diff --git a/ChangeLog b/ChangeLog index dbd051c2..0721a932 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,23 @@ +2006-01-30 Joel E. Denny + + During deterministic GLR operation, user actions should be able to + influence the parse by changing yychar. To make this easier to fix and + to make glr.c easier to evolve in general, don't maintain yytoken in + parallel with yychar; just compute yytoken when needed. + * tests/glr-regression.at (Incorrect lookahead during deterministic + GLR): Check that setting yychar in a user action has the intended + effect. + * data/glr.c (yyGLRStack): Remove yytokenp member. + (yyclearin): Don't set *yytokenp. + (yyprocessOneStack, yyreportSyntaxError, yyrecoverSyntaxError): Examine + yychar rather than *yytokenp to determine the current lookahead. + Compute yytoken locally when needed. + (yyparse): Likewise. Remove the local yytoken that yytokenp used to + point to. + + * doc/bison.texinfo (Bison Options): Remove stray sentence fragment + after `--report' documentation. + 2006-01-30 Paul Eggert * src/parse-gram.y (grammar_declaration): Location of printer diff --git a/data/glr.c b/data/glr.c index e35cf78b..3430f1bb 100644 --- a/data/glr.c +++ b/data/glr.c @@ -803,7 +803,6 @@ struct yyGLRStack { YYSTYPE yyval; YYLTYPE yyloc; ])[ - yySymbol* yytokenp; YYJMP_BUF yyexception_buffer; yyGLRStackItem* yyitems; yyGLRStackItem* yynextFree; @@ -910,7 +909,7 @@ yyuserAction (yyRuleNum yyn, int yyrhslen, yyGLRStackItem* yyvsp, # undef YYRECOVERING # define YYRECOVERING (yystackp->yyerrState != 0) # undef yyclearin -# define yyclearin (yychar = *(yystackp->yytokenp) = YYEMPTY) +# define yyclearin (yychar = YYEMPTY) # undef YYFILL # define YYFILL(N) yyfill (yyvsp, &yylow, N, yynormal) # undef YYBACKUP @@ -1929,7 +1928,6 @@ yyprocessOneStack (yyGLRStack* yystackp, size_t yyk, int yyaction; const short int* yyconflicts; yyRuleNum yyrule; - yySymbol* const yytokenp = yystackp->yytokenp; while (yystackp->yytops.yystates[yyk] != NULL) { @@ -1953,15 +1951,18 @@ yyprocessOneStack (yyGLRStack* yystackp, size_t yyk, } else { + yySymbol yytoken; yystackp->yytops.yylookaheadNeeds[yyk] = yytrue; - if (*yytokenp == YYEMPTY) + if (yychar == YYEMPTY) { YYDPRINTF ((stderr, "Reading a token: ")); yychar = YYLEX; - *yytokenp = YYTRANSLATE (yychar); - YY_SYMBOL_PRINT ("Next token is", *yytokenp, &yylval, &yylloc); + yytoken = YYTRANSLATE (yychar); + YY_SYMBOL_PRINT ("Next token is", yytoken, &yylval, &yylloc); } - yygetLRActions (yystate, *yytokenp, &yyaction, &yyconflicts); + else + yytoken = YYTRANSLATE (yychar); + yygetLRActions (yystate, yytoken, &yyaction, &yyconflicts); while (*yyconflicts != 0) { @@ -1999,12 +2000,12 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[) if (yystackp->yyerrState == 0) { #if YYERROR_VERBOSE - yySymbol* const yytokenp = yystackp->yytokenp; int yyn; yyn = yypact[yystackp->yytops.yystates[0]->yylrState]; if (YYPACT_NINF < yyn && yyn < YYLAST) { - size_t yysize0 = yytnamerr (NULL, yytokenName (*yytokenp)); + yySymbol yytoken = YYTRANSLATE (yychar); + size_t yysize0 = yytnamerr (NULL, yytokenName (yytoken)); size_t yysize = yysize0; size_t yysize1; yybool yysize_overflow = yyfalse; @@ -2032,7 +2033,7 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[) int yyxend = yychecklim < YYNTOKENS ? yychecklim : YYNTOKENS; int yycount = 1; - yyarg[0] = yytokenName (*yytokenp); + yyarg[0] = yytokenName (yytoken); yyfmt = yystpcpy (yyformat, yyunexpected); for (yyx = yyxbegin; yyx < yyxend; ++yyx) @@ -2100,7 +2101,6 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[) /*ARGSUSED*/ static void yyrecoverSyntaxError (yyGLRStack* yystackp]b4_user_formals[) { - yySymbol* const yytokenp = yystackp->yytokenp; size_t yyk; int yyj; @@ -2109,9 +2109,10 @@ yyrecoverSyntaxError (yyGLRStack* yystackp]b4_user_formals[) reductions. Skip tokens until we can proceed. */ while (YYID (yytrue)) { - if (*yytokenp == YYEOF) + yySymbol yytoken; + if (yychar == YYEOF) yyFail (yystackp][]b4_lpure_args[, NULL); - if (*yytokenp != YYEMPTY) + if (yychar != YYEMPTY) {]b4_location_if([[ /* We throw away the lookahead, but the error range of the shifted error token must take it into account. */ @@ -2120,18 +2121,19 @@ yyrecoverSyntaxError (yyGLRStack* yystackp]b4_user_formals[) yyerror_range[1].yystate.yyloc = yys->yyloc; yyerror_range[2].yystate.yyloc = yylloc; YYLLOC_DEFAULT ((yys->yyloc), yyerror_range, 2);]])[ + yytoken = YYTRANSLATE (yychar); yydestruct ("Error: discarding", - *yytokenp, &yylval]b4_location_if([, &yylloc])[]b4_user_args[); + yytoken, &yylval]b4_location_if([, &yylloc])[]b4_user_args[); } YYDPRINTF ((stderr, "Reading a token: ")); yychar = YYLEX; - *yytokenp = YYTRANSLATE (yychar); - YY_SYMBOL_PRINT ("Next token is", *yytokenp, &yylval, &yylloc); + yytoken = YYTRANSLATE (yychar); + YY_SYMBOL_PRINT ("Next token is", yytoken, &yylval, &yylloc); yyj = yypact[yystackp->yytops.yystates[0]->yylrState]; if (yyis_pact_ninf (yyj)) return; - yyj += *yytokenp; - if (yyj < 0 || YYLAST < yyj || yycheck[yyj] != *yytokenp) + yyj += yytoken; + if (yyj < 0 || YYLAST < yyj || yycheck[yyj] != yytoken) { if (yydefact[yystackp->yytops.yystates[0]->yylrState] != 0) return; @@ -2209,7 +2211,6 @@ yyrecoverSyntaxError (yyGLRStack* yystackp]b4_user_formals[) ]b4_c_ansi_function_def([yyparse], [int], b4_parse_param)[ { int yyresult; - yySymbol yytoken; yyGLRStack yystack; yyGLRStack* const yystackp = &yystack; size_t yyposn; @@ -2217,7 +2218,6 @@ yyrecoverSyntaxError (yyGLRStack* yystackp]b4_user_formals[) YYDPRINTF ((stderr, "Starting parse\n")); yychar = YYEMPTY; - yytoken = YYEMPTY; yylval = yyval_default; ]b4_location_if([ #if YYLTYPE_IS_TRIVIAL @@ -2244,7 +2244,6 @@ b4_syncline([@oline@], [@ofile@])])dnl case 2: goto yyexhaustedlab; default: goto yybuglab; } - yystack.yytokenp = &yytoken; yyglrShift (&yystack, 0, 0, 0, &yylval, &yylloc); yyposn = 0; @@ -2277,24 +2276,24 @@ b4_syncline([@oline@], [@ofile@])])dnl } else { - if (yytoken == YYEMPTY) + yySymbol yytoken; + if (yychar == YYEMPTY) { YYDPRINTF ((stderr, "Reading a token: ")); yychar = YYLEX; yytoken = YYTRANSLATE (yychar); YY_SYMBOL_PRINT ("Next token is", yytoken, &yylval, &yylloc); } + else + yytoken = YYTRANSLATE (yychar); yygetLRActions (yystate, yytoken, &yyaction, &yyconflicts); if (*yyconflicts != 0) break; if (yyisShiftAction (yyaction)) { YY_SYMBOL_PRINT ("Shifting", yytoken, &yylval, &yylloc); - if (yytoken != YYEOF) - { - yychar = YYEMPTY; - yytoken = YYEMPTY; - } + if (yychar != YYEOF) + yychar = YYEMPTY; yyposn += 1; yyglrShift (&yystack, 0, yyaction, yyposn, &yylval, &yylloc); if (0 < yystack.yyerrState) @@ -2346,12 +2345,11 @@ b4_syncline([@oline@], [@ofile@])])dnl /* If any yyglrShift call fails, it will fail after shifting. Thus, a copy of yylval will already be on stack 0 in the event of a - failure in the following loop. Thus, yytoken is set to YYEMPTY + failure in the following loop. Thus, yychar is set to YYEMPTY before the loop to make sure the user destructor for yylval isn't called twice. */ - yytoken_to_shift = yytoken; + yytoken_to_shift = YYTRANSLATE (yychar); yychar = YYEMPTY; - yytoken = YYEMPTY; yyposn += 1; for (yys = 0; yys < yyn; yys += 1) { @@ -2412,9 +2410,10 @@ b4_syncline([@oline@], [@ofile@])])dnl goto yyreturn; yyreturn: - if (yytoken != YYEOF && yytoken != YYEMPTY) + if (yychar != YYEOF && yychar != YYEMPTY) yydestruct ("Cleanup: discarding lookahead", - yytoken, &yylval]b4_location_if([, &yylloc])[]b4_user_args[); + YYTRANSLATE (yychar), + &yylval]b4_location_if([, &yylloc])[]b4_user_args[); /* If the stack is well-formed, pop the stack until it is empty, destroying its entries as we go. But free the stack regardless diff --git a/doc/bison.texinfo b/doc/bison.texinfo index c0c56c0d..c004a842 100644 --- a/doc/bison.texinfo +++ b/doc/bison.texinfo @@ -6889,8 +6889,6 @@ Implies @code{state} and augments the description of the automaton with the full set of items for each state, instead of its core only. @end table -For instance, on the following grammar - @item -v @itemx --verbose Pretend that @code{%verbose} was specified, i.e, write an extra output diff --git a/src/parse-gram.c b/src/parse-gram.c index d923bc4f..2a28ff98 100644 --- a/src/parse-gram.c +++ b/src/parse-gram.c @@ -1912,7 +1912,7 @@ yyreduce: { symbol_list *list; for (list = (yyvsp[(2) - (2)].list); list; list = list->next) - symbol_printer_set (list->sym, (yyvsp[(1) - (2)].chars), list->location); + symbol_printer_set (list->sym, (yyvsp[(1) - (2)].chars), (yylsp[(1) - (2)])); symbol_list_free ((yyvsp[(2) - (2)].list)); } break; diff --git a/src/parse-gram.h b/src/parse-gram.h index cf303fd8..2f651109 100644 --- a/src/parse-gram.h +++ b/src/parse-gram.h @@ -148,7 +148,7 @@ typedef union YYSTYPE uniqstr uniqstr; } /* Line 1536 of yacc.c. */ -#line 152 "parse-gram.h" +#line 152 "y.tab.h" YYSTYPE; # define yystype YYSTYPE /* obsolescent; will be withdrawn */ # define YYSTYPE_IS_DECLARED 1 diff --git a/tests/glr-regression.at b/tests/glr-regression.at index 536f5eb8..8e6cd780 100644 --- a/tests/glr-regression.at +++ b/tests/glr-regression.at @@ -1016,7 +1016,8 @@ AT_CLEANUP ## ------------------------------------------------------------------------- ## ## Incorrect lookahead during deterministic GLR. See ## -## . ## +## and ## +## . ## ## ------------------------------------------------------------------------- ## AT_SETUP([Incorrect lookahead during deterministic GLR]) @@ -1027,7 +1028,8 @@ AT_DATA_GRAMMAR([glr-regr13.y], - Defaulted state with initial yychar: yychar == YYEMPTY. - Nondefaulted state: yychar != YYEMPTY. - Defaulted state after lookahead: yychar != YYEMPTY. - - Defaulted state after shift: yychar == YYEMPTY. */ + - Defaulted state after shift: yychar == YYEMPTY. + - User action changing the lookahead. */ %{ #include @@ -1045,7 +1047,7 @@ AT_DATA_GRAMMAR([glr-regr13.y], %% start: - defstate_init defstate_shift 'b' { + defstate_init defstate_shift 'b' change_lookahead 'a' { USE ($3); print_look_ahead ("start <- defstate_init defstate_shift 'b'"); } @@ -1075,6 +1077,11 @@ nondefstate: print_look_ahead ("nondefstate <- 'b'"); } ; +change_lookahead: + { + yychar = 'a'; + } + ; %%