cmd/internal/gc, cmd/yacc: restore remaining custom error messages
This CL extends cmd/yacc to expose a yyErrorVerbose variable that
changes the error messages from just "syntax error" to "syntax error:
unexpected ${tokname}".
It also moves the yyToknames table generation to after rules have been
processed so that entries can be generated for tokens that aren't
mentioned in the preamble (e.g., '.' in the case of go.y).
Lastly, it restores gc's old code for applying yytfix to yyToknames,
except that substituting "LLITERAL" with litbuf happens in Yyerror.
Fixes #9968.
Change-Id: Icec188d11fdabc1dae31b8a471c35b5c7f6deec7
Reviewed-on: https://go-review.googlesource.com/8432
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/src/cmd/internal/gc/subr.go b/src/cmd/internal/gc/subr.go
index 559bf74..689adee 100644
--- a/src/cmd/internal/gc/subr.go
+++ b/src/cmd/internal/gc/subr.go
@@ -55,7 +55,7 @@
}
}
-func adderr(line int, format string, args []interface{}) {
+func adderr(line int, format string, args ...interface{}) {
errors = append(errors, Error{
seq: len(errors),
lineno: line,
@@ -110,8 +110,8 @@
}
}
-func yyerrorl(line int, fmt_ string, args ...interface{}) {
- adderr(line, fmt_, args)
+func yyerrorl(line int, format string, args ...interface{}) {
+ adderr(line, format, args...)
hcrash()
nerrors++
@@ -124,15 +124,9 @@
var yyerror_lastsyntax int
-func Yyerror(fmt_ string, args ...interface{}) {
- // bison used to invoke yyerror("syntax error").
- // With Go yacc we get yyerror("%s", "syntax error").
- // Convert to keep the old code working.
- if fmt_ == "%s" && len(args) == 1 && args[0] == "syntax error" {
- fmt_ = "syntax error"
- args = nil
- }
- if strings.HasPrefix(fmt_, "syntax error") {
+func Yyerror(format string, args ...interface{}) {
+ msg := fmt.Sprintf(format, args...)
+ if strings.HasPrefix(msg, "syntax error") {
nsyntaxerrors++
yystate := theparser.(*yyParserImpl).state()
@@ -154,16 +148,6 @@
}
yyerror_lastsyntax = int(lexlineno)
- if strings.Contains(fmt_, "{ or {") || strings.Contains(fmt_, " or ?") || strings.Contains(fmt_, " or @") {
- // The grammar has { and LBRACE but both show up as {.
- // Rewrite syntax error referring to "{ or {" to say just "{".
- // The grammar has ? and @ but only for reading imports.
- // Silence them in ordinary errors.
- fmt_ = strings.Replace(fmt_, "{ or {", "{", -1)
- fmt_ = strings.Replace(fmt_, " or ?", "", -1)
- fmt_ = strings.Replace(fmt_, " or @", "", -1)
- }
-
// look for parse state-specific errors in list (see go.errors).
for i := range yymsg {
if yymsg[i].yystate == yystate && yymsg[i].yychar == yychar {
@@ -173,22 +157,31 @@
}
// plain "syntax error" gets "near foo" added
- if fmt_ == "syntax error" {
+ if msg == "syntax error" {
yyerrorl(int(lexlineno), "syntax error near %s", lexbuf.String())
return
}
- // if bison says "syntax error, more info"; print "syntax error: more info".
- if fmt_[12] == ',' {
- yyerrorl(int(lexlineno), "syntax error:%s", fmt_[13:])
- return
+ // TODO(mdempsky): Extend cmd/yacc's verbose error
+ // messages to suggest expected tokens like Bison:
+ // "syntax error: unexpected literal 2.01, expecting semicolon or newline or }"
+ if false {
+ // The grammar has { and LBRACE but both show up as {.
+ // Rewrite syntax error referring to "{ or {" to say just "{".
+ // The grammar has ? and @ but only for reading imports.
+ // Silence them in ordinary errors.
+ msg = strings.Replace(msg, "{ or {", "{", -1)
+ msg = strings.Replace(msg, " or ?", "", -1)
+ msg = strings.Replace(msg, " or @", "", -1)
}
- yyerrorl(int(lexlineno), "%s", fmt_)
+ msg = strings.Replace(msg, "LLITERAL", litbuf, -1)
+
+ yyerrorl(int(lexlineno), "%s", msg)
return
}
- adderr(parserline(), fmt_, args)
+ adderr(parserline(), "%s", msg)
hcrash()
nerrors++
@@ -200,13 +193,13 @@
}
func Warn(fmt_ string, args ...interface{}) {
- adderr(parserline(), fmt_, args)
+ adderr(parserline(), fmt_, args...)
hcrash()
}
func Warnl(line int, fmt_ string, args ...interface{}) {
- adderr(line, fmt_, args)
+ adderr(line, fmt_, args...)
if Debug['m'] != 0 {
Flusherrors()
}
