diff options
Diffstat (limited to 'src/pkg/go/parser/parser.go')
| -rw-r--r-- | src/pkg/go/parser/parser.go | 117 |
1 files changed, 38 insertions, 79 deletions
diff --git a/src/pkg/go/parser/parser.go b/src/pkg/go/parser/parser.go index 0f5582da9..270403aac 100644 --- a/src/pkg/go/parser/parser.go +++ b/src/pkg/go/parser/parser.go @@ -22,17 +22,6 @@ import ( ) -// Names to index the parser's commentIndex array. -const ( - leading = iota; // index of the leading comments entry - trailing; // index of the trailing comments entry -) - - -// Initial value for parser.commentsIndex. -var noIndex = [2]int{-1, -1}; - - // noPos is used when there is no corresponding source position for a token. var noPos token.Position; @@ -60,8 +49,10 @@ type parser struct { indent uint; // indentation used for tracing output // Comments - comments vector.Vector; // list of collected, unassociated comment groups - commentsIndex [2]int; // comments indexes of last leading/trailing comment group; or -1 + comments *ast.CommentGroup; // list of collected comments + lastComment *ast.CommentGroup; // last comment in the comments list + leadComment *ast.CommentGroup; // the last lead comment + lineComment *ast.CommentGroup; // the last line comment // Next token pos token.Position; // token position @@ -90,8 +81,6 @@ func (p *parser) init(filename string, src []byte, mode uint) { p.scanner.Init(filename, src, p, scannerMode(mode)); p.mode = mode; p.trace = mode & Trace != 0; // for convenience (p.trace is used frequently) - p.comments.Init(0); - p.commentsIndex = noIndex; p.next(); } @@ -190,42 +179,49 @@ func (p *parser) consumeCommentGroup() int { group[i] = list.At(i).(*ast.Comment); } - p.comments.Push(&ast.CommentGroup{group, endline}); + // add comment group to the comments list + g := &ast.CommentGroup{group, nil}; + if p.lastComment != nil { + p.lastComment.Next = g; + } else { + p.comments = g; + } + p.lastComment = g; + return endline; } // Advance to the next non-comment token. In the process, collect -// any comment groups encountered, and remember the last leading -// and trailing comments. +// any comment groups encountered, and remember the last lead and +// and line comments. // -// A leading comment is a comment group that starts and ends in a +// A lead comment is a comment group that starts and ends in a // line without any other tokens and that is followed by a non-comment // token on the line immediately after the comment group. // -// A trailing comment is a comment group that follows a non-comment +// A line comment is a comment group that follows a non-comment // token on the same line, and that has no tokens after it on the line // where it ends. // -// Leading and trailing comments may be considered documentation -// that is stored in the AST. In that case they are removed from -// the parser's list of unassociated comments (via getComment). +// Lead and line comments may be considered documentation that is +// stored in the AST. // func (p *parser) next() { - p.commentsIndex = noIndex; + p.leadComment = nil; + p.lineComment = nil; line := p.pos.Line; // current line p.next0(); if p.tok == token.COMMENT { if p.pos.Line == line { // The comment is on same line as previous token; it - // cannot be a leading comment but may be a trailing - // comment. + // cannot be a lead comment but may be a line comment. endline := p.consumeCommentGroup(); if p.pos.Line != endline { // The next token is on a different line, thus - // the last comment group is a trailing comment. - p.commentsIndex[trailing] = p.comments.Len() - 1; + // the last comment group is a line comment. + p.lineComment = p.lastComment; } } @@ -237,27 +233,13 @@ func (p *parser) next() { if endline >= 0 && endline+1 == p.pos.Line { // The next token is following on the line immediately after the - // comment group, thus the last comment group is a leading comment. - p.commentsIndex[leading] = p.comments.Len() - 1; + // comment group, thus the last comment group is a lead comment. + p.leadComment = p.lastComment; } } } -// Get leading/trailing comment group, if any. -func (p *parser) getComment(kind int) *ast.CommentGroup { - i := p.commentsIndex[kind]; - if i >= 0 { - // get comment and remove if from the list of unassociated comment groups - c := p.comments.At(i).(*ast.CommentGroup); - p.comments.Set(i, nil); // clear entry - p.commentsIndex[kind] = -1; // comment was consumed - return c; - } - return nil; -} - - func (p *parser) errorExpected(pos token.Position, msg string) { msg = "expected " + msg; if pos.Offset == p.pos.Offset { @@ -435,7 +417,7 @@ func (p *parser) parseFieldDecl() *ast.Field { defer un(trace(p, "FieldDecl")); } - doc := p.getComment(leading); + doc := p.leadComment; // a list of identifiers looks like a list of type names list := vector.New(0); @@ -496,9 +478,9 @@ func (p *parser) parseStructType() *ast.StructType { list.Push(f); if p.tok == token.SEMICOLON { p.next(); - f.Comment = p.getComment(trailing); + f.Comment = p.lineComment; } else { - f.Comment = p.getComment(trailing); + f.Comment = p.lineComment; break; } } @@ -680,7 +662,7 @@ func (p *parser) parseMethodSpec() *ast.Field { defer un(trace(p, "MethodSpec")); } - doc := p.getComment(leading); + doc := p.leadComment; var idents []*ast.Ident; var typ ast.Expr; x := p.parseQualifiedIdent(); @@ -1680,7 +1662,7 @@ func (p *parser) parseStmt() ast.Stmt { type parseSpecFunction func(p *parser, doc *ast.CommentGroup, getSemi bool) (spec ast.Spec, gotSemi bool) -// Consume semicolon if there is one and getSemi is set, and get any trailing comment. +// Consume semicolon if there is one and getSemi is set, and get any line comment. // Return the comment if any and indicate if a semicolon was consumed. // func (p *parser) parseComment(getSemi bool) (comment *ast.CommentGroup, gotSemi bool) { @@ -1688,7 +1670,7 @@ func (p *parser) parseComment(getSemi bool) (comment *ast.CommentGroup, gotSemi p.next(); gotSemi = true; } - return p.getComment(trailing), gotSemi; + return p.lineComment, gotSemi; } @@ -1772,7 +1754,7 @@ func (p *parser) parseGenDecl(keyword token.Token, f parseSpecFunction, getSemi defer un(trace(p, keyword.String() + "Decl")); } - doc := p.getComment(leading); + doc := p.leadComment; pos := p.expect(keyword); var lparen, rparen token.Position; list := vector.New(0); @@ -1780,7 +1762,7 @@ func (p *parser) parseGenDecl(keyword token.Token, f parseSpecFunction, getSemi lparen = p.pos; p.next(); for p.tok != token.RPAREN && p.tok != token.EOF { - doc := p.getComment(leading); + doc := p.leadComment; spec, semi := f(p, doc, true); // consume semicolon if any list.Push(spec); if !semi { @@ -1845,7 +1827,7 @@ func (p *parser) parseFunctionDecl() *ast.FuncDecl { defer un(trace(p, "FunctionDecl")); } - doc := p.getComment(leading); + doc := p.leadComment; pos := p.expect(token.FUNC); var recv *ast.Field; @@ -1883,13 +1865,7 @@ func (p *parser) parseDecl(getSemi bool) (decl ast.Decl, gotSemi bool) { case token.FUNC: decl = p.parseFunctionDecl(); - // Do not use parseComment here to consume a semicolon - // because we don't want to remove a trailing comment - // from the list of unassociated comments. - if getSemi && p.tok == token.SEMICOLON { - p.next(); - gotSemi = true; - } + _, gotSemi := p.parseComment(getSemi); return decl, gotSemi; default: @@ -1915,7 +1891,7 @@ func (p *parser) parseFile() *ast.File { } // package clause - comment := p.getComment(leading); + doc := p.leadComment; pos := p.expect(token.PACKAGE); ident := p.parseIdent(); var decls []ast.Decl; @@ -1946,22 +1922,5 @@ func (p *parser) parseFile() *ast.File { } } - // convert comments list - // 1) determine number of remaining comments - n := 0; - for i := 0; i < p.comments.Len(); i++ { - if p.comments.At(i) != nil { - n++; - } - } - // 2) convert the remaining comments - comments := make([]*ast.CommentGroup, n); - for i, j := 0, 0; i < p.comments.Len(); i++ { - if p.comments.At(i) != nil { - comments[j] = p.comments.At(i).(*ast.CommentGroup); - j++; - } - } - - return &ast.File{comment, pos, ident, decls, comments}; + return &ast.File{doc, pos, ident, decls, p.comments}; } |