blob: ec03639449990ddbfba9669992d37f660a461953 [file] [log] [blame]
// 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.
//go:build go1.16
// +build go1.16
// This file contains support functions for parsing .go files
// accessed via godoc's file system fs.
package godoc
import (
"bytes"
"go/ast"
"go/parser"
"go/token"
"io/fs"
pathpkg "path"
)
var linePrefix = []byte("//line ")
// This function replaces source lines starting with "//line " with a blank line.
// It does this irrespective of whether the line is truly a line comment or not;
// e.g., the line may be inside a string, or a /*-style comment; however that is
// rather unlikely (proper testing would require a full Go scan which we want to
// avoid for performance).
func replaceLinePrefixCommentsWithBlankLine(src []byte) {
for {
i := bytes.Index(src, linePrefix)
if i < 0 {
break // we're done
}
// 0 <= i && i+len(linePrefix) <= len(src)
if i == 0 || src[i-1] == '\n' {
// at beginning of line: blank out line
for i < len(src) && src[i] != '\n' {
src[i] = ' '
i++
}
} else {
// not at beginning of line: skip over prefix
i += len(linePrefix)
}
// i <= len(src)
src = src[i:]
}
}
func parseFile(fsys fs.FS, fset *token.FileSet, filename string, mode parser.Mode) (*ast.File, error) {
src, err := fs.ReadFile(fsys, toFS(filename))
if err != nil {
return nil, err
}
// Temporary ad-hoc fix for issue 5247.
// TODO(gri,dmitshur) Remove this in favor of a better fix, eventually (see issue 32092).
replaceLinePrefixCommentsWithBlankLine(src)
return parser.ParseFile(fset, filename, src, mode)
}
func parseFiles(fsys fs.FS, fset *token.FileSet, relpath string, abspath string, localnames []string) (map[string]*ast.File, error) {
files := make(map[string]*ast.File)
for _, f := range localnames {
absname := pathpkg.Join(abspath, f)
file, err := parseFile(fsys, fset, absname, parser.ParseComments)
if err != nil {
return nil, err
}
files[pathpkg.Join(relpath, f)] = file
}
return files, nil
}