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cmd/compile: simplify lexer.ungetr

Change-Id: Id041c1b2d364aecd7a6613a53237f7de2c650a7e
Reviewed-on: https://go-review.googlesource.com/20599
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This commit is contained in:
Robert Griesemer 2016-03-11 13:55:53 -08:00
parent e2836935bb
commit e78ff3823e

View File

@ -886,6 +886,7 @@ const (
type lexer struct {
// source
bin *bufio.Reader
prevlineno int32 // line no. of most recently read character
nlsemi bool // if set, '\n' and EOF translate to ';'
@ -1003,7 +1004,7 @@ l0:
switch c {
case EOF:
l.ungetr(EOF) // return EOF again in future next call
l.ungetr()
// Treat EOF as "end of line" for the purposes
// of inserting a semicolon.
if nlsemi {
@ -1023,7 +1024,7 @@ l0:
case '.':
c1 = l.getr()
if isDigit(c1) {
l.ungetr(c1)
l.ungetr()
l.number('.')
return
}
@ -1036,7 +1037,7 @@ l0:
goto lx
}
l.ungetr(c1)
l.ungetr()
c1 = '.'
}
@ -1086,7 +1087,7 @@ l0:
c = l.getlinepragma()
for {
if c == '\n' || c == EOF {
l.ungetr(c)
l.ungetr()
goto l0
}
@ -1240,7 +1241,7 @@ l0:
goto l0
}
l.ungetr(c1)
l.ungetr()
lx:
if Debug['x'] != 0 {
@ -1269,7 +1270,7 @@ binop:
c1 = l.getr()
binop1:
if c1 != '=' {
l.ungetr(c1)
l.ungetr()
l.op = op
l.prec = prec
goto lx
@ -1312,7 +1313,7 @@ func (l *lexer) ident(c rune) {
}
cp = nil
l.ungetr(c)
l.ungetr()
name := lexbuf.Bytes()
@ -1478,7 +1479,7 @@ func (l *lexer) number(c rune) {
}
}
l.ungetr(c)
l.ungetr()
if isInt {
if malformedOctal {
@ -1591,7 +1592,7 @@ func (l *lexer) rune() {
if c := l.getr(); c != '\'' {
Yyerror("missing '")
l.ungetr(c)
l.ungetr()
}
x := new(Mpint)
@ -1892,6 +1893,7 @@ func pragcgo(text string) {
func (l *lexer) getr() rune {
redo:
l.prevlineno = lexlineno
r, w, err := l.bin.ReadRune()
if err != nil {
if err != io.EOF {
@ -1918,11 +1920,9 @@ redo:
return r
}
func (l *lexer) ungetr(r rune) {
func (l *lexer) ungetr() {
l.bin.UnreadRune()
if r == '\n' && importpkg == nil {
lexlineno--
}
lexlineno = l.prevlineno
}
// onechar lexes a single character within a rune or interpreted string literal,
@ -1932,12 +1932,12 @@ func (l *lexer) onechar(quote rune) (r rune, b byte, ok bool) {
switch c {
case EOF:
Yyerror("eof in string")
l.ungetr(EOF)
l.ungetr()
return
case '\n':
Yyerror("newline in string")
l.ungetr('\n')
l.ungetr()
return
case '\\':
@ -1971,7 +1971,7 @@ func (l *lexer) onechar(quote rune) (r rune, b byte, ok bool) {
}
Yyerror("non-octal character in escape sequence: %c", c)
l.ungetr(c)
l.ungetr()
}
if x > 255 {
@ -2029,7 +2029,7 @@ func (l *lexer) hexchar(n int) uint32 {
d = uint32(c - 'A' + 10)
default:
Yyerror("non-hex character in escape sequence: %c", c)
l.ungetr(c)
l.ungetr()
return x
}
x = x*16 + d