X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/d5eb0826afb8ede89bfe314671f2b37db55bd817..bcbbf654863dd285b176a0f54a75a28c4bdac1d3:/data/lalr1.java diff --git a/data/lalr1.java b/data/lalr1.java index 5010ba6a..103c03dd 100644 --- a/data/lalr1.java +++ b/data/lalr1.java @@ -1,6 +1,6 @@ # Java skeleton for Bison -*- autoconf -*- -# Copyright (C) 2007, 2008, 2009 Free Software Foundation, Inc. +# Copyright (C) 2007-2012 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 @@ -25,7 +25,7 @@ m4_ifval(m4_defn([b4_symbol_destructors]), m4_divert_push(0)dnl @output(b4_parser_file_name@)@ b4_copyright([Skeleton implementation for Bison LALR(1) parsers in Java], - [2007, 2008, 2009]) + [2007-2012]) b4_percent_define_ifdef([package], [package b4_percent_define_get([package]); ])[/* First part of user declarations. */ @@ -102,7 +102,7 @@ b4_token_enums(b4_tokens) private ]b4_location_type[ yylloc (YYStack rhs, int n) { if (n > 0) - return new ]b4_location_type[ (rhs.locationAt (1).begin, rhs.locationAt (n).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); }]])[ @@ -255,14 +255,14 @@ b4_lexer_if([[ } public final void pop () { - height--; + pop (1); } public final void pop (int num) { // Avoid memory leaks... garbage collection is a white lie! if (num > 0) { - java.util.Arrays.fill (valueStack, height - num + 1, height, null); - ]b4_locations_if([[java.util.Arrays.fill (locStack, height - num + 1, height, null);]])[ + java.util.Arrays.fill (valueStack, height - num + 1, height + 1, null); + ]b4_locations_if([[java.util.Arrays.fill (locStack, height - num + 1, height + 1, null);]])[ } height -= num; } @@ -284,7 +284,7 @@ b4_lexer_if([[ { out.print ("Stack now"); - for (int i = 0; i < height; i++) + for (int i = 0; i <= height; i++) { out.print (' '); out.print (stateStack[i]); @@ -308,11 +308,9 @@ b4_lexer_if([[ * printing an error message. */ public static final int YYERROR = 2; - /** - * Returned by a Bison action in order to print an error message and start - * error recovery. */ - public static final int YYFAIL = 3; - + // Internal return codes that are not supported for user semantic + // actions. + private static final int YYERRLAB = 3; private static final int YYNEWSTATE = 4; private static final int YYDEFAULT = 5; private static final int YYREDUCE = 6; @@ -456,8 +454,6 @@ b4_lexer_if([[ /// Semantic value of the lookahead. b4_yystype[ yylval = null; - int yyresult; - yycdebug ("Starting parse\n"); yyerrstatus_ = 0; @@ -529,7 +525,7 @@ m4_popdef([b4_at_dollar])])dnl else if ((yyn = yytable_[yyn]) <= 0) { if (yy_table_value_is_error_ (yyn)) - label = YYFAIL; + label = YYERRLAB; else { yyn = -yyn; @@ -563,7 +559,7 @@ m4_popdef([b4_at_dollar])])dnl case YYDEFAULT: yyn = yydefact_[yystate]; if (yyn == 0) - label = YYFAIL; + label = YYERRLAB; else label = YYREDUCE; break; @@ -580,12 +576,14 @@ m4_popdef([b4_at_dollar])])dnl /*------------------------------------. | yyerrlab -- here on detecting error | `------------------------------------*/ - case YYFAIL: + case YYERRLAB: /* If not already recovering from an error, report this error. */ if (yyerrstatus_ == 0) { - ++yynerrs_; - yyerror (]b4_locations_if([yylloc, ])[yysyntax_error (yystate, yytoken)); + ++yynerrs_; + if (yychar == yyempty_) + yytoken = yyempty_; + yyerror (]b4_locations_if([yylloc, ])[yysyntax_error (yystate, yytoken)); } ]b4_locations_if([yyerrloc = yylloc;])[ @@ -644,7 +642,7 @@ m4_popdef([b4_at_dollar])])dnl } /* Pop the current state because it cannot handle the error token. */ - if (yystack.height == 1) + if (yystack.height == 0) return false; ]b4_locations_if([yyerrloc = yystack.locationAt (0);])[ @@ -685,41 +683,73 @@ m4_popdef([b4_at_dollar])])dnl { if (errorVerbose) { - int yyn = yypact_[yystate]; - if (yypact_ninf_ < yyn && yyn <= yylast_) + /* There are many possibilities here to consider: + - Assume YYFAIL is not used. It's too flawed to consider. + See + + for details. YYERROR is fine as it does not invoke this + function. + - 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 tok) 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. (However, yychar is currently out + of scope during semantic actions.) + - 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 (tok != yyempty_) { - StringBuffer res; - - /* 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_; - int count = 0; - for (int x = yyxbegin; x < yyxend; ++x) - if (yycheck_[x + yyn] == x && x != yyterror_ - && !yy_table_value_is_error_ (yycheck_[x + yyn])) - ++count; - - // FIXME: This method of building the message is not compatible - // with internationalization. - res = new StringBuffer ("syntax error, unexpected "); - res.append (yytnamerr_ (yytname_[tok])); - if (count < 5) - { - count = 0; - for (int x = yyxbegin; x < yyxend; ++x) - if (yycheck_[x + yyn] == x && x != yyterror_ - && !yy_table_value_is_error_ (yycheck_[x + yyn])) - { - res.append (count++ == 0 ? ", expecting " : " or "); - res.append (yytnamerr_ (yytname_[x])); - } - } - return res.toString (); + // FIXME: This method of building the message is not compatible + // with internationalization. + StringBuffer res = + new StringBuffer ("syntax error, unexpected "); + res.append (yytnamerr_ (yytname_[tok])); + 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_; + int count = 0; + for (int x = yyxbegin; x < yyxend; ++x) + if (yycheck_[x + yyn] == x && x != yyterror_ + && !yy_table_value_is_error_ (yytable_[x + yyn])) + ++count; + if (count < 5) + { + count = 0; + for (int x = yyxbegin; x < yyxend; ++x) + if (yycheck_[x + yyn] == x && x != yyterror_ + && !yy_table_value_is_error_ (yytable_[x + yyn])) + { + res.append (count++ == 0 ? ", expecting " : " or "); + res.append (yytnamerr_ (yytname_[x])); + } + } + } + return res.toString (); } } @@ -741,7 +771,7 @@ m4_popdef([b4_at_dollar])])dnl */ private static boolean yy_table_value_is_error_ (int yyvalue) { - return yyvalue == 0 || yyvalue == yytable_ninf_; + return yyvalue == yytable_ninf_; } /* YYPACT[STATE-NUM] -- Index in YYTABLE of the portion describing @@ -775,7 +805,7 @@ m4_popdef([b4_at_dollar])])dnl /* YYTABLE[YYPACT[STATE-NUM]]. What to do in state STATE-NUM. If positive, shift that token. If negative, reduce the rule which - number is the opposite. If zero or YYTABLE_NINF_, syntax error. */ + number is the opposite. If YYTABLE_NINF_, syntax error. */ private static final ]b4_int_type_for([b4_table])[ yytable_ninf_ = ]b4_table_ninf[; private static final ]b4_int_type_for([b4_table])[ yytable_[] =