diff options
Diffstat (limited to 'src/pkg/go/parser/interface.go')
| -rw-r--r-- | src/pkg/go/parser/interface.go | 177 |
1 files changed, 57 insertions, 120 deletions
diff --git a/src/pkg/go/parser/interface.go b/src/pkg/go/parser/interface.go index 4f980fc65..f1b4ce34d 100644 --- a/src/pkg/go/parser/interface.go +++ b/src/pkg/go/parser/interface.go @@ -8,8 +8,8 @@ package parser import ( "bytes" + "errors" "go/ast" - "go/scanner" "go/token" "io" "io/ioutil" @@ -21,7 +21,7 @@ import ( // otherwise it returns an error. If src == nil, readSource returns // the result of reading the file specified by filename. // -func readSource(filename string, src interface{}) ([]byte, os.Error) { +func readSource(filename string, src interface{}) ([]byte, error) { if src != nil { switch s := src.(type) { case string: @@ -35,86 +35,30 @@ func readSource(filename string, src interface{}) ([]byte, os.Error) { } case io.Reader: var buf bytes.Buffer - _, err := io.Copy(&buf, s) - if err != nil { + if _, err := io.Copy(&buf, s); err != nil { return nil, err } return buf.Bytes(), nil - default: - return nil, os.NewError("invalid source") } + return nil, errors.New("invalid source") } - return ioutil.ReadFile(filename) } -func (p *parser) errors() os.Error { - mode := scanner.Sorted - if p.mode&SpuriousErrors == 0 { - mode = scanner.NoMultiples - } - return p.GetError(mode) -} - -// ParseExpr parses a Go expression and returns the corresponding -// AST node. The fset, filename, and src arguments have the same interpretation -// as for ParseFile. If there is an error, the result expression -// may be nil or contain a partial AST. -// -func ParseExpr(fset *token.FileSet, filename string, src interface{}) (ast.Expr, os.Error) { - data, err := readSource(filename, src) - if err != nil { - return nil, err - } - - var p parser - p.init(fset, filename, data, 0) - x := p.parseRhs() - if p.tok == token.SEMICOLON { - p.next() // consume automatically inserted semicolon, if any - } - p.expect(token.EOF) - - return x, p.errors() -} - -// ParseStmtList parses a list of Go statements and returns the list -// of corresponding AST nodes. The fset, filename, and src arguments have the same -// interpretation as for ParseFile. If there is an error, the node -// list may be nil or contain partial ASTs. +// A Mode value is a set of flags (or 0). +// They control the amount of source code parsed and other optional +// parser functionality. // -func ParseStmtList(fset *token.FileSet, filename string, src interface{}) ([]ast.Stmt, os.Error) { - data, err := readSource(filename, src) - if err != nil { - return nil, err - } - - var p parser - p.init(fset, filename, data, 0) - list := p.parseStmtList() - p.expect(token.EOF) - - return list, p.errors() -} - -// ParseDeclList parses a list of Go declarations and returns the list -// of corresponding AST nodes. The fset, filename, and src arguments have the same -// interpretation as for ParseFile. If there is an error, the node -// list may be nil or contain partial ASTs. -// -func ParseDeclList(fset *token.FileSet, filename string, src interface{}) ([]ast.Decl, os.Error) { - data, err := readSource(filename, src) - if err != nil { - return nil, err - } - - var p parser - p.init(fset, filename, data, 0) - list := p.parseDeclList() - p.expect(token.EOF) - - return list, p.errors() -} +type Mode uint + +const ( + PackageClauseOnly Mode = 1 << iota // parsing stops after package clause + ImportsOnly // parsing stops after import declarations + ParseComments // parse comments and add them to AST + Trace // print a trace of parsed productions + DeclarationErrors // report declaration errors + SpuriousErrors // report all (not just the first) errors per line +) // ParseFile parses the source code of a single Go source file and returns // the corresponding ast.File node. The source code may be provided via @@ -123,7 +67,6 @@ func ParseDeclList(fset *token.FileSet, filename string, src interface{}) ([]ast // If src != nil, ParseFile parses the source from src and the filename is // only used when recording position information. The type of the argument // for the src parameter must be string, []byte, or io.Reader. -// // If src == nil, ParseFile parses the file specified by filename. // // The mode parameter controls the amount of source text parsed and other @@ -132,49 +75,18 @@ func ParseDeclList(fset *token.FileSet, filename string, src interface{}) ([]ast // // If the source couldn't be read, the returned AST is nil and the error // indicates the specific failure. If the source was read but syntax -// errors were found, the result is a partial AST (with ast.BadX nodes +// errors were found, the result is a partial AST (with ast.Bad* nodes // representing the fragments of erroneous source code). Multiple errors // are returned via a scanner.ErrorList which is sorted by file position. // -func ParseFile(fset *token.FileSet, filename string, src interface{}, mode uint) (*ast.File, os.Error) { - data, err := readSource(filename, src) +func ParseFile(fset *token.FileSet, filename string, src interface{}, mode Mode) (*ast.File, error) { + text, err := readSource(filename, src) if err != nil { return nil, err } - var p parser - p.init(fset, filename, data, mode) - file := p.parseFile() // parseFile reads to EOF - - return file, p.errors() -} - -// ParseFiles calls ParseFile for each file in the filenames list and returns -// a map of package name -> package AST with all the packages found. The mode -// bits are passed to ParseFile unchanged. Position information is recorded -// in the file set fset. -// -// Files with parse errors are ignored. In this case the map of packages may -// be incomplete (missing packages and/or incomplete packages) and the first -// error encountered is returned. -// -func ParseFiles(fset *token.FileSet, filenames []string, mode uint) (pkgs map[string]*ast.Package, first os.Error) { - pkgs = make(map[string]*ast.Package) - for _, filename := range filenames { - if src, err := ParseFile(fset, filename, nil, mode); err == nil { - name := src.Name.Name - pkg, found := pkgs[name] - if !found { - // TODO(gri) Use NewPackage here; reconsider ParseFiles API. - pkg = &ast.Package{name, nil, nil, make(map[string]*ast.File)} - pkgs[name] = pkg - } - pkg.Files[filename] = src - } else if first == nil { - first = err - } - } - return + p.init(fset, filename, text, mode) + return p.parseFile(), p.errors() } // ParseDir calls ParseFile for the files in the directory specified by path and @@ -185,9 +97,9 @@ func ParseFiles(fset *token.FileSet, filenames []string, mode uint) (pkgs map[st // // If the directory couldn't be read, a nil map and the respective error are // returned. If a parse error occurred, a non-nil but incomplete map and the -// error are returned. +// first error encountered are returned. // -func ParseDir(fset *token.FileSet, path string, filter func(*os.FileInfo) bool, mode uint) (map[string]*ast.Package, os.Error) { +func ParseDir(fset *token.FileSet, path string, filter func(os.FileInfo) bool, mode Mode) (pkgs map[string]*ast.Package, first error) { fd, err := os.Open(path) if err != nil { return nil, err @@ -199,16 +111,41 @@ func ParseDir(fset *token.FileSet, path string, filter func(*os.FileInfo) bool, return nil, err } - filenames := make([]string, len(list)) - n := 0 - for i := 0; i < len(list); i++ { - d := &list[i] + pkgs = make(map[string]*ast.Package) + for _, d := range list { if filter == nil || filter(d) { - filenames[n] = filepath.Join(path, d.Name) - n++ + filename := filepath.Join(path, d.Name()) + if src, err := ParseFile(fset, filename, nil, mode); err == nil { + name := src.Name.Name + pkg, found := pkgs[name] + if !found { + pkg = &ast.Package{ + Name: name, + Files: make(map[string]*ast.File), + } + pkgs[name] = pkg + } + pkg.Files[filename] = src + } else if first == nil { + first = err + } } } - filenames = filenames[0:n] - return ParseFiles(fset, filenames, mode) + return +} + +// ParseExpr is a convenience function for obtaining the AST of an expression x. +// The position information recorded in the AST is undefined. +// +func ParseExpr(x string) (ast.Expr, error) { + // parse x within the context of a complete package for correct scopes; + // use //line directive for correct positions in error messages and put + // x alone on a separate line (handles line comments), followed by a ';' + // to force an error if the expression is incomplete + file, err := ParseFile(token.NewFileSet(), "", "package p;func _(){_=\n//line :1\n"+x+"\n;}", 0) + if err != nil { + return nil, err + } + return file.Decls[0].(*ast.FuncDecl).Body.List[0].(*ast.AssignStmt).Rhs[0], nil } |