Ejemplo n.º 1
0
// computeTrackBits sets a.track to the necessary 'track' bits for the pointer queries.
func (a *analysis) computeTrackBits() {
	var queryTypes []types.Type
	for v := range a.config.Queries {
		queryTypes = append(queryTypes, v.Type())
	}
	for v := range a.config.IndirectQueries {
		queryTypes = append(queryTypes, mustDeref(v.Type()))
	}
	for _, t := range queryTypes {
		switch t.Underlying().(type) {
		case *types.Chan:
			a.track |= trackChan
		case *types.Map:
			a.track |= trackMap
		case *types.Pointer:
			a.track |= trackPtr
		case *types.Slice:
			a.track |= trackSlice
		case *types.Interface:
			a.track = trackAll
			return
		}
		if rVObj := a.reflectValueObj; rVObj != nil && types.Identical(t, rVObj.Type()) {
			a.track = trackAll
			return
		}
	}
}
Ejemplo n.º 2
0
// containsAllIdsOf reports whether the method identifiers of T are a
// superset of those in U.  If U belongs to an interface type, the
// result is equal to types.Assignable(T, U), but is cheaper to compute.
//
// TODO(gri): make this a method of *types.MethodSet.
//
func containsAllIdsOf(T, U *types.MethodSet) bool {
	t, tlen := 0, T.Len()
	u, ulen := 0, U.Len()
	for t < tlen && u < ulen {
		tMeth := T.At(t).Obj()
		uMeth := U.At(u).Obj()
		tId := tMeth.Id()
		uId := uMeth.Id()
		if tId > uId {
			// U has a method T lacks: fail.
			return false
		}
		if tId < uId {
			// T has a method U lacks: ignore it.
			t++
			continue
		}
		// U and T both have a method of this Id.  Check types.
		if !types.Identical(tMeth.Type(), uMeth.Type()) {
			return false // type mismatch
		}
		u++
		t++
	}
	return u == ulen
}
Ejemplo n.º 3
0
Archivo: map.go Proyecto: 2722/lantern
// Set sets the map entry for key to val,
// and returns the previous entry, if any.
func (m *Map) Set(key types.Type, value interface{}) (prev interface{}) {
	if m.table != nil {
		hash := m.hasher.Hash(key)
		bucket := m.table[hash]
		var hole *entry
		for i, e := range bucket {
			if e.key == nil {
				hole = &bucket[i]
			} else if types.Identical(key, e.key) {
				prev = e.value
				bucket[i].value = value
				return
			}
		}

		if hole != nil {
			*hole = entry{key, value} // overwrite deleted entry
		} else {
			m.table[hash] = append(bucket, entry{key, value})
		}
	} else {
		if m.hasher.memo == nil {
			m.hasher = MakeHasher()
		}
		hash := m.hasher.Hash(key)
		m.table = map[uint32][]entry{hash: {entry{key, value}}}
	}

	m.length++
	return
}
Ejemplo n.º 4
0
func (c *funcContext) translateImplicitConversion(expr ast.Expr, desiredType types.Type) *expression {
	if desiredType == nil {
		return c.translateExpr(expr)
	}

	exprType := c.p.TypeOf(expr)
	if types.Identical(exprType, desiredType) {
		return c.translateExpr(expr)
	}

	basicExprType, isBasicExpr := exprType.Underlying().(*types.Basic)
	if isBasicExpr && basicExprType.Kind() == types.UntypedNil {
		return c.formatExpr("%e", c.zeroValue(desiredType))
	}

	switch desiredType.Underlying().(type) {
	case *types.Slice:
		return c.formatExpr("$subslice(new %1s(%2e.$array), %2e.$offset, %2e.$offset + %2e.$length)", c.typeName(desiredType), expr)

	case *types.Interface:
		if typesutil.IsJsObject(exprType) {
			// wrap JS object into js.Object struct when converting to interface
			return c.formatExpr("new $jsObjectPtr(%e)", expr)
		}
		if isWrapped(exprType) {
			return c.formatExpr("new %s(%e)", c.typeName(exprType), expr)
		}
		if _, isStruct := exprType.Underlying().(*types.Struct); isStruct {
			return c.formatExpr("new %1e.constructor.elem(%1e)", expr)
		}
	}

	return c.translateExpr(expr)
}
Ejemplo n.º 5
0
// assign records pairs of distinct types that are related by
// assignability, where the left-hand side is an interface and both
// sides have methods.
//
// It should be called for all assignability checks, type assertions,
// explicit conversions and comparisons between two types, unless the
// types are uninteresting (e.g. lhs is a concrete type, or the empty
// interface; rhs has no methods).
//
func (f *Finder) assign(lhs, rhs types.Type) {
	if types.Identical(lhs, rhs) {
		return
	}
	if !isInterface(lhs) {
		return
	}
	if f.msetcache.MethodSet(lhs).Len() == 0 {
		return
	}
	if f.msetcache.MethodSet(rhs).Len() == 0 {
		return
	}
	// canonicalize types
	lhsc, ok := f.canon.At(lhs).(types.Type)
	if !ok {
		lhsc = lhs
		f.canon.Set(lhs, lhsc)
	}
	rhsc, ok := f.canon.At(rhs).(types.Type)
	if !ok {
		rhsc = rhs
		f.canon.Set(rhs, rhsc)
	}
	// record the pair
	f.Result[Constraint{lhsc, rhsc}] = true
}
Ejemplo n.º 6
0
// typeAssert checks whether dynamic type of itf is instr.AssertedType.
// It returns the extracted value on success, and panics on failure,
// unless instr.CommaOk, in which case it always returns a "value,ok" tuple.
//
func typeAssert(i *interpreter, instr *ssa.TypeAssert, itf iface) value {
	var v value
	err := ""
	if itf.t == nil {
		err = fmt.Sprintf("interface conversion: interface is nil, not %s", instr.AssertedType)

	} else if idst, ok := instr.AssertedType.Underlying().(*types.Interface); ok {
		v = itf
		err = checkInterface(i, idst, itf)

	} else if types.Identical(itf.t, instr.AssertedType) {
		v = copyVal(itf.v) // extract value

	} else {
		err = fmt.Sprintf("interface conversion: interface is %s, not %s", itf.t, instr.AssertedType)
	}

	if err != "" {
		if !instr.CommaOk {
			panic(err)
		}
		return tuple{zero(instr.AssertedType), false}
	}
	if instr.CommaOk {
		return tuple{v, true}
	}
	return v
}
Ejemplo n.º 7
0
func checkEqualButNotIdentical(t *testing.T, x, y types.Type, comment string) {
	if !types.Identical(x, y) {
		t.Errorf("%s: not equal: %s, %s", comment, x, y)
	}
	if x == y {
		t.Errorf("%s: identical: %v, %v", comment, x, y)
	}
}
Ejemplo n.º 8
0
Archivo: map.go Proyecto: 2722/lantern
// At returns the map entry for the given key.
// The result is nil if the entry is not present.
//
func (m *Map) At(key types.Type) interface{} {
	if m != nil && m.table != nil {
		for _, e := range m.table[m.hasher.Hash(key)] {
			if e.key != nil && types.Identical(key, e.key) {
				return e.value
			}
		}
	}
	return nil
}
Ejemplo n.º 9
0
// findAssignments returns the set of types to or from which type T is
// assigned in the program syntax.
func (r *renamer) findAssignments(T types.Type) map[types.Type]bool {
	if r.satisfyConstraints == nil {
		// Compute on demand: it's expensive.
		var f satisfy.Finder
		for _, info := range r.packages {
			f.Find(&info.Info, info.Files)
		}
		r.satisfyConstraints = f.Result
	}

	result := make(map[types.Type]bool)
	for key := range r.satisfyConstraints {
		// key = (lhs, rhs) where lhs is always an interface.
		if types.Identical(key.RHS, T) {
			result[key.LHS] = true
		}
		if isInterface(T) && types.Identical(key.LHS, T) {
			// must check both sides
			result[key.RHS] = true
		}
	}
	return result
}
Ejemplo n.º 10
0
func hasType(pkg *grinder.Package, fn *ast.FuncDecl, edit *grinder.EditBuffer, x, v ast.Expr) bool {
	// Does x (by itself) default to v's type?
	// Find the scope in which x appears.
	xScope := pkg.Info.Scopes[fn.Type]
	ast.Inspect(fn.Body, func(z ast.Node) bool {
		if z == nil {
			return false
		}
		if x.Pos() < z.Pos() || z.End() <= x.Pos() {
			return false
		}
		scope := pkg.Info.Scopes[z]
		if scope != nil {
			xScope = scope
		}
		return true
	})
	xs := edit.TextAt(x.Pos(), x.End())
	xt, err := types.Eval(pkg.FileSet, pkg.Types, xScope.Pos(), xs)
	if err != nil {
		return false
	}
	vt := pkg.Info.Types[v]
	if types.Identical(xt.Type, vt.Type) {
		return true
	}

	// Might be untyped.
	vb, ok1 := vt.Type.(*types.Basic)
	xb, ok2 := xt.Type.(*types.Basic)
	if ok1 && ok2 {
		switch xb.Kind() {
		case types.UntypedInt:
			return vb.Kind() == types.Int
		case types.UntypedBool:
			return vb.Kind() == types.Bool
		case types.UntypedRune:
			return vb.Kind() == types.Rune
		case types.UntypedFloat:
			return vb.Kind() == types.Float64
		case types.UntypedComplex:
			return vb.Kind() == types.Complex128
		case types.UntypedString:
			return vb.Kind() == types.String
		}
	}
	return false
}
Ejemplo n.º 11
0
Archivo: map.go Proyecto: 2722/lantern
// Delete removes the entry with the given key, if any.
// It returns true if the entry was found.
//
func (m *Map) Delete(key types.Type) bool {
	if m != nil && m.table != nil {
		hash := m.hasher.Hash(key)
		bucket := m.table[hash]
		for i, e := range bucket {
			if e.key != nil && types.Identical(key, e.key) {
				// We can't compact the bucket as it
				// would disturb iterators.
				bucket[i] = entry{}
				m.length--
				return true
			}
		}
	}
	return false
}
Ejemplo n.º 12
0
// isErrorMethodCall reports whether the call is of a method with signature
//	func Error() string
// where "string" is the universe's string type. We know the method is called "Error".
func (f *File) isErrorMethodCall(call *ast.CallExpr) bool {
	typ := f.pkg.types[call].Type
	if typ != nil {
		// We know it's called "Error", so just check the function signature
		// (stringerType has exactly one method, String).
		if stringerType != nil && stringerType.NumMethods() == 1 {
			return types.Identical(f.pkg.types[call.Fun].Type, stringerType.Method(0).Type())
		}
	}
	// Without types, we can still check by hand.
	// Is it a selector expression? Otherwise it's a function call, not a method call.
	sel, ok := call.Fun.(*ast.SelectorExpr)
	if !ok {
		return false
	}
	// The package is type-checked, so if there are no arguments, we're done.
	if len(call.Args) > 0 {
		return false
	}
	// Check the type of the method declaration
	typ = f.pkg.types[sel].Type
	if typ == nil {
		return false
	}
	// The type must be a signature, but be sure for safety.
	sig, ok := typ.(*types.Signature)
	if !ok {
		return false
	}
	// There must be a receiver for it to be a method call. Otherwise it is
	// a function, not something that satisfies the error interface.
	if sig.Recv() == nil {
		return false
	}
	// There must be no arguments. Already verified by type checking, but be thorough.
	if sig.Params().Len() > 0 {
		return false
	}
	// Finally the real questions.
	// There must be one result.
	if sig.Results().Len() != 1 {
		return false
	}
	// It must have return type "string" from the universe.
	return sig.Results().At(0).Type() == types.Typ[types.String]
}
Ejemplo n.º 13
0
// assign records pairs of distinct types that are related by
// assignability, where the left-hand side is an interface and both
// sides have methods.
//
// It should be called for all assignability checks, type assertions,
// explicit conversions and comparisons between two types, unless the
// types are uninteresting (e.g. lhs is a concrete type, or the empty
// interface; rhs has no methods).
//
func (f *Finder) assign(lhs, rhs types.Type) {
	if types.Identical(lhs, rhs) {
		return
	}
	if !isInterface(lhs) {
		return
	}

	if f.msetcache.MethodSet(lhs).Len() == 0 {
		return
	}
	if f.msetcache.MethodSet(rhs).Len() == 0 {
		return
	}
	// record the pair
	f.Result[Constraint{lhs, rhs}] = true
}
Ejemplo n.º 14
0
// isValuePreserving returns true if a conversion from ut_src to
// ut_dst is value-preserving, i.e. just a change of type.
// Precondition: neither argument is a named type.
//
func isValuePreserving(ut_src, ut_dst types.Type) bool {
	// Identical underlying types?
	if types.Identical(ut_dst, ut_src) {
		return true
	}

	switch ut_dst.(type) {
	case *types.Chan:
		// Conversion between channel types?
		_, ok := ut_src.(*types.Chan)
		return ok

	case *types.Pointer:
		// Conversion between pointers with identical base types?
		_, ok := ut_src.(*types.Pointer)
		return ok
	}
	return false
}
Ejemplo n.º 15
0
func checkFuncValue(t *testing.T, prog *ssa.Program, obj *types.Func) {
	fn := prog.FuncValue(obj)
	// fmt.Printf("FuncValue(%s) = %s\n", obj, fn) // debugging
	if fn == nil {
		if obj.Name() != "interfaceMethod" {
			t.Errorf("FuncValue(%s) == nil", obj)
		}
		return
	}
	if fnobj := fn.Object(); fnobj != obj {
		t.Errorf("FuncValue(%s).Object() == %s; value was %s",
			obj, fnobj, fn.Name())
		return
	}
	if !types.Identical(fn.Type(), obj.Type()) {
		t.Errorf("FuncValue(%s).Type() == %s", obj, fn.Type())
		return
	}
}
Ejemplo n.º 16
0
func checkConstValue(t *testing.T, prog *ssa.Program, obj *types.Const) {
	c := prog.ConstValue(obj)
	// fmt.Printf("ConstValue(%s) = %s\n", obj, c) // debugging
	if c == nil {
		t.Errorf("ConstValue(%s) == nil", obj)
		return
	}
	if !types.Identical(c.Type(), obj.Type()) {
		t.Errorf("ConstValue(%s).Type() == %s", obj, c.Type())
		return
	}
	if obj.Name() != "nil" {
		if !exact.Compare(c.Value, token.EQL, obj.Val()) {
			t.Errorf("ConstValue(%s).Value (%s) != %s",
				obj, c.Value, obj.Val())
			return
		}
	}
}
Ejemplo n.º 17
0
// checkShadowing checks whether the identifier shadows an identifier in an outer scope.
func checkShadowing(f *File, ident *ast.Ident) {
	if ident.Name == "_" {
		// Can't shadow the blank identifier.
		return
	}
	obj := f.pkg.defs[ident]
	if obj == nil {
		return
	}
	// obj.Parent.Parent is the surrounding scope. If we can find another declaration
	// starting from there, we have a shadowed identifier.
	_, shadowed := obj.Parent().Parent().LookupParent(obj.Name(), obj.Pos())
	if shadowed == nil {
		return
	}
	// Don't complain if it's shadowing a universe-declared identifier; that's fine.
	if shadowed.Parent() == types.Universe {
		return
	}
	if *strictShadowing {
		// The shadowed identifier must appear before this one to be an instance of shadowing.
		if shadowed.Pos() > ident.Pos() {
			return
		}
	} else {
		// Don't complain if the span of validity of the shadowed identifier doesn't include
		// the shadowing identifier.
		span, ok := f.pkg.spans[shadowed]
		if !ok {
			f.Badf(ident.Pos(), "internal error: no range for %s", ident.Name)
			return
		}
		if !span.contains(ident.Pos()) {
			return
		}
	}
	// Don't complain if the types differ: that implies the programmer really wants two different things.
	if types.Identical(obj.Type(), shadowed.Type()) {
		f.Badf(ident.Pos(), "declaration of %s shadows declaration at %s", obj.Name(), f.loc(shadowed.Pos()))
	}
}
Ejemplo n.º 18
0
// findVisibleErrs returns a mapping from each package-level variable of type "error" to nil.
func findVisibleErrs(prog *ssa.Program, qpos *QueryPos) map[*ssa.Global]ssa.Value {
	globals := make(map[*ssa.Global]ssa.Value)
	for _, pkg := range prog.AllPackages() {
		for _, mem := range pkg.Members {
			gbl, ok := mem.(*ssa.Global)
			if !ok {
				continue
			}
			gbltype := gbl.Type()
			// globals are always pointers
			if !types.Identical(deref(gbltype), builtinErrorType) {
				continue
			}
			if !isAccessibleFrom(gbl.Object(), qpos.info.Pkg) {
				continue
			}
			globals[gbl] = nil
		}
	}
	return globals
}
Ejemplo n.º 19
0
// emitCompare emits to f code compute the boolean result of
// comparison comparison 'x op y'.
//
func emitCompare(f *Function, op token.Token, x, y Value, pos token.Pos) Value {
	xt := x.Type().Underlying()
	yt := y.Type().Underlying()

	// Special case to optimise a tagless SwitchStmt so that
	// these are equivalent
	//   switch { case e: ...}
	//   switch true { case e: ... }
	//   if e==true { ... }
	// even in the case when e's type is an interface.
	// TODO(adonovan): opt: generalise to x==true, false!=y, etc.
	if x == vTrue && op == token.EQL {
		if yt, ok := yt.(*types.Basic); ok && yt.Info()&types.IsBoolean != 0 {
			return y
		}
	}

	if types.Identical(xt, yt) {
		// no conversion necessary
	} else if _, ok := xt.(*types.Interface); ok {
		y = emitConv(f, y, x.Type())
	} else if _, ok := yt.(*types.Interface); ok {
		x = emitConv(f, x, y.Type())
	} else if _, ok := x.(*Const); ok {
		x = emitConv(f, x, y.Type())
	} else if _, ok := y.(*Const); ok {
		y = emitConv(f, y, x.Type())
	} else {
		// other cases, e.g. channels.  No-op.
	}

	v := &BinOp{
		Op: op,
		X:  x,
		Y:  y,
	}
	v.setPos(pos)
	v.setType(tBool)
	return f.emit(v)
}
Ejemplo n.º 20
0
func checkUnusedResult(f *File, n ast.Node) {
	call, ok := unparen(n.(*ast.ExprStmt).X).(*ast.CallExpr)
	if !ok {
		return // not a call statement
	}
	fun := unparen(call.Fun)

	if f.pkg.types[fun].IsType() {
		return // a conversion, not a call
	}

	selector, ok := fun.(*ast.SelectorExpr)
	if !ok {
		return // neither a method call nor a qualified ident
	}

	sel, ok := f.pkg.selectors[selector]
	if ok && sel.Kind() == types.MethodVal {
		// method (e.g. foo.String())
		obj := sel.Obj().(*types.Func)
		sig := sel.Type().(*types.Signature)
		if types.Identical(sig, sigNoArgsStringResult) {
			if unusedStringMethods[obj.Name()] {
				f.Badf(call.Lparen, "result of (%s).%s call not used",
					sig.Recv().Type(), obj.Name())
			}
		}
	} else if !ok {
		// package-qualified function (e.g. fmt.Errorf)
		obj, _ := f.pkg.uses[selector.Sel]
		if obj, ok := obj.(*types.Func); ok {
			qname := obj.Pkg().Path() + "." + obj.Name()
			if unusedFuncs[qname] {
				f.Badf(call.Lparen, "result of %v call not used", qname)
			}
		}
	}
}
Ejemplo n.º 21
0
func checkVarValue(t *testing.T, prog *ssa.Program, pkg *ssa.Package, ref []ast.Node, obj *types.Var, expKind string, wantAddr bool) {
	// The prefix of all assertions messages.
	prefix := fmt.Sprintf("VarValue(%s @ L%d)",
		obj, prog.Fset.Position(ref[0].Pos()).Line)

	v, gotAddr := prog.VarValue(obj, pkg, ref)

	// Kind is the concrete type of the ssa Value.
	gotKind := "nil"
	if v != nil {
		gotKind = fmt.Sprintf("%T", v)[len("*ssa."):]
	}

	// fmt.Printf("%s = %v (kind %q; expect %q) wantAddr=%t gotAddr=%t\n", prefix, v, gotKind, expKind, wantAddr, gotAddr) // debugging

	// Check the kinds match.
	// "nil" indicates expected failure (e.g. optimized away).
	if expKind != gotKind {
		t.Errorf("%s concrete type == %s, want %s", prefix, gotKind, expKind)
	}

	// Check the types match.
	// If wantAddr, the expected type is the object's address.
	if v != nil {
		expType := obj.Type()
		if wantAddr {
			expType = types.NewPointer(expType)
			if !gotAddr {
				t.Errorf("%s: got value, want address", prefix)
			}
		} else if gotAddr {
			t.Errorf("%s: got address, want value", prefix)
		}
		if !types.Identical(v.Type(), expType) {
			t.Errorf("%s.Type() == %s, want %s", prefix, v.Type(), expType)
		}
	}
}
Ejemplo n.º 22
0
// matchType reports whether the two type ASTs denote identical types.
func (tr *Transformer) matchType(x, y ast.Expr) bool {
	tx := tr.info.Types[x].Type
	ty := tr.info.Types[y].Type
	return types.Identical(tx, ty)
}
Ejemplo n.º 23
0
// lintVarDecls examines variable declarations. It complains about declarations with
// redundant LHS types that can be inferred from the RHS.
func (f *file) lintVarDecls() {
	var lastGen *ast.GenDecl // last GenDecl entered.

	f.walk(func(node ast.Node) bool {
		switch v := node.(type) {
		case *ast.GenDecl:
			if v.Tok != token.CONST && v.Tok != token.VAR {
				return false
			}
			lastGen = v
			return true
		case *ast.ValueSpec:
			if lastGen.Tok == token.CONST {
				return false
			}
			if len(v.Names) > 1 || v.Type == nil || len(v.Values) == 0 {
				return false
			}
			rhs := v.Values[0]
			// An underscore var appears in a common idiom for compile-time interface satisfaction,
			// as in "var _ Interface = (*Concrete)(nil)".
			if isIdent(v.Names[0], "_") {
				return false
			}
			// If the RHS is a zero value, suggest dropping it.
			zero := false
			if lit, ok := rhs.(*ast.BasicLit); ok {
				zero = zeroLiteral[lit.Value]
			} else if isIdent(rhs, "nil") {
				zero = true
			}
			if zero {
				f.errorf(rhs, 0.9, category("zero-value"), "should drop = %s from declaration of var %s; it is the zero value", f.render(rhs), v.Names[0])
				return false
			}
			lhsTyp := f.pkg.typeOf(v.Type)
			rhsTyp := f.pkg.typeOf(rhs)
			if lhsTyp != nil && rhsTyp != nil && !types.Identical(lhsTyp, rhsTyp) {
				// Assignment to a different type is not redundant.
				return false
			}

			// The next three conditions are for suppressing the warning in situations
			// where we were unable to typecheck.

			// If the LHS type is an interface, don't warn, since it is probably a
			// concrete type on the RHS. Note that our feeble lexical check here
			// will only pick up interface{} and other literal interface types;
			// that covers most of the cases we care to exclude right now.
			if _, ok := v.Type.(*ast.InterfaceType); ok {
				return false
			}
			// If the RHS is an untyped const, only warn if the LHS type is its default type.
			if defType, ok := f.isUntypedConst(rhs); ok && !isIdent(v.Type, defType) {
				return false
			}
			// If the LHS is a known weaker type, and we couldn't type check both sides,
			// don't warn.
			if lhsTyp == nil || rhsTyp == nil {
				if knownWeakerTypes[f.render(v.Type)] {
					return false
				}
			}

			f.errorf(v.Type, 0.8, category("type-inference"), "should omit type %s from declaration of var %s; it will be inferred from the right-hand side", f.render(v.Type), v.Names[0])
			return false
		}
		return true
	})
}
Ejemplo n.º 24
0
func (x rtype) eq(_ types.Type, y interface{}) bool {
	return types.Identical(x.t, y.(rtype).t)
}
Ejemplo n.º 25
0
// nil-tolerant variant of types.Identical.
func sameType(x, y types.Type) bool {
	if x == nil {
		return y == nil
	}
	return y != nil && types.Identical(x, y)
}
Ejemplo n.º 26
0
func (c *funcContext) translateStmt(stmt ast.Stmt, label *types.Label) {
	c.SetPos(stmt.Pos())

	stmt = filter.IncDecStmt(stmt, c.p.Info)
	stmt = filter.Assign(stmt, c.p.Info)

	switch s := stmt.(type) {
	case *ast.BlockStmt:
		c.translateStmtList(s.List)

	case *ast.IfStmt:
		if s.Init != nil {
			c.translateStmt(s.Init, nil)
		}
		var caseClauses []ast.Stmt
		ifStmt := s
		for {
			caseClauses = append(caseClauses, &ast.CaseClause{List: []ast.Expr{ifStmt.Cond}, Body: ifStmt.Body.List})
			switch elseStmt := ifStmt.Else.(type) {
			case *ast.IfStmt:
				if elseStmt.Init != nil {
					caseClauses = append(caseClauses, &ast.CaseClause{List: nil, Body: []ast.Stmt{elseStmt}})
					break
				}
				ifStmt = elseStmt
				continue
			case *ast.BlockStmt:
				caseClauses = append(caseClauses, &ast.CaseClause{List: nil, Body: elseStmt.List})
			case *ast.EmptyStmt, nil:
				// no else clause
			default:
				panic(fmt.Sprintf("Unhandled else: %T\n", elseStmt))
			}
			break
		}
		c.translateBranchingStmt(caseClauses, false, nil, nil, nil, c.Flattened[s])

	case *ast.SwitchStmt:
		if s.Init != nil {
			c.translateStmt(s.Init, nil)
		}

		tag := s.Tag
		if tag == nil {
			tag = ast.NewIdent("true")
			c.p.Types[tag] = types.TypeAndValue{Type: types.Typ[types.Bool], Value: exact.MakeBool(true)}
		}

		if c.p.Types[tag].Value == nil {
			refVar := c.newVariable("_ref")
			c.Printf("%s = %s;", refVar, c.translateExpr(tag))
			tag = c.newIdent(refVar, c.p.Types[tag].Type)
		}

		translateCond := func(cond ast.Expr) *expression {
			return c.translateExpr(&ast.BinaryExpr{
				X:  tag,
				Op: token.EQL,
				Y:  cond,
			})
		}
		c.translateBranchingStmt(s.Body.List, true, translateCond, nil, label, c.Flattened[s])

	case *ast.TypeSwitchStmt:
		if s.Init != nil {
			c.translateStmt(s.Init, nil)
		}
		refVar := c.newVariable("_ref")
		var expr ast.Expr
		var printCaseBodyPrefix func(index int)
		switch a := s.Assign.(type) {
		case *ast.AssignStmt:
			expr = a.Rhs[0].(*ast.TypeAssertExpr).X
			printCaseBodyPrefix = func(index int) {
				value := refVar
				caseClause := s.Body.List[index].(*ast.CaseClause)
				if len(caseClause.List) == 1 {
					t := c.p.Types[caseClause.List[0]].Type
					if _, isInterface := t.Underlying().(*types.Interface); !isInterface && !types.Identical(t, types.Typ[types.UntypedNil]) {
						value += ".$val"
					}
				}
				c.Printf("%s = %s;", c.objectName(c.p.Implicits[caseClause]), value)
			}
		case *ast.ExprStmt:
			expr = a.X.(*ast.TypeAssertExpr).X
		}
		c.Printf("%s = %s;", refVar, c.translateExpr(expr))
		translateCond := func(cond ast.Expr) *expression {
			if types.Identical(c.p.Types[cond].Type, types.Typ[types.UntypedNil]) {
				return c.formatExpr("%s === $ifaceNil", refVar)
			}
			return c.formatExpr("$assertType(%s, %s, true)[1]", refVar, c.typeName(c.p.Types[cond].Type))
		}
		c.translateBranchingStmt(s.Body.List, true, translateCond, printCaseBodyPrefix, label, c.Flattened[s])

	case *ast.ForStmt:
		if s.Init != nil {
			c.translateStmt(s.Init, nil)
		}
		cond := func() string {
			if s.Cond == nil {
				return "true"
			}
			return c.translateExpr(s.Cond).String()
		}
		c.translateLoopingStmt(cond, s.Body, nil, func() {
			if s.Post != nil {
				c.translateStmt(s.Post, nil)
			}
		}, label, c.Flattened[s])

	case *ast.RangeStmt:
		refVar := c.newVariable("_ref")
		c.Printf("%s = %s;", refVar, c.translateExpr(s.X))

		switch t := c.p.Types[s.X].Type.Underlying().(type) {
		case *types.Basic:
			iVar := c.newVariable("_i")
			c.Printf("%s = 0;", iVar)
			runeVar := c.newVariable("_rune")
			c.translateLoopingStmt(func() string { return iVar + " < " + refVar + ".length" }, s.Body, func() {
				c.Printf("%s = $decodeRune(%s, %s);", runeVar, refVar, iVar)
				if !isBlank(s.Key) {
					c.Printf("%s", c.translateAssign(s.Key, iVar, types.Typ[types.Int], s.Tok == token.DEFINE))
				}
				if !isBlank(s.Value) {
					c.Printf("%s", c.translateAssign(s.Value, runeVar+"[0]", types.Typ[types.Rune], s.Tok == token.DEFINE))
				}
			}, func() {
				c.Printf("%s += %s[1];", iVar, runeVar)
			}, label, c.Flattened[s])

		case *types.Map:
			iVar := c.newVariable("_i")
			c.Printf("%s = 0;", iVar)
			keysVar := c.newVariable("_keys")
			c.Printf("%s = $keys(%s);", keysVar, refVar)
			c.translateLoopingStmt(func() string { return iVar + " < " + keysVar + ".length" }, s.Body, func() {
				entryVar := c.newVariable("_entry")
				c.Printf("%s = %s[%s[%s]];", entryVar, refVar, keysVar, iVar)
				c.translateStmt(&ast.IfStmt{
					Cond: c.newIdent(entryVar+" === undefined", types.Typ[types.Bool]),
					Body: &ast.BlockStmt{List: []ast.Stmt{&ast.BranchStmt{Tok: token.CONTINUE}}},
				}, nil)
				if !isBlank(s.Key) {
					c.Printf("%s", c.translateAssign(s.Key, entryVar+".k", t.Key(), s.Tok == token.DEFINE))
				}
				if !isBlank(s.Value) {
					c.Printf("%s", c.translateAssign(s.Value, entryVar+".v", t.Elem(), s.Tok == token.DEFINE))
				}
			}, func() {
				c.Printf("%s++;", iVar)
			}, label, c.Flattened[s])

		case *types.Array, *types.Pointer, *types.Slice:
			var length string
			var elemType types.Type
			switch t2 := t.(type) {
			case *types.Array:
				length = fmt.Sprintf("%d", t2.Len())
				elemType = t2.Elem()
			case *types.Pointer:
				length = fmt.Sprintf("%d", t2.Elem().Underlying().(*types.Array).Len())
				elemType = t2.Elem().Underlying().(*types.Array).Elem()
			case *types.Slice:
				length = refVar + ".$length"
				elemType = t2.Elem()
			}
			iVar := c.newVariable("_i")
			c.Printf("%s = 0;", iVar)
			c.translateLoopingStmt(func() string { return iVar + " < " + length }, s.Body, func() {
				if !isBlank(s.Key) {
					c.Printf("%s", c.translateAssign(s.Key, iVar, types.Typ[types.Int], s.Tok == token.DEFINE))
				}
				if !isBlank(s.Value) {
					c.Printf("%s", c.translateAssign(s.Value, c.translateImplicitConversion(c.setType(&ast.IndexExpr{
						X:     c.newIdent(refVar, t),
						Index: c.newIdent(iVar, types.Typ[types.Int]),
					}, elemType), elemType).String(), elemType, s.Tok == token.DEFINE))
				}
			}, func() {
				c.Printf("%s++;", iVar)
			}, label, c.Flattened[s])

		case *types.Chan:
			okVar := c.newIdent(c.newVariable("_ok"), types.Typ[types.Bool])
			key := s.Key
			tok := s.Tok
			if key == nil {
				key = ast.NewIdent("_")
				tok = token.ASSIGN
			}
			forStmt := &ast.ForStmt{
				Body: &ast.BlockStmt{
					List: []ast.Stmt{
						&ast.AssignStmt{
							Lhs: []ast.Expr{
								key,
								okVar,
							},
							Rhs: []ast.Expr{
								c.setType(&ast.UnaryExpr{X: c.newIdent(refVar, t), Op: token.ARROW}, types.NewTuple(types.NewVar(0, nil, "", t.Elem()), types.NewVar(0, nil, "", types.Typ[types.Bool]))),
							},
							Tok: tok,
						},
						&ast.IfStmt{
							Cond: &ast.UnaryExpr{X: okVar, Op: token.NOT},
							Body: &ast.BlockStmt{List: []ast.Stmt{&ast.BranchStmt{Tok: token.BREAK}}},
						},
						s.Body,
					},
				},
			}
			c.Flattened[forStmt] = true
			c.translateStmt(forStmt, label)

		default:
			panic("")
		}

	case *ast.BranchStmt:
		normalLabel := ""
		blockingLabel := ""
		data := c.flowDatas[nil]
		if s.Label != nil {
			normalLabel = " " + s.Label.Name
			blockingLabel = " s" // use explicit label "s", because surrounding loop may not be flattened
			data = c.flowDatas[c.p.Uses[s.Label].(*types.Label)]
		}
		switch s.Tok {
		case token.BREAK:
			c.PrintCond(data.endCase == 0, fmt.Sprintf("break%s;", normalLabel), fmt.Sprintf("$s = %d; continue%s;", data.endCase, blockingLabel))
		case token.CONTINUE:
			data.postStmt()
			c.PrintCond(data.beginCase == 0, fmt.Sprintf("continue%s;", normalLabel), fmt.Sprintf("$s = %d; continue%s;", data.beginCase, blockingLabel))
		case token.GOTO:
			c.PrintCond(false, "goto "+s.Label.Name, fmt.Sprintf("$s = %d; continue;", c.labelCase(c.p.Uses[s.Label].(*types.Label))))
		case token.FALLTHROUGH:
			// handled in CaseClause
		default:
			panic("Unhandled branch statment: " + s.Tok.String())
		}

	case *ast.ReturnStmt:
		results := s.Results
		if c.resultNames != nil {
			if len(s.Results) != 0 {
				c.translateStmt(&ast.AssignStmt{
					Lhs: c.resultNames,
					Tok: token.ASSIGN,
					Rhs: s.Results,
				}, nil)
			}
			results = c.resultNames
		}
		c.Printf("return%s;", c.translateResults(results))

	case *ast.DeferStmt:
		isBuiltin := false
		isJs := false
		switch fun := s.Call.Fun.(type) {
		case *ast.Ident:
			var builtin *types.Builtin
			builtin, isBuiltin = c.p.Uses[fun].(*types.Builtin)
			if isBuiltin && builtin.Name() == "recover" {
				c.Printf("$deferred.push([$recover, []]);")
				return
			}
		case *ast.SelectorExpr:
			isJs = typesutil.IsJsPackage(c.p.Uses[fun.Sel].Pkg())
		}
		sig := c.p.Types[s.Call.Fun].Type.Underlying().(*types.Signature)
		args := c.translateArgs(sig, s.Call.Args, s.Call.Ellipsis.IsValid(), true)
		if isBuiltin || isJs {
			vars := make([]string, len(s.Call.Args))
			callArgs := make([]ast.Expr, len(s.Call.Args))
			for i, arg := range s.Call.Args {
				v := c.newVariable("_arg")
				vars[i] = v
				callArgs[i] = c.newIdent(v, c.p.Types[arg].Type)
			}
			call := c.translateExpr(&ast.CallExpr{
				Fun:      s.Call.Fun,
				Args:     callArgs,
				Ellipsis: s.Call.Ellipsis,
			})
			c.Printf("$deferred.push([function(%s) { %s; }, [%s]]);", strings.Join(vars, ", "), call, strings.Join(args, ", "))
			return
		}
		c.Printf("$deferred.push([%s, [%s]]);", c.translateExpr(s.Call.Fun), strings.Join(args, ", "))

	case *ast.AssignStmt:
		if s.Tok != token.ASSIGN && s.Tok != token.DEFINE {
			panic(s.Tok)
		}

		if s.Tok == token.DEFINE {
			for _, lhs := range s.Lhs {
				if !isBlank(lhs) {
					obj := c.p.Defs[lhs.(*ast.Ident)]
					if obj == nil {
						obj = c.p.Uses[lhs.(*ast.Ident)]
					}
					c.setType(lhs, obj.Type())
				}
			}
		}

		switch {
		case len(s.Lhs) == 1 && len(s.Rhs) == 1:
			lhs := astutil.RemoveParens(s.Lhs[0])
			if isBlank(lhs) {
				if analysis.HasSideEffect(s.Rhs[0], c.p.Info.Info) {
					c.Printf("%s;", c.translateExpr(s.Rhs[0]).String())
				}
				return
			}
			lhsType := c.p.Types[s.Lhs[0]].Type
			c.Printf("%s", c.translateAssignOfExpr(lhs, s.Rhs[0], lhsType, s.Tok == token.DEFINE))

		case len(s.Lhs) > 1 && len(s.Rhs) == 1:
			tupleVar := c.newVariable("_tuple")
			out := tupleVar + " = " + c.translateExpr(s.Rhs[0]).String() + ";"
			tuple := c.p.Types[s.Rhs[0]].Type.(*types.Tuple)
			for i, lhs := range s.Lhs {
				lhs = astutil.RemoveParens(lhs)
				if !isBlank(lhs) {
					lhsType := c.p.Types[s.Lhs[i]].Type
					out += " " + c.translateAssignOfExpr(lhs, c.newIdent(fmt.Sprintf("%s[%d]", tupleVar, i), tuple.At(i).Type()), lhsType, s.Tok == token.DEFINE)
				}
			}
			c.Printf("%s", out)
		case len(s.Lhs) == len(s.Rhs):
			tmpVars := make([]string, len(s.Rhs))
			var parts []string
			for i, rhs := range s.Rhs {
				tmpVars[i] = c.newVariable("_tmp")
				if isBlank(astutil.RemoveParens(s.Lhs[i])) {
					if analysis.HasSideEffect(rhs, c.p.Info.Info) {
						c.Printf("%s;", c.translateExpr(rhs).String())
					}
					continue
				}
				lhsType := c.p.Types[s.Lhs[i]].Type
				parts = append(parts, c.translateAssignOfExpr(c.newIdent(tmpVars[i], c.p.Types[s.Lhs[i]].Type), rhs, lhsType, true))
			}
			for i, lhs := range s.Lhs {
				lhs = astutil.RemoveParens(lhs)
				if !isBlank(lhs) {
					t := c.p.Types[lhs].Type
					parts = append(parts, c.translateAssignOfExpr(lhs, c.newIdent(tmpVars[i], t), t, s.Tok == token.DEFINE))
				}
			}
			c.Printf("%s", strings.Join(parts, " "))

		default:
			panic("Invalid arity of AssignStmt.")

		}

	case *ast.DeclStmt:
		decl := s.Decl.(*ast.GenDecl)
		switch decl.Tok {
		case token.VAR:
			for _, spec := range s.Decl.(*ast.GenDecl).Specs {
				valueSpec := spec.(*ast.ValueSpec)
				lhs := make([]ast.Expr, len(valueSpec.Names))
				for i, name := range valueSpec.Names {
					lhs[i] = name
				}
				rhs := valueSpec.Values
				isTuple := false
				if len(rhs) == 1 {
					_, isTuple = c.p.Types[rhs[0]].Type.(*types.Tuple)
				}
				for len(rhs) < len(lhs) && !isTuple {
					rhs = append(rhs, nil)
				}
				c.translateStmt(&ast.AssignStmt{
					Lhs: lhs,
					Tok: token.DEFINE,
					Rhs: rhs,
				}, nil)
			}
		case token.TYPE:
			for _, spec := range decl.Specs {
				o := c.p.Defs[spec.(*ast.TypeSpec).Name].(*types.TypeName)
				c.p.typeNames = append(c.p.typeNames, o)
				c.p.objectNames[o] = c.newVariableWithLevel(o.Name(), true)
				c.p.dependencies[o] = true
			}
		case token.CONST:
			// skip, constants are inlined
		}

	case *ast.ExprStmt:
		expr := c.translateExpr(s.X)
		if expr != nil && expr.String() != "" {
			c.Printf("%s;", expr)
		}

	case *ast.LabeledStmt:
		label := c.p.Defs[s.Label].(*types.Label)
		if c.GotoLabel[label] {
			c.PrintCond(false, s.Label.Name+":", fmt.Sprintf("case %d:", c.labelCase(label)))
		}
		c.translateStmt(s.Stmt, label)

	case *ast.GoStmt:
		c.Printf("$go(%s, [%s]);", c.translateExpr(s.Call.Fun), strings.Join(c.translateArgs(c.p.Types[s.Call.Fun].Type.Underlying().(*types.Signature), s.Call.Args, s.Call.Ellipsis.IsValid(), false), ", "))

	case *ast.SendStmt:
		chanType := c.p.Types[s.Chan].Type.Underlying().(*types.Chan)
		call := &ast.CallExpr{
			Fun:  c.newIdent("$send", types.NewSignature(nil, types.NewTuple(types.NewVar(0, nil, "", chanType), types.NewVar(0, nil, "", chanType.Elem())), nil, false)),
			Args: []ast.Expr{s.Chan, s.Value},
		}
		c.Blocking[call] = true
		c.translateStmt(&ast.ExprStmt{X: call}, label)

	case *ast.SelectStmt:
		var channels []string
		var caseClauses []ast.Stmt
		flattened := false
		hasDefault := false
		for i, s := range s.Body.List {
			clause := s.(*ast.CommClause)
			switch comm := clause.Comm.(type) {
			case nil:
				channels = append(channels, "[]")
				hasDefault = true
			case *ast.ExprStmt:
				channels = append(channels, c.formatExpr("[%e]", astutil.RemoveParens(comm.X).(*ast.UnaryExpr).X).String())
			case *ast.AssignStmt:
				channels = append(channels, c.formatExpr("[%e]", astutil.RemoveParens(comm.Rhs[0]).(*ast.UnaryExpr).X).String())
			case *ast.SendStmt:
				channels = append(channels, c.formatExpr("[%e, %e]", comm.Chan, comm.Value).String())
			default:
				panic(fmt.Sprintf("unhandled: %T", comm))
			}
			indexLit := &ast.BasicLit{Kind: token.INT}
			c.p.Types[indexLit] = types.TypeAndValue{Type: types.Typ[types.Int], Value: exact.MakeInt64(int64(i))}
			caseClauses = append(caseClauses, &ast.CaseClause{
				List: []ast.Expr{indexLit},
				Body: clause.Body,
			})
			flattened = flattened || c.Flattened[clause]
		}

		selectCall := c.setType(&ast.CallExpr{
			Fun:  c.newIdent("$select", types.NewSignature(nil, types.NewTuple(types.NewVar(0, nil, "", types.NewInterface(nil, nil))), types.NewTuple(types.NewVar(0, nil, "", types.Typ[types.Int])), false)),
			Args: []ast.Expr{c.newIdent(fmt.Sprintf("[%s]", strings.Join(channels, ", ")), types.NewInterface(nil, nil))},
		}, types.Typ[types.Int])
		c.Blocking[selectCall] = !hasDefault
		selectionVar := c.newVariable("_selection")
		c.Printf("%s = %s;", selectionVar, c.translateExpr(selectCall))

		translateCond := func(cond ast.Expr) *expression {
			return c.formatExpr("%s[0] === %e", selectionVar, cond)
		}
		printCaseBodyPrefix := func(index int) {
			if assign, ok := s.Body.List[index].(*ast.CommClause).Comm.(*ast.AssignStmt); ok {
				switch rhsType := c.p.Types[assign.Rhs[0]].Type.(type) {
				case *types.Tuple:
					c.translateStmt(&ast.AssignStmt{Lhs: assign.Lhs, Rhs: []ast.Expr{c.newIdent(selectionVar+"[1]", rhsType)}, Tok: assign.Tok}, nil)
				default:
					c.translateStmt(&ast.AssignStmt{Lhs: assign.Lhs, Rhs: []ast.Expr{c.newIdent(selectionVar+"[1][0]", rhsType)}, Tok: assign.Tok}, nil)
				}
			}
		}
		c.translateBranchingStmt(caseClauses, true, translateCond, printCaseBodyPrefix, label, flattened)

	case *ast.EmptyStmt:
		// skip

	default:
		panic(fmt.Sprintf("Unhandled statement: %T\n", s))

	}
}
Ejemplo n.º 27
0
// Like isTest, but checks the signature too.
func isTestSig(f *Function, prefix string, sig *types.Signature) bool {
	return isTest(f.Name(), prefix) && types.Identical(f.Signature, sig)
}
Ejemplo n.º 28
0
// emitConv emits to f code to convert Value val to exactly type typ,
// and returns the converted value.  Implicit conversions are required
// by language assignability rules in assignments, parameter passing,
// etc.  Conversions cannot fail dynamically.
//
func emitConv(f *Function, val Value, typ types.Type) Value {
	t_src := val.Type()

	// Identical types?  Conversion is a no-op.
	if types.Identical(t_src, typ) {
		return val
	}

	ut_dst := typ.Underlying()
	ut_src := t_src.Underlying()

	// Just a change of type, but not value or representation?
	if isValuePreserving(ut_src, ut_dst) {
		c := &ChangeType{X: val}
		c.setType(typ)
		return f.emit(c)
	}

	// Conversion to, or construction of a value of, an interface type?
	if _, ok := ut_dst.(*types.Interface); ok {
		// Assignment from one interface type to another?
		if _, ok := ut_src.(*types.Interface); ok {
			c := &ChangeInterface{X: val}
			c.setType(typ)
			return f.emit(c)
		}

		// Untyped nil constant?  Return interface-typed nil constant.
		if ut_src == tUntypedNil {
			return nilConst(typ)
		}

		// Convert (non-nil) "untyped" literals to their default type.
		if t, ok := ut_src.(*types.Basic); ok && t.Info()&types.IsUntyped != 0 {
			val = emitConv(f, val, DefaultType(ut_src))
		}

		f.Pkg.needMethodsOf(val.Type())
		mi := &MakeInterface{X: val}
		mi.setType(typ)
		return f.emit(mi)
	}

	// Conversion of a compile-time constant value?
	if c, ok := val.(*Const); ok {
		if _, ok := ut_dst.(*types.Basic); ok || c.IsNil() {
			// Conversion of a compile-time constant to
			// another constant type results in a new
			// constant of the destination type and
			// (initially) the same abstract value.
			// We don't truncate the value yet.
			return NewConst(c.Value, typ)
		}

		// We're converting from constant to non-constant type,
		// e.g. string -> []byte/[]rune.
	}

	// A representation-changing conversion?
	// At least one of {ut_src,ut_dst} must be *Basic.
	// (The other may be []byte or []rune.)
	_, ok1 := ut_src.(*types.Basic)
	_, ok2 := ut_dst.(*types.Basic)
	if ok1 || ok2 {
		c := &Convert{X: val}
		c.setType(typ)
		return f.emit(c)
	}

	panic(fmt.Sprintf("in %s: cannot convert %s (%s) to %s", f, val, val.Type(), typ))
}
Ejemplo n.º 29
0
func (c *funcContext) translateBuiltin(name string, sig *types.Signature, args []ast.Expr, ellipsis bool) *expression {
	switch name {
	case "new":
		t := sig.Results().At(0).Type().(*types.Pointer)
		if c.p.Pkg.Path() == "syscall" && types.Identical(t.Elem().Underlying(), types.Typ[types.Uintptr]) {
			return c.formatExpr("new Uint8Array(8)")
		}
		switch t.Elem().Underlying().(type) {
		case *types.Struct, *types.Array:
			return c.formatExpr("%e", c.zeroValue(t.Elem()))
		default:
			return c.formatExpr("$newDataPointer(%e, %s)", c.zeroValue(t.Elem()), c.typeName(t))
		}
	case "make":
		switch argType := c.p.TypeOf(args[0]).Underlying().(type) {
		case *types.Slice:
			t := c.typeName(c.p.TypeOf(args[0]))
			if len(args) == 3 {
				return c.formatExpr("$makeSlice(%s, %f, %f)", t, args[1], args[2])
			}
			return c.formatExpr("$makeSlice(%s, %f)", t, args[1])
		case *types.Map:
			return c.formatExpr("{}")
		case *types.Chan:
			length := "0"
			if len(args) == 2 {
				length = c.translateExpr(args[1]).String()
			}
			return c.formatExpr("new %s(%s)", c.typeName(c.p.TypeOf(args[0])), length)
		default:
			panic(fmt.Sprintf("Unhandled make type: %T\n", argType))
		}
	case "len":
		switch argType := c.p.TypeOf(args[0]).Underlying().(type) {
		case *types.Basic:
			return c.formatExpr("%e.length", args[0])
		case *types.Slice:
			return c.formatExpr("%e.$length", args[0])
		case *types.Pointer:
			return c.formatExpr("(%e, %d)", args[0], argType.Elem().(*types.Array).Len())
		case *types.Map:
			return c.formatExpr("$keys(%e).length", args[0])
		case *types.Chan:
			return c.formatExpr("%e.$buffer.length", args[0])
		// length of array is constant
		default:
			panic(fmt.Sprintf("Unhandled len type: %T\n", argType))
		}
	case "cap":
		switch argType := c.p.TypeOf(args[0]).Underlying().(type) {
		case *types.Slice, *types.Chan:
			return c.formatExpr("%e.$capacity", args[0])
		case *types.Pointer:
			return c.formatExpr("(%e, %d)", args[0], argType.Elem().(*types.Array).Len())
		// capacity of array is constant
		default:
			panic(fmt.Sprintf("Unhandled cap type: %T\n", argType))
		}
	case "panic":
		return c.formatExpr("$panic(%s)", c.translateImplicitConversion(args[0], types.NewInterface(nil, nil)))
	case "append":
		if ellipsis || len(args) == 1 {
			argStr := c.translateArgs(sig, args, ellipsis, false)
			return c.formatExpr("$appendSlice(%s, %s)", argStr[0], argStr[1])
		}
		sliceType := sig.Results().At(0).Type().Underlying().(*types.Slice)
		return c.formatExpr("$append(%e, %s)", args[0], strings.Join(c.translateExprSlice(args[1:], sliceType.Elem()), ", "))
	case "delete":
		keyType := c.p.TypeOf(args[0]).Underlying().(*types.Map).Key()
		return c.formatExpr(`delete %e[%s.keyFor(%s)]`, args[0], c.typeName(keyType), c.translateImplicitConversion(args[1], keyType))
	case "copy":
		if basic, isBasic := c.p.TypeOf(args[1]).Underlying().(*types.Basic); isBasic && isString(basic) {
			return c.formatExpr("$copyString(%e, %e)", args[0], args[1])
		}
		return c.formatExpr("$copySlice(%e, %e)", args[0], args[1])
	case "print", "println":
		return c.formatExpr("console.log(%s)", strings.Join(c.translateExprSlice(args, nil), ", "))
	case "complex":
		argStr := c.translateArgs(sig, args, ellipsis, false)
		return c.formatExpr("new %s(%s, %s)", c.typeName(sig.Results().At(0).Type()), argStr[0], argStr[1])
	case "real":
		return c.formatExpr("%e.$real", args[0])
	case "imag":
		return c.formatExpr("%e.$imag", args[0])
	case "recover":
		return c.formatExpr("$recover()")
	case "close":
		return c.formatExpr(`$close(%e)`, args[0])
	default:
		panic(fmt.Sprintf("Unhandled builtin: %s\n", name))
	}
}
Ejemplo n.º 30
0
func (c *funcContext) translateConversion(expr ast.Expr, desiredType types.Type) *expression {
	exprType := c.p.TypeOf(expr)
	if types.Identical(exprType, desiredType) {
		return c.translateExpr(expr)
	}

	if c.p.Pkg.Path() == "reflect" {
		if call, isCall := expr.(*ast.CallExpr); isCall && types.Identical(c.p.TypeOf(call.Fun), types.Typ[types.UnsafePointer]) {
			if ptr, isPtr := desiredType.(*types.Pointer); isPtr {
				if named, isNamed := ptr.Elem().(*types.Named); isNamed {
					switch named.Obj().Name() {
					case "arrayType", "chanType", "funcType", "interfaceType", "mapType", "ptrType", "sliceType", "structType":
						return c.formatExpr("%e.kindType", call.Args[0]) // unsafe conversion
					default:
						return c.translateExpr(expr)
					}
				}
			}
		}
	}

	switch t := desiredType.Underlying().(type) {
	case *types.Basic:
		switch {
		case isInteger(t):
			basicExprType := exprType.Underlying().(*types.Basic)
			switch {
			case is64Bit(t):
				if !is64Bit(basicExprType) {
					if basicExprType.Kind() == types.Uintptr { // this might be an Object returned from reflect.Value.Pointer()
						return c.formatExpr("new %1s(0, %2e.constructor === Number ? %2e : 1)", c.typeName(desiredType), expr)
					}
					return c.formatExpr("new %s(0, %e)", c.typeName(desiredType), expr)
				}
				return c.formatExpr("new %1s(%2h, %2l)", c.typeName(desiredType), expr)
			case is64Bit(basicExprType):
				if !isUnsigned(t) && !isUnsigned(basicExprType) {
					return c.fixNumber(c.formatParenExpr("%1l + ((%1h >> 31) * 4294967296)", expr), t)
				}
				return c.fixNumber(c.formatExpr("%s.$low", c.translateExpr(expr)), t)
			case isFloat(basicExprType):
				return c.formatParenExpr("%e >> 0", expr)
			case types.Identical(exprType, types.Typ[types.UnsafePointer]):
				return c.translateExpr(expr)
			default:
				return c.fixNumber(c.translateExpr(expr), t)
			}
		case isFloat(t):
			if t.Kind() == types.Float32 && exprType.Underlying().(*types.Basic).Kind() == types.Float64 {
				return c.formatExpr("$fround(%e)", expr)
			}
			return c.formatExpr("%f", expr)
		case isComplex(t):
			return c.formatExpr("new %1s(%2r, %2i)", c.typeName(desiredType), expr)
		case isString(t):
			value := c.translateExpr(expr)
			switch et := exprType.Underlying().(type) {
			case *types.Basic:
				if is64Bit(et) {
					value = c.formatExpr("%s.$low", value)
				}
				if isNumeric(et) {
					return c.formatExpr("$encodeRune(%s)", value)
				}
				return value
			case *types.Slice:
				if types.Identical(et.Elem().Underlying(), types.Typ[types.Rune]) {
					return c.formatExpr("$runesToString(%s)", value)
				}
				return c.formatExpr("$bytesToString(%s)", value)
			default:
				panic(fmt.Sprintf("Unhandled conversion: %v\n", et))
			}
		case t.Kind() == types.UnsafePointer:
			if unary, isUnary := expr.(*ast.UnaryExpr); isUnary && unary.Op == token.AND {
				if indexExpr, isIndexExpr := unary.X.(*ast.IndexExpr); isIndexExpr {
					return c.formatExpr("$sliceToArray(%s)", c.translateConversionToSlice(indexExpr.X, types.NewSlice(types.Typ[types.Uint8])))
				}
				if ident, isIdent := unary.X.(*ast.Ident); isIdent && ident.Name == "_zero" {
					return c.formatExpr("new Uint8Array(0)")
				}
			}
			if ptr, isPtr := c.p.TypeOf(expr).(*types.Pointer); c.p.Pkg.Path() == "syscall" && isPtr {
				if s, isStruct := ptr.Elem().Underlying().(*types.Struct); isStruct {
					array := c.newVariable("_array")
					target := c.newVariable("_struct")
					c.Printf("%s = new Uint8Array(%d);", array, sizes32.Sizeof(s))
					c.Delayed(func() {
						c.Printf("%s = %s, %s;", target, c.translateExpr(expr), c.loadStruct(array, target, s))
					})
					return c.formatExpr("%s", array)
				}
			}
			if call, ok := expr.(*ast.CallExpr); ok {
				if id, ok := call.Fun.(*ast.Ident); ok && id.Name == "new" {
					return c.formatExpr("new Uint8Array(%d)", int(sizes32.Sizeof(c.p.TypeOf(call.Args[0]))))
				}
			}
		}

	case *types.Slice:
		switch et := exprType.Underlying().(type) {
		case *types.Basic:
			if isString(et) {
				if types.Identical(t.Elem().Underlying(), types.Typ[types.Rune]) {
					return c.formatExpr("new %s($stringToRunes(%e))", c.typeName(desiredType), expr)
				}
				return c.formatExpr("new %s($stringToBytes(%e))", c.typeName(desiredType), expr)
			}
		case *types.Array, *types.Pointer:
			return c.formatExpr("new %s(%e)", c.typeName(desiredType), expr)
		}

	case *types.Pointer:
		if s, isStruct := t.Elem().Underlying().(*types.Struct); isStruct {
			if c.p.Pkg.Path() == "syscall" && types.Identical(exprType, types.Typ[types.UnsafePointer]) {
				array := c.newVariable("_array")
				target := c.newVariable("_struct")
				return c.formatExpr("(%s = %e, %s = %e, %s, %s)", array, expr, target, c.zeroValue(t.Elem()), c.loadStruct(array, target, s), target)
			}
			return c.formatExpr("$pointerOfStructConversion(%e, %s)", expr, c.typeName(t))
		}

		if !types.Identical(exprType, types.Typ[types.UnsafePointer]) {
			exprTypeElem := exprType.Underlying().(*types.Pointer).Elem()
			ptrVar := c.newVariable("_ptr")
			getterConv := c.translateConversion(c.setType(&ast.StarExpr{X: c.newIdent(ptrVar, exprType)}, exprTypeElem), t.Elem())
			setterConv := c.translateConversion(c.newIdent("$v", t.Elem()), exprTypeElem)
			return c.formatExpr("(%1s = %2e, new %3s(function() { return %4s; }, function($v) { %1s.$set(%5s); }, %1s.$target))", ptrVar, expr, c.typeName(desiredType), getterConv, setterConv)
		}

	case *types.Interface:
		if types.Identical(exprType, types.Typ[types.UnsafePointer]) {
			return c.translateExpr(expr)
		}
	}

	return c.translateImplicitConversionWithCloning(expr, desiredType)
}