// Generate an error message.
std::string
Parser::yysyntax_error_ (int yystate)
{
std::string res;
YYUSE (yystate);
#if YYERROR_VERBOSE
int yyn = yypact_[yystate];
if (yypact_ninf_ < yyn && yyn <= yylast_)
{
/* Start YYX at -YYN if negative to avoid negative indexes in
YYCHECK. */
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_;
int count = 0;
for (int x = yyxbegin; x < yyxend; ++x)
if (yycheck_[x + yyn] == x && x != yyterror_)
++count;
// FIXME: This method of building the message is not compatible
// with internationalization. It should work like yacc.c does it.
// That is, first build a string that looks like this:
// "syntax error, unexpected %s or %s or %s"
// Then, invoke YY_ on this string.
// Finally, use the string as a format to output
// yytname_[tok], etc.
// Until this gets fixed, this message appears in English only.
res = "syntax error, unexpected ";
res += yytnamerr_ (yytname_[tok]);
if (count < 5)
{
count = 0;
for (int x = yyxbegin; x < yyxend; ++x)
if (yycheck_[x + yyn] == x && x != yyterror_)
{
res += (!count++) ? ", expecting " : " or ";
res += yytnamerr_ (yytname_[x]);
}
}
}
else
#endif
res = YY_("syntax error");
return res;
}
// Generate an error message.
std::string
Parser::yysyntax_error_ (state_type yystate, symbol_number_type yytoken) const
{
std::string yyres;
// 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
yyla. (However, yyla is currently not documented for users.)
- 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_;
for (int yyx = yyxbegin; yyx < yyxend; ++yyx)
if (yycheck_[yyx + yyn] == yyx && yyx != yyterror_
&& !yy_table_value_is_error_ (yytable_[yyx + yyn]))
{
if (yycount == YYERROR_VERBOSE_ARGS_MAXIMUM)
{
yycount = 1;
break;
}
else
yyarg[yycount++] = yytname_[yyx];
}
}
}
char const* yyformat = YY_NULLPTR;
switch (yycount)
{
#define YYCASE_(N, S) \
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_(4, YY_("syntax error, unexpected %s, expecting %s or %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)
if (yyp[0] == '%' && yyp[1] == 's' && yyi < yycount)
{
yyres += yytnamerr_ (yyarg[yyi++]);
++yyp;
}
else
yyres += *yyp;
return yyres;
}
