+++ /dev/null
-// 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 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 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() }
projects / dotfiles / .git / blobdiff