Stowage/go
2
0
Fork 0
mirror of https://github.com/golang/go.git synced 2025-12-08 06:10:04 +00:00
Code Issues Projects Releases Packages Wiki Activity

[dev.inline] cmd/compile/internal/syntax: clean up error and pragma handling

Browse source 
Reviewed in and cherry-picked from https://go-review.googlesource.com/#/c/33873/.

- simplify error handling in source.go
  (move handling of first error into parser, where it belongs)

- clean up error handling in scanner.go

- move pragma and position base handling from scanner
  to parser where it belongs

- have separate error methods in parser to avoid confusion
  with handlers from scanner.go and source.go

- (source.go) and (scanner.go, source.go, tokens.go)
  may be stand-alone packages if so desired, which means
  these files are now less entangled and easier to maintain

Change-Id: I81510fc7ef943b78eaa49092c0eab2075a05878c
Reviewed-on: https://go-review.googlesource.com/34235
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This commit is contained in:
Robert Griesemer 2016-12-01 22:04:49 -08:00
parent e97c8a592f
commit 54ef0447fe
4 changed files with 128 additions and 102 deletions
Download patch file Download diff file Expand all files Collapse all files

82
src/cmd/compile/internal/syntax/scanner.go
View file

@ -2,39 +2,43 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// This file implements scanner, a lexical tokenizer for
// Go source. After initialization, consecutive calls of
// next advance the scanner one token at a time.
//
// This file, source.go, and tokens.go are self-contained
// (go tool compile scanner.go source.go tokens.go compiles)
// and thus could be made into its own package.
package syntax
import (
"fmt"
"io"
"strconv"
"strings"
"unicode"
"unicode/utf8"
)
type scanner struct {
source
nlsemi bool // if set '\n' and EOF translate to ';'
pragma Pragma
pragh func(line, col uint, msg string)
gcCompat bool // TODO(gri) remove this eventually (only here so we can build w/o parser)
nlsemi bool // if set '\n' and EOF translate to ';'
// current token, valid after calling next()
base *PosBase
line, col uint
tok token
lit string // valid if tok is _Name or _Literal
kind LitKind // valid if tok is _Literal
op Operator // valid if tok is _Operator, _AssignOp, or _IncOp
prec int // valid if tok is _Operator, _AssignOp, or _IncOp
pragh PragmaHandler
}
func (s *scanner) init(filename string, src io.Reader, errh ErrorHandler, pragh PragmaHandler) {
func (s *scanner) init(src io.Reader, errh, pragh func(line, col uint, msg string), gcCompat bool) {
s.source.init(src, errh)
s.nlsemi = false
s.base = NewFileBase(filename)
s.pragh = pragh
s.gcCompat = gcCompat
s.nlsemi = false
}
func (s *scanner) next() {
@ -331,7 +335,7 @@ func (s *scanner) ident() {
}
func (s *scanner) isCompatRune(c rune, start bool) bool {
if !gcCompat || c < utf8.RuneSelf {
if !s.gcCompat || c < utf8.RuneSelf {
return false
}
if start && unicode.IsNumber(c) {
@ -461,7 +465,7 @@ func (s *scanner) stdString() {
break
}
if r < 0 {
s.error_at(s.line, s.col, "string not terminated")
s.errh(s.line, s.col, "string not terminated")
break
}
}
@ -481,7 +485,7 @@ func (s *scanner) rawString() {
break
}
if r < 0 {
s.error_at(s.line, s.col, "string not terminated")
s.errh(s.line, s.col, "string not terminated")
break
}
}
@ -538,23 +542,18 @@ func (s *scanner) skipLine(r rune) {
}
func (s *scanner) lineComment() {
// recognize pragmas
prefix := ""
r := s.getr()
switch r {
case 'g':
if s.pragh == nil {
s.skipLine(r)
return
}
prefix = "go:"
case 'l':
prefix = "line "
default:
if s.pragh == nil || (r != 'g' && r != 'l') {
s.skipLine(r)
return
}
// s.pragh != nil && (r == 'g' || r == 'l')
// recognize pragmas
prefix := "go:"
if r == 'l' {
prefix = "line "
}
for _, m := range prefix {
if r != m {
s.skipLine(r)
@ -563,34 +562,15 @@ func (s *scanner) lineComment() {
r = s.getr()
}
// pragma text without prefix and line ending (which may be "\r\n" if Windows)
// pragma text without line ending (which may be "\r\n" if Windows),
s.startLit()
s.skipLine(r)
text := strings.TrimSuffix(string(s.stopLit()), "\r")
// process //line filename:line pragma
if prefix[0] == 'l' {
// Want to use LastIndexByte below but it's not defined in Go1.4 and bootstrap fails.
i := strings.LastIndex(text, ":") // look from right (Windows filenames may contain ':')
if i < 0 {
return
}
nstr := text[i+1:]
n, err := strconv.Atoi(nstr)
if err != nil || n <= 0 || n > lineMax {
s.error_at(s.line0, s.col0-uint(len(nstr)), "invalid line number: "+nstr)
return
}
s.base = NewLinePragmaBase(MakePos(s.base.Pos().Base(), s.line, s.col), text[:i], uint(n))
// TODO(gri) Return here once we rely exclusively
// on node positions for line number information,
// and remove //line pragma handling elsewhere.
if s.pragh == nil {
return
}
text := s.stopLit()
if i := len(text) - 1; i >= 0 && text[i] == '\r' {
text = text[:i]
}
s.pragma |= s.pragh(s.line, prefix+text)
s.pragh(s.line, s.col+2, prefix+string(text)) // +2 since pragma text starts after //
}
func (s *scanner) fullComment() {
@ -603,7 +583,7 @@ func (s *scanner) fullComment() {
}
}
if r < 0 {
s.error_at(s.line, s.col, "comment not terminated")
s.errh(s.line, s.col, "comment not terminated")
return
}
}
@ -651,7 +631,7 @@ func (s *scanner) escape(quote rune) bool {
if c < 0 {
return true // complain in caller about EOF
}
if gcCompat {
if s.gcCompat {
name := "hex"
if base == 8 {
name = "octal"