diff options
Diffstat (limited to 'gcc-4.8.1/libgo/go/go/types/gcimporter.go')
| -rw-r--r-- | gcc-4.8.1/libgo/go/go/types/gcimporter.go | 908 |
1 files changed, 0 insertions, 908 deletions
diff --git a/gcc-4.8.1/libgo/go/go/types/gcimporter.go b/gcc-4.8.1/libgo/go/go/types/gcimporter.go deleted file mode 100644 index edd3e4dec..000000000 --- a/gcc-4.8.1/libgo/go/go/types/gcimporter.go +++ /dev/null @@ -1,908 +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 implements an Importer for gc-generated object files. - -package types - -import ( - "bufio" - "errors" - "fmt" - "go/ast" - "go/build" - "go/token" - "io" - "math/big" - "os" - "path/filepath" - "strconv" - "strings" - "text/scanner" -) - -var pkgExts = [...]string{".a", ".5", ".6", ".8"} - -// 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). -// If no file was found, an empty filename is returned. -// -func FindPkg(path, srcDir string) (filename, id string) { - if len(path) == 0 { - return - } - - id = path - var noext string - switch { - default: - // "x" -> "$GOPATH/pkg/$GOOS_$GOARCH/x.ext", "x" - // Don't require the source files to be present. - bp, _ := build.Import(path, srcDir, build.FindOnly|build.AllowBinary) - if bp.PkgObj == "" { - return - } - noext = bp.PkgObj - if strings.HasSuffix(noext, ".a") { - noext = noext[:len(noext)-len(".a")] - } - - 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 - } - - // try extensions - for _, ext := range pkgExts { - filename = noext + ext - if f, err := os.Stat(filename); err == nil && !f.IsDir() { - return - } - } - - filename = "" // not found - return -} - -// GcImportData imports a package by reading the gc-generated export data, -// adds the corresponding package object to the imports map indexed by id, -// and returns the object. -// -// The imports 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 imports[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 GcImportData(imports map[string]*Package, filename, id string, data *bufio.Reader) (pkg *Package, err error) { - // support for gcParser error handling - defer func() { - if r := recover(); r != nil { - err = r.(importError) // will re-panic if r is not an importError - } - }() - - var p gcParser - p.init(filename, id, data, imports) - pkg = p.parseExport() - - return -} - -// GcImport imports a gc-generated package given its import path, adds the -// corresponding package object to the imports map, and returns the object. -// Local import paths are interpreted relative to the current working directory. -// The imports map must contains all packages already imported. -// GcImport satisfies the ast.Importer signature. -// -func GcImport(imports map[string]*Package, path string) (pkg *Package, err error) { - if path == "unsafe" { - return Unsafe, nil - } - - srcDir, err := os.Getwd() - if err != nil { - return - } - filename, id := FindPkg(path, srcDir) - if filename == "" { - err = errors.New("can't find import: " + id) - return - } - - // no need to re-import if the package was imported completely before - if pkg = imports[id]; pkg != nil && pkg.Complete { - return - } - - // open file - f, err := os.Open(filename) - if err != nil { - return - } - defer func() { - f.Close() - if err != nil { - // Add file name to error. - err = fmt.Errorf("reading export data: %s: %v", filename, err) - } - }() - - buf := bufio.NewReader(f) - if err = FindGcExportData(buf); err != nil { - return - } - - pkg, err = GcImportData(imports, filename, id, buf) - - return -} - -// ---------------------------------------------------------------------------- -// gcParser - -// gcParser parses the exports inside a gc compiler-produced -// object/archive file and populates its scope with the results. -type gcParser 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 - imports map[string]*Package // package id -> package object -} - -func (p *gcParser) init(filename, id string, src io.Reader, imports map[string]*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.imports = imports -} - -func (p *gcParser) 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 = "" - } - // leave for debugging - if false { - fmt.Printf("%s: %q -> %q\n", scanner.TokenString(p.tok), p.scanner.TokenText(), p.lit) - } -} - -func declConst(scope *Scope, name string) *Const { - // the constant may have been imported before - if it exists - // already in the respective scope, return that constant - if obj := scope.Lookup(name); obj != nil { - return obj.(*Const) - } - // otherwise create a new constant and insert it into the scope - obj := &Const{Name: name} - scope.Insert(obj) - return obj -} - -func declTypeName(scope *Scope, name string) *TypeName { - if obj := scope.Lookup(name); obj != nil { - return obj.(*TypeName) - } - obj := &TypeName{Name: name} - // a named type may be referred to before the underlying type - // is known - set it up - obj.Type = &NamedType{Obj: obj} - scope.Insert(obj) - return obj -} - -func declVar(scope *Scope, name string) *Var { - if obj := scope.Lookup(name); obj != nil { - return obj.(*Var) - } - obj := &Var{Name: name} - scope.Insert(obj) - return obj -} - -func declFunc(scope *Scope, name string) *Func { - if obj := scope.Lookup(name); obj != nil { - return obj.(*Func) - } - obj := &Func{Name: name} - 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 *gcParser) 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 *gcParser) errorf(format string, args ...interface{}) { - p.error(fmt.Sprintf(format, args...)) -} - -func (p *gcParser) 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 *gcParser) 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 *gcParser) expectKeyword(keyword string) { - lit := p.expect(scanner.Ident) - if lit != keyword { - p.errorf("expected keyword %s, got %q", keyword, lit) - } -} - -// ---------------------------------------------------------------------------- -// Import declarations - -// ImportPath = string_lit . -// -func (p *gcParser) parsePkgId() *Package { - 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 { - pkg = &Package{Scope: new(Scope)} - p.imports[id] = pkg - } - - return pkg -} - -// dotIdentifier = ( ident | '·' ) { ident | int | '·' } . -func (p *gcParser) 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 -} - -// ExportedName = "@" ImportPath "." dotIdentifier . -// -func (p *gcParser) parseExportedName() (*Package, string) { - p.expect('@') - pkg := p.parsePkgId() - p.expect('.') - name := p.parseDotIdent() - return pkg, name -} - -// ---------------------------------------------------------------------------- -// Types - -// BasicType = identifier . -// -func (p *gcParser) parseBasicType() Type { - id := p.expect(scanner.Ident) - obj := Universe.Lookup(id) - if obj, ok := obj.(*TypeName); ok { - return obj.Type - } - p.errorf("not a basic type: %s", id) - return nil -} - -// ArrayType = "[" int_lit "]" Type . -// -func (p *gcParser) parseArrayType() Type { - // "[" already consumed and lookahead known not to be "]" - lit := p.expect(scanner.Int) - p.expect(']') - elt := p.parseType() - n, err := strconv.ParseInt(lit, 10, 64) - if err != nil { - p.error(err) - } - return &Array{Len: n, Elt: elt} -} - -// MapType = "map" "[" Type "]" Type . -// -func (p *gcParser) parseMapType() Type { - p.expectKeyword("map") - p.expect('[') - key := p.parseType() - p.expect(']') - elt := p.parseType() - return &Map{Key: key, Elt: elt} -} - -// Name = identifier | "?" | ExportedName . -// -func (p *gcParser) parseName() (pkg *Package, name string) { - switch p.tok { - case scanner.Ident: - name = p.lit - p.next() - case '?': - // anonymous - p.next() - case '@': - // exported name prefixed with package path - pkg, name = p.parseExportedName() - default: - p.error("name expected") - } - return -} - -// Field = Name Type [ string_lit ] . -// -func (p *gcParser) parseField() *Field { - var f Field - f.Pkg, f.Name = p.parseName() - f.Type = p.parseType() - if p.tok == scanner.String { - f.Tag = p.expect(scanner.String) - } - if f.Name == "" { - // anonymous field - typ must be T or *T and T must be a type name - if typ, ok := deref(f.Type).(*NamedType); ok && typ.Obj != nil { - f.Name = typ.Obj.GetName() - f.IsAnonymous = true - } else { - p.errorf("anonymous field expected") - } - } - return &f -} - -// StructType = "struct" "{" [ FieldList ] "}" . -// FieldList = Field { ";" Field } . -// -func (p *gcParser) parseStructType() Type { - var fields []*Field - - p.expectKeyword("struct") - p.expect('{') - for p.tok != '}' { - if len(fields) > 0 { - p.expect(';') - } - fields = append(fields, p.parseField()) - } - p.expect('}') - - return &Struct{Fields: fields} -} - -// Parameter = ( identifier | "?" ) [ "..." ] Type [ string_lit ] . -// -func (p *gcParser) parseParameter() (par *Var, isVariadic bool) { - _, name := p.parseName() - if name == "" { - name = "_" // cannot access unnamed identifiers - } - if p.tok == '.' { - p.expectSpecial("...") - isVariadic = true - } - typ := p.parseType() - // ignore argument tag (e.g. "noescape") - if p.tok == scanner.String { - p.next() - } - par = &Var{Name: name, Type: typ} - return -} - -// Parameters = "(" [ ParameterList ] ")" . -// ParameterList = { Parameter "," } Parameter . -// -func (p *gcParser) parseParameters() (list []*Var, isVariadic bool) { - p.expect('(') - for p.tok != ')' { - 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 *gcParser) parseSignature() *Signature { - params, isVariadic := p.parseParameters() - - // optional result type - var results []*Var - switch p.tok { - case scanner.Ident, '[', '*', '<', '@': - // single, unnamed result - results = []*Var{{Type: p.parseType()}} - case '(': - // named or multiple result(s) - var variadic bool - results, variadic = p.parseParameters() - if variadic { - p.error("... not permitted on result type") - } - } - - return &Signature{Params: params, Results: results, IsVariadic: 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 *gcParser) parseInterfaceType() Type { - var methods []*Method - - p.expectKeyword("interface") - p.expect('{') - for p.tok != '}' { - if len(methods) > 0 { - p.expect(';') - } - pkg, name := p.parseName() - typ := p.parseSignature() - methods = append(methods, &Method{QualifiedName{pkg, name}, typ}) - } - p.expect('}') - - return &Interface{Methods: methods} -} - -// ChanType = ( "chan" [ "<-" ] | "<-" "chan" ) Type . -// -func (p *gcParser) parseChanType() Type { - dir := ast.SEND | ast.RECV - if p.tok == scanner.Ident { - p.expectKeyword("chan") - if p.tok == '<' { - p.expectSpecial("<-") - dir = ast.SEND - } - } else { - p.expectSpecial("<-") - p.expectKeyword("chan") - dir = ast.RECV - } - elt := p.parseType() - return &Chan{Dir: dir, Elt: elt} -} - -// 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 *gcParser) parseType() Type { - switch p.tok { - case scanner.Ident: - switch p.lit { - default: - return p.parseBasicType() - case "struct": - return p.parseStructType() - case "func": - // FuncType - p.next() - return p.parseSignature() - case "interface": - return p.parseInterfaceType() - case "map": - return p.parseMapType() - case "chan": - return p.parseChanType() - } - case '@': - // TypeName - pkg, name := p.parseExportedName() - return declTypeName(pkg.Scope, name).Type - case '[': - p.next() // look ahead - if p.tok == ']' { - // SliceType - p.next() - return &Slice{Elt: p.parseType()} - } - return p.parseArrayType() - case '*': - // PointerType - p.next() - return &Pointer{Base: p.parseType()} - case '<': - return p.parseChanType() - case '(': - // "(" Type ")" - p.next() - typ := p.parseType() - p.expect(')') - return typ - } - p.errorf("expected type, got %s (%q)", scanner.TokenString(p.tok), p.lit) - return nil -} - -// ---------------------------------------------------------------------------- -// Declarations - -// ImportDecl = "import" identifier string_lit . -// -func (p *gcParser) parseImportDecl() { - p.expectKeyword("import") - // The identifier has no semantic meaning in the import data. - // It exists so that error messages can print the real package - // name: binary.ByteOrder instead of "encoding/binary".ByteOrder. - name := p.expect(scanner.Ident) - pkg := p.parsePkgId() - assert(pkg.Name == "" || pkg.Name == name) - pkg.Name = name -} - -// int_lit = [ "+" | "-" ] { "0" ... "9" } . -// -func (p *gcParser) parseInt() (neg bool, val string) { - switch p.tok { - case '-': - neg = true - fallthrough - case '+': - p.next() - } - val = p.expect(scanner.Int) - return -} - -// number = int_lit [ "p" int_lit ] . -// -func (p *gcParser) parseNumber() (x operand) { - x.mode = constant - - // mantissa - neg, val := p.parseInt() - mant, ok := new(big.Int).SetString(val, 0) - assert(ok) - if neg { - mant.Neg(mant) - } - - if p.lit == "p" { - // exponent (base 2) - p.next() - neg, val = p.parseInt() - exp64, err := strconv.ParseUint(val, 10, 0) - if err != nil { - p.error(err) - } - exp := uint(exp64) - if neg { - denom := big.NewInt(1) - denom.Lsh(denom, exp) - x.typ = Typ[UntypedFloat] - x.val = normalizeRatConst(new(big.Rat).SetFrac(mant, denom)) - return - } - if exp > 0 { - mant.Lsh(mant, exp) - } - x.typ = Typ[UntypedFloat] - x.val = normalizeIntConst(mant) - return - } - - x.typ = Typ[UntypedInt] - x.val = normalizeIntConst(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 *gcParser) parseConstDecl() { - p.expectKeyword("const") - pkg, name := p.parseExportedName() - obj := declConst(pkg.Scope, name) - var x operand - if p.tok != '=' { - obj.Type = p.parseType() - } - p.expect('=') - switch p.tok { - case scanner.Ident: - // bool_lit - if p.lit != "true" && p.lit != "false" { - p.error("expected true or false") - } - x.typ = Typ[UntypedBool] - x.val = p.lit == "true" - p.next() - - case '-', scanner.Int: - // int_lit - x = p.parseNumber() - - case '(': - // complex_lit or rune_lit - p.next() - if p.tok == scanner.Char { - p.next() - p.expect('+') - x = p.parseNumber() - x.typ = Typ[UntypedRune] - p.expect(')') - break - } - re := p.parseNumber() - p.expect('+') - im := p.parseNumber() - p.expectKeyword("i") - p.expect(')') - x.typ = Typ[UntypedComplex] - // TODO(gri) fix this - _, _ = re, im - x.val = zeroConst - - case scanner.Char: - // rune_lit - x.setConst(token.CHAR, p.lit) - p.next() - - case scanner.String: - // string_lit - x.setConst(token.STRING, p.lit) - p.next() - - default: - p.errorf("expected literal got %s", scanner.TokenString(p.tok)) - } - if obj.Type == nil { - obj.Type = x.typ - } - assert(x.val != nil) - obj.Val = x.val -} - -// TypeDecl = "type" ExportedName Type . -// -func (p *gcParser) parseTypeDecl() { - p.expectKeyword("type") - pkg, name := p.parseExportedName() - obj := declTypeName(pkg.Scope, 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() - - if name := obj.Type.(*NamedType); name.Underlying == nil { - name.Underlying = typ - } -} - -// VarDecl = "var" ExportedName Type . -// -func (p *gcParser) parseVarDecl() { - p.expectKeyword("var") - pkg, name := p.parseExportedName() - obj := declVar(pkg.Scope, name) - obj.Type = p.parseType() -} - -// Func = Signature [ Body ] . -// Body = "{" ... "}" . -// -func (p *gcParser) parseFunc() *Signature { - sig := p.parseSignature() - 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 *gcParser) parseMethodDecl() { - // "func" already consumed - p.expect('(') - recv, _ := p.parseParameter() // receiver - p.expect(')') - - // determine receiver base type object - typ := recv.Type - if ptr, ok := typ.(*Pointer); ok { - typ = ptr.Base - } - base := typ.(*NamedType) - - // parse method name, signature, and possibly inlined body - pkg, name := p.parseName() // unexported method names in imports are qualified with their package. - sig := p.parseFunc() - sig.Recv = recv - - // add method to type unless type was imported before - // and method exists already - // TODO(gri) investigate if this can be avoided - for _, m := range base.Methods { - if m.Name == name { - return // method was added before - } - } - base.Methods = append(base.Methods, &Method{QualifiedName{pkg, name}, sig}) -} - -// FuncDecl = "func" ExportedName Func . -// -func (p *gcParser) parseFuncDecl() { - // "func" already consumed - pkg, name := p.parseExportedName() - typ := p.parseFunc() - declFunc(pkg.Scope, name).Type = typ -} - -// Decl = [ ImportDecl | ConstDecl | TypeDecl | VarDecl | FuncDecl | MethodDecl ] "\n" . -// -func (p *gcParser) parseDecl() { - 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 } "$$" . -// PackageClause = "package" identifier [ "safe" ] "\n" . -// -func (p *gcParser) parseExport() *Package { - p.expectKeyword("package") - name := p.expect(scanner.Ident) - if p.tok != '\n' { - // A package is safe if it was compiled with the -u flag, - // which disables the unsafe package. - // TODO(gri) remember "safe" package - p.expectKeyword("safe") - } - p.expect('\n') - - pkg := p.imports[p.id] - if pkg == nil { - pkg = &Package{Name: name, Scope: new(Scope)} - p.imports[p.id] = pkg - } - - for p.tok != '$' && p.tok != scanner.EOF { - p.parseDecl() - } - - if ch := p.scanner.Peek(); p.tok != '$' || ch != '$' { - // don't call next()/expect() since reading past the - // export data may cause scanner errors (e.g. NUL chars) - p.errorf("expected '$$', got %s %c", scanner.TokenString(p.tok), ch) - } - - if n := p.scanner.ErrorCount; n != 0 { - p.errorf("expected no scanner errors, got %d", n) - } - - // package was imported completely and without errors - pkg.Complete = true - - return pkg -} |