goyacc: provide -p flag to set prefix for names.
This should allow multiple goyacc grammars to be
compiled into the same binary. There's a chance it
Fixes #1562.
R=rsc, r2
CC=golang-dev
https://golang.org/cl/4256044
diff --git a/src/cmd/goyacc/Makefile b/src/cmd/goyacc/Makefile
index 54b8f33..ac0f427 100644
--- a/src/cmd/goyacc/Makefile
+++ b/src/cmd/goyacc/Makefile
@@ -11,7 +11,7 @@
include ../../Make.cmd
units: goyacc units.y
- ./goyacc units.y
+ ./goyacc -p units_ units.y
$(GC) y.go
$(LD) -o units y.$O
diff --git a/src/cmd/goyacc/doc.go b/src/cmd/goyacc/doc.go
index 686f757..aa5bd58 100644
--- a/src/cmd/goyacc/doc.go
+++ b/src/cmd/goyacc/doc.go
@@ -17,7 +17,8 @@
The file units.y in this directory is a yacc grammar for a version of
the Unix tool units, also written in Go and largely transliterated
-from the Plan 9 C version.
+from the Plan 9 C version. It needs the flag "-p units_" (see
+below).
The generated parser is reentrant. Parse expects to be given an
argument that conforms to the following interface:
@@ -31,8 +32,14 @@
information in lval (which replaces the usual yylval).
Error is equivalent to yyerror in the original yacc.
-Code inside the parser may refer to the variable yylex
+Code inside the parser may refer to the variable yylex,
which holds the yyLexer passed to Parse.
+The "-p prefix" flag to goyacc sets the prefix, by default yy, that
+begins the names of symbols, including types, the parser, and the
+lexer, generated and referenced by goyacc's generated code. Setting
+it to distinct values allows multiple grammars to be used in a
+single binary.
+
*/
package documentation
diff --git a/src/cmd/goyacc/goyacc.go b/src/cmd/goyacc/goyacc.go
index c9fa6bf..32816b7 100644
--- a/src/cmd/goyacc/goyacc.go
+++ b/src/cmd/goyacc/goyacc.go
@@ -153,9 +153,17 @@
var fcode = &bytes.Buffer{} // saved code
var foutput *bufio.Writer // y.output file
-var oflag string // -o [y.go] - y.go file
-var vflag string // -v [y.output] - y.output file
-var lflag bool // -l - disable line directives
+var oflag string // -o [y.go] - y.go file
+var vflag string // -v [y.output] - y.output file
+var lflag bool // -l - disable line directives
+var prefix string // name prefix for identifiers, default yy
+
+func init() {
+ flag.StringVar(&oflag, "o", "y.go", "parser output")
+ flag.StringVar(&prefix, "p", "yy", "name prefix to use in generated code")
+ flag.StringVar(&vflag, "v", "y.output", "create parsing tables")
+ flag.BoolVar(&lflag, "l", false, "disable line directives")
+}
var stacksize = 200
@@ -349,10 +357,6 @@
stderr = bufio.NewWriter(os.NewFile(2, "stderr"))
foutput = nil
- flag.StringVar(&oflag, "o", "", "parser output")
- flag.StringVar(&vflag, "v", "", "create parsing tables")
- flag.BoolVar(&lflag, "l", false, "disable line directives")
-
flag.Parse()
if flag.NArg() != 1 {
usage()
@@ -362,6 +366,7 @@
fmt.Fprintf(stderr, "yacc: stack size too small\n")
usage()
}
+ yaccpar = strings.Replace(yaccpartext, "$$", prefix, -1)
openup()
defin(0, "$end")
@@ -506,20 +511,20 @@
}
// put out names of token names
- fmt.Fprintf(ftable, "var\tyyToknames\t =[]string {\n")
+ fmt.Fprintf(ftable, "var\t%sToknames\t =[]string {\n", prefix)
for i := TOKSTART; i <= ntokens; i++ {
fmt.Fprintf(ftable, "\t\"%v\",\n", tokset[i].name)
}
fmt.Fprintf(ftable, "}\n")
// put out names of state names
- fmt.Fprintf(ftable, "var\tyyStatenames\t =[]string {\n")
+ fmt.Fprintf(ftable, "var\t%sStatenames\t =[]string {\n", prefix)
// for i:=TOKSTART; i<=ntokens; i++ {
// fmt.Fprintf(ftable, "\t\"%v\",\n", tokset[i].name);
// }
fmt.Fprintf(ftable, "}\n")
- fmt.Fprintf(fcode, "switch yynt {\n")
+ fmt.Fprintf(fcode, "switch %snt {\n", prefix)
moreprod()
prdptr[0] = []int{NTBASE, start, 1, 0}
@@ -648,8 +653,8 @@
error("default action causes potential type clash")
}
fmt.Fprintf(fcode, "\ncase %v:", nprod)
- fmt.Fprintf(fcode, "\n\tYYVAL.%v = YYS[yypt-0].%v;",
- typeset[tempty], typeset[tempty])
+ fmt.Fprintf(fcode, "\n\t%sVAL.%v = %sS[%spt-0].%v;",
+ prefix, typeset[tempty], prefix, prefix, typeset[tempty])
}
moreprod()
prdptr[nprod] = make([]int, mem)
@@ -666,9 +671,9 @@
fmt.Fprintf(fcode, "\n\t}")
- fmt.Fprintf(ftable, "const yyEofCode = 1\n")
- fmt.Fprintf(ftable, "const yyErrCode = 2\n")
- fmt.Fprintf(ftable, "const yyMaxDepth = %v\n", stacksize)
+ fmt.Fprintf(ftable, "const %sEofCode = 1\n", prefix)
+ fmt.Fprintf(ftable, "const %sErrCode = 2\n", prefix)
+ fmt.Fprintf(ftable, "const %sMaxDepth = %v\n", prefix, stacksize)
//
// copy any postfix code
@@ -1034,7 +1039,7 @@
if !lflag {
fmt.Fprintf(ftable, "\n//line %v:%v\n", infile, lineno)
}
- fmt.Fprintf(ftable, "type\tyySymType\tstruct")
+ fmt.Fprintf(ftable, "type\t%sSymType\tstruct", prefix)
level := 0
@@ -1197,7 +1202,7 @@
c = getrune(finput)
}
if c == '$' {
- fmt.Fprintf(fcode, "YYVAL")
+ fmt.Fprintf(fcode, "%sVAL", prefix)
// put out the proper tag...
if ntypes != 0 {
@@ -1258,7 +1263,7 @@
ungetrune(finput, c)
continue loop
}
- fmt.Fprintf(fcode, "YYS[yypt-%v]", max-j-1)
+ fmt.Fprintf(fcode, "%sS[%spt-%v]", prefix, prefix, max-j-1)
// put out the proper tag
if ntypes != 0 {
@@ -2067,7 +2072,7 @@
var c, u, v int
fmt.Fprintf(ftable, "\n//line yacctab:1\n")
- fmt.Fprintf(ftable, "var\tyyExca = []int {\n")
+ fmt.Fprintf(ftable, "var\t%sExca = []int {\n", prefix)
noset := mkset()
@@ -2140,10 +2145,10 @@
}
fmt.Fprintf(ftable, "}\n")
- fmt.Fprintf(ftable, "const\tyyNprod\t= %v\n", nprod)
- fmt.Fprintf(ftable, "const\tyyPrivate\t= %v\n", PRIVATE)
- fmt.Fprintf(ftable, "var\tyyTokenNames []string\n")
- fmt.Fprintf(ftable, "var\tyyStates []string\n")
+ fmt.Fprintf(ftable, "const\t%sNprod\t= %v\n", prefix, nprod)
+ fmt.Fprintf(ftable, "const\t%sPrivate\t= %v\n", prefix, PRIVATE)
+ fmt.Fprintf(ftable, "var\t%sTokenNames []string\n", prefix)
+ fmt.Fprintf(ftable, "var\t%sStates []string\n", prefix)
}
//
@@ -2718,10 +2723,10 @@
// write out the optimized parser
//
func aoutput() {
- fmt.Fprintf(ftable, "const\tyyLast\t= %v\n", maxa+1)
- arout("yyAct", amem, maxa+1)
- arout("yyPact", indgo, nstate)
- arout("yyPgo", pgo, nnonter+1)
+ fmt.Fprintf(ftable, "const\t%sLast\t= %v\n", prefix, maxa+1)
+ arout("Act", amem, maxa+1)
+ arout("Pact", indgo, nstate)
+ arout("Pgo", pgo, nnonter+1)
}
//
@@ -2730,7 +2735,7 @@
func others() {
var i, j int
- arout("yyR1", levprd, nprod)
+ arout("R1", levprd, nprod)
aryfil(temp1, nprod, 0)
//
@@ -2739,7 +2744,7 @@
for i = 1; i < nprod; i++ {
temp1[i] = len(prdptr[i]) - 2
}
- arout("yyR2", temp1, nprod)
+ arout("R2", temp1, nprod)
aryfil(temp1, nstate, -1000)
for i = 0; i <= ntokens; i++ {
@@ -2752,8 +2757,8 @@
temp1[j] = -i
}
}
- arout("yyChk", temp1, nstate)
- arout("yyDef", defact, nstate)
+ arout("Chk", temp1, nstate)
+ arout("Def", defact, nstate)
// put out token translation tables
// table 1 has 0-256
@@ -2778,7 +2783,7 @@
temp1[i] = YYLEXUNK
}
}
- arout("yyTok1", temp1, c+1)
+ arout("Tok1", temp1, c+1)
// table 2 has PRIVATE-PRIVATE+256
aryfil(temp1, 256, 0)
@@ -2797,10 +2802,10 @@
}
}
}
- arout("yyTok2", temp1, c+1)
+ arout("Tok2", temp1, c+1)
// table 3 has everything else
- fmt.Fprintf(ftable, "var\tyyTok3\t= []int {\n")
+ fmt.Fprintf(ftable, "var\t%sTok3\t= []int {\n", prefix)
c = 0
for i = 1; i <= ntokens; i++ {
j = tokset[i].value
@@ -2829,13 +2834,14 @@
// copy yaccpar
fmt.Fprintf(ftable, "\n//line yaccpar:1\n")
- parts := strings.Split(yaccpar, "yyrun()", 2)
+ parts := strings.Split(yaccpar, prefix+"run()", 2)
fmt.Fprintf(ftable, "%v", parts[0])
ftable.Write(fcode.Bytes())
fmt.Fprintf(ftable, "%v", parts[1])
}
func arout(s string, v []int, n int) {
+ s = prefix + s
fmt.Fprintf(ftable, "var\t%v\t= []int {\n", s)
for i := 0; i < n; i++ {
if i%10 == 0 {
@@ -3076,86 +3082,84 @@
os.Exit(status)
}
-var yaccpar = `
+var yaccpar string // will be processed version of yaccpartext: s/$$/prefix/g
+var yaccpartext = `
/* parser for yacc output */
-var yyDebug = 0
+var $$Debug = 0
-type yyLexer interface {
- Lex(lval *yySymType) int
+type $$Lexer interface {
+ Lex(lval *$$SymType) int
Error(s string)
}
-const yyFlag = -1000
+const $$Flag = -1000
-func yyTokname(yyc int) string {
- if yyc > 0 && yyc <= len(yyToknames) {
- if yyToknames[yyc-1] != "" {
- return yyToknames[yyc-1]
+func $$Tokname(c int) string {
+ if c > 0 && c <= len($$Toknames) {
+ if $$Toknames[c-1] != "" {
+ return $$Toknames[c-1]
}
}
- return fmt.Sprintf("tok-%v", yyc)
+ return fmt.Sprintf("tok-%v", c)
}
-func yyStatname(yys int) string {
- if yys >= 0 && yys < len(yyStatenames) {
- if yyStatenames[yys] != "" {
- return yyStatenames[yys]
+func $$Statname(s int) string {
+ if s >= 0 && s < len($$Statenames) {
+ if $$Statenames[s] != "" {
+ return $$Statenames[s]
}
}
- return fmt.Sprintf("state-%v", yys)
+ return fmt.Sprintf("state-%v", s)
}
-func yylex1(yylex yyLexer, lval *yySymType) int {
- var yychar int
- var c int
-
- yychar = yylex.Lex(lval)
- if yychar <= 0 {
- c = yyTok1[0]
+func $$lex1(lex $$Lexer, lval *$$SymType) int {
+ c := 0
+ char := lex.Lex(lval)
+ if char <= 0 {
+ c = $$Tok1[0]
goto out
}
- if yychar < len(yyTok1) {
- c = yyTok1[yychar]
+ if char < len($$Tok1) {
+ c = $$Tok1[char]
goto out
}
- if yychar >= yyPrivate {
- if yychar < yyPrivate+len(yyTok2) {
- c = yyTok2[yychar-yyPrivate]
+ if char >= $$Private {
+ if char < $$Private+len($$Tok2) {
+ c = $$Tok2[char-$$Private]
goto out
}
}
- for i := 0; i < len(yyTok3); i += 2 {
- c = yyTok3[i+0]
- if c == yychar {
- c = yyTok3[i+1]
+ for i := 0; i < len($$Tok3); i += 2 {
+ c = $$Tok3[i+0]
+ if c == char {
+ c = $$Tok3[i+1]
goto out
}
}
- c = 0
out:
if c == 0 {
- c = yyTok2[1] /* unknown char */
+ c = $$Tok2[1] /* unknown char */
}
- if yyDebug >= 3 {
- fmt.Printf("lex %U %s\n", uint(yychar), yyTokname(c))
+ if $$Debug >= 3 {
+ fmt.Printf("lex %U %s\n", uint(char), $$Tokname(c))
}
return c
}
-func yyParse(yylex yyLexer) int {
- var yyn int
- var yylval yySymType
- var YYVAL yySymType
- YYS := make([]yySymType, yyMaxDepth)
+func $$Parse($$lex $$Lexer) int {
+ var $$n int
+ var $$lval $$SymType
+ var $$VAL $$SymType
+ $$S := make([]$$SymType, $$MaxDepth)
Nerrs := 0 /* number of errors */
Errflag := 0 /* error recovery flag */
- yystate := 0
- yychar := -1
- yyp := -1
- goto yystack
+ $$state := 0
+ $$char := -1
+ $$p := -1
+ goto $$stack
ret0:
return 0
@@ -3163,80 +3167,80 @@
ret1:
return 1
-yystack:
+$$stack:
/* put a state and value onto the stack */
- if yyDebug >= 4 {
- fmt.Printf("char %v in %v\n", yyTokname(yychar), yyStatname(yystate))
+ if $$Debug >= 4 {
+ fmt.Printf("char %v in %v\n", $$Tokname($$char), $$Statname($$state))
}
- yyp++
- if yyp >= len(YYS) {
- nyys := make([]yySymType, len(YYS)*2)
- copy(nyys, YYS)
- YYS = nyys
+ $$p++
+ if $$p >= len($$S) {
+ nyys := make([]$$SymType, len($$S)*2)
+ copy(nyys, $$S)
+ $$S = nyys
}
- YYS[yyp] = YYVAL
- YYS[yyp].yys = yystate
+ $$S[$$p] = $$VAL
+ $$S[$$p].yys = $$state
-yynewstate:
- yyn = yyPact[yystate]
- if yyn <= yyFlag {
- goto yydefault /* simple state */
+$$newstate:
+ $$n = $$Pact[$$state]
+ if $$n <= $$Flag {
+ goto $$default /* simple state */
}
- if yychar < 0 {
- yychar = yylex1(yylex, &yylval)
+ if $$char < 0 {
+ $$char = $$lex1($$lex, &$$lval)
}
- yyn += yychar
- if yyn < 0 || yyn >= yyLast {
- goto yydefault
+ $$n += $$char
+ if $$n < 0 || $$n >= $$Last {
+ goto $$default
}
- yyn = yyAct[yyn]
- if yyChk[yyn] == yychar { /* valid shift */
- yychar = -1
- YYVAL = yylval
- yystate = yyn
+ $$n = $$Act[$$n]
+ if $$Chk[$$n] == $$char { /* valid shift */
+ $$char = -1
+ $$VAL = $$lval
+ $$state = $$n
if Errflag > 0 {
Errflag--
}
- goto yystack
+ goto $$stack
}
-yydefault:
+$$default:
/* default state action */
- yyn = yyDef[yystate]
- if yyn == -2 {
- if yychar < 0 {
- yychar = yylex1(yylex, &yylval)
+ $$n = $$Def[$$state]
+ if $$n == -2 {
+ if $$char < 0 {
+ $$char = $$lex1($$lex, &$$lval)
}
/* look through exception table */
- yyxi := 0
+ xi := 0
for {
- if yyExca[yyxi+0] == -1 && yyExca[yyxi+1] == yystate {
+ if $$Exca[xi+0] == -1 && $$Exca[xi+1] == $$state {
break
}
- yyxi += 2
+ xi += 2
}
- for yyxi += 2; ; yyxi += 2 {
- yyn = yyExca[yyxi+0]
- if yyn < 0 || yyn == yychar {
+ for xi += 2; ; xi += 2 {
+ $$n = $$Exca[xi+0]
+ if $$n < 0 || $$n == $$char {
break
}
}
- yyn = yyExca[yyxi+1]
- if yyn < 0 {
+ $$n = $$Exca[xi+1]
+ if $$n < 0 {
goto ret0
}
}
- if yyn == 0 {
+ if $$n == 0 {
/* error ... attempt to resume parsing */
switch Errflag {
case 0: /* brand new error */
- yylex.Error("syntax error")
+ $$lex.Error("syntax error")
Nerrs++
- if yyDebug >= 1 {
- fmt.Printf("%s", yyStatname(yystate))
- fmt.Printf("saw %s\n", yyTokname(yychar))
+ if $$Debug >= 1 {
+ fmt.Printf("%s", $$Statname($$state))
+ fmt.Printf("saw %s\n", $$Tokname($$char))
}
fallthrough
@@ -3244,64 +3248,64 @@
Errflag = 3
/* find a state where "error" is a legal shift action */
- for yyp >= 0 {
- yyn = yyPact[YYS[yyp].yys] + yyErrCode
- if yyn >= 0 && yyn < yyLast {
- yystate = yyAct[yyn] /* simulate a shift of "error" */
- if yyChk[yystate] == yyErrCode {
- goto yystack
+ for $$p >= 0 {
+ $$n = $$Pact[$$S[$$p].yys] + $$ErrCode
+ if $$n >= 0 && $$n < $$Last {
+ $$state = $$Act[$$n] /* simulate a shift of "error" */
+ if $$Chk[$$state] == $$ErrCode {
+ goto $$stack
}
}
- /* the current yyp has no shift onn "error", pop stack */
- if yyDebug >= 2 {
+ /* the current p has no shift onn "error", pop stack */
+ if $$Debug >= 2 {
fmt.Printf("error recovery pops state %d, uncovers %d\n",
- YYS[yyp].yys, YYS[yyp-1].yys)
+ $$S[$$p].yys, $$S[$$p-1].yys)
}
- yyp--
+ $$p--
}
/* there is no state on the stack with an error shift ... abort */
goto ret1
case 3: /* no shift yet; clobber input char */
- if yyDebug >= 2 {
- fmt.Printf("error recovery discards %s\n", yyTokname(yychar))
+ if $$Debug >= 2 {
+ fmt.Printf("error recovery discards %s\n", $$Tokname($$char))
}
- if yychar == yyEofCode {
+ if $$char == $$EofCode {
goto ret1
}
- yychar = -1
- goto yynewstate /* try again in the same state */
+ $$char = -1
+ goto $$newstate /* try again in the same state */
}
}
- /* reduction by production yyn */
- if yyDebug >= 2 {
- fmt.Printf("reduce %v in:\n\t%v\n", yyn, yyStatname(yystate))
+ /* reduction by production $$n */
+ if $$Debug >= 2 {
+ fmt.Printf("reduce %v in:\n\t%v\n", $$n, $$Statname($$state))
}
- yynt := yyn
- yypt := yyp
- _ = yypt // guard against "declared and not used"
+ $$nt := $$n
+ $$pt := $$p
+ _ = $$pt // guard against "declared and not used"
- yyp -= yyR2[yyn]
- YYVAL = YYS[yyp+1]
+ $$p -= $$R2[$$n]
+ $$VAL = $$S[$$p+1]
/* consult goto table to find next state */
- yyn = yyR1[yyn]
- yyg := yyPgo[yyn]
- yyj := yyg + YYS[yyp].yys + 1
+ $$n = $$R1[$$n]
+ $$g := $$Pgo[$$n]
+ $$j := $$g + $$S[$$p].yys + 1
- if yyj >= yyLast {
- yystate = yyAct[yyg]
+ if $$j >= $$Last {
+ $$state = $$Act[$$g]
} else {
- yystate = yyAct[yyj]
- if yyChk[yystate] != -yyn {
- yystate = yyAct[yyg]
+ $$state = $$Act[$$j]
+ if $$Chk[$$state] != -$$n {
+ $$state = $$Act[$$g]
}
}
// dummy call; replaced with literal code
- yyrun()
- goto yystack /* stack new state and value */
+ $$run()
+ goto $$stack /* stack new state and value */
}
`
diff --git a/src/cmd/goyacc/units.y b/src/cmd/goyacc/units.y
index a7d472f..5d3f9ac 100644
--- a/src/cmd/goyacc/units.y
+++ b/src/cmd/goyacc/units.y
@@ -6,6 +6,9 @@
// Distributed under the terms of the Lucent Public License Version 1.02
// See http://plan9.bell-labs.com/plan9/license.html
+// Generate parser with prefix "units_":
+// goyacc -p "units_"
+
%{
// units.y
@@ -215,7 +218,7 @@
type UnitsLex int
-func (UnitsLex) Lex(yylval *yySymType) int {
+func (UnitsLex) Lex(yylval *units_SymType) int {
var c, i int
c = peekrune
@@ -319,7 +322,7 @@
continue
}
peekrune = ':'
- yyParse(UnitsLex(0))
+ units_Parse(UnitsLex(0))
}
/*
@@ -340,7 +343,7 @@
}
peekrune = '?'
nerrors = 0
- yyParse(UnitsLex(0))
+ units_Parse(UnitsLex(0))
if nerrors != 0 {
continue
}
