mirror
/
go
mirror of https://github.com/golang/go.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

go/token: implement PositionFor accessors 

Package addition.

PositionFor permits access to both, positions
adjusted by //line comments (like the Position
accessors), and unadjusted "raw" positions
unaffected by //line comments.

Raw positions are required for correct formatting
of source code via go/printer which until now had
to manually fix adjusted positions.

Fixes #7702.

LGTM=adonovan
R=adonovan
CC=golang-codereviews
https://golang.org/cl/135110044
This commit is contained in:
Robert Griesemer 2014-08-28 12:16:06 -07:00
parent b155e79f23
commit e66ff2b908
2 changed files with 116 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

51
src/pkg/go/token/position.go
View File

@ -2,8 +2,6 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// TODO(gri) consider making this a separate package outside the go directory.
package token
import (
@ -184,6 +182,7 @@ func (f *File) SetLines(lines []int) bool {
}
// SetLinesForContent sets the line offsets for the given file content.
// It ignores position-altering //line comments.
func (f *File) SetLinesForContent(content []byte) {
var lines []int
line := 0
@ -255,7 +254,6 @@ func (f *File) Offset(p Pos) int {
// p must be a Pos value in that file or NoPos.
//
func (f *File) Line(p Pos) int {
// TODO(gri) this can be implemented much more efficiently
return f.Position(p).Line
}
@ -263,13 +261,16 @@ func searchLineInfos(a []lineInfo, x int) int {
return sort.Search(len(a), func(i int) bool { return a[i].Offset > x }) - 1
}
// info returns the file name, line, and column number for a file offset.
func (f *File) info(offset int) (filename string, line, column int) {
// unpack returns the filename and line and column number for a file offset.
// If adjusted is set, unpack will return the filename and line information
// possibly adjusted by //line comments; otherwise those comments are ignored.
//
func (f *File) unpack(offset int, adjusted bool) (filename string, line, column int) {
filename = f.name
if i := searchInts(f.lines, offset); i >= 0 {
line, column = i+1, offset-f.lines[i]+1
}
if len(f.infos) > 0 {
if adjusted && len(f.infos) > 0 {
// almost no files have extra line infos
if i := searchLineInfos(f.infos, offset); i >= 0 {
alt := &f.infos[i]
@ -282,26 +283,35 @@ func (f *File) info(offset int) (filename string, line, column int) {
return
}
func (f *File) position(p Pos) (pos Position) {
func (f *File) position(p Pos, adjusted bool) (pos Position) {
offset := int(p) - f.base
pos.Offset = offset
pos.Filename, pos.Line, pos.Column = f.info(offset)
pos.Filename, pos.Line, pos.Column = f.unpack(offset, adjusted)
return
}
// Position returns the Position value for the given file position p;
// p must be a Pos value in that file or NoPos.
// PositionFor returns the Position value for the given file position p.
// If adjusted is set, the position may be adjusted by position-altering
// //line comments; otherwise those comments are ignored.
// p must be a Pos value in f or NoPos.
//
func (f *File) Position(p Pos) (pos Position) {
func (f *File) PositionFor(p Pos, adjusted bool) (pos Position) {
if p != NoPos {
if int(p) < f.base || int(p) > f.base+f.size {
panic("illegal Pos value")
}
pos = f.position(p)
pos = f.position(p, adjusted)
}
return
}
// Position returns the Position value for the given file position p.
// Calling f.Position(p) is equivalent to calling f.PositionFor(p, true).
//
func (f *File) Position(p Pos) (pos Position) {
return f.PositionFor(p, true)
}
// -----------------------------------------------------------------------------
// FileSet
@ -427,16 +437,27 @@ func (s *FileSet) File(p Pos) (f *File) {
return
}
// Position converts a Pos in the fileset into a general Position.
func (s *FileSet) Position(p Pos) (pos Position) {
// PositionFor converts a Pos p in the fileset into a Position value.
// If adjusted is set, the position may be adjusted by position-altering
// //line comments; otherwise those comments are ignored.
// p must be a Pos value in s or NoPos.
//
func (s *FileSet) PositionFor(p Pos, adjusted bool) (pos Position) {
if p != NoPos {
if f := s.file(p); f != nil {
pos = f.position(p)
pos = f.position(p, adjusted)
}
}
return
}
// Position converts a Pos p in the fileset into a Position value.
// Calling s.Position(p) is equivalent to calling s.PositionFor(p, true).
//
func (s *FileSet) Position(p Pos) (pos Position) {
return s.PositionFor(p, true)
}
// -----------------------------------------------------------------------------
// Helper functions

101
src/pkg/go/token/position_test.go
View File

@ -11,18 +11,18 @@ import (
"testing"
)
func checkPos(t *testing.T, msg string, p, q Position) {
if p.Filename != q.Filename {
t.Errorf("%s: expected filename = %q; got %q", msg, q.Filename, p.Filename)
func checkPos(t *testing.T, msg string, got, want Position) {
if got.Filename != want.Filename {
t.Errorf("%s: got filename = %q; want %q", msg, got.Filename, want.Filename)
}
if p.Offset != q.Offset {
t.Errorf("%s: expected offset = %d; got %d", msg, q.Offset, p.Offset)
if got.Offset != want.Offset {
t.Errorf("%s: got offset = %d; want %d", msg, got.Offset, want.Offset)
}
if p.Line != q.Line {
t.Errorf("%s: expected line = %d; got %d", msg, q.Line, p.Line)
if got.Line != want.Line {
t.Errorf("%s: got line = %d; want %d", msg, got.Line, want.Line)
}
if p.Column != q.Column {
t.Errorf("%s: expected column = %d; got %d", msg, q.Column, p.Column)
if got.Column != want.Column {
t.Errorf("%s: got column = %d; want %d", msg, got.Column, want.Column)
}
}
@ -68,7 +68,7 @@ func verifyPositions(t *testing.T, fset *FileSet, f *File, lines []int) {
p := f.Pos(offs)
offs2 := f.Offset(p)
if offs2 != offs {
t.Errorf("%s, Offset: expected offset %d; got %d", f.Name(), offs, offs2)
t.Errorf("%s, Offset: got offset %d; want %d", f.Name(), offs2, offs)
}
line, col := linecol(lines, offs)
msg := fmt.Sprintf("%s (offs = %d, p = %d)", f.Name(), offs, p)
@ -93,16 +93,16 @@ func TestPositions(t *testing.T) {
for _, test := range tests {
// verify consistency of test case
if test.source != nil && len(test.source) != test.size {
t.Errorf("%s: inconsistent test case: expected file size %d; got %d", test.filename, test.size, len(test.source))
t.Errorf("%s: inconsistent test case: got file size %d; want %d", test.filename, len(test.source), test.size)
}
// add file and verify name and size
f := fset.AddFile(test.filename, fset.Base()+delta, test.size)
if f.Name() != test.filename {
t.Errorf("expected filename %q; got %q", test.filename, f.Name())
t.Errorf("got filename %q; want %q", f.Name(), test.filename)
}
if f.Size() != test.size {
t.Errorf("%s: expected file size %d; got %d", f.Name(), test.size, f.Size())
t.Errorf("%s: got file size %d; want %d", f.Name(), f.Size(), test.size)
}
if fset.File(f.Pos(0)) != f {
t.Errorf("%s: f.Pos(0) was not found in f", f.Name())
@ -112,12 +112,12 @@ func TestPositions(t *testing.T) {
for i, offset := range test.lines {
f.AddLine(offset)
if f.LineCount() != i+1 {
t.Errorf("%s, AddLine: expected line count %d; got %d", f.Name(), i+1, f.LineCount())
t.Errorf("%s, AddLine: got line count %d; want %d", f.Name(), f.LineCount(), i+1)
}
// adding the same offset again should be ignored
f.AddLine(offset)
if f.LineCount() != i+1 {
t.Errorf("%s, AddLine: expected unchanged line count %d; got %d", f.Name(), i+1, f.LineCount())
t.Errorf("%s, AddLine: got unchanged line count %d; want %d", f.Name(), f.LineCount(), i+1)
}
verifyPositions(t, fset, f, test.lines[0:i+1])
}
@ -127,7 +127,7 @@ func TestPositions(t *testing.T) {
t.Errorf("%s: SetLines failed", f.Name())
}
if f.LineCount() != len(test.lines) {
t.Errorf("%s, SetLines: expected line count %d; got %d", f.Name(), len(test.lines), f.LineCount())
t.Errorf("%s, SetLines: got line count %d; want %d", f.Name(), f.LineCount(), len(test.lines))
}
verifyPositions(t, fset, f, test.lines)
@ -139,7 +139,7 @@ func TestPositions(t *testing.T) {
}
f.SetLinesForContent(src)
if f.LineCount() != len(test.lines) {
t.Errorf("%s, SetLinesForContent: expected line count %d; got %d", f.Name(), len(test.lines), f.LineCount())
t.Errorf("%s, SetLinesForContent: got line count %d; want %d", f.Name(), f.LineCount(), len(test.lines))
}
verifyPositions(t, fset, f, test.lines)
}
@ -177,13 +177,13 @@ func TestFiles(t *testing.T) {
j := 0
fset.Iterate(func(f *File) bool {
if f.Name() != tests[j].filename {
t.Errorf("expected filename = %s; got %s", tests[j].filename, f.Name())
t.Errorf("got filename = %s; want %s", f.Name(), tests[j].filename)
}
j++
return true
})
if j != i+1 {
t.Errorf("expected %d files; got %d", i+1, j)
t.Errorf("got %d files; want %d", j, i+1)
}
}
}
@ -195,7 +195,7 @@ func TestFileSetPastEnd(t *testing.T) {
fset.AddFile(test.filename, fset.Base(), test.size)
}
if f := fset.File(Pos(fset.Base())); f != nil {
t.Errorf("expected nil, got %v", f)
t.Errorf("got %v, want nil", f)
}
}
@ -209,7 +209,7 @@ func TestFileSetCacheUnlikely(t *testing.T) {
for file, pos := range offsets {
f := fset.File(Pos(pos))
if f.Name() != file {
t.Errorf("expecting %q at position %d, got %q", file, pos, f.Name())
t.Errorf("got %q at position %d, want %q", f.Name(), pos, file)
}
}
}
@ -236,3 +236,62 @@ func TestFileSetRace(t *testing.T) {
}
stop.Wait()
}
func TestPositionFor(t *testing.T) {
src := []byte(`
foo
b
ar
//line :100
foobar
//line bar:3
done
`)
const filename = "foo"
fset := NewFileSet()
f := fset.AddFile(filename, fset.Base(), len(src))
f.SetLinesForContent(src)
// verify position info
for i, offs := range f.lines {
got1 := f.PositionFor(f.Pos(offs), false)
got2 := f.PositionFor(f.Pos(offs), true)
got3 := f.Position(f.Pos(offs))
want := Position{filename, offs, i + 1, 1}
checkPos(t, "1. PositionFor unadjusted", got1, want)
checkPos(t, "1. PositionFor adjusted", got2, want)
checkPos(t, "1. Position", got3, want)
}
// manually add //line info on lines l1, l2
const l1, l2 = 5, 7
f.AddLineInfo(f.lines[l1-1], "", 100)
f.AddLineInfo(f.lines[l2-1], "bar", 3)
// unadjusted position info must remain unchanged
for i, offs := range f.lines {
got1 := f.PositionFor(f.Pos(offs), false)
want := Position{filename, offs, i + 1, 1}
checkPos(t, "2. PositionFor unadjusted", got1, want)
}
// adjusted position info should have changed
for i, offs := range f.lines {
got2 := f.PositionFor(f.Pos(offs), true)
got3 := f.Position(f.Pos(offs))
want := Position{filename, offs, i + 1, 1}
// manually compute wanted filename and line
line := want.Line
if i+1 >= l1 {
want.Filename = ""
want.Line = line - l1 + 100
}
if i+1 >= l2 {
want.Filename = "bar"
want.Line = line - l2 + 3
}
checkPos(t, "3. PositionFor adjusted", got2, want)
checkPos(t, "3. Position", got3, want)
}
}