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-rw-r--r--src/go/token/example_test.go77
-rw-r--r--src/go/token/position.go552
-rw-r--r--src/go/token/position_test.go341
-rw-r--r--src/go/token/serialize.go71
-rw-r--r--src/go/token/serialize_test.go111
-rw-r--r--src/go/token/token.go340
-rw-r--r--src/go/token/token_test.go33
7 files changed, 1525 insertions, 0 deletions
diff --git a/src/go/token/example_test.go b/src/go/token/example_test.go
new file mode 100644
index 0000000..0011703
--- /dev/null
+++ b/src/go/token/example_test.go
@@ -0,0 +1,77 @@
+// Copyright 2018 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.
+
+package token_test
+
+import (
+ "fmt"
+ "go/ast"
+ "go/parser"
+ "go/token"
+)
+
+func Example_retrievePositionInfo() {
+ fset := token.NewFileSet()
+
+ const src = `package main
+
+import "fmt"
+
+import "go/token"
+
+//line :1:5
+type p = token.Pos
+
+const bad = token.NoPos
+
+//line fake.go:42:11
+func ok(pos p) bool {
+ return pos != bad
+}
+
+/*line :7:9*/func main() {
+ fmt.Println(ok(bad) == bad.IsValid())
+}
+`
+
+ f, err := parser.ParseFile(fset, "main.go", src, 0)
+ if err != nil {
+ fmt.Println(err)
+ return
+ }
+
+ // Print the location and kind of each declaration in f.
+ for _, decl := range f.Decls {
+ // Get the filename, line, and column back via the file set.
+ // We get both the relative and absolute position.
+ // The relative position is relative to the last line directive.
+ // The absolute position is the exact position in the source.
+ pos := decl.Pos()
+ relPosition := fset.Position(pos)
+ absPosition := fset.PositionFor(pos, false)
+
+ // Either a FuncDecl or GenDecl, since we exit on error.
+ kind := "func"
+ if gen, ok := decl.(*ast.GenDecl); ok {
+ kind = gen.Tok.String()
+ }
+
+ // If the relative and absolute positions differ, show both.
+ fmtPosition := relPosition.String()
+ if relPosition != absPosition {
+ fmtPosition += "[" + absPosition.String() + "]"
+ }
+
+ fmt.Printf("%s: %s\n", fmtPosition, kind)
+ }
+
+ //Output:
+ //
+ // main.go:3:1: import
+ // main.go:5:1: import
+ // main.go:1:5[main.go:8:1]: type
+ // main.go:3:1[main.go:10:1]: const
+ // fake.go:42:11[main.go:13:1]: func
+ // fake.go:7:9[main.go:17:14]: func
+}
diff --git a/src/go/token/position.go b/src/go/token/position.go
new file mode 100644
index 0000000..a21f5fd
--- /dev/null
+++ b/src/go/token/position.go
@@ -0,0 +1,552 @@
+// Copyright 2010 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.
+
+package token
+
+import (
+ "fmt"
+ "sort"
+ "sync"
+)
+
+// -----------------------------------------------------------------------------
+// Positions
+
+// Position describes an arbitrary source position
+// including the file, line, and column location.
+// A Position is valid if the line number is > 0.
+//
+type Position struct {
+ Filename string // filename, if any
+ Offset int // offset, starting at 0
+ Line int // line number, starting at 1
+ Column int // column number, starting at 1 (byte count)
+}
+
+// IsValid reports whether the position is valid.
+func (pos *Position) IsValid() bool { return pos.Line > 0 }
+
+// String returns a string in one of several forms:
+//
+// file:line:column valid position with file name
+// file:line valid position with file name but no column (column == 0)
+// line:column valid position without file name
+// line valid position without file name and no column (column == 0)
+// file invalid position with file name
+// - invalid position without file name
+//
+func (pos Position) String() string {
+ s := pos.Filename
+ if pos.IsValid() {
+ if s != "" {
+ s += ":"
+ }
+ s += fmt.Sprintf("%d", pos.Line)
+ if pos.Column != 0 {
+ s += fmt.Sprintf(":%d", pos.Column)
+ }
+ }
+ if s == "" {
+ s = "-"
+ }
+ return s
+}
+
+// Pos is a compact encoding of a source position within a file set.
+// It can be converted into a Position for a more convenient, but much
+// larger, representation.
+//
+// The Pos value for a given file is a number in the range [base, base+size],
+// where base and size are specified when a file is added to the file set.
+// The difference between a Pos value and the corresponding file base
+// corresponds to the byte offset of that position (represented by the Pos value)
+// from the beginning of the file. Thus, the file base offset is the Pos value
+// representing the first byte in the file.
+//
+// To create the Pos value for a specific source offset (measured in bytes),
+// first add the respective file to the current file set using FileSet.AddFile
+// and then call File.Pos(offset) for that file. Given a Pos value p
+// for a specific file set fset, the corresponding Position value is
+// obtained by calling fset.Position(p).
+//
+// Pos values can be compared directly with the usual comparison operators:
+// If two Pos values p and q are in the same file, comparing p and q is
+// equivalent to comparing the respective source file offsets. If p and q
+// are in different files, p < q is true if the file implied by p was added
+// to the respective file set before the file implied by q.
+//
+type Pos int
+
+// The zero value for Pos is NoPos; there is no file and line information
+// associated with it, and NoPos.IsValid() is false. NoPos is always
+// smaller than any other Pos value. The corresponding Position value
+// for NoPos is the zero value for Position.
+//
+const NoPos Pos = 0
+
+// IsValid reports whether the position is valid.
+func (p Pos) IsValid() bool {
+ return p != NoPos
+}
+
+// -----------------------------------------------------------------------------
+// File
+
+// A File is a handle for a file belonging to a FileSet.
+// A File has a name, size, and line offset table.
+//
+type File struct {
+ set *FileSet
+ name string // file name as provided to AddFile
+ base int // Pos value range for this file is [base...base+size]
+ size int // file size as provided to AddFile
+
+ // lines and infos are protected by mutex
+ mutex sync.Mutex
+ lines []int // lines contains the offset of the first character for each line (the first entry is always 0)
+ infos []lineInfo
+}
+
+// Name returns the file name of file f as registered with AddFile.
+func (f *File) Name() string {
+ return f.name
+}
+
+// Base returns the base offset of file f as registered with AddFile.
+func (f *File) Base() int {
+ return f.base
+}
+
+// Size returns the size of file f as registered with AddFile.
+func (f *File) Size() int {
+ return f.size
+}
+
+// LineCount returns the number of lines in file f.
+func (f *File) LineCount() int {
+ f.mutex.Lock()
+ n := len(f.lines)
+ f.mutex.Unlock()
+ return n
+}
+
+// AddLine adds the line offset for a new line.
+// The line offset must be larger than the offset for the previous line
+// and smaller than the file size; otherwise the line offset is ignored.
+//
+func (f *File) AddLine(offset int) {
+ f.mutex.Lock()
+ if i := len(f.lines); (i == 0 || f.lines[i-1] < offset) && offset < f.size {
+ f.lines = append(f.lines, offset)
+ }
+ f.mutex.Unlock()
+}
+
+// MergeLine merges a line with the following line. It is akin to replacing
+// the newline character at the end of the line with a space (to not change the
+// remaining offsets). To obtain the line number, consult e.g. Position.Line.
+// MergeLine will panic if given an invalid line number.
+//
+func (f *File) MergeLine(line int) {
+ if line < 1 {
+ panic(fmt.Sprintf("invalid line number %d (should be >= 1)", line))
+ }
+ f.mutex.Lock()
+ defer f.mutex.Unlock()
+ if line >= len(f.lines) {
+ panic(fmt.Sprintf("invalid line number %d (should be < %d)", line, len(f.lines)))
+ }
+ // To merge the line numbered <line> with the line numbered <line+1>,
+ // we need to remove the entry in lines corresponding to the line
+ // numbered <line+1>. The entry in lines corresponding to the line
+ // numbered <line+1> is located at index <line>, since indices in lines
+ // are 0-based and line numbers are 1-based.
+ copy(f.lines[line:], f.lines[line+1:])
+ f.lines = f.lines[:len(f.lines)-1]
+}
+
+// SetLines sets the line offsets for a file and reports whether it succeeded.
+// The line offsets are the offsets of the first character of each line;
+// for instance for the content "ab\nc\n" the line offsets are {0, 3}.
+// An empty file has an empty line offset table.
+// Each line offset must be larger than the offset for the previous line
+// and smaller than the file size; otherwise SetLines fails and returns
+// false.
+// Callers must not mutate the provided slice after SetLines returns.
+//
+func (f *File) SetLines(lines []int) bool {
+ // verify validity of lines table
+ size := f.size
+ for i, offset := range lines {
+ if i > 0 && offset <= lines[i-1] || size <= offset {
+ return false
+ }
+ }
+
+ // set lines table
+ f.mutex.Lock()
+ f.lines = lines
+ f.mutex.Unlock()
+ return true
+}
+
+// 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
+ for offset, b := range content {
+ if line >= 0 {
+ lines = append(lines, line)
+ }
+ line = -1
+ if b == '\n' {
+ line = offset + 1
+ }
+ }
+
+ // set lines table
+ f.mutex.Lock()
+ f.lines = lines
+ f.mutex.Unlock()
+}
+
+// LineStart returns the Pos value of the start of the specified line.
+// It ignores any alternative positions set using AddLineColumnInfo.
+// LineStart panics if the 1-based line number is invalid.
+func (f *File) LineStart(line int) Pos {
+ if line < 1 {
+ panic(fmt.Sprintf("invalid line number %d (should be >= 1)", line))
+ }
+ f.mutex.Lock()
+ defer f.mutex.Unlock()
+ if line > len(f.lines) {
+ panic(fmt.Sprintf("invalid line number %d (should be < %d)", line, len(f.lines)))
+ }
+ return Pos(f.base + f.lines[line-1])
+}
+
+// A lineInfo object describes alternative file, line, and column
+// number information (such as provided via a //line directive)
+// for a given file offset.
+type lineInfo struct {
+ // fields are exported to make them accessible to gob
+ Offset int
+ Filename string
+ Line, Column int
+}
+
+// AddLineInfo is like AddLineColumnInfo with a column = 1 argument.
+// It is here for backward-compatibility for code prior to Go 1.11.
+//
+func (f *File) AddLineInfo(offset int, filename string, line int) {
+ f.AddLineColumnInfo(offset, filename, line, 1)
+}
+
+// AddLineColumnInfo adds alternative file, line, and column number
+// information for a given file offset. The offset must be larger
+// than the offset for the previously added alternative line info
+// and smaller than the file size; otherwise the information is
+// ignored.
+//
+// AddLineColumnInfo is typically used to register alternative position
+// information for line directives such as //line filename:line:column.
+//
+func (f *File) AddLineColumnInfo(offset int, filename string, line, column int) {
+ f.mutex.Lock()
+ if i := len(f.infos); i == 0 || f.infos[i-1].Offset < offset && offset < f.size {
+ f.infos = append(f.infos, lineInfo{offset, filename, line, column})
+ }
+ f.mutex.Unlock()
+}
+
+// Pos returns the Pos value for the given file offset;
+// the offset must be <= f.Size().
+// f.Pos(f.Offset(p)) == p.
+//
+func (f *File) Pos(offset int) Pos {
+ if offset > f.size {
+ panic(fmt.Sprintf("invalid file offset %d (should be <= %d)", offset, f.size))
+ }
+ return Pos(f.base + offset)
+}
+
+// Offset returns the offset for the given file position p;
+// p must be a valid Pos value in that file.
+// f.Offset(f.Pos(offset)) == offset.
+//
+func (f *File) Offset(p Pos) int {
+ if int(p) < f.base || int(p) > f.base+f.size {
+ panic(fmt.Sprintf("invalid Pos value %d (should be in [%d, %d[)", p, f.base, f.base+f.size))
+ }
+ return int(p) - f.base
+}
+
+// Line returns the line number for the given file position p;
+// p must be a Pos value in that file or NoPos.
+//
+func (f *File) Line(p Pos) int {
+ return f.Position(p).Line
+}
+
+func searchLineInfos(a []lineInfo, x int) int {
+ return sort.Search(len(a), func(i int) bool { return a[i].Offset > x }) - 1
+}
+
+// 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) {
+ f.mutex.Lock()
+ defer f.mutex.Unlock()
+ filename = f.name
+ if i := searchInts(f.lines, offset); i >= 0 {
+ line, column = i+1, offset-f.lines[i]+1
+ }
+ if adjusted && len(f.infos) > 0 {
+ // few files have extra line infos
+ if i := searchLineInfos(f.infos, offset); i >= 0 {
+ alt := &f.infos[i]
+ filename = alt.Filename
+ if i := searchInts(f.lines, alt.Offset); i >= 0 {
+ // i+1 is the line at which the alternative position was recorded
+ d := line - (i + 1) // line distance from alternative position base
+ line = alt.Line + d
+ if alt.Column == 0 {
+ // alternative column is unknown => relative column is unknown
+ // (the current specification for line directives requires
+ // this to apply until the next PosBase/line directive,
+ // not just until the new newline)
+ column = 0
+ } else if d == 0 {
+ // the alternative position base is on the current line
+ // => column is relative to alternative column
+ column = alt.Column + (offset - alt.Offset)
+ }
+ }
+ }
+ }
+ return
+}
+
+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.unpack(offset, adjusted)
+ return
+}
+
+// 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) PositionFor(p Pos, adjusted bool) (pos Position) {
+ if p != NoPos {
+ if int(p) < f.base || int(p) > f.base+f.size {
+ panic(fmt.Sprintf("invalid Pos value %d (should be in [%d, %d[)", p, f.base, f.base+f.size))
+ }
+ 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
+
+// A FileSet represents a set of source files.
+// Methods of file sets are synchronized; multiple goroutines
+// may invoke them concurrently.
+//
+// The byte offsets for each file in a file set are mapped into
+// distinct (integer) intervals, one interval [base, base+size]
+// per file. Base represents the first byte in the file, and size
+// is the corresponding file size. A Pos value is a value in such
+// an interval. By determining the interval a Pos value belongs
+// to, the file, its file base, and thus the byte offset (position)
+// the Pos value is representing can be computed.
+//
+// When adding a new file, a file base must be provided. That can
+// be any integer value that is past the end of any interval of any
+// file already in the file set. For convenience, FileSet.Base provides
+// such a value, which is simply the end of the Pos interval of the most
+// recently added file, plus one. Unless there is a need to extend an
+// interval later, using the FileSet.Base should be used as argument
+// for FileSet.AddFile.
+//
+type FileSet struct {
+ mutex sync.RWMutex // protects the file set
+ base int // base offset for the next file
+ files []*File // list of files in the order added to the set
+ last *File // cache of last file looked up
+}
+
+// NewFileSet creates a new file set.
+func NewFileSet() *FileSet {
+ return &FileSet{
+ base: 1, // 0 == NoPos
+ }
+}
+
+// Base returns the minimum base offset that must be provided to
+// AddFile when adding the next file.
+//
+func (s *FileSet) Base() int {
+ s.mutex.RLock()
+ b := s.base
+ s.mutex.RUnlock()
+ return b
+
+}
+
+// AddFile adds a new file with a given filename, base offset, and file size
+// to the file set s and returns the file. Multiple files may have the same
+// name. The base offset must not be smaller than the FileSet's Base(), and
+// size must not be negative. As a special case, if a negative base is provided,
+// the current value of the FileSet's Base() is used instead.
+//
+// Adding the file will set the file set's Base() value to base + size + 1
+// as the minimum base value for the next file. The following relationship
+// exists between a Pos value p for a given file offset offs:
+//
+// int(p) = base + offs
+//
+// with offs in the range [0, size] and thus p in the range [base, base+size].
+// For convenience, File.Pos may be used to create file-specific position
+// values from a file offset.
+//
+func (s *FileSet) AddFile(filename string, base, size int) *File {
+ s.mutex.Lock()
+ defer s.mutex.Unlock()
+ if base < 0 {
+ base = s.base
+ }
+ if base < s.base {
+ panic(fmt.Sprintf("invalid base %d (should be >= %d)", base, s.base))
+ }
+ if size < 0 {
+ panic(fmt.Sprintf("invalid size %d (should be >= 0)", size))
+ }
+ // base >= s.base && size >= 0
+ f := &File{set: s, name: filename, base: base, size: size, lines: []int{0}}
+ base += size + 1 // +1 because EOF also has a position
+ if base < 0 {
+ panic("token.Pos offset overflow (> 2G of source code in file set)")
+ }
+ // add the file to the file set
+ s.base = base
+ s.files = append(s.files, f)
+ s.last = f
+ return f
+}
+
+// Iterate calls f for the files in the file set in the order they were added
+// until f returns false.
+//
+func (s *FileSet) Iterate(f func(*File) bool) {
+ for i := 0; ; i++ {
+ var file *File
+ s.mutex.RLock()
+ if i < len(s.files) {
+ file = s.files[i]
+ }
+ s.mutex.RUnlock()
+ if file == nil || !f(file) {
+ break
+ }
+ }
+}
+
+func searchFiles(a []*File, x int) int {
+ return sort.Search(len(a), func(i int) bool { return a[i].base > x }) - 1
+}
+
+func (s *FileSet) file(p Pos) *File {
+ s.mutex.RLock()
+ // common case: p is in last file
+ if f := s.last; f != nil && f.base <= int(p) && int(p) <= f.base+f.size {
+ s.mutex.RUnlock()
+ return f
+ }
+ // p is not in last file - search all files
+ if i := searchFiles(s.files, int(p)); i >= 0 {
+ f := s.files[i]
+ // f.base <= int(p) by definition of searchFiles
+ if int(p) <= f.base+f.size {
+ s.mutex.RUnlock()
+ s.mutex.Lock()
+ s.last = f // race is ok - s.last is only a cache
+ s.mutex.Unlock()
+ return f
+ }
+ }
+ s.mutex.RUnlock()
+ return nil
+}
+
+// File returns the file that contains the position p.
+// If no such file is found (for instance for p == NoPos),
+// the result is nil.
+//
+func (s *FileSet) File(p Pos) (f *File) {
+ if p != NoPos {
+ f = s.file(p)
+ }
+ return
+}
+
+// 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 {
+ return 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
+
+func searchInts(a []int, x int) int {
+ // This function body is a manually inlined version of:
+ //
+ // return sort.Search(len(a), func(i int) bool { return a[i] > x }) - 1
+ //
+ // With better compiler optimizations, this may not be needed in the
+ // future, but at the moment this change improves the go/printer
+ // benchmark performance by ~30%. This has a direct impact on the
+ // speed of gofmt and thus seems worthwhile (2011-04-29).
+ // TODO(gri): Remove this when compilers have caught up.
+ i, j := 0, len(a)
+ for i < j {
+ h := i + (j-i)/2 // avoid overflow when computing h
+ // i ≤ h < j
+ if a[h] <= x {
+ i = h + 1
+ } else {
+ j = h
+ }
+ }
+ return i - 1
+}
diff --git a/src/go/token/position_test.go b/src/go/token/position_test.go
new file mode 100644
index 0000000..7d465df
--- /dev/null
+++ b/src/go/token/position_test.go
@@ -0,0 +1,341 @@
+// Copyright 2010 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.
+
+package token
+
+import (
+ "fmt"
+ "math/rand"
+ "sync"
+ "testing"
+)
+
+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 got.Offset != want.Offset {
+ t.Errorf("%s: got offset = %d; want %d", msg, got.Offset, want.Offset)
+ }
+ if got.Line != want.Line {
+ t.Errorf("%s: got line = %d; want %d", msg, got.Line, want.Line)
+ }
+ if got.Column != want.Column {
+ t.Errorf("%s: got column = %d; want %d", msg, got.Column, want.Column)
+ }
+}
+
+func TestNoPos(t *testing.T) {
+ if NoPos.IsValid() {
+ t.Errorf("NoPos should not be valid")
+ }
+ var fset *FileSet
+ checkPos(t, "nil NoPos", fset.Position(NoPos), Position{})
+ fset = NewFileSet()
+ checkPos(t, "fset NoPos", fset.Position(NoPos), Position{})
+}
+
+var tests = []struct {
+ filename string
+ source []byte // may be nil
+ size int
+ lines []int
+}{
+ {"a", []byte{}, 0, []int{}},
+ {"b", []byte("01234"), 5, []int{0}},
+ {"c", []byte("\n\n\n\n\n\n\n\n\n"), 9, []int{0, 1, 2, 3, 4, 5, 6, 7, 8}},
+ {"d", nil, 100, []int{0, 5, 10, 20, 30, 70, 71, 72, 80, 85, 90, 99}},
+ {"e", nil, 777, []int{0, 80, 100, 120, 130, 180, 267, 455, 500, 567, 620}},
+ {"f", []byte("package p\n\nimport \"fmt\""), 23, []int{0, 10, 11}},
+ {"g", []byte("package p\n\nimport \"fmt\"\n"), 24, []int{0, 10, 11}},
+ {"h", []byte("package p\n\nimport \"fmt\"\n "), 25, []int{0, 10, 11, 24}},
+}
+
+func linecol(lines []int, offs int) (int, int) {
+ prevLineOffs := 0
+ for line, lineOffs := range lines {
+ if offs < lineOffs {
+ return line, offs - prevLineOffs + 1
+ }
+ prevLineOffs = lineOffs
+ }
+ return len(lines), offs - prevLineOffs + 1
+}
+
+func verifyPositions(t *testing.T, fset *FileSet, f *File, lines []int) {
+ for offs := 0; offs < f.Size(); offs++ {
+ p := f.Pos(offs)
+ offs2 := f.Offset(p)
+ if offs2 != offs {
+ 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)
+ checkPos(t, msg, f.Position(f.Pos(offs)), Position{f.Name(), offs, line, col})
+ checkPos(t, msg, fset.Position(p), Position{f.Name(), offs, line, col})
+ }
+}
+
+func makeTestSource(size int, lines []int) []byte {
+ src := make([]byte, size)
+ for _, offs := range lines {
+ if offs > 0 {
+ src[offs-1] = '\n'
+ }
+ }
+ return src
+}
+
+func TestPositions(t *testing.T) {
+ const delta = 7 // a non-zero base offset increment
+ fset := NewFileSet()
+ for _, test := range tests {
+ // verify consistency of test case
+ if test.source != nil && len(test.source) != test.size {
+ 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("got filename %q; want %q", f.Name(), test.filename)
+ }
+ if f.Size() != test.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())
+ }
+
+ // add lines individually and verify all positions
+ for i, offset := range test.lines {
+ f.AddLine(offset)
+ if f.LineCount() != i+1 {
+ 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: got unchanged line count %d; want %d", f.Name(), f.LineCount(), i+1)
+ }
+ verifyPositions(t, fset, f, test.lines[0:i+1])
+ }
+
+ // add lines with SetLines and verify all positions
+ if ok := f.SetLines(test.lines); !ok {
+ t.Errorf("%s: SetLines failed", f.Name())
+ }
+ if f.LineCount() != len(test.lines) {
+ t.Errorf("%s, SetLines: got line count %d; want %d", f.Name(), f.LineCount(), len(test.lines))
+ }
+ verifyPositions(t, fset, f, test.lines)
+
+ // add lines with SetLinesForContent and verify all positions
+ src := test.source
+ if src == nil {
+ // no test source available - create one from scratch
+ src = makeTestSource(test.size, test.lines)
+ }
+ f.SetLinesForContent(src)
+ if f.LineCount() != len(test.lines) {
+ t.Errorf("%s, SetLinesForContent: got line count %d; want %d", f.Name(), f.LineCount(), len(test.lines))
+ }
+ verifyPositions(t, fset, f, test.lines)
+ }
+}
+
+func TestLineInfo(t *testing.T) {
+ fset := NewFileSet()
+ f := fset.AddFile("foo", fset.Base(), 500)
+ lines := []int{0, 42, 77, 100, 210, 220, 277, 300, 333, 401}
+ // add lines individually and provide alternative line information
+ for _, offs := range lines {
+ f.AddLine(offs)
+ f.AddLineInfo(offs, "bar", 42)
+ }
+ // verify positions for all offsets
+ for offs := 0; offs <= f.Size(); offs++ {
+ p := f.Pos(offs)
+ _, col := linecol(lines, offs)
+ msg := fmt.Sprintf("%s (offs = %d, p = %d)", f.Name(), offs, p)
+ checkPos(t, msg, f.Position(f.Pos(offs)), Position{"bar", offs, 42, col})
+ checkPos(t, msg, fset.Position(p), Position{"bar", offs, 42, col})
+ }
+}
+
+func TestFiles(t *testing.T) {
+ fset := NewFileSet()
+ for i, test := range tests {
+ base := fset.Base()
+ if i%2 == 1 {
+ // Setting a negative base is equivalent to
+ // fset.Base(), so test some of each.
+ base = -1
+ }
+ fset.AddFile(test.filename, base, test.size)
+ j := 0
+ fset.Iterate(func(f *File) bool {
+ if f.Name() != tests[j].filename {
+ t.Errorf("got filename = %s; want %s", f.Name(), tests[j].filename)
+ }
+ j++
+ return true
+ })
+ if j != i+1 {
+ t.Errorf("got %d files; want %d", j, i+1)
+ }
+ }
+}
+
+// FileSet.File should return nil if Pos is past the end of the FileSet.
+func TestFileSetPastEnd(t *testing.T) {
+ fset := NewFileSet()
+ for _, test := range tests {
+ fset.AddFile(test.filename, fset.Base(), test.size)
+ }
+ if f := fset.File(Pos(fset.Base())); f != nil {
+ t.Errorf("got %v, want nil", f)
+ }
+}
+
+func TestFileSetCacheUnlikely(t *testing.T) {
+ fset := NewFileSet()
+ offsets := make(map[string]int)
+ for _, test := range tests {
+ offsets[test.filename] = fset.Base()
+ fset.AddFile(test.filename, fset.Base(), test.size)
+ }
+ for file, pos := range offsets {
+ f := fset.File(Pos(pos))
+ if f.Name() != file {
+ t.Errorf("got %q at position %d, want %q", f.Name(), pos, file)
+ }
+ }
+}
+
+// issue 4345. Test that concurrent use of FileSet.Pos does not trigger a
+// race in the FileSet position cache.
+func TestFileSetRace(t *testing.T) {
+ fset := NewFileSet()
+ for i := 0; i < 100; i++ {
+ fset.AddFile(fmt.Sprintf("file-%d", i), fset.Base(), 1031)
+ }
+ max := int32(fset.Base())
+ var stop sync.WaitGroup
+ r := rand.New(rand.NewSource(7))
+ for i := 0; i < 2; i++ {
+ r := rand.New(rand.NewSource(r.Int63()))
+ stop.Add(1)
+ go func() {
+ for i := 0; i < 1000; i++ {
+ fset.Position(Pos(r.Int31n(max)))
+ }
+ stop.Done()
+ }()
+ }
+ stop.Wait()
+}
+
+// issue 16548. Test that concurrent use of File.AddLine and FileSet.PositionFor
+// does not trigger a race in the FileSet position cache.
+func TestFileSetRace2(t *testing.T) {
+ const N = 1e3
+ var (
+ fset = NewFileSet()
+ file = fset.AddFile("", -1, N)
+ ch = make(chan int, 2)
+ )
+
+ go func() {
+ for i := 0; i < N; i++ {
+ file.AddLine(i)
+ }
+ ch <- 1
+ }()
+
+ go func() {
+ pos := file.Pos(0)
+ for i := 0; i < N; i++ {
+ fset.PositionFor(pos, false)
+ }
+ ch <- 1
+ }()
+
+ <-ch
+ <-ch
+}
+
+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)
+ }
+}
+
+func TestLineStart(t *testing.T) {
+ const src = "one\ntwo\nthree\n"
+ fset := NewFileSet()
+ f := fset.AddFile("input", -1, len(src))
+ f.SetLinesForContent([]byte(src))
+
+ for line := 1; line <= 3; line++ {
+ pos := f.LineStart(line)
+ position := fset.Position(pos)
+ if position.Line != line || position.Column != 1 {
+ t.Errorf("LineStart(%d) returned wrong pos %d: %s", line, pos, position)
+ }
+ }
+}
diff --git a/src/go/token/serialize.go b/src/go/token/serialize.go
new file mode 100644
index 0000000..d0ea345
--- /dev/null
+++ b/src/go/token/serialize.go
@@ -0,0 +1,71 @@
+// 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.
+
+package token
+
+type serializedFile struct {
+ // fields correspond 1:1 to fields with same (lower-case) name in File
+ Name string
+ Base int
+ Size int
+ Lines []int
+ Infos []lineInfo
+}
+
+type serializedFileSet struct {
+ Base int
+ Files []serializedFile
+}
+
+// Read calls decode to deserialize a file set into s; s must not be nil.
+func (s *FileSet) Read(decode func(interface{}) error) error {
+ var ss serializedFileSet
+ if err := decode(&ss); err != nil {
+ return err
+ }
+
+ s.mutex.Lock()
+ s.base = ss.Base
+ files := make([]*File, len(ss.Files))
+ for i := 0; i < len(ss.Files); i++ {
+ f := &ss.Files[i]
+ files[i] = &File{
+ set: s,
+ name: f.Name,
+ base: f.Base,
+ size: f.Size,
+ lines: f.Lines,
+ infos: f.Infos,
+ }
+ }
+ s.files = files
+ s.last = nil
+ s.mutex.Unlock()
+
+ return nil
+}
+
+// Write calls encode to serialize the file set s.
+func (s *FileSet) Write(encode func(interface{}) error) error {
+ var ss serializedFileSet
+
+ s.mutex.Lock()
+ ss.Base = s.base
+ files := make([]serializedFile, len(s.files))
+ for i, f := range s.files {
+ f.mutex.Lock()
+ files[i] = serializedFile{
+ Name: f.name,
+ Base: f.base,
+ Size: f.size,
+ Lines: append([]int(nil), f.lines...),
+ Infos: append([]lineInfo(nil), f.infos...),
+ }
+ f.mutex.Unlock()
+ }
+ ss.Files = files
+ s.mutex.Unlock()
+
+ return encode(ss)
+}
diff --git a/src/go/token/serialize_test.go b/src/go/token/serialize_test.go
new file mode 100644
index 0000000..4e925ad
--- /dev/null
+++ b/src/go/token/serialize_test.go
@@ -0,0 +1,111 @@
+// 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.
+
+package token
+
+import (
+ "bytes"
+ "encoding/gob"
+ "fmt"
+ "testing"
+)
+
+// equal returns nil if p and q describe the same file set;
+// otherwise it returns an error describing the discrepancy.
+func equal(p, q *FileSet) error {
+ if p == q {
+ // avoid deadlock if p == q
+ return nil
+ }
+
+ // not strictly needed for the test
+ p.mutex.Lock()
+ q.mutex.Lock()
+ defer q.mutex.Unlock()
+ defer p.mutex.Unlock()
+
+ if p.base != q.base {
+ return fmt.Errorf("different bases: %d != %d", p.base, q.base)
+ }
+
+ if len(p.files) != len(q.files) {
+ return fmt.Errorf("different number of files: %d != %d", len(p.files), len(q.files))
+ }
+
+ for i, f := range p.files {
+ g := q.files[i]
+ if f.set != p {
+ return fmt.Errorf("wrong fileset for %q", f.name)
+ }
+ if g.set != q {
+ return fmt.Errorf("wrong fileset for %q", g.name)
+ }
+ if f.name != g.name {
+ return fmt.Errorf("different filenames: %q != %q", f.name, g.name)
+ }
+ if f.base != g.base {
+ return fmt.Errorf("different base for %q: %d != %d", f.name, f.base, g.base)
+ }
+ if f.size != g.size {
+ return fmt.Errorf("different size for %q: %d != %d", f.name, f.size, g.size)
+ }
+ for j, l := range f.lines {
+ m := g.lines[j]
+ if l != m {
+ return fmt.Errorf("different offsets for %q", f.name)
+ }
+ }
+ for j, l := range f.infos {
+ m := g.infos[j]
+ if l.Offset != m.Offset || l.Filename != m.Filename || l.Line != m.Line {
+ return fmt.Errorf("different infos for %q", f.name)
+ }
+ }
+ }
+
+ // we don't care about .last - it's just a cache
+ return nil
+}
+
+func checkSerialize(t *testing.T, p *FileSet) {
+ var buf bytes.Buffer
+ encode := func(x interface{}) error {
+ return gob.NewEncoder(&buf).Encode(x)
+ }
+ if err := p.Write(encode); err != nil {
+ t.Errorf("writing fileset failed: %s", err)
+ return
+ }
+ q := NewFileSet()
+ decode := func(x interface{}) error {
+ return gob.NewDecoder(&buf).Decode(x)
+ }
+ if err := q.Read(decode); err != nil {
+ t.Errorf("reading fileset failed: %s", err)
+ return
+ }
+ if err := equal(p, q); err != nil {
+ t.Errorf("filesets not identical: %s", err)
+ }
+}
+
+func TestSerialization(t *testing.T) {
+ p := NewFileSet()
+ checkSerialize(t, p)
+ // add some files
+ for i := 0; i < 10; i++ {
+ f := p.AddFile(fmt.Sprintf("file%d", i), p.Base()+i, i*100)
+ checkSerialize(t, p)
+ // add some lines and alternative file infos
+ line := 1000
+ for offs := 0; offs < f.Size(); offs += 40 + i {
+ f.AddLine(offs)
+ if offs%7 == 0 {
+ f.AddLineInfo(offs, fmt.Sprintf("file%d", offs), line)
+ line += 33
+ }
+ }
+ checkSerialize(t, p)
+ }
+}
diff --git a/src/go/token/token.go b/src/go/token/token.go
new file mode 100644
index 0000000..96a1079
--- /dev/null
+++ b/src/go/token/token.go
@@ -0,0 +1,340 @@
+// Copyright 2009 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.
+
+// Package token defines constants representing the lexical tokens of the Go
+// programming language and basic operations on tokens (printing, predicates).
+//
+package token
+
+import (
+ "strconv"
+ "unicode"
+ "unicode/utf8"
+)
+
+// Token is the set of lexical tokens of the Go programming language.
+type Token int
+
+// The list of tokens.
+const (
+ // Special tokens
+ ILLEGAL Token = iota
+ EOF
+ COMMENT
+
+ literal_beg
+ // Identifiers and basic type literals
+ // (these tokens stand for classes of literals)
+ IDENT // main
+ INT // 12345
+ FLOAT // 123.45
+ IMAG // 123.45i
+ CHAR // 'a'
+ STRING // "abc"
+ literal_end
+
+ operator_beg
+ // Operators and delimiters
+ ADD // +
+ SUB // -
+ MUL // *
+ QUO // /
+ REM // %
+
+ AND // &
+ OR // |
+ XOR // ^
+ SHL // <<
+ SHR // >>
+ AND_NOT // &^
+
+ ADD_ASSIGN // +=
+ SUB_ASSIGN // -=
+ MUL_ASSIGN // *=
+ QUO_ASSIGN // /=
+ REM_ASSIGN // %=
+
+ AND_ASSIGN // &=
+ OR_ASSIGN // |=
+ XOR_ASSIGN // ^=
+ SHL_ASSIGN // <<=
+ SHR_ASSIGN // >>=
+ AND_NOT_ASSIGN // &^=
+
+ LAND // &&
+ LOR // ||
+ ARROW // <-
+ INC // ++
+ DEC // --
+
+ EQL // ==
+ LSS // <
+ GTR // >
+ ASSIGN // =
+ NOT // !
+
+ NEQ // !=
+ LEQ // <=
+ GEQ // >=
+ DEFINE // :=
+ ELLIPSIS // ...
+
+ LPAREN // (
+ LBRACK // [
+ LBRACE // {
+ COMMA // ,
+ PERIOD // .
+
+ RPAREN // )
+ RBRACK // ]
+ RBRACE // }
+ SEMICOLON // ;
+ COLON // :
+ operator_end
+
+ keyword_beg
+ // Keywords
+ BREAK
+ CASE
+ CHAN
+ CONST
+ CONTINUE
+
+ DEFAULT
+ DEFER
+ ELSE
+ FALLTHROUGH
+ FOR
+
+ FUNC
+ GO
+ GOTO
+ IF
+ IMPORT
+
+ INTERFACE
+ MAP
+ PACKAGE
+ RANGE
+ RETURN
+
+ SELECT
+ STRUCT
+ SWITCH
+ TYPE
+ VAR
+ keyword_end
+)
+
+var tokens = [...]string{
+ ILLEGAL: "ILLEGAL",
+
+ EOF: "EOF",
+ COMMENT: "COMMENT",
+
+ IDENT: "IDENT",
+ INT: "INT",
+ FLOAT: "FLOAT",
+ IMAG: "IMAG",
+ CHAR: "CHAR",
+ STRING: "STRING",
+
+ ADD: "+",
+ SUB: "-",
+ MUL: "*",
+ QUO: "/",
+ REM: "%",
+
+ AND: "&",
+ OR: "|",
+ XOR: "^",
+ SHL: "<<",
+ SHR: ">>",
+ AND_NOT: "&^",
+
+ ADD_ASSIGN: "+=",
+ SUB_ASSIGN: "-=",
+ MUL_ASSIGN: "*=",
+ QUO_ASSIGN: "/=",
+ REM_ASSIGN: "%=",
+
+ AND_ASSIGN: "&=",
+ OR_ASSIGN: "|=",
+ XOR_ASSIGN: "^=",
+ SHL_ASSIGN: "<<=",
+ SHR_ASSIGN: ">>=",
+ AND_NOT_ASSIGN: "&^=",
+
+ LAND: "&&",
+ LOR: "||",
+ ARROW: "<-",
+ INC: "++",
+ DEC: "--",
+
+ EQL: "==",
+ LSS: "<",
+ GTR: ">",
+ ASSIGN: "=",
+ NOT: "!",
+
+ NEQ: "!=",
+ LEQ: "<=",
+ GEQ: ">=",
+ DEFINE: ":=",
+ ELLIPSIS: "...",
+
+ LPAREN: "(",
+ LBRACK: "[",
+ LBRACE: "{",
+ COMMA: ",",
+ PERIOD: ".",
+
+ RPAREN: ")",
+ RBRACK: "]",
+ RBRACE: "}",
+ SEMICOLON: ";",
+ COLON: ":",
+
+ BREAK: "break",
+ CASE: "case",
+ CHAN: "chan",
+ CONST: "const",
+ CONTINUE: "continue",
+
+ DEFAULT: "default",
+ DEFER: "defer",
+ ELSE: "else",
+ FALLTHROUGH: "fallthrough",
+ FOR: "for",
+
+ FUNC: "func",
+ GO: "go",
+ GOTO: "goto",
+ IF: "if",
+ IMPORT: "import",
+
+ INTERFACE: "interface",
+ MAP: "map",
+ PACKAGE: "package",
+ RANGE: "range",
+ RETURN: "return",
+
+ SELECT: "select",
+ STRUCT: "struct",
+ SWITCH: "switch",
+ TYPE: "type",
+ VAR: "var",
+}
+
+// String returns the string corresponding to the token tok.
+// For operators, delimiters, and keywords the string is the actual
+// token character sequence (e.g., for the token ADD, the string is
+// "+"). For all other tokens the string corresponds to the token
+// constant name (e.g. for the token IDENT, the string is "IDENT").
+//
+func (tok Token) String() string {
+ s := ""
+ if 0 <= tok && tok < Token(len(tokens)) {
+ s = tokens[tok]
+ }
+ if s == "" {
+ s = "token(" + strconv.Itoa(int(tok)) + ")"
+ }
+ return s
+}
+
+// A set of constants for precedence-based expression parsing.
+// Non-operators have lowest precedence, followed by operators
+// starting with precedence 1 up to unary operators. The highest
+// precedence serves as "catch-all" precedence for selector,
+// indexing, and other operator and delimiter tokens.
+//
+const (
+ LowestPrec = 0 // non-operators
+ UnaryPrec = 6
+ HighestPrec = 7
+)
+
+// Precedence returns the operator precedence of the binary
+// operator op. If op is not a binary operator, the result
+// is LowestPrecedence.
+//
+func (op Token) Precedence() int {
+ switch op {
+ case LOR:
+ return 1
+ case LAND:
+ return 2
+ case EQL, NEQ, LSS, LEQ, GTR, GEQ:
+ return 3
+ case ADD, SUB, OR, XOR:
+ return 4
+ case MUL, QUO, REM, SHL, SHR, AND, AND_NOT:
+ return 5
+ }
+ return LowestPrec
+}
+
+var keywords map[string]Token
+
+func init() {
+ keywords = make(map[string]Token)
+ for i := keyword_beg + 1; i < keyword_end; i++ {
+ keywords[tokens[i]] = i
+ }
+}
+
+// Lookup maps an identifier to its keyword token or IDENT (if not a keyword).
+//
+func Lookup(ident string) Token {
+ if tok, is_keyword := keywords[ident]; is_keyword {
+ return tok
+ }
+ return IDENT
+}
+
+// Predicates
+
+// IsLiteral returns true for tokens corresponding to identifiers
+// and basic type literals; it returns false otherwise.
+//
+func (tok Token) IsLiteral() bool { return literal_beg < tok && tok < literal_end }
+
+// IsOperator returns true for tokens corresponding to operators and
+// delimiters; it returns false otherwise.
+//
+func (tok Token) IsOperator() bool { return operator_beg < tok && tok < operator_end }
+
+// IsKeyword returns true for tokens corresponding to keywords;
+// it returns false otherwise.
+//
+func (tok Token) IsKeyword() bool { return keyword_beg < tok && tok < keyword_end }
+
+// IsExported reports whether name starts with an upper-case letter.
+//
+func IsExported(name string) bool {
+ ch, _ := utf8.DecodeRuneInString(name)
+ return unicode.IsUpper(ch)
+}
+
+// IsKeyword reports whether name is a Go keyword, such as "func" or "return".
+//
+func IsKeyword(name string) bool {
+ // TODO: opt: use a perfect hash function instead of a global map.
+ _, ok := keywords[name]
+ return ok
+}
+
+// IsIdentifier reports whether name is a Go identifier, that is, a non-empty
+// string made up of letters, digits, and underscores, where the first character
+// is not a digit. Keywords are not identifiers.
+//
+func IsIdentifier(name string) bool {
+ for i, c := range name {
+ if !unicode.IsLetter(c) && c != '_' && (i == 0 || !unicode.IsDigit(c)) {
+ return false
+ }
+ }
+ return name != "" && !IsKeyword(name)
+}
diff --git a/src/go/token/token_test.go b/src/go/token/token_test.go
new file mode 100644
index 0000000..eff38cc
--- /dev/null
+++ b/src/go/token/token_test.go
@@ -0,0 +1,33 @@
+// Copyright 2019 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.
+
+package token
+
+import "testing"
+
+func TestIsIdentifier(t *testing.T) {
+ tests := []struct {
+ name string
+ in string
+ want bool
+ }{
+ {"Empty", "", false},
+ {"Space", " ", false},
+ {"SpaceSuffix", "foo ", false},
+ {"Number", "123", false},
+ {"Keyword", "func", false},
+
+ {"LettersASCII", "foo", true},
+ {"MixedASCII", "_bar123", true},
+ {"UppercaseKeyword", "Func", true},
+ {"LettersUnicode", "fóö", true},
+ }
+ for _, test := range tests {
+ t.Run(test.name, func(t *testing.T) {
+ if got := IsIdentifier(test.in); got != test.want {
+ t.Fatalf("IsIdentifier(%q) = %t, want %v", test.in, got, test.want)
+ }
+ })
+ }
+}