X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/dcd5344dcde3ddc4761867134e6f8cc7b945ce1c..2bd435c36c0dfdefb07cef05dec851ec75bab20b:/data/lalr1.cc diff --git a/data/lalr1.cc b/data/lalr1.cc index 82e68244..237b246f 100644 --- a/data/lalr1.cc +++ b/data/lalr1.cc @@ -24,17 +24,14 @@ m4_define([b4_parser_class_name], b4_defines_if([], [b4_fatal([b4_skeleton[: using %%defines is mandatory]])]) -b4_percent_define_ifdef([[location_type]], [], +b4_percent_define_ifdef([[api.location.type]], [], [# Backward compatibility. m4_define([b4_location_constructors]) m4_include(b4_pkgdatadir/[location.cc])]) m4_include(b4_pkgdatadir/[stack.hh]) -# We do want M4 expansion after # for CPP macros. -m4_changecom() -m4_divert_push(0)dnl b4_defines_if( -[@output(b4_spec_defines_file@)@ +[b4_output_begin([b4_spec_defines_file]) b4_copyright([Skeleton interface for Bison LALR(1) parsers in C++], [2002-2012]) [ @@ -52,7 +49,7 @@ b4_copyright([Skeleton interface for Bison LALR(1) parsers in C++], #include #include #include "stack.hh" -]b4_percent_define_ifdef([[location_type]], [], +]b4_percent_define_ifdef([[api.location.type]], [], [[#include "location.hh"]])[ ]b4_YYDEBUG_define[ @@ -77,7 +74,7 @@ b4_user_stype typedef ]b4_api_PREFIX[STYPE semantic_type; #endif /// Symbol locations. - typedef ]b4_percent_define_get([[location_type]], + typedef ]b4_percent_define_get([[api.location.type]], [[location]])[ location_type; /// Tokens. struct token @@ -227,6 +224,7 @@ b4_user_stype /// \brief Reclaim the memory associated to a symbol. /// \param yymsg Why this token is reclaimed. + /// If null, do not display the symbol, just free it. /// \param yytype The symbol type. /// \param yyvaluep Its semantic value. /// \param yylocationp Its location. @@ -264,8 +262,11 @@ b4_user_stype ])[ ]b4_percent_code_get([[provides]])[ ]b4_cpp_guard_close([b4_spec_defines_file]) -])dnl -@output(b4_parser_file_name@)@ +b4_output_end() +]) + + +b4_output_begin([b4_parser_file_name]) b4_copyright([Skeleton implementation for Bison LALR(1) parsers in C++], [2002-2012]) b4_percent_code_get([[top]])[]dnl @@ -335,9 +336,9 @@ do { \ #else /* !]b4_api_PREFIX[DEBUG */ # define YYCDEBUG if (false) std::cerr -# define YY_SYMBOL_PRINT(Title, Type, Value, Location) -# define YY_REDUCE_PRINT(Rule) -# define YY_STACK_PRINT() +# define YY_SYMBOL_PRINT(Title, Type, Value, Location) YYUSE(Type) +# define YY_REDUCE_PRINT(Rule) static_cast(0) +# define YY_STACK_PRINT() static_cast(0) #endif /* !]b4_api_PREFIX[DEBUG */ @@ -446,7 +447,8 @@ do { \ YYUSE (yymsg); YYUSE (yyvaluep); - YY_SYMBOL_PRINT (yymsg, yytype, yyvaluep, yylocationp); + if (yymsg) + YY_SYMBOL_PRINT (yymsg, yytype, yyvaluep, yylocationp); switch (yytype) { @@ -510,17 +512,18 @@ do { \ int yychar = yyempty_; int yytoken = 0; - /* State. */ + // State. int yyn; int yylen = 0; int yystate = 0; - /* Error handling. */ + // Error handling. int yynerrs_ = 0; int yyerrstatus_ = 0; /// Semantic value of the lookahead. - semantic_type yylval; + static semantic_type yyval_default; + semantic_type yylval = yyval_default; /// Location of the lookahead. location_type yylloc; /// The locations where the error started and ended. @@ -533,6 +536,10 @@ do { \ int yyresult; + // FIXME: This shoud be completely indented. It is not yet to + // avoid gratuitous conflicts when merging into the master branch. + try + { YYCDEBUG << "Starting parse" << std::endl; ]m4_ifdef([b4_initial_action], [ @@ -573,14 +580,13 @@ b4_dollar_popdef])[]dnl /* Read a lookahead token. */ if (yychar == yyempty_) { - YYCDEBUG << "Reading a token: "; - yychar = ]b4_c_function_call([yylex], [int], - [b4_api_PREFIX[STYPE*], [&yylval]][]dnl + YYCDEBUG << "Reading a token: "; + yychar = ]b4_c_function_call([yylex], [int], + [b4_api_PREFIX[STYPE*], [&yylval]][]dnl b4_locations_if([, [[location*], [&yylloc]]])dnl m4_ifdef([b4_lex_param], [, ]b4_lex_param))[; } - /* Convert token to internal form. */ if (yychar <= yyeof_) { @@ -651,17 +657,21 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[; else yyval = yysemantic_stack_[0]; + // Compute the default @@$. { slice slice (yylocation_stack_, yylen); YYLLOC_DEFAULT (yyloc, slice, yylen); } + + // Perform the reduction. YY_REDUCE_PRINT (yyn); switch (yyn) { - ]b4_user_actions[ - default: - break; + ]b4_user_actions[ + 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. @@ -712,20 +722,19 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[; yyerror_range[1] = yylloc; if (yyerrstatus_ == 3) { - /* If just tried and failed to reuse lookahead token after an - error, discard it. */ - - if (yychar <= yyeof_) - { - /* Return failure if at end of input. */ - if (yychar == yyeof_) - YYABORT; - } - else - { - yydestruct_ ("Error: discarding", yytoken, &yylval, &yylloc); - yychar = yyempty_; - } + /* If just tried and failed to reuse lookahead token after an + error, discard it. */ + if (yychar <= yyeof_) + { + /* Return failure if at end of input. */ + if (yychar == yyeof_) + YYABORT; + } + else + { + yydestruct_ ("Error: discarding", yytoken, &yylval, &yylloc); + yychar = yyempty_; + } } /* Else will try to reuse lookahead token after shifting the error @@ -774,7 +783,7 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[; /* Pop the current state because it cannot handle the error token. */ if (yystate_stack_.height () == 1) - YYABORT; + YYABORT; yyerror_range[1] = yylocation_stack_[0]; yydestruct_ ("Error: popping", @@ -822,16 +831,42 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[; /* Do not reclaim the symbols of the rule which action triggered this YYABORT or YYACCEPT. */ yypop_ (yylen); - while (yystate_stack_.height () != 1) + while (1 < yystate_stack_.height ()) { - yydestruct_ ("Cleanup: popping", - yystos_[yystate_stack_[0]], - &yysemantic_stack_[0], - &yylocation_stack_[0]); - yypop_ (); + yydestruct_ ("Cleanup: popping", + yystos_[yystate_stack_[0]], + &yysemantic_stack_[0], + &yylocation_stack_[0]); + yypop_ (); } return yyresult; + } + catch (...) + { + YYCDEBUG << "Exception caught: cleaning lookahead and stack" + << std::endl; + // Do not try to display the values of the reclaimed symbols, + // as their printer might throw an exception. + if (yychar != yyempty_) + { + /* Make sure we have latest lookahead translation. See + comments at user semantic actions for why this is + necessary. */ + yytoken = yytranslate_ (yychar); + yydestruct_ (YY_NULL, yytoken, &yylval, &yylloc); + } + + while (1 < yystate_stack_.height ()) + { + yydestruct_ (YY_NULL, + yystos_[yystate_stack_[0]], + &yysemantic_stack_[0], + &yylocation_stack_[0]); + yypop_ (); + } + throw; + } } // Generate an error message. @@ -1105,4 +1140,4 @@ b4_error_verbose_if([int yystate, int yytoken], ]b4_namespace_close[ ]b4_epilogue[]dnl -m4_divert_pop(0) +b4_output_end()