func (c *compiler) VisitFuncType(f *ast.FuncType) TypeValue {
var fn_type types.Func
if f.Params != nil && len(f.Params.List) > 0 {
final_param_type := f.Params.List[len(f.Params.List)-1].Type
if _, varargs := final_param_type.(*ast.Ellipsis); varargs {
fn_type.IsVariadic = true
}
for i := 0; i < len(f.Params.List); i++ {
namecount := len(f.Params.List[i].Names)
typ := c.GetType(f.Params.List[i].Type)
if namecount == 0 {
arg := ast.NewObj(ast.Var, "_")
arg.Type = typ
fn_type.Params = append(fn_type.Params, arg)
} else {
args := make([]*ast.Object, namecount)
for j := 0; j < namecount; j++ {
ident := f.Params.List[i].Names[j]
if ident != nil {
args[j] = ident.Obj
} else {
args[j] = ast.NewObj(ast.Var, "_")
}
args[j].Type = typ
}
fn_type.Params = append(fn_type.Params, args...)
}
}
}
if f.Results != nil {
for i := 0; i < len(f.Results.List); i++ {
namecount := len(f.Results.List[i].Names)
typ := c.GetType(f.Results.List[i].Type)
if namecount > 0 {
results := make([]*ast.Object, namecount)
for j := 0; j < namecount; j++ {
ident := f.Results.List[i].Names[j]
if ident != nil {
results[j] = ident.Obj
} else {
results[j] = ast.NewObj(ast.Var, "_")
}
results[j].Type = typ
}
fn_type.Results = append(fn_type.Results, results...)
} else {
result := ast.NewObj(ast.Var, "_")
result.Type = typ
fn_type.Results = append(fn_type.Results, result)
}
}
}
return TypeValue{&fn_type}
}
// MethodOrEmbedSpec = Name [ Signature ] .
//
func (p *gcParser) parseMethodOrEmbedSpec() *ast.Object {
name := p.parseName()
if p.tok == '(' {
obj := ast.NewObj(ast.Fun, name)
obj.Type = p.parseSignature()
return obj
}
// TODO lookup name and return that type
return ast.NewObj(ast.Typ, "_")
}
// MethodOrEmbedSpec = Name [ Signature ] .
//
func (p *gcParser) parseMethodOrEmbedSpec() *ast.Object {
p.parseName()
if p.tok == '(' {
p.parseSignature()
// TODO(gri) compute method object
return ast.NewObj(ast.Fun, "_")
}
// TODO lookup name and return that type
return ast.NewObj(ast.Typ, "_")
}
func (p *parser) findIdent() *ast.Ident {
pos := p.pos
name := "_"
var obj *ast.Object
if p.tok == token.IDENT {
name = string(p.lit)
obj = p.funcScope.Lookup(name)
p.next()
} else {
p.expect(token.IDENT) // use expect() error handling
}
if obj == nil {
// No declaration found: either we are outside any function
// (p.funcScope == nil) or the identifier is not declared
// in any function. Try the file and package scope.
obj = p.fileScope.Lookup(name) // file scope is nested in package scope
if obj == nil {
// No declaration found anywhere: track as
// unresolved identifier in the package scope.
obj = ast.NewObj(ast.Err, pos, name)
p.pkgScope.Declare(obj)
}
}
return &ast.Ident{pos, obj}
}
func (p *parser) declareShortVar(decl *ast.AssignStmt, list []ast.Expr) {
// Go spec: A short variable declaration may redeclare variables
// provided they were originally declared in the same block with
// the same type, and at least one of the non-blank variables is new.
n := 0 // number of new variables
for _, x := range list {
if ident, isIdent := x.(*ast.Ident); isIdent {
assert(ident.Obj == nil, "identifier already declared or resolved")
obj := ast.NewObj(ast.Var, ident.Name)
// remember corresponding assignment for other tools
obj.Decl = decl
ident.Obj = obj
if ident.Name != "_" {
if alt := p.topScope.Insert(obj); alt != nil {
ident.Obj = alt // redeclaration
} else {
n++ // new declaration
}
}
} else {
p.errorExpected(x.Pos(), "identifier on left side of :=")
}
}
if n == 0 && p.mode&DeclarationErrors != 0 {
p.error(list[0].Pos(), "no new variables on left side of :=")
}
}
// MethodDecl = "func" Receiver Name Signature .
// Receiver = "(" ( identifier | "?" ) [ "*" ] ExportedName ")" [ FuncBody ].
//
func (p *gcParser) parseMethodDecl() {
// "func" already consumed
p.expect('(')
recv, _ := p.parseParameter() // receiver
p.expect(')')
// unexported method names in imports are qualified with their package.
fn := ast.NewObj(ast.Fun, p.parseName())
fnType := p.parseSignature()
fnType.Recv = recv
fn.Type = fnType
var recvType *Name
if ptr, isptr := recv.Type.(*Pointer); isptr {
recvType = ptr.Base.(*Name)
} else {
recvType = recv.Type.(*Name)
}
recvType.Methods = append(recvType.Methods, fn)
recvType.Methods.Sort()
if p.tok == '{' {
p.parseFuncBody()
}
}
// Declare inserts a named object of the given kind in scope.
func (p *gcParser) declare(scope *ast.Scope, kind ast.ObjKind, name string) *ast.Object {
// a type may have been declared before - if it exists
// already in the respective package scope, return that
// type
if kind == ast.Typ {
if obj := scope.Lookup(name); obj != nil {
assert(obj.Kind == ast.Typ)
return obj
}
}
// any other object must be a newly declared object -
// create it and insert it into the package scope
obj := ast.NewObj(kind, name)
if scope.Insert(obj) != nil {
p.errorf("already declared: %v %s", kind, obj.Name)
}
// a new type object is a named type and may be referred
// to before the underlying type is known - set it up
if kind == ast.Typ {
obj.Type = &Name{Obj: obj}
}
return obj
}
// collectMethods collects the method declarations from an AST File and
// returns a mapping from receiver types to their method FuncDecl's.
func (c *checker) collectMethods(file *ast.File) {
for _, decl := range file.Decls {
if funcdecl, ok := decl.(*ast.FuncDecl); ok && funcdecl.Recv != nil {
recvField := funcdecl.Recv.List[0]
var recv *ast.Ident
switch typ := recvField.Type.(type) {
case *ast.StarExpr:
recv = typ.X.(*ast.Ident)
case *ast.Ident:
recv = typ
case *ast.BadExpr:
return
}
if recv.Obj == nil {
// error reported elsewhere.
return
}
if recv.Obj.Kind != ast.Typ {
c.errorf(recv.Pos(), "%s is not a type", recv.Name)
return
}
// The Obj field of the funcdecl wll be nil, so we'll have to
// create a new one.
funcdecl.Name.Obj = ast.NewObj(ast.Fun, funcdecl.Name.String())
funcdecl.Name.Obj.Decl = funcdecl
c.methods[recv.Obj] = append(c.methods[recv.Obj], funcdecl.Name.Obj)
}
}
}
func define(kind ast.ObjKind, name string) *ast.Object {
obj := ast.NewObj(kind, name)
if scope.Insert(obj) != nil {
panic("types internal error: double declaration")
}
return obj
}
func simpleImporter(imports map[string]*ast.Object, path string) (*ast.Object, error) {
pkg := imports[path]
if pkg == nil {
// Guess the package name without importing it. Start with the last
// element of the path.
name := path[strings.LastIndex(path, "/")+1:]
// Trim commonly used prefixes and suffixes containing illegal name
// runes.
name = strings.TrimSuffix(name, ".go")
name = strings.TrimSuffix(name, "-go")
name = strings.TrimPrefix(name, "go.")
name = strings.TrimPrefix(name, "go-")
name = strings.TrimPrefix(name, "biogo.")
// It's also common for the last element of the path to contain an
// extra "go" prefix, but not always. TODO: examine unresolved ids to
// detect when trimming the "go" prefix is appropriate.
pkg = ast.NewObj(ast.Pkg, name)
pkg.Data = ast.NewScope(nil)
imports[path] = pkg
}
return pkg, nil
}
// ImportPath = string_lit .
//
func (p *gcParser) parsePkgId() *ast.Object {
id, err := strconv.Unquote(p.expect(scanner.String))
if err != nil {
p.error(err)
}
switch id {
case "":
// id == "" stands for the imported package id
// (only known at time of package installation)
id = p.id
case "unsafe":
// package unsafe is not in the imports map - handle explicitly
return Unsafe
}
pkg := p.imports[id]
if pkg == nil {
scope = ast.NewScope(nil)
pkg = ast.NewObj(ast.Pkg, "")
pkg.Data = scope
p.imports[id] = pkg
}
return pkg
}
// ExportedName = ImportPath "." dotIdentifier .
//
func (p *gcParser) parseExportedName(kind ast.ObjKind) *ast.Object {
pkg := p.parsePkgId()
p.expect('.')
name := p.parseDotIdent()
// a type may have been declared before - if it exists
// already in the respective package scope, return that
// type
scope := pkg.Data.(*ast.Scope)
if kind == ast.Typ {
if obj := scope.Lookup(name); obj != nil {
assert(obj.Kind == ast.Typ)
return obj
}
}
// any other object must be a newly declared object -
// create it and insert it into the package scope
obj := ast.NewObj(kind, name)
if scope.Insert(obj) != nil {
p.errorf("already declared: %s", obj.Name)
}
// a new type object is a named type and may be referred
// to before the underlying type is known - set it up
if kind == ast.Typ {
obj.Type = &Name{Obj: obj}
}
return obj
}
func parseImportSpec(p *parser, doc *ast.CommentGroup) ast.Spec {
if p.trace {
defer un(trace(p, "ImportSpec"))
}
var ident *ast.Ident
if p.tok == token.PERIOD {
ident = &ast.Ident{p.pos, ast.NewObj(ast.Pkg, p.pos, ".")}
p.next()
} else if p.tok == token.IDENT {
ident = p.parseIdent(ast.Pkg)
// TODO(gri) Make sure the ident is not already declared in the
// package scope. Also, cannot add the same name to
// the package scope later.
p.declIdent(p.fileScope, ident)
}
var path *ast.BasicLit
if p.tok == token.STRING {
path = &ast.BasicLit{p.pos, p.tok, p.lit}
p.next()
} else {
p.expect(token.STRING) // use expect() error handling
}
p.expectSemi()
return &ast.ImportSpec{doc, ident, path, p.lineComment}
}
// Export = "PackageClause { Decl } "$$" .
// PackageClause = "package" identifier [ "safe" ] "\n" .
//
func (p *gcParser) parseExport() *ast.Object {
p.expectKeyword("package")
name := p.expect(scanner.Ident)
if p.tok != '\n' {
// A package is safe if it was compiled with the -u flag,
// which disables the unsafe package.
// TODO(gri) remember "safe" package
p.expectKeyword("safe")
}
p.expect('\n')
assert(p.imports[p.id] == nil)
pkg := ast.NewObj(ast.Pkg, name)
pkg.Data = ast.NewScope(nil)
p.imports[p.id] = pkg
for p.tok != '$' && p.tok != scanner.EOF {
p.parseDecl()
}
if ch := p.scanner.Peek(); p.tok != '$' || ch != '$' {
// don't call next()/expect() since reading past the
// export data may cause scanner errors (e.g. NUL chars)
p.errorf("expected '$$', got %s %c", scanner.TokenString(p.tok), ch)
}
if n := p.scanner.ErrorCount; n != 0 {
p.errorf("expected no scanner errors, got %d", n)
}
return pkg
}
func init() {
scope = ast.NewScope(nil)
Universe = scope
Bool = defType("bool")
defType("byte") // TODO(gri) should be an alias for uint8
defType("complex64")
Complex128 = defType("complex128")
defType("float32")
Float64 = defType("float64")
defType("int8")
defType("int16")
defType("int32")
defType("int64")
String = defType("string")
defType("uint8")
defType("uint16")
defType("uint32")
defType("uint64")
Int = defType("int")
defType("uint")
defType("uintptr")
defConst("true")
defConst("false")
defConst("iota")
defConst("nil")
defFun("append")
defFun("cap")
defFun("close")
defFun("complex")
defFun("copy")
defFun("delete")
defFun("imag")
defFun("len")
defFun("make")
defFun("new")
defFun("panic")
defFun("print")
defFun("println")
defFun("real")
defFun("recover")
scope = ast.NewScope(nil)
Unsafe = ast.NewObj(ast.Pkg, "unsafe")
Unsafe.Data = scope
defType("Pointer")
defFun("Alignof")
defFun("New")
defFun("NewArray")
defFun("Offsetof")
defFun("Reflect")
defFun("Sizeof")
defFun("Typeof")
defFun("Unreflect")
}
// findField returns the object with the given name if visible in the type's scope.
// If no such object is found, an error is reported and a bad object is returned instead.
func (tc *typechecker) findField(typ *ast.Type, name *ast.Ident) (obj *ast.Object) {
// TODO(gri) This is simplistic at the moment and ignores anonymous fields.
obj = typ.Scope.Lookup(name.Name)
if obj == nil {
tc.Errorf(name.Pos(), "%s not declared", name.Name)
obj = ast.NewObj(ast.Bad, name.Name)
}
return
}
func (p *parser) parseIdent(kind ast.ObjKind) *ast.Ident {
obj := ast.NewObj(kind, p.pos, "_")
if p.tok == token.IDENT {
obj.Name = string(p.lit)
p.next()
} else {
p.expect(token.IDENT) // use expect() error handling
}
return &ast.Ident{obj.Pos, obj}
}
func importer(imports map[string]*ast.Object, path string) (*ast.Object, error) {
pkg := imports[path]
if pkg == nil {
name := path[strings.LastIndex(path, "/")+1:]
pkg = ast.NewObj(ast.Pkg, name)
pkg.Data = ast.NewScope(nil) // required by ast.NewPackage for dot-import
imports[path] = pkg
}
return pkg, nil
}
// poorMansImporter returns a (dummy) package object named
// by the last path component of the provided package path
// (as is the convention for packages). This is sufficient
// to resolve package identifiers without doing an actual
// import. It never returns an error.
//
func poorMansImporter(imports map[string]*ast.Object, path string) (*ast.Object, error) {
pkg := imports[path]
if pkg == nil {
// note that strings.LastIndex returns -1 if there is no "/"
pkg = ast.NewObj(ast.Pkg, path[strings.LastIndex(path, "/")+1:])
pkg.Data = ast.NewScope(nil) // required by ast.NewPackage for dot-import
imports[path] = pkg
}
return pkg, nil
}
// declInScope declares an object of a given kind and name in scope and sets the object's Decl and N fields.
// It returns the newly allocated object. If an object with the same name already exists in scope, an error
// is reported and the object is not inserted.
// (Objects with _ name are always inserted into a scope without errors, but they cannot be found.)
func (tc *typechecker) declInScope(scope *ast.Scope, kind ast.Kind, name *ast.Ident, decl interface{}, n int) *ast.Object {
obj := ast.NewObj(kind, name.Name)
obj.Decl = decl
obj.N = n
name.Obj = obj
if alt := scope.Insert(obj); alt != obj {
tc.Errorf(name.Pos(), "%s already declared at %s", name.Name, objPos(alt))
}
return obj
}
// collectFields collects struct fields tok = token.STRUCT), interface methods
// (tok = token.INTERFACE), and function arguments/results (tok = token.FUNC).
func (c *checker) collectFields(tok token.Token, list *ast.FieldList, cycleOk bool) (fields ObjList, tags []string, isVariadic bool) {
if list != nil {
for _, field := range list.List {
ftype := field.Type
if t, ok := ftype.(*ast.Ellipsis); ok {
ftype = t.Elt
isVariadic = true
}
typ := c.makeType(ftype, cycleOk)
if isVariadic {
typ = &Slice{Elt: typ}
}
tag := ""
if field.Tag != nil {
assert(field.Tag.Kind == token.STRING)
tag, _ = strconv.Unquote(field.Tag.Value)
}
if len(field.Names) > 0 {
// named fields
for _, name := range field.Names {
obj := name.Obj
obj.Type = typ
fields = append(fields, obj)
if tok == token.STRUCT {
tags = append(tags, tag)
}
}
} else {
// anonymous field
switch tok {
case token.STRUCT:
tags = append(tags, tag)
fallthrough
case token.FUNC:
obj := ast.NewObj(ast.Var, "")
obj.Type = typ
fields = append(fields, obj)
case token.INTERFACE:
utyp := Underlying(typ)
if typ, ok := utyp.(*Interface); ok {
// TODO(gri) This is not good enough. Check for double declarations!
fields = append(fields, typ.Methods...)
} else if _, ok := utyp.(*Bad); !ok {
// if utyp is Bad, don't complain (the root cause was reported before)
c.errorf(ftype.Pos(), "interface contains embedded non-interface type")
}
default:
panic("unreachable")
}
}
}
}
return
}
// find returns the object with the given name if visible in the current scope hierarchy.
// If no such object is found, an error is reported and a bad object is returned instead.
func (tc *typechecker) find(name *ast.Ident) (obj *ast.Object) {
for s := tc.topScope; s != nil && obj == nil; s = s.Outer {
obj = s.Lookup(name.Name)
}
if obj == nil {
tc.Errorf(name.Pos(), "%s not declared", name.Name)
obj = ast.NewObj(ast.Bad, name.Name)
}
name.Obj = obj
return
}
// MethodSpec = ( identifier | ExportedName ) Signature .
//
func (p *gcParser) parseMethodSpec() *ast.Object {
if p.tok == scanner.Ident {
p.expect(scanner.Ident)
} else {
p.parseExportedName()
}
p.parseSignature()
// TODO(gri) compute method object
return ast.NewObj(ast.Fun, "_")
}
func init() {
// Universe scope
Universe = ast.NewScope(nil)
// unsafe package and its scope
unsafe = ast.NewScope(nil)
Unsafe = ast.NewObj(ast.Pkg, "unsafe")
Unsafe.Data = unsafe
// predeclared types
for _, t := range Typ {
def(ast.Typ, t.Name).Type = t
}
for _, t := range aliases {
def(ast.Typ, t.Name).Type = t
}
// error type
{
res := ast.NewObj(ast.Var, "")
res.Type = Typ[String]
err := ast.NewObj(ast.Fun, "Error")
err.Type = &Signature{Results: ObjList{res}}
obj := def(ast.Typ, "error")
obj.Type = &NamedType{Underlying: &Interface{Methods: ObjList{err}}, Obj: obj}
}
// predeclared constants
for _, t := range predeclaredConstants {
obj := def(ast.Con, t.name)
obj.Type = Typ[t.kind]
obj.Data = t.val
}
// predeclared functions
for _, f := range predeclaredFunctions {
def(ast.Fun, f.name).Type = f
}
universeIota = Universe.Lookup("iota")
}
// declInScope declares an object of a given kind and name in scope and sets the object's Decl and N fields.
// It returns the newly allocated object. If an object with the same name already exists in scope, an error
// is reported and the object is not inserted.
func (tc *typechecker) declInScope(scope *ast.Scope, kind ast.ObjKind, name *ast.Ident, decl interface{}, n int) *ast.Object {
obj := ast.NewObj(kind, name.Name)
obj.Decl = decl
//obj.N = n
name.Obj = obj
if name.Name != "_" {
if alt := scope.Insert(obj); alt != nil {
tc.Errorf(name.Pos(), "%s already declared at %s", name.Name, tc.fset.Position(alt.Pos()).String())
}
}
return obj
}
func (v *refsSaver) importer() ast.Importer {
return func(imports map[string]*ast.Object, pkgPath string) (*ast.Object, error) {
if pkg, exists := imports[pkgPath]; exists {
return pkg, nil
}
if !strings.HasPrefix(pkgPath, v.pkgPrefix) {
return nil, errors.New("ignored")
}
pkg := ast.NewObj(ast.Pkg, path.Base(pkgPath))
imports[pkgPath] = pkg
return pkg, nil
}
}
func (p *parser) makeIdentList(list *vector.Vector) []*ast.Ident {
idents := make([]*ast.Ident, list.Len())
for i := 0; i < list.Len(); i++ {
ident, isIdent := list.At(i).(*ast.Ident)
if !isIdent {
pos := list.At(i).(ast.Expr).Pos()
p.errorExpected(pos, "identifier")
idents[i] = &ast.Ident{pos, ast.NewObj(ast.Err, pos, "")}
}
idents[i] = ident
}
return idents
}
func (c *compiler) VisitStructType(s *ast.StructType) TypeValue {
var typ = new(types.Struct)
if s.Fields != nil && s.Fields.List != nil {
tags := make(map[*ast.Object]string)
var i int = 0
for _, field := range s.Fields.List {
fieldtype := c.GetType(field.Type)
if field.Names != nil {
for _, name := range field.Names {
obj := name.Obj
if obj == nil {
obj = ast.NewObj(ast.Var, "_")
}
obj.Type = fieldtype
typ.Fields = append(typ.Fields, obj)
if field.Tag != nil {
tags[obj] = field.Tag.Value
}
}
i += len(field.Names)
} else {
obj := ast.NewObj(ast.Var, "_")
obj.Type = fieldtype
typ.Fields = append(typ.Fields, obj)
if field.Tag != nil {
tags[obj] = field.Tag.Value
}
i++
}
}
typ.Tags = make([]string, len(typ.Fields))
for i, field := range typ.Fields {
// TODO unquote string?
typ.Tags[i] = tags[field]
}
}
return TypeValue{typ}
}
func (p *parser) makeIdentList(list *vector.Vector) []*ast.Ident {
idents := make([]*ast.Ident, len(*list))
for i, x := range *list {
ident, isIdent := x.(*ast.Ident)
if !isIdent {
pos := x.(ast.Expr).Pos()
p.errorExpected(pos, "identifier")
ident = &ast.Ident{pos, ast.NewObj(ast.Err, pos, "_")}
}
idents[i] = ident
}
return idents
}
// NewTestFuncDecl creates a new FuncDecl for starndard testing
// without position.
func NewTestFuncDecl(name string) *ast.FuncDecl {
ident := ast.NewIdent(name)
ident.Obj = ast.NewObj(ast.Fun, name)
identVarT := ast.NewIdent("t")
identVarT.Obj = ast.NewObj(ast.Var, "t")
// params are params for func
params := &ast.FieldList{
List: []*ast.Field{
{
// t
Names: []*ast.Ident{
identVarT,
},
// *testing.T
Type: &ast.StarExpr{
X: &ast.SelectorExpr{
X: ast.NewIdent("testing"),
Sel: ast.NewIdent("T"),
},
},
},
},
}
funcType := &ast.FuncType{
Params: params,
}
return &ast.FuncDecl{
Name: ident,
Type: funcType,
Body: &ast.BlockStmt{},
}
}