# C++ skeleton for Bison
-# Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
-# 2010 Free Software Foundation, Inc.
+# Copyright (C) 2002-2011 Free Software Foundation, Inc.
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
b4_defines_if(
[@output(b4_spec_defines_file@)@
b4_copyright([Skeleton interface for Bison LALR(1) parsers in C++],
- [2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010])
+ [2002-2011])
dnl FIXME: This is wrong, we want computed header guards.
[
/* C++ LALR(1) parser skeleton written by Akim Demaille. */
])dnl
@output(b4_parser_file_name@)@
b4_copyright([Skeleton implementation for Bison LALR(1) parsers in C++],
- [2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010])
+ [2002-2011])
b4_percent_code_get([[top]])[]dnl
m4_if(b4_prefix, [yy], [],
[
default:
break;
}
+ /* User semantic actions sometimes alter yychar, and that requires
+ that yytoken be updated with the new translation. We take the
+ approach of translating immediately before every use of yytoken.
+ One alternative is translating here after every semantic action,
+ but that translation would be missed if the semantic action
+ invokes YYABORT, YYACCEPT, or YYERROR immediately after altering
+ yychar. In the case of YYABORT or YYACCEPT, an incorrect
+ destructor might then be invoked immediately. In the case of
+ YYERROR, subsequent parser actions might lead to an incorrect
+ destructor call or verbose syntax error message before the
+ lookahead is translated. */
YY_SYMBOL_PRINT ("-> $$ =", yyr1_[yyn], &yyval, &yyloc);
yypop_ (yylen);
| yyerrlab -- here on detecting error |
`------------------------------------*/
yyerrlab:
+ /* Make sure we have latest lookahead translation. See comments at
+ user semantic actions for why this is necessary. */
+ yytoken = yytranslate_ (yychar);
+
/* If not already recovering from an error, report this error. */
if (!yyerrstatus_)
{
++yynerrs_;
+ if (yychar == yyempty_)
+ yytoken = yyempty_;
error (yylloc, yysyntax_error_ (yystate, yytoken));
}
yyreturn:
if (yychar != yyempty_)
- yydestruct_ ("Cleanup: discarding lookahead", yytoken, &yylval, &yylloc);
+ {
+ /* Make sure we have latest lookahead translation. See comments
+ at user semantic actions for why this is necessary. */
+ yytoken = yytranslate_ (yychar);
+ yydestruct_ ("Cleanup: discarding lookahead", yytoken, &yylval,
+ &yylloc);
+ }
/* Do not reclaim the symbols of the rule which action triggered
this YYABORT or YYACCEPT. */
[int, int])[)
{]b4_error_verbose_if([[
std::string yyres;
- int yyn = yypact_[yystate];
- if (yypact_ninf_ < yyn && yyn <= yylast_)
+ // Number of reported tokens (one for the "unexpected", one per
+ // "expected").
+ size_t yycount = 0;
+ // Its maximum.
+ enum { YYERROR_VERBOSE_ARGS_MAXIMUM = 5 };
+ // Arguments of yyformat.
+ char const *yyarg[YYERROR_VERBOSE_ARGS_MAXIMUM];
+
+ /* There are many possibilities here to consider:
+ - If this state is a consistent state with a default action, then
+ the only way this function was invoked is if the default action
+ is an error action. In that case, don't check for expected
+ tokens because there are none.
+ - The only way there can be no lookahead present (in yytoken) is
+ if this state is a consistent state with a default action.
+ Thus, detecting the absence of a lookahead is sufficient to
+ determine that there is no unexpected or expected token to
+ report. In that case, just report a simple "syntax error".
+ - Don't assume there isn't a lookahead just because this state is
+ a consistent state with a default action. There might have
+ been a previous inconsistent state, consistent state with a
+ non-default action, or user semantic action that manipulated
+ yychar.
+ - Of course, the expected token list depends on states to have
+ correct lookahead information, and it depends on the parser not
+ to perform extra reductions after fetching a lookahead from the
+ scanner and before detecting a syntax error. Thus, state
+ merging (from LALR or IELR) and default reductions corrupt the
+ expected token list. However, the list is correct for
+ canonical LR with one exception: it will still contain any
+ token that will not be accepted due to an error action in a
+ later state.
+ */
+ if (yytoken != yyempty_)
{
+ yyarg[yycount++] = yytname_[yytoken];
+ int yyn = yypact_[yystate];
+ if (!yy_pact_value_is_default_ (yyn))
+ {
/* Start YYX at -YYN if negative to avoid negative indexes in
YYCHECK. In other words, skip the first -YYN actions for
this state because they are default actions. */
int yyxbegin = yyn < 0 ? -yyn : 0;
-
/* Stay within bounds of both yycheck and yytname. */
int yychecklim = yylast_ - yyn + 1;
int yyxend = yychecklim < yyntokens_ ? yychecklim : yyntokens_;
-
- // Number of reported tokens (one for the "unexpected", one per
- // "expected").
- size_t yycount = 0;
- // Its maximum.
- enum { YYERROR_VERBOSE_ARGS_MAXIMUM = 5 };
- // Arguments of yyformat.
- char const *yyarg[YYERROR_VERBOSE_ARGS_MAXIMUM];
- yyarg[yycount++] = yytname_[yytoken];
for (int yyx = yyxbegin; yyx < yyxend; ++yyx)
if (yycheck_[yyx + yyn] == yyx && yyx != yyterror_
&& !yy_table_value_is_error_ (yytable_[yyx + yyn]))
else
yyarg[yycount++] = yytname_[yyx];
}
+ }
+ }
char const* yyformat = 0;
switch (yycount)
case N: \
yyformat = S; \
break
+ YYCASE_(0, YY_("syntax error"));
YYCASE_(1, YY_("syntax error, unexpected %s"));
YYCASE_(2, YY_("syntax error, unexpected %s, expecting %s"));
YYCASE_(3, YY_("syntax error, unexpected %s, expecting %s or %s"));
YYCASE_(5, YY_("syntax error, unexpected %s, expecting %s or %s or %s or %s"));
#undef YYCASE_
}
+
// Argument number.
size_t yyi = 0;
for (char const* yyp = yyformat; *yyp; ++yyp)
}
else
yyres += *yyp;
- }
- else
- yyres = YY_("syntax error");
return yyres;]], [[
return YY_("syntax error");]])[
}
dnl
@output(b4_dir_prefix[]stack.hh@)@
b4_copyright([Stack handling for Bison parsers in C++],
- [2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010])[
+ [2002-2011])[
#ifndef BISON_STACK_HH
# define BISON_STACK_HH
projects / bison.git / blobdiff