X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/38435078b14ad063d7bc9e82a7db9bac366b2e65..544b863511c3cb996d05ccabdbf6be92b36c9b68:/data/lalr1.cc?ds=sidebyside diff --git a/data/lalr1.cc b/data/lalr1.cc index 646ee904..99b8e9e8 100644 --- a/data/lalr1.cc +++ b/data/lalr1.cc @@ -1,6 +1,6 @@ # C++ skeleton for Bison -# Copyright (C) 2002-2010 Free Software Foundation, Inc. +# Copyright (C) 2002-2012 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 @@ -115,7 +115,7 @@ m4_popdef([b4_dollar_dollar])dnl m4_pushdef([b4_copyright_years], - [2002-2010]) + [2002-2012]) m4_define([b4_parser_class_name], [b4_percent_define_get([[parser_class_name]])]) @@ -157,6 +157,8 @@ dnl FIXME: This is wrong, we want computed header guards. b4_variant_define b4_namespace_close])[ +]b4_null_define[ + /* Enabling traces. */ #ifndef YYDEBUG # define YYDEBUG ]b4_parse_trace_if([1], [0])[ @@ -209,6 +211,9 @@ b4_namespace_close])[ /// \param msg a description of the syntax error. virtual void error (]b4_locations_if([const location_type& loc, ])[const std::string& msg); + /// Report a syntax error. + void error (const syntax_error& err); + private: /// State numbers. typedef int state_type; @@ -336,7 +341,7 @@ b4_namespace_close])[ yyfinal_ = ]b4_final_state_number[, //< Termination state number. yyterror_ = 1, yyerrcode_ = 256, - yyntokens_ = ]b4_tokens_number[, //< Number of tokens. + yyntokens_ = ]b4_tokens_number[ //< Number of tokens. }; ]b4_parse_param_vars[ @@ -426,14 +431,14 @@ b4_percent_code_get[]dnl } \ } while (false) -# define YY_REDUCE_PRINT(Rule) \ - do { \ +# define YY_REDUCE_PRINT(Rule) \ + do { \ if (yydebug_) \ - yy_reduce_print_ (Rule); \ + yy_reduce_print_ (Rule); \ } while (false) -# define YY_STACK_PRINT() \ - do { \ +# define YY_STACK_PRINT() \ + do { \ if (yydebug_) \ yystack_print_ (); \ } while (false) @@ -441,7 +446,7 @@ b4_percent_code_get[]dnl #else /* !YYDEBUG */ # define YYCDEBUG if (false) std::cerr -# define YY_SYMBOL_PRINT(Title, Symbol) static_cast(0) +# define YY_SYMBOL_PRINT(Title, Symbol) YYUSE(Symbol) # define YY_REDUCE_PRINT(Rule) static_cast(0) # define YY_STACK_PRINT() static_cast(0) @@ -545,7 +550,6 @@ b4_percent_code_get[]dnl symbol_base_type& yysym) const { int yytype = yysym.type_get (); - YYUSE (yymsg); if (yymsg) YY_SYMBOL_PRINT (yymsg, yysym); @@ -575,7 +579,7 @@ b4_percent_code_get[]dnl { ]b4_symbol_foreach([b4_symbol_printer])dnl [ default: - break; + break; } yyo << ')'; } @@ -711,7 +715,7 @@ m4_popdef([b4_at_dollar])])dnl location values to have been already stored, initialize these stacks with a primary value. */ yystack_ = stack_type (0); - yypush_ (0, 0, yyla); + yypush_ (YY_NULL, 0, yyla); // A new symbol was pushed on the stack. yynewstate: @@ -735,13 +739,21 @@ m4_popdef([b4_at_dollar])])dnl if (yyempty) { YYCDEBUG << "Reading a token: "; + try + { ]b4_lex_symbol_if( -[ yyla = b4_c_function_call([yylex], [symbol_type], - m4_ifdef([b4_lex_param], b4_lex_param));], -[ yyla.type = yytranslate_ (b4_c_function_call([yylex], [int], - [[YYSTYPE*], [&yyla.value]][]dnl +[ yyla = b4_c_function_call([yylex], [symbol_type], + m4_ifdef([b4_lex_param], b4_lex_param));], +[ yyla.type = yytranslate_ (b4_c_function_call([yylex], [int], + [[YYSTYPE*], [&yyla.value]][]dnl b4_locations_if([, [[location*], [&yyla.location]]])dnl m4_ifdef([b4_lex_param], [, ]b4_lex_param)));])[ + } + catch (const syntax_error& yyexc) + { + error (yyexc); + goto yyerrlab1; + } yyempty = false; } YY_SYMBOL_PRINT ("Next token is", yyla); @@ -756,10 +768,10 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param)));])[ yyn = yytable_[yyn]; if (yyn <= 0) { - if (yy_table_value_is_error_ (yyn)) - goto yyerrlab; - yyn = -yyn; - goto yyreduce; + if (yy_table_value_is_error_ (yyn)) + goto yyerrlab; + yyn = -yyn; + goto yyreduce; } /* Discard the token being shifted. */ @@ -818,14 +830,13 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param)));])[ switch (yyn) { ]b4_user_actions[ - default: + default: break; } } catch (const syntax_error& yyexc) { - error (]b4_args(b4_locations_if([yyexc.location]), - [[yyexc.what()]])[); + error (yyexc); YYERROR; } YY_SYMBOL_PRINT ("-> $$ =", yylhs); @@ -842,14 +853,14 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param)));])[ // in the debug trace, it's possibly junk. Hence yymsg = 0. // Besides, that keeps exactly the same traces as with the other // Bison skeletons. - yy_destroy_ (0, yystack_[i]);]])[ + yy_destroy_ (YY_NULL, yystack_[i]);]])[ yypop_ (yylen); yylen = 0; YY_STACK_PRINT (); /* Shift the result of the reduction. */ - yypush_ (0, yylhs); + yypush_ (YY_NULL, yylhs); goto yynewstate; /*--------------------------------------. @@ -859,16 +870,17 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param)));])[ /* If not already recovering from an error, report this error. */ if (!yyerrstatus_) { - ++yynerrs_; - error (]b4_args(b4_locations_if([yyla.location]), - [[yysyntax_error_ (yystack_[0].state, yyla.type)]])[); + ++yynerrs_; + error (]b4_args(b4_locations_if([yyla.location]), + [[yysyntax_error_ (yystack_[0].state, + yyempty ? yyempty_ : yyla.type)]])[); } ]b4_locations_if([[ yyerror_range[1].location = yyla.location;]])[ if (yyerrstatus_ == 3) { - /* If just tried and failed to reuse lookahead token after an + /* If just tried and failed to reuse lookahead token after an error, discard it. */ /* Return failure if at end of input. */ @@ -878,7 +890,7 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param)));])[ { yy_destroy_ ("Error: discarding", yyla); yyempty = true; - } + } } /* Else will try to reuse lookahead token after shifting the error @@ -909,7 +921,7 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param)));])[ | yyerrlab1 -- common code for both syntax error and YYERROR. | `-------------------------------------------------------------*/ yyerrlab1: - yyerrstatus_ = 3; /* Each real token shifted decrements this. */ + yyerrstatus_ = 3; /* Each real token shifted decrements this. */ { stack_symbol_type error_token; for (;;) @@ -964,82 +976,116 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param)));])[ yypop_ (yylen); while (yystack_.size () != 1) { - yy_destroy_ ("Cleanup: popping", yystack_[0]); - yypop_ (); + yy_destroy_ ("Cleanup: popping", yystack_[0]); + yypop_ (); } return yyresult; } + void + ]b4_parser_class_name[::error (const syntax_error& yyexc) + { + error (]b4_args(b4_locations_if([yyexc.location]), + [[yyexc.what()]])[); + } + // Generate an error message. std::string ]b4_parser_class_name[::yysyntax_error_ (]dnl b4_error_verbose_if([state_type yystate, int yytoken], [int, int])[) - { - std::string yyres;]b4_error_verbose_if([[ - int yyn = yypact_[yystate]; - if (yypact_ninf_ < yyn && yyn <= yylast_) + {]b4_error_verbose_if([[ + 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_) { - /* 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])) + int yyn = yypact_[yystate]; + if (!yy_pact_value_is_default_ (yyn)) { - if (yycount == YYERROR_VERBOSE_ARGS_MAXIMUM) - { - yycount = 1; - break; - } - else - yyarg[yycount++] = yytname_[yyx]; + /* 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 = 0; - switch (yycount) - { -#define YYCASE_(N, S) \ - case N: \ - yyformat = S; \ - break - 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")); + char const* yyformat = YY_NULL; + 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; } - else - ]])dnl -[ yyres = YY_("syntax error"); - return yyres; + + // 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;]], [[ + return YY_("syntax error");]])[ } @@ -1070,7 +1116,7 @@ b4_error_verbose_if([state_type yystate, int yytoken], for (stack_type::const_iterator i = yystack_.begin (), i_end = yystack_.end (); - i != i_end; ++i) + i != i_end; ++i) *yycdebug_ << ' ' << i->state; *yycdebug_ << std::endl; } @@ -1083,7 +1129,7 @@ b4_error_verbose_if([state_type yystate, int yytoken], int yynrhs = yyr2_[yyrule]; /* Print the symbols being reduced, and their result. */ *yycdebug_ << "Reducing stack by rule " << yyrule - 1 - << " (line " << yylno << "):" << std::endl; + << " (line " << yylno << "):" << std::endl; /* The symbols being reduced. */ for (int yyi = 0; yyi < yynrhs; yyi++) YY_SYMBOL_PRINT (" $" << yyi + 1 << " =",