(e.Y)
		_, isInterface := t2.Underlying().(*types.Interface)
		if isInterface || types.Identical(t, types.Typ[types.UntypedNil]) {
			t = t2
		}

		if basic, isBasic := t.Underlying().(*types.Basic); isBasic && isNumeric(basic) {
			if is64Bit(basic) {
				switch e.Op {
				case token.MUL:
					return c.formatExpr("$mul64(%e, %e)", e.X, e.Y)
				case token.QUO:
					return c.formatExpr("$div64(%e, %e, false)", e.X, e.Y)
				case token.REM:
					return c.formatExpr("$div64(%e, %e, true)", e.X, e.Y)
				case token.SHL:
					return c.formatExpr("$shiftLeft64(%e, %f)", e.X, e.Y)
				case token.SHR:
					return c.formatExpr("$shiftRight%s(%e, %f)", toJavaScriptType(basic), e.X, e.Y)
				case token.EQL:
					return c.formatExpr("(%1h === %2h && %1l === %2l)", e.X, e.Y)
				case token.LSS:
					return c.formatExpr("(%1h < %2h || (%1h === %2h && %1l < %2l))", e.X, e.Y)
				case token.LEQ:
					return c.formatExpr("(%1h < %2h || (%1h === %2h && %1l <= %2l))", e.X, e.Y)
				case token.GTR:
					return c.formatExpr("(%1h > %2h || (%1h === %2h && %1l > %2l))", e.X, e.Y)
				case token.GEQ:
					return c.formatExpr("(%1h > %2h || (%1h === %2h && %1l >= %2l))", e.X, e.Y)
				case token.ADD, token.SUB:
					return c.formatExpr("new %3s(%1h %4t %2h, %1l %4t %2l)", e.X, e.Y, c.typeName(t), e.Op)
				case token.AND, token.OR, token.XOR:
					return c.formatExpr("new %3s(%1h %4t %2h, (%1l %4t %2l) >>> 0)", e.X, e.Y, c.typeName(t), e.Op)
				case token.AND_NOT:
					return c.formatExpr("new %3s(%1h & ~%2h, (%1l & ~%2l) >>> 0)", e.X, e.Y, c.typeName(t))
				default:
					panic(e.Op)
				}
			}

			if isComplex(basic) {
				switch e.Op {
				case token.EQL:
					return c.formatExpr("(%1r === %2r && %1i === %2i)", e.X, e.Y)
				case token.ADD, token.SUB:
					return c.formatExpr("new %3s(%1r %4t %2r, %1i %4t %2i)", e.X, e.Y, c.typeName(t), e.Op)
				case token.MUL:
					return c.formatExpr("new %3s(%1r * %2r - %1i * %2i, %1r * %2i + %1i * %2r)", e.X, e.Y, c.typeName(t))
				case token.QUO:
					return c.formatExpr("$divComplex(%e, %e)", e.X, e.Y)
				default:
					panic(e.Op)
				}
			}

			switch e.Op {
			case token.EQL:
				return c.formatParenExpr("%e === %e", e.X, e.Y)
			case token.LSS, token.LEQ, token.GTR, token.GEQ:
				return c.formatExpr("%e %t %e", e.X, e.Op, e.Y)
			case token.ADD, token.SUB:
				return c.fixNumber(c.formatExpr("%e %t %e", e.X, e.Op, e.Y), basic)
			case token.MUL:
				switch basic.Kind() {
				case types.Int32:
					return c.formatParenExpr("(((%1e >>> 16 << 16) * %2e >> 0) + (%1e << 16 >>> 16) * %2e) >> 0", e.X, e.Y)
				case types.Uint32, types.Uintptr:
					return c.formatParenExpr("(((%1e >>> 16 << 16) * %2e >>> 0) + (%1e << 16 >>> 16) * %2e) >>> 0", e.X, e.Y)
				}
				return c.fixNumber(c.formatExpr("%e * %e", e.X, e.Y), basic)
			case token.QUO:
				if isInteger(basic) {
					// cut off decimals
					shift := ">>"
					if isUnsigned(basic) {
						shift = ">>>"
					}
					return c.formatExpr(`(%1s = %2e / %3e, (%1s === %1s && %1s !== 1/0 && %1s !== -1/0) ? %1s %4s 0 : $throwRuntimeError("integer divide by zero"))`, c.newVariable("_q"), e.X, e.Y, shift)
				}
				if basic.Kind() == types.Float32 {
					return c.fixNumber(c.formatExpr("%e / %e", e.X, e.Y), basic)
				}
				return c.formatExpr("%e / %e", e.X, e.Y)
			case token.REM:
				return c.formatExpr(`(%1s = %2e %% %3e, %1s === %1s ? %1s : $throwRuntimeError("integer divide by zero"))`, c.newVariable("_r"), e.X, e.Y)
			case token.SHL, token.SHR:
				op := e.Op.String()
				if e.Op == token.SHR && isUnsigned(basic) {
					op = ">>>"
				}
				if c.p.Types[e.Y].Value != nil {
					return c.fixNumber(c.formatExpr("%e %s %e", e.X, op, e.Y), basic)
				}
				if e.Op == token.SHR && !isUnsigned(basic) {
					return c.fixNumber(c.formatParenExpr("%e >> $min(%e, 31)", e.X, e.Y), basic)
				}
				y := c.newVariable("y")
				return c.fixNumber(c.formatExpr("(%s = %s, %s < 32 ? (%e %s %s) : 0)", y, c.translateImplicitConversion(e.Y, types.Typ[types.Uint]), y, e.X, op, y), basic)
			case token.AND, token.OR:
				if isUnsigned(basic) {
					return c.formatParenExpr("(%e %t %e) >>> 0", e.X, e.Op, e.Y)
				}
				return c.formatParenExpr("%e %t %e", e.X, e.Op, e.Y)
			case token.AND_NOT:
				return c.fixNumber(c.formatParenExpr("%e & ~%e", e.X, e.Y), basic)
			case token.XOR:
				return c.fixNumber(c.formatParenExpr("%e ^ %e", e.X, e.Y), basic)
			default:
				panic(e.Op)
			}
		}

		switch e.Op {
		case token.ADD, token.LSS, token.LEQ, token.GTR, token.GEQ:
			return c.formatExpr("%e %t %e", e.X, e.Op, e.Y)
		case token.LAND:
			if c.Blocking[e.Y] {
				skipCase := c.caseCounter
				c.caseCounter++
				resultVar := c.newVariable("_v")
				c.Printf("if (!(%s)) { %s = false; $s = %d; continue s; }", c.translateExpr(e.X), resultVar, skipCase)
				c.Printf("%s = %s; case %d:", resultVar, c.translateExpr(e.Y), skipCase)
				return c.formatExpr("%s", resultVar)
			}
			return c.formatExpr("%e && %e", e.X, e.Y)
		case token.LOR:
			if c.Blocking[e.Y] {
				skipCase := c.caseCounter
				c.caseCounter++
				resultVar := c.newVariable("_v")
				c.Printf("if (%s) { %s = true; $s = %d; continue s; }", c.translateExpr(e.X), resultVar, skipCase)
				c.Printf("%s = %s; case %d:", resultVar, c.translateExpr(e.Y), skipCase)
				return c.formatExpr("%s", resultVar)
			}
			return c.formatExpr("%e || %e", e.X, e.Y)
		case token.EQL:
			switch u := t.Underlying().(type) {
			case *types.Array, *types.Struct:
				return c.formatExpr("$equal(%e, %e, %s)", e.X, e.Y, c.typeName(t))
			case *types.Interface:
				return c.formatExpr("$interfaceIsEqual(%s, %s)", c.translateImplicitConversion(e.X, t), c.translateImplicitConversion(e.Y, t))
			case *types.Pointer:
				if _, ok := u.Elem().Underlying().(*types.Array); ok {
					return c.formatExpr("$equal(%s, %s, %s)", c.translateImplicitConversion(e.X, t), c.translateImplicitConversion(e.Y, t), c.typeName(u.Elem()))
				}
			case *types.Basic:
				if isBoolean(u) {
					if b, ok := analysis.BoolValue(e.X, c.p.Info.Info); ok && b {
						return c.translateExpr(e.Y)
					}
					if b, ok := analysis.BoolValue(e.Y, c.p.Info.Info); ok && b {
						return c.translateExpr(e.X)
					}
				}
			}
			return c.formatExpr("%s === %s", c.translateImplicitConversion(e.X, t), c.translateImplicitConversion(e.Y, t))
		default:
			panic(e.Op)
		}

	case *ast.ParenExpr:
		return c.formatParenExpr("%e", e.X)

	case *ast.IndexExpr:
		switch t := c.p.TypeOf(e.X).Underlying().(type) {
		case *types.Array, *types.Pointer:
			pattern := rangeCheck("%1e[%2f]", c.p.Types[e.Index].Value != nil, true)
			if _, ok := t.(*types.Pointer); ok { // check pointer for nix (attribute getter causes a panic)
				pattern = `(%1e.nilCheck, ` + pattern + `)`
			}
			return c.formatExpr(pattern, e.X, e.Index)
		case *types.Slice:
			return c.formatExpr(rangeCheck("%1e.$array[%1e.$offset + %2f]", c.p.Types[e.Index].Value != nil, false), e.X, e.Index)
		case *types.Map:
			if typesutil.IsJsObject(c.p.TypeOf(e.Index)) {
				c.p.errList = append(c.p.errList, types.Error{Fset: c.p.fileSet, Pos: e.Index.Pos(), Msg: "cannot use js.Object as map key"})
			}
			key := fmt.Sprintf("%s.keyFor(%s)", c.typeName(t.Key()), c.translateImplicitConversion(e.Index, t.Key()))
			if _, isTuple := exprType.(*types.Tuple); isTuple {
				return c.formatExpr(`(%1s = %2e[%3s], %1s !== undefined ? [%1s.v, true] : [%4e, false])`, c.newVariable("_entry"), e.X, key, c.zeroValue(t.Elem()))
			}
			return c.formatExpr(`(%1s = %2e[%3s], %1s !== undefined ? %1s.v : %4e)`, c.newVariable("_entry"), e.X, key, c.zeroValue(t.Elem()))
		case *types.Basic:
			return c.formatExpr("%e.charCodeAt(%f)", e.X, e.Index)
		default:
			panic(fmt.Sprintf("Unhandled IndexExpr: %T\n", t))
		}

	case *ast.SliceExpr:
		if b, isBasic := c.p.TypeOf(e.X).Underlying().(*types.Basic); isBasic && isString(b) {
			switch {
			case e.Low == nil && e.High == nil:
				return c.translateExpr(e.X)
			case e.Low == nil:
				return c.formatExpr("%e.substring(0, %f)", e.X, e.High)
			case e.High == nil:
				return c.formatExpr("%e.substring(%f)", e.X, e.Low)
			default:
				return c.formatExpr("%e.substring(%f, %f)", e.X, e.Low, e.High)
			}
		}
		slice := c.translateConversionToSlice(e.X, exprType)
		switch {
		case e.Low == nil && e.High == nil:
			return c.formatExpr("%s", slice)
		case e.Low == nil:
			if e.Max != nil {
				return c.formatExpr("$subslice(%s, 0, %f, %f)", slice, e.High, e.Max)
			}
			return c.formatExpr("$subslice(%s, 0, %f)", slice, e.High)
		case e.High == nil:
			return c.formatExpr("$subslice(%s, %f)", slice, e.Low)
		default:
			if e.Max != nil {
				return c.formatExpr("$subslice(%s, %f, %f, %f)", slice, e.Low, e.High, e.Max)
			}
			return c.formatExpr("$subslice(%s, %f, %f)", slice, e.Low, e.High)
		}

	case *ast.SelectorExpr:
		sel, ok := c.p.Selections[e]
		if !ok {
			// qualified identifier
			return c.formatExpr("%s", c.objectName(obj))
		}

		switch sel.Kind() {
		case types.FieldVal:
			fields, jsTag := c.translateSelection(sel, e.Pos())
			if jsTag != "" {
				if _, ok := sel.Type().(*types.Signature); ok {
					return c.formatExpr("$internalize(%1e.%2s.%3s, %4s, %1e.%2s)", e.X, strings.Join(fields, "."), jsTag, c.typeName(sel.Type()))
				}
				return c.internalize(c.formatExpr("%e.%s.%s", e.X, strings.Join(fields, "."), jsTag), sel.Type())
			}
			return c.formatExpr("%e.%s", e.X, strings.Join(fields, "."))
		case types.MethodVal:
			recv := c.makeReceiver(e.X, sel)
			return c.formatExpr(`$methodVal(%s, "%s")`, recv, sel.Obj().(*types.Func).Name())
		case types.MethodExpr:
			if !sel.Obj().Exported() {
				c.p.dependencies[sel.Obj()] = true
			}
			return c.formatExpr(`$methodExpr(%s, "%s")`, c.typeName(sel.Recv()), sel.Obj().(*types.Func).Name())
		default:
			panic(fmt.Sprintf("unexpected sel.Kind(): %T", sel.Kind()))
		}

	case *ast.CallExpr:
		plainFun := astutil.RemoveParens(e.Fun)

		if astutil.IsTypeExpr(plainFun, c.p.Info.Info) {
			return c.formatExpr("%s", c.translateConversion(e.Args[0], c.p.TypeOf(plainFun)))
		}

		sig := c.p.TypeOf(plainFun).Underlying().(*types.Signature)

		switch f := plainFun.(type) {
		case *ast.Ident:
			obj := c.p.Uses[f]
			if o, ok := obj.(*types.Builtin); ok {
				return c.translateBuiltin(o.Name(), sig, e.Args, e.Ellipsis.IsValid())
			}
			if typesutil.IsJsPackage(obj.Pkg()) && obj.Name() == "InternalObject" {
				return c.translateExpr(e.Args[0])
			}
			return c.translateCall(e, sig, c.translateExpr(f))

		case *ast.SelectorExpr:
			sel, ok := c.p.Selections[f]
			if !ok {
				// qualified identifier
				obj := c.p.Uses[f.Sel]
				if typesutil.IsJsPackage(obj.Pkg()) {
					switch obj.Name() {
					case "Debugger":
						return c.formatExpr("debugger")
					case "InternalObject":
						return c.translateExpr(e.Args[0])
					case "MakeFunc":
						return c.formatExpr("(function() { return $externalize(%e(this, new ($sliceType($jsObjectPtr))($global.Array.prototype.slice.call(arguments, []))), $emptyInterface); })", e.Args[0])
					}
				}
				return c.translateCall(e, sig, c.translateExpr(f))
			}

			externalizeExpr := func(e ast.Expr) string {
				t := c.p.TypeOf(e)
				if types.Identical(t, types.Typ[types.UntypedNil]) {
					return "null"
				}
				return c.externalize(c.translateExpr(e).String(), t)
			}
			externalizeArgs := func(args []ast.Expr) string {
				s := make([]string, len(args))
				for i, arg := range args {
					s[i] = externalizeExpr(arg)
				}
				return strings.Join(s, ", ")
			}

			switch sel.Kind() {
			case types.MethodVal:
				recv := c.makeReceiver(f.X, sel)

				if typesutil.IsJsPackage(sel.Obj().Pkg()) {
					globalRef := func(id string) string {
						if recv.String() == "$global" && id[0] == '$' {
							return id
						}
						return recv.String() + "." + id
					}
					switch sel.Obj().Name() {
					case "Get":
						if id, ok := c.identifierConstant(e.Args[0]); ok {
							return c.formatExpr("%s", globalRef(id))
						}
						return c.formatExpr("%s[$externalize(%e, $String)]", recv, e.Args[0])
					case "Set":
						if id, ok := c.identifierConstant(e.Args[0]); ok {
							return c.formatExpr("%s = %s", globalRef(id), externalizeExpr(e.Args[1]))
						}
						return c.formatExpr("%s[$externalize(%e, $String)] = %s", recv, e.Args[0], externalizeExpr(e.Args[1]))
					case "Delete":
						return c.formatExpr("delete %s[$externalize(%e, $String)]", recv, e.Args[0])
					case "Length":
						return c.formatExpr("$parseInt(%s.length)", recv)
					case "Index":
						return c.formatExpr("%s[%e]", recv, e.Args[0])
					case "SetIndex":
						return c.formatExpr("%s[%e] = %s", recv, e.Args[0], externalizeExpr(e.Args[1]))
					case "Call":
						if id, ok := c.identifierConstant(e.Args[0]); ok {
							if e.Ellipsis.IsValid() {
								objVar := c.newVariable("obj")
								return c.formatExpr("(%s = %s, %s.%s.apply(%s, %s))", objVar, recv, objVar, id, objVar, externalizeExpr(e.Args[1]))
							}
							return c.formatExpr("%s(%s)", globalRef(id), externalizeArgs(e.Args[1:]))
						}
						if e.Ellipsis.IsValid() {
							objVar := c.newVariable("obj")
							return c.formatExpr("(%s = %s, %s[$externalize(%e, $String)].apply(%s, %s))", objVar, recv, objVar, e.Args[0], objVar, externalizeExpr(e.Args[1]))
						}
						return c.formatExpr("%s[$externalize(%e, $String)](%s)", recv, e.Args[0], externalizeArgs(e.Args[1:]))
					case "Invoke":
						if e.Ellipsis.IsValid() {
							return c.formatExpr("%s.apply(undefined, %s)", recv, externalizeExpr(e.Args[0]))
						}
						return c.formatExpr("%s(%s)", recv, externalizeArgs(e.Args))
					case "New":
						if e.Ellipsis.IsValid() {
							return c.formatExpr("new ($global.Function.prototype.bind.apply(%s, [undefined].concat(%s)))", recv, externalizeExpr(e.Args[0]))
						}
						return c.formatExpr("new (%s)(%s)", recv, externalizeArgs(e.Args))
					case "Bool":
						return c.internalize(recv, types.Typ[types.Bool])
					case "String":
						return c.internalize(recv, types.Typ[types.String])
					case "Int":
						return c.internalize(recv, types.Typ[types.Int])
					case "Int64":
						return c.internalize(recv, types.Typ[types.Int64])
					case "Uint64":
						return c.internalize(recv, types.Typ[types.Uint64])
					case "Float":
						return c.internalize(recv, types.Typ[types.Float64])
					case "Interface":
						return c.internalize(recv, types.NewInterface(nil, nil))
					case "Unsafe":
						return recv
					default:
						panic("Invalid js package object: " + sel.Obj().Name())
					}
				}

				methodName := sel.Obj().Name()
				if reservedKeywords[methodName] {
					methodName += "$"
				}
				return c.translateCall(e, sig, c.formatExpr("%s.%s", recv, methodName))

			case types.FieldVal:
				fields, jsTag := c.translateSelection(sel, f.Pos())
				if jsTag != "" {
					call := c.formatExpr("%e.%s.%s(%s)", f.X, strings.Join(fields, "."), jsTag, externalizeArgs(e.Args))
					switch sig.Results().Len() {
					case 0:
						return call
					case 1:
						return c.internalize(call, sig.Results().At(0).Type())
					default:
						c.p.errList = append(c.p.errList, types.Error{Fset: c.p.fileSet, Pos: f.Pos(), Msg: "field with js tag can not have func type with multiple results"})
					}
				}
				return c.translateCall(e, sig, c.formatExpr("%e.%s", f.X, strings.Join(fields, ".")))

			case types.MethodExpr:
				return c.translateCall(e, sig, c.translateExpr(f))

			default:
				panic(fmt.Sprintf("unexpected sel.Kind(): %T", sel.Kind()))
			}
		default:
			return c.translateCall(e, sig, c.translateExpr(plainFun))
		}

	case *ast.StarExpr:
		if typesutil.IsJsObject(c.p.TypeOf(e.X)) {
			return c.formatExpr("new $jsObjectPtr(%e)", e.X)
		}
		if c1, isCall := e.X.(*ast.CallExpr); isCall && len(c1.Args) == 1 {
			if c2, isCall := c1.Args[0].(*ast.CallExpr); isCall && len(c2.Args) == 1 && types.Identical(c.p.TypeOf(c2.Fun), types.Typ[types.UnsafePointer]) {
				if unary, isUnary := c2.Args[0].(*ast.UnaryExpr); isUnary && unary.Op == token.AND {
					return c.translateExpr(unary.X) // unsafe conversion
				}
			}
		}
		switch exprType.Underlying().(type) {
		case *types.Struct, *types.Array:
			return c.translateExpr(e.X)
		}
		return c.formatExpr("%e.$get()", e.X)

	case *ast.TypeAssertExpr:
		if e.Type == nil {
			return c.translateExpr(e.X)
		}
		t := c.p.TypeOf(e.Type)
		if _, isTuple := exprType.(*types.Tuple); isTuple {
			return c.formatExpr("$assertType(%e, %s, true)", e.X, c.typeName(t))
		}
		return c.formatExpr("$assertType(%e, %s)", e.X, c.typeName(t))

	case *ast.Ident:
		if e.Name == "_" {
			panic("Tried to translate underscore identifier.")
		}
		switch o := obj.(type) {
		case *types.Var, *types.Const:
			return c.formatExpr("%s", c.objectName(o))
		case *types.Func:
			return c.formatExpr("%s", c.objectName(o))
		case *types.TypeName:
			return c.formatExpr("%s", c.typeName(o.Type()))
		case *types.Nil:
			if typesutil.IsJsObject(exprType) {
				return c.formatExpr("null")
			}
			switch t := exprType.Underlying().(type) {
			case *types.Basic:
				if t.Kind() != types.UnsafePointer {
					panic("unexpected basic type")
				}
				return c.formatExpr("0")
			case *types.Slice, *types.Pointer, *types.Chan:
				return c.formatExpr("%s.nil", c.typeName(exprType))
			case *types.Map:
				return c.formatExpr("false")
			case *types.Interface:
				return c.formatExpr("$ifaceNil")
			case *types.Signature:
				return c.formatExpr("$throwNilPointerError")
			default:
				panic(fmt.Sprintf("unexpected type: %T", t))
			}
		default:
			panic(fmt.Sprintf("Unhandled object: %T\n", o))
		}

	case *this:
		if isWrapped(c.p.TypeOf(e)) {
			return c.formatExpr("this.$val")
		}
		return c.formatExpr("this")

	case nil:
		return c.formatExpr("")

	default:
		panic(fmt.Sprintf("Unhandled expression: %T\n", e))

	}
}
Beispiel #8
0
// Run runs program analysis and computes the resulting markup,
// populating *result in a thread-safe manner, first with type
// information then later with pointer analysis information if
// enabled by the pta flag.
//
func Run(pta bool, result *Result) {
	conf := loader.Config{
		AllowErrors: true,
	}

	// Silence the default error handler.
	// Don't print all errors; we'll report just
	// one per errant package later.
	conf.TypeChecker.Error = func(e error) {}

	var roots, args []string // roots[i] ends with os.PathSeparator

	// Enumerate packages in $GOROOT.
	root := filepath.Join(runtime.GOROOT(), "src") + string(os.PathSeparator)
	roots = append(roots, root)
	args = allPackages(root)
	log.Printf("GOROOT=%s: %s\n", root, args)

	// Enumerate packages in $GOPATH.
	for i, dir := range filepath.SplitList(build.Default.GOPATH) {
		root := filepath.Join(dir, "src") + string(os.PathSeparator)
		roots = append(roots, root)
		pkgs := allPackages(root)
		log.Printf("GOPATH[%d]=%s: %s\n", i, root, pkgs)
		args = append(args, pkgs...)
	}

	// Uncomment to make startup quicker during debugging.
	//args = []string{"golang.org/x/tools/cmd/godoc"}
	//args = []string{"fmt"}

	if _, err := conf.FromArgs(args, true); err != nil {
		// TODO(adonovan): degrade gracefully, not fail totally.
		// (The crippling case is a parse error in an external test file.)
		result.setStatusf("Analysis failed: %s.", err) // import error
		return
	}

	result.setStatusf("Loading and type-checking packages...")
	iprog, err := conf.Load()
	if iprog != nil {
		// Report only the first error of each package.
		for _, info := range iprog.AllPackages {
			for _, err := range info.Errors {
				fmt.Fprintln(os.Stderr, err)
				break
			}
		}
		log.Printf("Loaded %d packages.", len(iprog.AllPackages))
	}
	if err != nil {
		result.setStatusf("Loading failed: %s.\n", err)
		return
	}

	// Create SSA-form program representation.
	// Only the transitively error-free packages are used.
	prog := ssautil.CreateProgram(iprog, ssa.GlobalDebug)

	// Compute the set of main packages, including testmain.
	allPackages := prog.AllPackages()
	var mainPkgs []*ssa.Package
	if testmain := prog.CreateTestMainPackage(allPackages...); testmain != nil {
		mainPkgs = append(mainPkgs, testmain)
		if p := testmain.Const("packages"); p != nil {
			log.Printf("Tested packages: %v", exact.StringVal(p.Value.Value))
		}
	}
	for _, pkg := range allPackages {
		if pkg.Pkg.Name() == "main" && pkg.Func("main") != nil {
			mainPkgs = append(mainPkgs, pkg)
		}
	}
	log.Print("Transitively error-free main packages: ", mainPkgs)

	// Build SSA code for bodies of all functions in the whole program.
	result.setStatusf("Constructing SSA form...")
	prog.Build()
	log.Print("SSA construction complete")

	a := analysis{
		result: result,
		prog:   prog,
		pcgs:   make(map[*ssa.Package]*packageCallGraph),
	}

	// Build a mapping from openable filenames to godoc file URLs,
	// i.e. "/src/" plus path relative to GOROOT/src or GOPATH[i]/src.
	a.path2url = make(map[string]string)
	for _, info := range iprog.AllPackages {
	nextfile:
		for _, f := range info.Files {
			if f.Pos() == 0 {
				continue // e.g. files generated by cgo
			}
			abs := iprog.Fset.File(f.Pos()).Name()
			// Find the root to which this file belongs.
			for _, root := range roots {
				rel := strings.TrimPrefix(abs, root)
				if len(rel) < len(abs) {
					a.path2url[abs] = "/src/" + filepath.ToSlash(rel)
					continue nextfile
				}
			}

			log.Printf("Can't locate file %s (package %q) beneath any root",
				abs, info.Pkg.Path())
		}
	}

	// Add links for scanner, parser, type-checker errors.
	// TODO(adonovan): fix: these links can overlap with
	// identifier markup, causing the renderer to emit some
	// characters twice.
	errors := make(map[token.Position][]string)
	for _, info := range iprog.AllPackages {
		for _, err := range info.Errors {
			switch err := err.(type) {
			case types.Error:
				posn := a.prog.Fset.Position(err.Pos)
				errors[posn] = append(errors[posn], err.Msg)
			case scanner.ErrorList:
				for _, e := range err {
					errors[e.Pos] = append(errors[e.Pos], e.Msg)
				}
			default:
				log.Printf("Package %q has error (%T) without position: %v\n",
					info.Pkg.Path(), err, err)
			}
		}
	}
	for posn, errs := range errors {
		fi, offset := a.fileAndOffsetPosn(posn)
		fi.addLink(errorLink{
			start: offset,
			msg:   strings.Join(errs, "\n"),
		})
	}

	// ---------- type-based analyses ----------

	// Compute the all-pairs IMPLEMENTS relation.
	// Collect all named types, even local types
	// (which can have methods via promotion)
	// and the built-in "error".
	errorType := types.Universe.Lookup("error").Type().(*types.Named)
	a.allNamed = append(a.allNamed, errorType)
	for _, info := range iprog.AllPackages {
		for _, obj := range info.Defs {
			if obj, ok := obj.(*types.TypeName); ok {
				a.allNamed = append(a.allNamed, obj.Type().(*types.Named))
			}
		}
	}
	log.Print("Computing implements relation...")
	facts := computeImplements(&a.prog.MethodSets, a.allNamed)

	// Add the type-based analysis results.
	log.Print("Extracting type info...")
	for _, info := range iprog.AllPackages {
		a.doTypeInfo(info, facts)
	}

	a.visitInstrs(pta)

	result.setStatusf("Type analysis complete.")

	if pta {
		a.pointer(mainPkgs)
	}
}
Beispiel #9
0
// exprInternal contains the core of type checking of expressions.
// Must only be called by rawExpr.
//
func (check *Checker) exprInternal(x *operand, e ast.Expr, hint Type) exprKind {
	// make sure x has a valid state in case of bailout
	// (was issue 5770)
	x.mode = invalid
	x.typ = Typ[Invalid]

	switch e := e.(type) {
	case *ast.BadExpr:
		goto Error // error was reported before

	case *ast.Ident:
		check.ident(x, e, nil, nil)

	case *ast.Ellipsis:
		// ellipses are handled explicitly where they are legal
		// (array composite literals and parameter lists)
		check.error(e.Pos(), "invalid use of '...'")
		goto Error

	case *ast.BasicLit:
		x.setConst(e.Kind, e.Value)
		if x.mode == invalid {
			check.invalidAST(e.Pos(), "invalid literal %v", e.Value)
			goto Error
		}

	case *ast.FuncLit:
		if sig, ok := check.typ(e.Type).(*Signature); ok {
			// Anonymous functions are considered part of the
			// init expression/func declaration which contains
			// them: use existing package-level declaration info.
			check.funcBody(check.decl, "", sig, e.Body)
			x.mode = value
			x.typ = sig
		} else {
			check.invalidAST(e.Pos(), "invalid function literal %s", e)
			goto Error
		}

	case *ast.CompositeLit:
		typ := hint
		openArray := false
		if e.Type != nil {
			// [...]T array types may only appear with composite literals.
			// Check for them here so we don't have to handle ... in general.
			typ = nil
			if atyp, _ := e.Type.(*ast.ArrayType); atyp != nil && atyp.Len != nil {
				if ellip, _ := atyp.Len.(*ast.Ellipsis); ellip != nil && ellip.Elt == nil {
					// We have an "open" [...]T array type.
					// Create a new ArrayType with unknown length (-1)
					// and finish setting it up after analyzing the literal.
					typ = &Array{len: -1, elem: check.typ(atyp.Elt)}
					openArray = true
				}
			}
			if typ == nil {
				typ = check.typ(e.Type)
			}
		}
		if typ == nil {
			// TODO(gri) provide better error messages depending on context
			check.error(e.Pos(), "missing type in composite literal")
			goto Error
		}

		switch typ, _ := deref(typ); utyp := typ.Underlying().(type) {
		case *Struct:
			if len(e.Elts) == 0 {
				break
			}
			fields := utyp.fields
			if _, ok := e.Elts[0].(*ast.KeyValueExpr); ok {
				// all elements must have keys
				visited := make([]bool, len(fields))
				for _, e := range e.Elts {
					kv, _ := e.(*ast.KeyValueExpr)
					if kv == nil {
						check.error(e.Pos(), "mixture of field:value and value elements in struct literal")
						continue
					}
					key, _ := kv.Key.(*ast.Ident)
					if key == nil {
						check.errorf(kv.Pos(), "invalid field name %s in struct literal", kv.Key)
						continue
					}
					i := fieldIndex(utyp.fields, check.pkg, key.Name)
					if i < 0 {
						check.errorf(kv.Pos(), "unknown field %s in struct literal", key.Name)
						continue
					}
					fld := fields[i]
					check.recordUse(key, fld)
					// 0 <= i < len(fields)
					if visited[i] {
						check.errorf(kv.Pos(), "duplicate field name %s in struct literal", key.Name)
						continue
					}
					visited[i] = true
					check.expr(x, kv.Value)
					etyp := fld.typ
					if !check.assignment(x, etyp) {
						if x.mode != invalid {
							check.errorf(x.pos(), "cannot use %s as %s value in struct literal", x, etyp)
						}
						continue
					}
				}
			} else {
				// no element must have a key
				for i, e := range e.Elts {
					if kv, _ := e.(*ast.KeyValueExpr); kv != nil {
						check.error(kv.Pos(), "mixture of field:value and value elements in struct literal")
						continue
					}
					check.expr(x, e)
					if i >= len(fields) {
						check.error(x.pos(), "too many values in struct literal")
						break // cannot continue
					}
					// i < len(fields)
					fld := fields[i]
					if !fld.Exported() && fld.pkg != check.pkg {
						check.errorf(x.pos(), "implicit assignment to unexported field %s in %s literal", fld.name, typ)
						continue
					}
					etyp := fld.typ
					if !check.assignment(x, etyp) {
						if x.mode != invalid {
							check.errorf(x.pos(), "cannot use %s as %s value in struct literal", x, etyp)
						}
						continue
					}
				}
				if len(e.Elts) < len(fields) {
					check.error(e.Rbrace, "too few values in struct literal")
					// ok to continue
				}
			}

		case *Array:
			n := check.indexedElts(e.Elts, utyp.elem, utyp.len)
			// if we have an "open" [...]T array, set the length now that we know it
			if openArray {
				utyp.len = n
			}

		case *Slice:
			check.indexedElts(e.Elts, utyp.elem, -1)

		case *Map:
			visited := make(map[interface{}][]Type, len(e.Elts))
			for _, e := range e.Elts {
				kv, _ := e.(*ast.KeyValueExpr)
				if kv == nil {
					check.error(e.Pos(), "missing key in map literal")
					continue
				}
				check.exprWithHint(x, kv.Key, utyp.key)
				if !check.assignment(x, utyp.key) {
					if x.mode != invalid {
						check.errorf(x.pos(), "cannot use %s as %s key in map literal", x, utyp.key)
					}
					continue
				}
				if x.mode == constant {
					duplicate := false
					// if the key is of interface type, the type is also significant when checking for duplicates
					if _, ok := utyp.key.Underlying().(*Interface); ok {
						for _, vtyp := range visited[x.val] {
							if Identical(vtyp, x.typ) {
								duplicate = true
								break
							}
						}
						visited[x.val] = append(visited[x.val], x.typ)
					} else {
						_, duplicate = visited[x.val]
						visited[x.val] = nil
					}
					if duplicate {
						check.errorf(x.pos(), "duplicate key %s in map literal", x.val)
						continue
					}
				}
				check.exprWithHint(x, kv.Value, utyp.elem)
				if !check.assignment(x, utyp.elem) {
					if x.mode != invalid {
						check.errorf(x.pos(), "cannot use %s as %s value in map literal", x, utyp.elem)
					}
					continue
				}
			}

		default:
			// if utyp is invalid, an error was reported before
			if utyp != Typ[Invalid] {
				check.errorf(e.Pos(), "invalid composite literal type %s", typ)
				goto Error
			}
		}

		x.mode = value
		x.typ = typ

	case *ast.ParenExpr:
		kind := check.rawExpr(x, e.X, nil)
		x.expr = e
		return kind

	case *ast.SelectorExpr:
		check.selector(x, e)

	case *ast.IndexExpr:
		check.expr(x, e.X)
		if x.mode == invalid {
			goto Error
		}

		valid := false
		length := int64(-1) // valid if >= 0
		switch typ := x.typ.Underlying().(type) {
		case *Basic:
			if isString(typ) {
				valid = true
				if x.mode == constant {
					length = int64(len(exact.StringVal(x.val)))
				}
				// an indexed string always yields a byte value
				// (not a constant) even if the string and the
				// index are constant
				x.mode = value
				x.typ = UniverseByte // use 'byte' name
			}

		case *Array:
			valid = true
			length = typ.len
			if x.mode != variable {
				x.mode = value
			}
			x.typ = typ.elem

		case *Pointer:
			if typ, _ := typ.base.Underlying().(*Array); typ != nil {
				valid = true
				length = typ.len
				x.mode = variable
				x.typ = typ.elem
			}

		case *Slice:
			valid = true
			x.mode = variable
			x.typ = typ.elem

		case *Map:
			var key operand
			check.expr(&key, e.Index)
			if !check.assignment(&key, typ.key) {
				if key.mode != invalid {
					check.invalidOp(key.pos(), "cannot use %s as map index of type %s", &key, typ.key)
				}
				goto Error
			}
			x.mode = mapindex
			x.typ = typ.elem
			x.expr = e
			return expression
		}

		if !valid {
			check.invalidOp(x.pos(), "cannot index %s", x)
			goto Error
		}

		if e.Index == nil {
			check.invalidAST(e.Pos(), "missing index for %s", x)
			goto Error
		}

		check.index(e.Index, length)
		// ok to continue

	case *ast.SliceExpr:
		check.expr(x, e.X)
		if x.mode == invalid {
			goto Error
		}

		valid := false
		length := int64(-1) // valid if >= 0
		switch typ := x.typ.Underlying().(type) {
		case *Basic:
			if isString(typ) {
				if slice3(e) {
					check.invalidOp(x.pos(), "3-index slice of string")
					goto Error
				}
				valid = true
				if x.mode == constant {
					length = int64(len(exact.StringVal(x.val)))
				}
				// spec: "For untyped string operands the result
				// is a non-constant value of type string."
				if typ.kind == UntypedString {
					x.typ = Typ[String]
				}
			}

		case *Array:
			valid = true
			length = typ.len
			if x.mode != variable {
				check.invalidOp(x.pos(), "cannot slice %s (value not addressable)", x)
				goto Error
			}
			x.typ = &Slice{elem: typ.elem}

		case *Pointer:
			if typ, _ := typ.base.Underlying().(*Array); typ != nil {
				valid = true
				length = typ.len
				x.typ = &Slice{elem: typ.elem}
			}

		case *Slice:
			valid = true
			// x.typ doesn't change
		}

		if !valid {
			check.invalidOp(x.pos(), "cannot slice %s", x)
			goto Error
		}

		x.mode = value

		// spec: "Only the first index may be omitted; it defaults to 0."
		if slice3(e) && (e.High == nil || sliceMax(e) == nil) {
			check.error(e.Rbrack, "2nd and 3rd index required in 3-index slice")
			goto Error
		}

		// check indices
		var ind [3]int64
		for i, expr := range []ast.Expr{e.Low, e.High, sliceMax(e)} {
			x := int64(-1)
			switch {
			case expr != nil:
				// The "capacity" is only known statically for strings, arrays,
				// and pointers to arrays, and it is the same as the length for
				// those types.
				max := int64(-1)
				if length >= 0 {
					max = length + 1
				}
				if t, ok := check.index(expr, max); ok && t >= 0 {
					x = t
				}
			case i == 0:
				// default is 0 for the first index
				x = 0
			case length >= 0:
				// default is length (== capacity) otherwise
				x = length
			}
			ind[i] = x
		}

		// constant indices must be in range
		// (check.index already checks that existing indices >= 0)
	L:
		for i, x := range ind[:len(ind)-1] {
			if x > 0 {
				for _, y := range ind[i+1:] {
					if y >= 0 && x > y {
						check.errorf(e.Rbrack, "invalid slice indices: %d > %d", x, y)
						break L // only report one error, ok to continue
					}
				}
			}
		}

	case *ast.TypeAssertExpr:
		check.expr(x, e.X)
		if x.mode == invalid {
			goto Error
		}
		xtyp, _ := x.typ.Underlying().(*Interface)
		if xtyp == nil {
			check.invalidOp(x.pos(), "%s is not an interface", x)
			goto Error
		}
		// x.(type) expressions are handled explicitly in type switches
		if e.Type == nil {
			check.invalidAST(e.Pos(), "use of .(type) outside type switch")
			goto Error
		}
		T := check.typ(e.Type)
		if T == Typ[Invalid] {
			goto Error
		}
		check.typeAssertion(x.pos(), x, xtyp, T)
		x.mode = commaok
		x.typ = T

	case *ast.CallExpr:
		return check.call(x, e)

	case *ast.StarExpr:
		check.exprOrType(x, e.X)
		switch x.mode {
		case invalid:
			goto Error
		case typexpr:
			x.typ = &Pointer{base: x.typ}
		default:
			if typ, ok := x.typ.Underlying().(*Pointer); ok {
				x.mode = variable
				x.typ = typ.base
			} else {
				check.invalidOp(x.pos(), "cannot indirect %s", x)
				goto Error
			}
		}

	case *ast.UnaryExpr:
		check.expr(x, e.X)
		if x.mode == invalid {
			goto Error
		}
		check.unary(x, e.Op)
		if x.mode == invalid {
			goto Error
		}
		if e.Op == token.ARROW {
			x.expr = e
			return statement // receive operations may appear in statement context
		}

	case *ast.BinaryExpr:
		check.binary(x, e.X, e.Y, e.Op)
		if x.mode == invalid {
			goto Error
		}

	case *ast.KeyValueExpr:
		// key:value expressions are handled in composite literals
		check.invalidAST(e.Pos(), "no key:value expected")
		goto Error

	case *ast.ArrayType, *ast.StructType, *ast.FuncType,
		*ast.InterfaceType, *ast.MapType, *ast.ChanType:
		x.mode = typexpr
		x.typ = check.typ(e)
		// Note: rawExpr (caller of exprInternal) will call check.recordTypeAndValue
		// even though check.typ has already called it. This is fine as both
		// times the same expression and type are recorded. It is also not a
		// performance issue because we only reach here for composite literal
		// types, which are comparatively rare.

	default:
		panic(fmt.Sprintf("%s: unknown expression type %T", check.fset.Position(e.Pos()), e))
	}

	// everything went well
	x.expr = e
	return expression

Error:
	x.mode = invalid
	x.expr = e
	return statement // avoid follow-up errors
}
Beispiel #10
0
// builtin type-checks a call to the built-in specified by id and
// returns true if the call is valid, with *x holding the result;
// but x.expr is not set. If the call is invalid, the result is
// false, and *x is undefined.
//
func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ bool) {
	// append is the only built-in that permits the use of ... for the last argument
	bin := predeclaredFuncs[id]
	if call.Ellipsis.IsValid() && id != _Append {
		check.invalidOp(call.Ellipsis, "invalid use of ... with built-in %s", bin.name)
		check.use(call.Args...)
		return
	}

	// For len(x) and cap(x) we need to know if x contains any function calls or
	// receive operations. Save/restore current setting and set hasCallOrRecv to
	// false for the evaluation of x so that we can check it afterwards.
	// Note: We must do this _before_ calling unpack because unpack evaluates the
	//       first argument before we even call arg(x, 0)!
	if id == _Len || id == _Cap {
		defer func(b bool) {
			check.hasCallOrRecv = b
		}(check.hasCallOrRecv)
		check.hasCallOrRecv = false
	}

	// determine actual arguments
	var arg getter
	nargs := len(call.Args)
	switch id {
	default:
		// make argument getter
		arg, nargs, _ = unpack(func(x *operand, i int) { check.expr(x, call.Args[i]) }, nargs, false)
		if arg == nil {
			return
		}
		// evaluate first argument, if present
		if nargs > 0 {
			arg(x, 0)
			if x.mode == invalid {
				return
			}
		}
	case _Make, _New, _Offsetof, _Trace:
		// arguments require special handling
	}

	// check argument count
	{
		msg := ""
		if nargs < bin.nargs {
			msg = "not enough"
		} else if !bin.variadic && nargs > bin.nargs {
			msg = "too many"
		}
		if msg != "" {
			check.invalidOp(call.Rparen, "%s arguments for %s (expected %d, found %d)", msg, call, bin.nargs, nargs)
			return
		}
	}

	switch id {
	case _Append:
		// append(s S, x ...T) S, where T is the element type of S
		// spec: "The variadic function append appends zero or more values x to s of type
		// S, which must be a slice type, and returns the resulting slice, also of type S.
		// The values x are passed to a parameter of type ...T where T is the element type
		// of S and the respective parameter passing rules apply."
		S := x.typ
		var T Type
		if s, _ := S.Underlying().(*Slice); s != nil {
			T = s.elem
		} else {
			check.invalidArg(x.pos(), "%s is not a slice", x)
			return
		}

		// remember arguments that have been evaluated already
		alist := []operand{*x}

		// spec: "As a special case, append also accepts a first argument assignable
		// to type []byte with a second argument of string type followed by ... .
		// This form appends the bytes of the string.
		if nargs == 2 && call.Ellipsis.IsValid() && x.assignableTo(check.conf, NewSlice(universeByte)) {
			arg(x, 1)
			if x.mode == invalid {
				return
			}
			if isString(x.typ) {
				if check.Types != nil {
					sig := makeSig(S, S, x.typ)
					sig.variadic = true
					check.recordBuiltinType(call.Fun, sig)
				}
				x.mode = value
				x.typ = S
				break
			}
			alist = append(alist, *x)
			// fallthrough
		}

		// check general case by creating custom signature
		sig := makeSig(S, S, NewSlice(T)) // []T required for variadic signature
		sig.variadic = true
		check.arguments(x, call, sig, func(x *operand, i int) {
			// only evaluate arguments that have not been evaluated before
			if i < len(alist) {
				*x = alist[i]
				return
			}
			arg(x, i)
		}, nargs)
		// ok to continue even if check.arguments reported errors

		x.mode = value
		x.typ = S
		if check.Types != nil {
			check.recordBuiltinType(call.Fun, sig)
		}

	case _Cap, _Len:
		// cap(x)
		// len(x)
		mode := invalid
		var typ Type
		var val exact.Value
		switch typ = implicitArrayDeref(x.typ.Underlying()); t := typ.(type) {
		case *Basic:
			if isString(t) && id == _Len {
				if x.mode == constant {
					mode = constant
					val = exact.MakeInt64(int64(len(exact.StringVal(x.val))))
				} else {
					mode = value
				}
			}

		case *Array:
			mode = value
			// spec: "The expressions len(s) and cap(s) are constants
			// if the type of s is an array or pointer to an array and
			// the expression s does not contain channel receives or
			// function calls; in this case s is not evaluated."
			if !check.hasCallOrRecv {
				mode = constant
				val = exact.MakeInt64(t.len)
			}

		case *Slice, *Chan:
			mode = value

		case *Map:
			if id == _Len {
				mode = value
			}
		}

		if mode == invalid {
			check.invalidArg(x.pos(), "%s for %s", x, bin.name)
			return
		}

		x.mode = mode
		x.typ = Typ[Int]
		x.val = val
		if check.Types != nil && mode != constant {
			check.recordBuiltinType(call.Fun, makeSig(x.typ, typ))
		}

	case _Close:
		// close(c)
		c, _ := x.typ.Underlying().(*Chan)
		if c == nil {
			check.invalidArg(x.pos(), "%s is not a channel", x)
			return
		}
		if c.dir == RecvOnly {
			check.invalidArg(x.pos(), "%s must not be a receive-only channel", x)
			return
		}

		x.mode = novalue
		if check.Types != nil {
			check.recordBuiltinType(call.Fun, makeSig(nil, c))
		}

	case _Complex:
		// complex(x, y realT) complexT
		if !check.complexArg(x) {
			return
		}

		var y operand
		arg(&y, 1)
		if y.mode == invalid {
			return
		}
		if !check.complexArg(&y) {
			return
		}

		check.convertUntyped(x, y.typ)
		if x.mode == invalid {
			return
		}
		check.convertUntyped(&y, x.typ)
		if y.mode == invalid {
			return
		}

		if !Identical(x.typ, y.typ) {
			check.invalidArg(x.pos(), "mismatched types %s and %s", x.typ, y.typ)
			return
		}

		if x.mode == constant && y.mode == constant {
			x.val = exact.BinaryOp(x.val, token.ADD, exact.MakeImag(y.val))
		} else {
			x.mode = value
		}

		realT := x.typ
		complexT := Typ[Invalid]
		switch realT.Underlying().(*Basic).kind {
		case Float32:
			complexT = Typ[Complex64]
		case Float64:
			complexT = Typ[Complex128]
		case UntypedInt, UntypedRune, UntypedFloat:
			if x.mode == constant {
				realT = defaultType(realT).(*Basic)
				complexT = Typ[UntypedComplex]
			} else {
				// untyped but not constant; probably because one
				// operand is a non-constant shift of untyped lhs
				realT = Typ[Float64]
				complexT = Typ[Complex128]
			}
		default:
			check.invalidArg(x.pos(), "float32 or float64 arguments expected")
			return
		}

		x.typ = complexT
		if check.Types != nil && x.mode != constant {
			check.recordBuiltinType(call.Fun, makeSig(complexT, realT, realT))
		}

		if x.mode != constant {
			// The arguments have now their final types, which at run-
			// time will be materialized. Update the expression trees.
			// If the current types are untyped, the materialized type
			// is the respective default type.
			// (If the result is constant, the arguments are never
			// materialized and there is nothing to do.)
			check.updateExprType(x.expr, realT, true)
			check.updateExprType(y.expr, realT, true)
		}

	case _Copy:
		// copy(x, y []T) int
		var dst Type
		if t, _ := x.typ.Underlying().(*Slice); t != nil {
			dst = t.elem
		}

		var y operand
		arg(&y, 1)
		if y.mode == invalid {
			return
		}
		var src Type
		switch t := y.typ.Underlying().(type) {
		case *Basic:
			if isString(y.typ) {
				src = universeByte
			}
		case *Slice:
			src = t.elem
		}

		if dst == nil || src == nil {
			check.invalidArg(x.pos(), "copy expects slice arguments; found %s and %s", x, &y)
			return
		}

		if !Identical(dst, src) {
			check.invalidArg(x.pos(), "arguments to copy %s and %s have different element types %s and %s", x, &y, dst, src)
			return
		}

		if check.Types != nil {
			check.recordBuiltinType(call.Fun, makeSig(Typ[Int], x.typ, y.typ))
		}
		x.mode = value
		x.typ = Typ[Int]

	case _Delete:
		// delete(m, k)
		m, _ := x.typ.Underlying().(*Map)
		if m == nil {
			check.invalidArg(x.pos(), "%s is not a map", x)
			return
		}
		arg(x, 1) // k
		if x.mode == invalid {
			return
		}

		if !x.assignableTo(check.conf, m.key) {
			check.invalidArg(x.pos(), "%s is not assignable to %s", x, m.key)
			return
		}

		x.mode = novalue
		if check.Types != nil {
			check.recordBuiltinType(call.Fun, makeSig(nil, m, m.key))
		}

	case _Imag, _Real:
		// imag(complexT) realT
		// real(complexT) realT
		if !isComplex(x.typ) {
			check.invalidArg(x.pos(), "%s must be a complex number", x)
			return
		}
		if x.mode == constant {
			if id == _Real {
				x.val = exact.Real(x.val)
			} else {
				x.val = exact.Imag(x.val)
			}
		} else {
			x.mode = value
		}
		var k BasicKind
		switch x.typ.Underlying().(*Basic).kind {
		case Complex64:
			k = Float32
		case Complex128:
			k = Float64
		case UntypedComplex:
			k = UntypedFloat
		default:
			unreachable()
		}

		if check.Types != nil && x.mode != constant {
			check.recordBuiltinType(call.Fun, makeSig(Typ[k], x.typ))
		}
		x.typ = Typ[k]

	case _Make:
		// make(T, n)
		// make(T, n, m)
		// (no argument evaluated yet)
		arg0 := call.Args[0]
		T := check.typ(arg0)
		if T == Typ[Invalid] {
			return
		}

		var min int // minimum number of arguments
		switch T.Underlying().(type) {
		case *Slice:
			min = 2
		case *Map, *Chan:
			min = 1
		default:
			check.invalidArg(arg0.Pos(), "cannot make %s; type must be slice, map, or channel", arg0)
			return
		}
		if nargs < min || min+1 < nargs {
			check.errorf(call.Pos(), "%s expects %d or %d arguments; found %d", call, min, min+1, nargs)
			return
		}
		var sizes []int64 // constant integer arguments, if any
		for _, arg := range call.Args[1:] {
			if s, ok := check.index(arg, -1); ok && s >= 0 {
				sizes = append(sizes, s)
			}
		}
		if len(sizes) == 2 && sizes[0] > sizes[1] {
			check.invalidArg(call.Args[1].Pos(), "length and capacity swapped")
			// safe to continue
		}
		x.mode = value
		x.typ = T
		if check.Types != nil {
			params := [...]Type{T, Typ[Int], Typ[Int]}
			check.recordBuiltinType(call.Fun, makeSig(x.typ, params[:1+len(sizes)]...))
		}

	case _New:
		// new(T)
		// (no argument evaluated yet)
		T := check.typ(call.Args[0])
		if T == Typ[Invalid] {
			return
		}

		x.mode = value
		x.typ = &Pointer{base: T}
		if check.Types != nil {
			check.recordBuiltinType(call.Fun, makeSig(x.typ, T))
		}

	case _Panic:
		// panic(x)
		T := new(Interface)
		if !check.assignment(x, T) {
			assert(x.mode == invalid)
			return
		}

		x.mode = novalue
		if check.Types != nil {
			check.recordBuiltinType(call.Fun, makeSig(nil, T))
		}

	case _Print, _Println:
		// print(x, y, ...)
		// println(x, y, ...)
		var params []Type
		if nargs > 0 {
			params = make([]Type, nargs)
			for i := 0; i < nargs; i++ {
				if i > 0 {
					arg(x, i) // first argument already evaluated
				}
				if !check.assignment(x, nil) {
					assert(x.mode == invalid)
					return
				}
				params[i] = x.typ
			}
		}

		x.mode = novalue
		if check.Types != nil {
			check.recordBuiltinType(call.Fun, makeSig(nil, params...))
		}

	case _Recover:
		// recover() interface{}
		x.mode = value
		x.typ = new(Interface)
		if check.Types != nil {
			check.recordBuiltinType(call.Fun, makeSig(x.typ))
		}

	case _Alignof:
		// unsafe.Alignof(x T) uintptr
		if !check.assignment(x, nil) {
			assert(x.mode == invalid)
			return
		}

		x.mode = constant
		x.val = exact.MakeInt64(check.conf.alignof(x.typ))
		x.typ = Typ[Uintptr]
		// result is constant - no need to record signature

	case _Offsetof:
		// unsafe.Offsetof(x T) uintptr, where x must be a selector
		// (no argument evaluated yet)
		arg0 := call.Args[0]
		selx, _ := unparen(arg0).(*ast.SelectorExpr)
		if selx == nil {
			check.invalidArg(arg0.Pos(), "%s is not a selector expression", arg0)
			check.use(arg0)
			return
		}

		check.expr(x, selx.X)
		if x.mode == invalid {
			return
		}

		base := derefStructPtr(x.typ)
		sel := selx.Sel.Name
		obj, index, indirect := LookupFieldOrMethod(base, false, check.pkg, sel)
		switch obj.(type) {
		case nil:
			check.invalidArg(x.pos(), "%s has no single field %s", base, sel)
			return
		case *Func:
			// TODO(gri) Using derefStructPtr may result in methods being found
			// that don't actually exist. An error either way, but the error
			// message is confusing. See: http://play.golang.org/p/al75v23kUy ,
			// but go/types reports: "invalid argument: x.m is a method value".
			check.invalidArg(arg0.Pos(), "%s is a method value", arg0)
			return
		}
		if indirect {
			check.invalidArg(x.pos(), "field %s is embedded via a pointer in %s", sel, base)
			return
		}

		// TODO(gri) Should we pass x.typ instead of base (and indirect report if derefStructPtr indirected)?
		check.recordSelection(selx, FieldVal, base, obj, index, false)

		offs := check.conf.offsetof(base, index)
		x.mode = constant
		x.val = exact.MakeInt64(offs)
		x.typ = Typ[Uintptr]
		// result is constant - no need to record signature

	case _Sizeof:
		// unsafe.Sizeof(x T) uintptr
		if !check.assignment(x, nil) {
			assert(x.mode == invalid)
			return
		}

		x.mode = constant
		x.val = exact.MakeInt64(check.conf.sizeof(x.typ))
		x.typ = Typ[Uintptr]
		// result is constant - no need to record signature

	case _Assert:
		// assert(pred) causes a typechecker error if pred is false.
		// The result of assert is the value of pred if there is no error.
		// Note: assert is only available in self-test mode.
		if x.mode != constant || !isBoolean(x.typ) {
			check.invalidArg(x.pos(), "%s is not a boolean constant", x)
			return
		}
		if x.val.Kind() != exact.Bool {
			check.errorf(x.pos(), "internal error: value of %s should be a boolean constant", x)
			return
		}
		if !exact.BoolVal(x.val) {
			check.errorf(call.Pos(), "%s failed", call)
			// compile-time assertion failure - safe to continue
		}
		// result is constant - no need to record signature

	case _Trace:
		// trace(x, y, z, ...) dumps the positions, expressions, and
		// values of its arguments. The result of trace is the value
		// of the first argument.
		// Note: trace is only available in self-test mode.
		// (no argument evaluated yet)
		if nargs == 0 {
			check.dump("%s: trace() without arguments", call.Pos())
			x.mode = novalue
			break
		}
		var t operand
		x1 := x
		for _, arg := range call.Args {
			check.rawExpr(x1, arg, nil) // permit trace for types, e.g.: new(trace(T))
			check.dump("%s: %s", x1.pos(), x1)
			x1 = &t // use incoming x only for first argument
		}
		// trace is only available in test mode - no need to record signature

	default:
		unreachable()
	}

	return true
}
Beispiel #11
0
// newValueFromConst converts a constant value to an LLVM value.
func (fr *frame) newValueFromConst(v exact.Value, typ types.Type) *govalue {
	switch {
	case v == nil:
		llvmtyp := fr.types.ToLLVM(typ)
		return newValue(llvm.ConstNull(llvmtyp), typ)

	case isString(typ):
		if isUntyped(typ) {
			typ = types.Typ[types.String]
		}
		llvmtyp := fr.types.ToLLVM(typ)
		strval := exact.StringVal(v)
		strlen := len(strval)
		i8ptr := llvm.PointerType(llvm.Int8Type(), 0)
		var ptr llvm.Value
		if strlen > 0 {
			init := llvm.ConstString(strval, false)
			ptr = llvm.AddGlobal(fr.module.Module, init.Type(), "")
			ptr.SetInitializer(init)
			ptr.SetLinkage(llvm.InternalLinkage)
			ptr = llvm.ConstBitCast(ptr, i8ptr)
		} else {
			ptr = llvm.ConstNull(i8ptr)
		}
		len_ := llvm.ConstInt(fr.types.inttype, uint64(strlen), false)
		llvmvalue := llvm.Undef(llvmtyp)
		llvmvalue = llvm.ConstInsertValue(llvmvalue, ptr, []uint32{0})
		llvmvalue = llvm.ConstInsertValue(llvmvalue, len_, []uint32{1})
		return newValue(llvmvalue, typ)

	case isInteger(typ):
		if isUntyped(typ) {
			typ = types.Typ[types.Int]
		}
		llvmtyp := fr.types.ToLLVM(typ)
		var llvmvalue llvm.Value
		if isUnsigned(typ) {
			v, _ := exact.Uint64Val(v)
			llvmvalue = llvm.ConstInt(llvmtyp, v, false)
		} else {
			v, _ := exact.Int64Val(v)
			llvmvalue = llvm.ConstInt(llvmtyp, uint64(v), true)
		}
		return newValue(llvmvalue, typ)

	case isBoolean(typ):
		if isUntyped(typ) {
			typ = types.Typ[types.Bool]
		}
		return newValue(boolLLVMValue(exact.BoolVal(v)), typ)

	case isFloat(typ):
		if isUntyped(typ) {
			typ = types.Typ[types.Float64]
		}
		llvmtyp := fr.types.ToLLVM(typ)
		floatval, _ := exact.Float64Val(v)
		llvmvalue := llvm.ConstFloat(llvmtyp, floatval)
		return newValue(llvmvalue, typ)

	case typ == types.Typ[types.UnsafePointer]:
		llvmtyp := fr.types.ToLLVM(typ)
		v, _ := exact.Uint64Val(v)
		llvmvalue := llvm.ConstInt(fr.types.inttype, v, false)
		llvmvalue = llvm.ConstIntToPtr(llvmvalue, llvmtyp)
		return newValue(llvmvalue, typ)

	case isComplex(typ):
		if isUntyped(typ) {
			typ = types.Typ[types.Complex128]
		}
		llvmtyp := fr.types.ToLLVM(typ)
		floattyp := llvmtyp.StructElementTypes()[0]
		llvmvalue := llvm.ConstNull(llvmtyp)
		realv := exact.Real(v)
		imagv := exact.Imag(v)
		realfloatval, _ := exact.Float64Val(realv)
		imagfloatval, _ := exact.Float64Val(imagv)
		llvmre := llvm.ConstFloat(floattyp, realfloatval)
		llvmim := llvm.ConstFloat(floattyp, imagfloatval)
		llvmvalue = llvm.ConstInsertValue(llvmvalue, llvmre, []uint32{0})
		llvmvalue = llvm.ConstInsertValue(llvmvalue, llvmim, []uint32{1})
		return newValue(llvmvalue, typ)
	}

	// Special case for string -> [](byte|rune)
	if u, ok := typ.Underlying().(*types.Slice); ok && isInteger(u.Elem()) {
		if v.Kind() == exact.String {
			strval := fr.newValueFromConst(v, types.Typ[types.String])
			return fr.convert(strval, typ)
		}
	}

	panic(fmt.Sprintf("unhandled: t=%s(%T), v=%v(%T)", typ, typ, v, v))
}