diff options
Diffstat (limited to 'vendor/golang.org/x/tools/go/internal/gcimporter/gcimporter.go')
| -rw-r--r-- | vendor/golang.org/x/tools/go/internal/gcimporter/gcimporter.go | 1078 |
1 files changed, 0 insertions, 1078 deletions
diff --git a/vendor/golang.org/x/tools/go/internal/gcimporter/gcimporter.go b/vendor/golang.org/x/tools/go/internal/gcimporter/gcimporter.go deleted file mode 100644 index 9cf18660..00000000 --- a/vendor/golang.org/x/tools/go/internal/gcimporter/gcimporter.go +++ /dev/null @@ -1,1078 +0,0 @@ -// Copyright 2011 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -// This file is a modified copy of $GOROOT/src/go/internal/gcimporter/gcimporter.go, -// but it also contains the original source-based importer code for Go1.6. -// Once we stop supporting 1.6, we can remove that code. - -// Package gcimporter provides various functions for reading -// gc-generated object files that can be used to implement the -// Importer interface defined by the Go 1.5 standard library package. -package gcimporter // import "golang.org/x/tools/go/internal/gcimporter" - -import ( - "bufio" - "errors" - "fmt" - "go/build" - "go/constant" - "go/token" - "go/types" - "io" - "io/ioutil" - "os" - "path/filepath" - "sort" - "strconv" - "strings" - "text/scanner" -) - -// debugging/development support -const debug = false - -var pkgExts = [...]string{".a", ".o"} - -// FindPkg returns the filename and unique package id for an import -// path based on package information provided by build.Import (using -// the build.Default build.Context). A relative srcDir is interpreted -// relative to the current working directory. -// If no file was found, an empty filename is returned. -// -func FindPkg(path, srcDir string) (filename, id string) { - if path == "" { - return - } - - var noext string - switch { - default: - // "x" -> "$GOPATH/pkg/$GOOS_$GOARCH/x.ext", "x" - // Don't require the source files to be present. - if abs, err := filepath.Abs(srcDir); err == nil { // see issue 14282 - srcDir = abs - } - bp, _ := build.Import(path, srcDir, build.FindOnly|build.AllowBinary) - if bp.PkgObj == "" { - id = path // make sure we have an id to print in error message - return - } - noext = strings.TrimSuffix(bp.PkgObj, ".a") - id = bp.ImportPath - - case build.IsLocalImport(path): - // "./x" -> "/this/directory/x.ext", "/this/directory/x" - noext = filepath.Join(srcDir, path) - id = noext - - case filepath.IsAbs(path): - // for completeness only - go/build.Import - // does not support absolute imports - // "/x" -> "/x.ext", "/x" - noext = path - id = path - } - - if false { // for debugging - if path != id { - fmt.Printf("%s -> %s\n", path, id) - } - } - - // try extensions - for _, ext := range pkgExts { - filename = noext + ext - if f, err := os.Stat(filename); err == nil && !f.IsDir() { - return - } - } - - filename = "" // not found - return -} - -// ImportData imports a package by reading the gc-generated export data, -// adds the corresponding package object to the packages map indexed by id, -// and returns the object. -// -// The packages map must contains all packages already imported. The data -// reader position must be the beginning of the export data section. The -// filename is only used in error messages. -// -// If packages[id] contains the completely imported package, that package -// can be used directly, and there is no need to call this function (but -// there is also no harm but for extra time used). -// -func ImportData(packages map[string]*types.Package, filename, id string, data io.Reader) (pkg *types.Package, err error) { - // support for parser error handling - defer func() { - switch r := recover().(type) { - case nil: - // nothing to do - case importError: - err = r - default: - panic(r) // internal error - } - }() - - var p parser - p.init(filename, id, data, packages) - pkg = p.parseExport() - - return -} - -// Import imports a gc-generated package given its import path and srcDir, adds -// the corresponding package object to the packages map, and returns the object. -// The packages map must contain all packages already imported. -// -func Import(packages map[string]*types.Package, path, srcDir string, lookup func(path string) (io.ReadCloser, error)) (pkg *types.Package, err error) { - var rc io.ReadCloser - var filename, id string - if lookup != nil { - // With custom lookup specified, assume that caller has - // converted path to a canonical import path for use in the map. - if path == "unsafe" { - return types.Unsafe, nil - } - id = path - - // No need to re-import if the package was imported completely before. - if pkg = packages[id]; pkg != nil && pkg.Complete() { - return - } - f, err := lookup(path) - if err != nil { - return nil, err - } - rc = f - } else { - filename, id = FindPkg(path, srcDir) - if filename == "" { - if path == "unsafe" { - return types.Unsafe, nil - } - return nil, fmt.Errorf("can't find import: %q", id) - } - - // no need to re-import if the package was imported completely before - if pkg = packages[id]; pkg != nil && pkg.Complete() { - return - } - - // open file - f, err := os.Open(filename) - if err != nil { - return nil, err - } - defer func() { - if err != nil { - // add file name to error - err = fmt.Errorf("%s: %v", filename, err) - } - }() - rc = f - } - defer rc.Close() - - var hdr string - buf := bufio.NewReader(rc) - if hdr, err = FindExportData(buf); err != nil { - return - } - - switch hdr { - case "$$\n": - // Work-around if we don't have a filename; happens only if lookup != nil. - // Either way, the filename is only needed for importer error messages, so - // this is fine. - if filename == "" { - filename = path - } - return ImportData(packages, filename, id, buf) - - case "$$B\n": - var data []byte - data, err = ioutil.ReadAll(buf) - if err != nil { - break - } - - // TODO(gri): allow clients of go/importer to provide a FileSet. - // Or, define a new standard go/types/gcexportdata package. - fset := token.NewFileSet() - - // The indexed export format starts with an 'i'; the older - // binary export format starts with a 'c', 'd', or 'v' - // (from "version"). Select appropriate importer. - if len(data) > 0 && data[0] == 'i' { - _, pkg, err = IImportData(fset, packages, data[1:], id) - } else { - _, pkg, err = BImportData(fset, packages, data, id) - } - - default: - err = fmt.Errorf("unknown export data header: %q", hdr) - } - - return -} - -// ---------------------------------------------------------------------------- -// Parser - -// TODO(gri) Imported objects don't have position information. -// Ideally use the debug table line info; alternatively -// create some fake position (or the position of the -// import). That way error messages referring to imported -// objects can print meaningful information. - -// parser parses the exports inside a gc compiler-produced -// object/archive file and populates its scope with the results. -type parser struct { - scanner scanner.Scanner - tok rune // current token - lit string // literal string; only valid for Ident, Int, String tokens - id string // package id of imported package - sharedPkgs map[string]*types.Package // package id -> package object (across importer) - localPkgs map[string]*types.Package // package id -> package object (just this package) -} - -func (p *parser) init(filename, id string, src io.Reader, packages map[string]*types.Package) { - p.scanner.Init(src) - p.scanner.Error = func(_ *scanner.Scanner, msg string) { p.error(msg) } - p.scanner.Mode = scanner.ScanIdents | scanner.ScanInts | scanner.ScanChars | scanner.ScanStrings | scanner.ScanComments | scanner.SkipComments - p.scanner.Whitespace = 1<<'\t' | 1<<' ' - p.scanner.Filename = filename // for good error messages - p.next() - p.id = id - p.sharedPkgs = packages - if debug { - // check consistency of packages map - for _, pkg := range packages { - if pkg.Name() == "" { - fmt.Printf("no package name for %s\n", pkg.Path()) - } - } - } -} - -func (p *parser) next() { - p.tok = p.scanner.Scan() - switch p.tok { - case scanner.Ident, scanner.Int, scanner.Char, scanner.String, '·': - p.lit = p.scanner.TokenText() - default: - p.lit = "" - } - if debug { - fmt.Printf("%s: %q -> %q\n", scanner.TokenString(p.tok), p.scanner.TokenText(), p.lit) - } -} - -func declTypeName(pkg *types.Package, name string) *types.TypeName { - scope := pkg.Scope() - if obj := scope.Lookup(name); obj != nil { - return obj.(*types.TypeName) - } - obj := types.NewTypeName(token.NoPos, pkg, name, nil) - // a named type may be referred to before the underlying type - // is known - set it up - types.NewNamed(obj, nil, nil) - scope.Insert(obj) - return obj -} - -// ---------------------------------------------------------------------------- -// Error handling - -// Internal errors are boxed as importErrors. -type importError struct { - pos scanner.Position - err error -} - -func (e importError) Error() string { - return fmt.Sprintf("import error %s (byte offset = %d): %s", e.pos, e.pos.Offset, e.err) -} - -func (p *parser) error(err interface{}) { - if s, ok := err.(string); ok { - err = errors.New(s) - } - // panic with a runtime.Error if err is not an error - panic(importError{p.scanner.Pos(), err.(error)}) -} - -func (p *parser) errorf(format string, args ...interface{}) { - p.error(fmt.Sprintf(format, args...)) -} - -func (p *parser) expect(tok rune) string { - lit := p.lit - if p.tok != tok { - p.errorf("expected %s, got %s (%s)", scanner.TokenString(tok), scanner.TokenString(p.tok), lit) - } - p.next() - return lit -} - -func (p *parser) expectSpecial(tok string) { - sep := 'x' // not white space - i := 0 - for i < len(tok) && p.tok == rune(tok[i]) && sep > ' ' { - sep = p.scanner.Peek() // if sep <= ' ', there is white space before the next token - p.next() - i++ - } - if i < len(tok) { - p.errorf("expected %q, got %q", tok, tok[0:i]) - } -} - -func (p *parser) expectKeyword(keyword string) { - lit := p.expect(scanner.Ident) - if lit != keyword { - p.errorf("expected keyword %s, got %q", keyword, lit) - } -} - -// ---------------------------------------------------------------------------- -// Qualified and unqualified names - -// PackageId = string_lit . -// -func (p *parser) parsePackageId() string { - id, err := strconv.Unquote(p.expect(scanner.String)) - if err != nil { - p.error(err) - } - // id == "" stands for the imported package id - // (only known at time of package installation) - if id == "" { - id = p.id - } - return id -} - -// PackageName = ident . -// -func (p *parser) parsePackageName() string { - return p.expect(scanner.Ident) -} - -// dotIdentifier = ( ident | '·' ) { ident | int | '·' } . -func (p *parser) parseDotIdent() string { - ident := "" - if p.tok != scanner.Int { - sep := 'x' // not white space - for (p.tok == scanner.Ident || p.tok == scanner.Int || p.tok == '·') && sep > ' ' { - ident += p.lit - sep = p.scanner.Peek() // if sep <= ' ', there is white space before the next token - p.next() - } - } - if ident == "" { - p.expect(scanner.Ident) // use expect() for error handling - } - return ident -} - -// QualifiedName = "@" PackageId "." ( "?" | dotIdentifier ) . -// -func (p *parser) parseQualifiedName() (id, name string) { - p.expect('@') - id = p.parsePackageId() - p.expect('.') - // Per rev f280b8a485fd (10/2/2013), qualified names may be used for anonymous fields. - if p.tok == '?' { - p.next() - } else { - name = p.parseDotIdent() - } - return -} - -// getPkg returns the package for a given id. If the package is -// not found, create the package and add it to the p.localPkgs -// and p.sharedPkgs maps. name is the (expected) name of the -// package. If name == "", the package name is expected to be -// set later via an import clause in the export data. -// -// id identifies a package, usually by a canonical package path like -// "encoding/json" but possibly by a non-canonical import path like -// "./json". -// -func (p *parser) getPkg(id, name string) *types.Package { - // package unsafe is not in the packages maps - handle explicitly - if id == "unsafe" { - return types.Unsafe - } - - pkg := p.localPkgs[id] - if pkg == nil { - // first import of id from this package - pkg = p.sharedPkgs[id] - if pkg == nil { - // first import of id by this importer; - // add (possibly unnamed) pkg to shared packages - pkg = types.NewPackage(id, name) - p.sharedPkgs[id] = pkg - } - // add (possibly unnamed) pkg to local packages - if p.localPkgs == nil { - p.localPkgs = make(map[string]*types.Package) - } - p.localPkgs[id] = pkg - } else if name != "" { - // package exists already and we have an expected package name; - // make sure names match or set package name if necessary - if pname := pkg.Name(); pname == "" { - pkg.SetName(name) - } else if pname != name { - p.errorf("%s package name mismatch: %s (given) vs %s (expected)", id, pname, name) - } - } - return pkg -} - -// parseExportedName is like parseQualifiedName, but -// the package id is resolved to an imported *types.Package. -// -func (p *parser) parseExportedName() (pkg *types.Package, name string) { - id, name := p.parseQualifiedName() - pkg = p.getPkg(id, "") - return -} - -// ---------------------------------------------------------------------------- -// Types - -// BasicType = identifier . -// -func (p *parser) parseBasicType() types.Type { - id := p.expect(scanner.Ident) - obj := types.Universe.Lookup(id) - if obj, ok := obj.(*types.TypeName); ok { - return obj.Type() - } - p.errorf("not a basic type: %s", id) - return nil -} - -// ArrayType = "[" int_lit "]" Type . -// -func (p *parser) parseArrayType(parent *types.Package) types.Type { - // "[" already consumed and lookahead known not to be "]" - lit := p.expect(scanner.Int) - p.expect(']') - elem := p.parseType(parent) - n, err := strconv.ParseInt(lit, 10, 64) - if err != nil { - p.error(err) - } - return types.NewArray(elem, n) -} - -// MapType = "map" "[" Type "]" Type . -// -func (p *parser) parseMapType(parent *types.Package) types.Type { - p.expectKeyword("map") - p.expect('[') - key := p.parseType(parent) - p.expect(']') - elem := p.parseType(parent) - return types.NewMap(key, elem) -} - -// Name = identifier | "?" | QualifiedName . -// -// For unqualified and anonymous names, the returned package is the parent -// package unless parent == nil, in which case the returned package is the -// package being imported. (The parent package is not nil if the the name -// is an unqualified struct field or interface method name belonging to a -// type declared in another package.) -// -// For qualified names, the returned package is nil (and not created if -// it doesn't exist yet) unless materializePkg is set (which creates an -// unnamed package with valid package path). In the latter case, a -// subsequent import clause is expected to provide a name for the package. -// -func (p *parser) parseName(parent *types.Package, materializePkg bool) (pkg *types.Package, name string) { - pkg = parent - if pkg == nil { - pkg = p.sharedPkgs[p.id] - } - switch p.tok { - case scanner.Ident: - name = p.lit - p.next() - case '?': - // anonymous - p.next() - case '@': - // exported name prefixed with package path - pkg = nil - var id string - id, name = p.parseQualifiedName() - if materializePkg { - pkg = p.getPkg(id, "") - } - default: - p.error("name expected") - } - return -} - -func deref(typ types.Type) types.Type { - if p, _ := typ.(*types.Pointer); p != nil { - return p.Elem() - } - return typ -} - -// Field = Name Type [ string_lit ] . -// -func (p *parser) parseField(parent *types.Package) (*types.Var, string) { - pkg, name := p.parseName(parent, true) - - if name == "_" { - // Blank fields should be package-qualified because they - // are unexported identifiers, but gc does not qualify them. - // Assuming that the ident belongs to the current package - // causes types to change during re-exporting, leading - // to spurious "can't assign A to B" errors from go/types. - // As a workaround, pretend all blank fields belong - // to the same unique dummy package. - const blankpkg = "<_>" - pkg = p.getPkg(blankpkg, blankpkg) - } - - typ := p.parseType(parent) - anonymous := false - if name == "" { - // anonymous field - typ must be T or *T and T must be a type name - switch typ := deref(typ).(type) { - case *types.Basic: // basic types are named types - pkg = nil // objects defined in Universe scope have no package - name = typ.Name() - case *types.Named: - name = typ.Obj().Name() - default: - p.errorf("anonymous field expected") - } - anonymous = true - } - tag := "" - if p.tok == scanner.String { - s := p.expect(scanner.String) - var err error - tag, err = strconv.Unquote(s) - if err != nil { - p.errorf("invalid struct tag %s: %s", s, err) - } - } - return types.NewField(token.NoPos, pkg, name, typ, anonymous), tag -} - -// StructType = "struct" "{" [ FieldList ] "}" . -// FieldList = Field { ";" Field } . -// -func (p *parser) parseStructType(parent *types.Package) types.Type { - var fields []*types.Var - var tags []string - - p.expectKeyword("struct") - p.expect('{') - for i := 0; p.tok != '}' && p.tok != scanner.EOF; i++ { - if i > 0 { - p.expect(';') - } - fld, tag := p.parseField(parent) - if tag != "" && tags == nil { - tags = make([]string, i) - } - if tags != nil { - tags = append(tags, tag) - } - fields = append(fields, fld) - } - p.expect('}') - - return types.NewStruct(fields, tags) -} - -// Parameter = ( identifier | "?" ) [ "..." ] Type [ string_lit ] . -// -func (p *parser) parseParameter() (par *types.Var, isVariadic bool) { - _, name := p.parseName(nil, false) - // remove gc-specific parameter numbering - if i := strings.Index(name, "·"); i >= 0 { - name = name[:i] - } - if p.tok == '.' { - p.expectSpecial("...") - isVariadic = true - } - typ := p.parseType(nil) - if isVariadic { - typ = types.NewSlice(typ) - } - // ignore argument tag (e.g. "noescape") - if p.tok == scanner.String { - p.next() - } - // TODO(gri) should we provide a package? - par = types.NewVar(token.NoPos, nil, name, typ) - return -} - -// Parameters = "(" [ ParameterList ] ")" . -// ParameterList = { Parameter "," } Parameter . -// -func (p *parser) parseParameters() (list []*types.Var, isVariadic bool) { - p.expect('(') - for p.tok != ')' && p.tok != scanner.EOF { - if len(list) > 0 { - p.expect(',') - } - par, variadic := p.parseParameter() - list = append(list, par) - if variadic { - if isVariadic { - p.error("... not on final argument") - } - isVariadic = true - } - } - p.expect(')') - - return -} - -// Signature = Parameters [ Result ] . -// Result = Type | Parameters . -// -func (p *parser) parseSignature(recv *types.Var) *types.Signature { - params, isVariadic := p.parseParameters() - - // optional result type - var results []*types.Var - if p.tok == '(' { - var variadic bool - results, variadic = p.parseParameters() - if variadic { - p.error("... not permitted on result type") - } - } - - return types.NewSignature(recv, types.NewTuple(params...), types.NewTuple(results...), isVariadic) -} - -// InterfaceType = "interface" "{" [ MethodList ] "}" . -// MethodList = Method { ";" Method } . -// Method = Name Signature . -// -// The methods of embedded interfaces are always "inlined" -// by the compiler and thus embedded interfaces are never -// visible in the export data. -// -func (p *parser) parseInterfaceType(parent *types.Package) types.Type { - var methods []*types.Func - - p.expectKeyword("interface") - p.expect('{') - for i := 0; p.tok != '}' && p.tok != scanner.EOF; i++ { - if i > 0 { - p.expect(';') - } - pkg, name := p.parseName(parent, true) - sig := p.parseSignature(nil) - methods = append(methods, types.NewFunc(token.NoPos, pkg, name, sig)) - } - p.expect('}') - - // Complete requires the type's embedded interfaces to be fully defined, - // but we do not define any - return types.NewInterface(methods, nil).Complete() -} - -// ChanType = ( "chan" [ "<-" ] | "<-" "chan" ) Type . -// -func (p *parser) parseChanType(parent *types.Package) types.Type { - dir := types.SendRecv - if p.tok == scanner.Ident { - p.expectKeyword("chan") - if p.tok == '<' { - p.expectSpecial("<-") - dir = types.SendOnly - } - } else { - p.expectSpecial("<-") - p.expectKeyword("chan") - dir = types.RecvOnly - } - elem := p.parseType(parent) - return types.NewChan(dir, elem) -} - -// Type = -// BasicType | TypeName | ArrayType | SliceType | StructType | -// PointerType | FuncType | InterfaceType | MapType | ChanType | -// "(" Type ")" . -// -// BasicType = ident . -// TypeName = ExportedName . -// SliceType = "[" "]" Type . -// PointerType = "*" Type . -// FuncType = "func" Signature . -// -func (p *parser) parseType(parent *types.Package) types.Type { - switch p.tok { - case scanner.Ident: - switch p.lit { - default: - return p.parseBasicType() - case "struct": - return p.parseStructType(parent) - case "func": - // FuncType - p.next() - return p.parseSignature(nil) - case "interface": - return p.parseInterfaceType(parent) - case "map": - return p.parseMapType(parent) - case "chan": - return p.parseChanType(parent) - } - case '@': - // TypeName - pkg, name := p.parseExportedName() - return declTypeName(pkg, name).Type() - case '[': - p.next() // look ahead - if p.tok == ']' { - // SliceType - p.next() - return types.NewSlice(p.parseType(parent)) - } - return p.parseArrayType(parent) - case '*': - // PointerType - p.next() - return types.NewPointer(p.parseType(parent)) - case '<': - return p.parseChanType(parent) - case '(': - // "(" Type ")" - p.next() - typ := p.parseType(parent) - p.expect(')') - return typ - } - p.errorf("expected type, got %s (%q)", scanner.TokenString(p.tok), p.lit) - return nil -} - -// ---------------------------------------------------------------------------- -// Declarations - -// ImportDecl = "import" PackageName PackageId . -// -func (p *parser) parseImportDecl() { - p.expectKeyword("import") - name := p.parsePackageName() - p.getPkg(p.parsePackageId(), name) -} - -// int_lit = [ "+" | "-" ] { "0" ... "9" } . -// -func (p *parser) parseInt() string { - s := "" - switch p.tok { - case '-': - s = "-" - p.next() - case '+': - p.next() - } - return s + p.expect(scanner.Int) -} - -// number = int_lit [ "p" int_lit ] . -// -func (p *parser) parseNumber() (typ *types.Basic, val constant.Value) { - // mantissa - mant := constant.MakeFromLiteral(p.parseInt(), token.INT, 0) - if mant == nil { - panic("invalid mantissa") - } - - if p.lit == "p" { - // exponent (base 2) - p.next() - exp, err := strconv.ParseInt(p.parseInt(), 10, 0) - if err != nil { - p.error(err) - } - if exp < 0 { - denom := constant.MakeInt64(1) - denom = constant.Shift(denom, token.SHL, uint(-exp)) - typ = types.Typ[types.UntypedFloat] - val = constant.BinaryOp(mant, token.QUO, denom) - return - } - if exp > 0 { - mant = constant.Shift(mant, token.SHL, uint(exp)) - } - typ = types.Typ[types.UntypedFloat] - val = mant - return - } - - typ = types.Typ[types.UntypedInt] - val = mant - return -} - -// ConstDecl = "const" ExportedName [ Type ] "=" Literal . -// Literal = bool_lit | int_lit | float_lit | complex_lit | rune_lit | string_lit . -// bool_lit = "true" | "false" . -// complex_lit = "(" float_lit "+" float_lit "i" ")" . -// rune_lit = "(" int_lit "+" int_lit ")" . -// string_lit = `"` { unicode_char } `"` . -// -func (p *parser) parseConstDecl() { - p.expectKeyword("const") - pkg, name := p.parseExportedName() - - var typ0 types.Type - if p.tok != '=' { - // constant types are never structured - no need for parent type - typ0 = p.parseType(nil) - } - - p.expect('=') - var typ types.Type - var val constant.Value - switch p.tok { - case scanner.Ident: - // bool_lit - if p.lit != "true" && p.lit != "false" { - p.error("expected true or false") - } - typ = types.Typ[types.UntypedBool] - val = constant.MakeBool(p.lit == "true") - p.next() - - case '-', scanner.Int: - // int_lit - typ, val = p.parseNumber() - - case '(': - // complex_lit or rune_lit - p.next() - if p.tok == scanner.Char { - p.next() - p.expect('+') - typ = types.Typ[types.UntypedRune] - _, val = p.parseNumber() - p.expect(')') - break - } - _, re := p.parseNumber() - p.expect('+') - _, im := p.parseNumber() - p.expectKeyword("i") - p.expect(')') - typ = types.Typ[types.UntypedComplex] - val = constant.BinaryOp(re, token.ADD, constant.MakeImag(im)) - - case scanner.Char: - // rune_lit - typ = types.Typ[types.UntypedRune] - val = constant.MakeFromLiteral(p.lit, token.CHAR, 0) - p.next() - - case scanner.String: - // string_lit - typ = types.Typ[types.UntypedString] - val = constant.MakeFromLiteral(p.lit, token.STRING, 0) - p.next() - - default: - p.errorf("expected literal got %s", scanner.TokenString(p.tok)) - } - - if typ0 == nil { - typ0 = typ - } - - pkg.Scope().Insert(types.NewConst(token.NoPos, pkg, name, typ0, val)) -} - -// TypeDecl = "type" ExportedName Type . -// -func (p *parser) parseTypeDecl() { - p.expectKeyword("type") - pkg, name := p.parseExportedName() - obj := declTypeName(pkg, name) - - // The type object may have been imported before and thus already - // have a type associated with it. We still need to parse the type - // structure, but throw it away if the object already has a type. - // This ensures that all imports refer to the same type object for - // a given type declaration. - typ := p.parseType(pkg) - - if name := obj.Type().(*types.Named); name.Underlying() == nil { - name.SetUnderlying(typ) - } -} - -// VarDecl = "var" ExportedName Type . -// -func (p *parser) parseVarDecl() { - p.expectKeyword("var") - pkg, name := p.parseExportedName() - typ := p.parseType(pkg) - pkg.Scope().Insert(types.NewVar(token.NoPos, pkg, name, typ)) -} - -// Func = Signature [ Body ] . -// Body = "{" ... "}" . -// -func (p *parser) parseFunc(recv *types.Var) *types.Signature { - sig := p.parseSignature(recv) - if p.tok == '{' { - p.next() - for i := 1; i > 0; p.next() { - switch p.tok { - case '{': - i++ - case '}': - i-- - } - } - } - return sig -} - -// MethodDecl = "func" Receiver Name Func . -// Receiver = "(" ( identifier | "?" ) [ "*" ] ExportedName ")" . -// -func (p *parser) parseMethodDecl() { - // "func" already consumed - p.expect('(') - recv, _ := p.parseParameter() // receiver - p.expect(')') - - // determine receiver base type object - base := deref(recv.Type()).(*types.Named) - - // parse method name, signature, and possibly inlined body - _, name := p.parseName(nil, false) - sig := p.parseFunc(recv) - - // methods always belong to the same package as the base type object - pkg := base.Obj().Pkg() - - // add method to type unless type was imported before - // and method exists already - // TODO(gri) This leads to a quadratic algorithm - ok for now because method counts are small. - base.AddMethod(types.NewFunc(token.NoPos, pkg, name, sig)) -} - -// FuncDecl = "func" ExportedName Func . -// -func (p *parser) parseFuncDecl() { - // "func" already consumed - pkg, name := p.parseExportedName() - typ := p.parseFunc(nil) - pkg.Scope().Insert(types.NewFunc(token.NoPos, pkg, name, typ)) -} - -// Decl = [ ImportDecl | ConstDecl | TypeDecl | VarDecl | FuncDecl | MethodDecl ] "\n" . -// -func (p *parser) parseDecl() { - if p.tok == scanner.Ident { - switch p.lit { - case "import": - p.parseImportDecl() - case "const": - p.parseConstDecl() - case "type": - p.parseTypeDecl() - case "var": - p.parseVarDecl() - case "func": - p.next() // look ahead - if p.tok == '(' { - p.parseMethodDecl() - } else { - p.parseFuncDecl() - } - } - } - p.expect('\n') -} - -// ---------------------------------------------------------------------------- -// Export - -// Export = "PackageClause { Decl } "$$" . -// PackageClause = "package" PackageName [ "safe" ] "\n" . -// -func (p *parser) parseExport() *types.Package { - p.expectKeyword("package") - name := p.parsePackageName() - if p.tok == scanner.Ident && p.lit == "safe" { - // package was compiled with -u option - ignore - p.next() - } - p.expect('\n') - - pkg := p.getPkg(p.id, name) - - for p.tok != '$' && p.tok != scanner.EOF { - p.parseDecl() - } - - if ch := p.scanner.Peek(); p.tok != '$' || ch != '$' { - // don't call next()/expect() since reading past the - // export data may cause scanner errors (e.g. NUL chars) - p.errorf("expected '$$', got %s %c", scanner.TokenString(p.tok), ch) - } - - if n := p.scanner.ErrorCount; n != 0 { - p.errorf("expected no scanner errors, got %d", n) - } - - // Record all locally referenced packages as imports. - var imports []*types.Package - for id, pkg2 := range p.localPkgs { - if pkg2.Name() == "" { - p.errorf("%s package has no name", id) - } - if id == p.id { - continue // avoid self-edge - } - imports = append(imports, pkg2) - } - sort.Sort(byPath(imports)) - pkg.SetImports(imports) - - // package was imported completely and without errors - pkg.MarkComplete() - - return pkg -} - -type byPath []*types.Package - -func (a byPath) Len() int { return len(a) } -func (a byPath) Swap(i, j int) { a[i], a[j] = a[j], a[i] } -func (a byPath) Less(i, j int) bool { return a[i].Path() < a[j].Path() } |