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all: don't emit an error message when the scanner returns YYERRCODE

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I'm quite pleased to see that the tricky case of glr.c was already
prepared by the changes to support syntax_error exceptions.  Better
yet, it is actually syntax_error that becomes a special case of the
general pattern: make yytoken be YYERRCODE.

* data/skeletons/glr.c (YYFAULTYTOK): Remove the now useless (Basil)
Faulty token.
Instead, use the error token.
* data/skeletons/lalr1.d, data/skeletons/lalr1.java: When computing
the action, first check the case of the error token.

* tests/calc.at: Check cases for the error token symbols before and
after it.
This commit is contained in:
Akim Demaille
2020-04-26 14:48:59 +02:00
parent 58e79539fc
commit b254b36db8
6 changed files with 121 additions and 76 deletions
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77
data/skeletons/lalr1.java
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@@ -164,12 +164,12 @@ import java.text.MessageFormat;
}
}
private ]b4_location_type[ yylloc (YYStack rhs, int n)
private ]b4_location_type[ yylloc(YYStack rhs, int n)
{
if (0 < n)
return new ]b4_location_type[ (rhs.locationAt (n-1).begin, rhs.locationAt (0).end);
return new ]b4_location_type[(rhs.locationAt(n-1).begin, rhs.locationAt(0).end);
else
return new ]b4_location_type[ (rhs.locationAt (0).end);
return new ]b4_location_type[(rhs.locationAt(0).end);
}]])[
]b4_declare_symbol_enum[
@@ -615,41 +615,55 @@ b4_dollar_popdef[]dnl
yySymbolPrint ("Next token is", yytoken,
yylval]b4_locations_if([, yylloc])[);]])[
/* If the proper action on seeing token YYTOKEN is to reduce or to
detect an error, take that action. */
yyn += yytoken.getCode ();
if (yyn < 0 || YYLAST_ < yyn || yycheck_[yyn] != yytoken.getCode ())
label = YYDEFAULT;
/* <= 0 means reduce or error. */
else if ((yyn = yytable_[yyn]) <= 0)
if (yytoken == SymbolKind.]b4_symbol_prefix[YYERRCODE)
{
if (yyTableValueIsError (yyn))
label = YYERRLAB;
else
{
yyn = -yyn;
label = YYREDUCE;
}
// The scanner already issued an error message, process directly
// to error recovery. But do not keep the error token as
// lookahead, it is too special and may lead us to an endless
// loop in error recovery. */
yychar = Lexer.]b4_percent_define_get([api.token.prefix])[YYUNDEF;
yytoken = SymbolKind.]b4_symbol_prefix[YYUNDEF;]b4_locations_if([[
yyerrloc = yylloc;]])[
label = YYERRLAB1;
}
else
{
/* Shift the lookahead token. */]b4_parse_trace_if([[
yySymbolPrint ("Shifting", yytoken,
yylval]b4_locations_if([, yylloc])[);
/* If the proper action on seeing token YYTOKEN is to reduce or to
detect an error, take that action. */
yyn += yytoken.getCode ();
if (yyn < 0 || YYLAST_ < yyn || yycheck_[yyn] != yytoken.getCode ())
label = YYDEFAULT;
/* <= 0 means reduce or error. */
else if ((yyn = yytable_[yyn]) <= 0)
{
if (yyTableValueIsError (yyn))
label = YYERRLAB;
else
{
yyn = -yyn;
label = YYREDUCE;
}
}
else
{
/* Shift the lookahead token. */]b4_parse_trace_if([[
yySymbolPrint ("Shifting", yytoken,
yylval]b4_locations_if([, yylloc])[);
]])[
/* Discard the token being shifted. */
yychar = YYEMPTY_;
/* Discard the token being shifted. */
yychar = YYEMPTY_;
/* Count tokens shifted since error; after three, turn off error
status. */
if (yyerrstatus_ > 0)
--yyerrstatus_;
/* Count tokens shifted since error; after three, turn off error
status. */
if (yyerrstatus_ > 0)
--yyerrstatus_;
yystate = yyn;
yystack.push (yystate, yylval]b4_locations_if([, yylloc])[);
label = YYNEWSTATE;
yystate = yyn;
yystack.push (yystate, yylval]b4_locations_if([, yylloc])[);
label = YYNEWSTATE;
}
}
break;
@@ -685,7 +699,6 @@ b4_dollar_popdef[]dnl
yytoken = null;
yyreportSyntaxError (new Context (yystack, yytoken]b4_locations_if([[, yylloc]])[));
}
]b4_locations_if([[
yyerrloc = yylloc;]])[
if (yyerrstatus_ == 3)