X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/f16b08196c780556cbf50691e2944960aebc46f6..671850a1c3e1aaac93a89fabc6d810be6a4a77fe:/tests/conflicts.at?ds=inline diff --git a/tests/conflicts.at b/tests/conflicts.at index 5e7df4a4..819b992d 100644 --- a/tests/conflicts.at +++ b/tests/conflicts.at @@ -1,6 +1,6 @@ # Exercising Bison on conflicts. -*- Autotest -*- -# Copyright (C) 2002, 2003, 2004, 2005, 2007 Free Software Foundation, Inc. +# Copyright (C) 2002-2005, 2007-2015 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 @@ -17,6 +17,248 @@ AT_BANNER([[Conflicts.]]) +## ------------------------- ## +## Token declaration order. ## +## ------------------------- ## + +# This test checks that token are declared left to right when in a precedence +# statement. + +AT_SETUP([Token declaration order]) + +AT_BISON_OPTION_PUSHDEFS + +AT_DATA_GRAMMAR([[input.y]], +[[%code { + #include + ]AT_YYERROR_DECLARE[ + ]AT_YYLEX_DECLARE[ +} +%token A B C +%token D +%right E F G +%right H I +%right J +%left K +%left L M N +%nonassoc O P Q +%precedence R S T U +%precedence V W +%% +exp: A +%% +]AT_YYERROR_DEFINE[ +]AT_YYLEX_DEFINE[ +int main (void) +{ + assert (A < B); + assert (B < C); + assert (C < D); + assert (D < E); + assert (E < F); + assert (F < G); + assert (G < H); + assert (H < I); + assert (I < J); + assert (J < K); + assert (K < L); + assert (L < M); + assert (M < N); + assert (N < O); + assert (O < P); + assert (P < Q); + assert (Q < R); + assert (R < S); + assert (S < T); + assert (T < U); + assert (U < V); + assert (V < W); + return 0; +} +]]) + +AT_BISON_CHECK([-o input.c input.y]) +AT_COMPILE([input]) + +AT_PARSER_CHECK([./input]) + +AT_BISON_OPTION_POPDEFS + +AT_CLEANUP + + +## --------------------------------------------------- ## +## Token declaration order: literals vs. identifiers. ## +## --------------------------------------------------- ## + +# This test checks that when several tokens are declared by the same keyword, +# some of them defined as a character ('a'), others as simple textual reference +# (A), they are declared correctly left to right. +# Previously, the following test would declare the states in the order 'o' 'p' +# M N, instead of M N 'o' 'p'. + +AT_SETUP([Token declaration order: literals vs. identifiers]) + +AT_DATA_GRAMMAR([[input.y]], +[[%token 'a' 'b' C D +%token E F 'g' 'h' +%right 'i' 'j' K L +%right M N 'o' 'p' +%% +exp: 'a' + | 'b' + | C + | D + | E + | F + | 'g' + | 'h' + | 'i' + | 'j' + | K + | L + | M + | N + | 'o' + | 'p' +; +%% +]]) + +AT_BISON_CHECK([[--report=all -o input.c input.y]], 0, [], [ignore]) +AT_CHECK([[cat input.output | sed -n '/^State 0$/,/^State 1$/p']], 0, +[[State 0 + + 0 $accept: . exp $end + 1 exp: . 'a' + 2 | . 'b' + 3 | . C + 4 | . D + 5 | . E + 6 | . F + 7 | . 'g' + 8 | . 'h' + 9 | . 'i' + 10 | . 'j' + 11 | . K + 12 | . L + 13 | . M + 14 | . N + 15 | . 'o' + 16 | . 'p' + + 'a' shift, and go to state 1 + 'b' shift, and go to state 2 + C shift, and go to state 3 + D shift, and go to state 4 + E shift, and go to state 5 + F shift, and go to state 6 + 'g' shift, and go to state 7 + 'h' shift, and go to state 8 + 'i' shift, and go to state 9 + 'j' shift, and go to state 10 + K shift, and go to state 11 + L shift, and go to state 12 + M shift, and go to state 13 + N shift, and go to state 14 + 'o' shift, and go to state 15 + 'p' shift, and go to state 16 + + exp go to state 17 + + +State 1 +]]) + +AT_CLEANUP + + +## ------------------------------- ## +## Useless associativity warning. ## +## ------------------------------- ## + +AT_SETUP([Useless associativity warning]) + +AT_DATA([[input.y]], +[[%token EQ "=" PL "+" ST "*" LP "(" +%nonassoc "=" +%left "+" +%left "*" +%precedence "(" +%% +stmt: + exp +| "var" "=" exp +; + +exp: + exp "+" exp +| exp "*" "num" +| "(" exp ")" +| "num" +; +]]) + +AT_BISON_CHECK([-Wprecedence input.y], 0, [], +[[input.y:2.1-9: warning: useless precedence and associativity for "=" [-Wprecedence] +input.y:4.1-5: warning: useless associativity for "*", use %precedence [-Wprecedence] +input.y:5.1-11: warning: useless precedence for "(" [-Wprecedence] +]]) + +AT_CLEANUP + + +## ---------------------------- ## +## Useless precedence warning. ## +## ---------------------------- ## + +AT_SETUP([Useless precedence warning]) + +AT_DATA([[input.y]], +[[%token A B U V W X Y Z +%precedence Z +%left X +%precedence Y +%left W +%right V +%nonassoc U +%% +a: b + | a U b + | f +; +b: c + | b V c +; +c: d + | c W d +; +d: A + | d X d + | d Y A +; +f: B + | f Z B +; +]]) + +AT_BISON_CHECK([-Wprecedence -fcaret -o input.c input.y], 0, [], +[[input.y:7.1-9: warning: useless precedence and associativity for U [-Wprecedence] + %nonassoc U + ^^^^^^^^^ +input.y:6.1-6: warning: useless precedence and associativity for V [-Wprecedence] + %right V + ^^^^^^ +input.y:5.1-5: warning: useless precedence and associativity for W [-Wprecedence] + %left W + ^^^^^ +input.y:2.1-11: warning: useless precedence for Z [-Wprecedence] + %precedence Z + ^^^^^^^^^^^ +]]) + +AT_CLEANUP + ## ---------------- ## ## S/R in initial. ## @@ -36,8 +278,14 @@ exp: e 'e'; e: 'e' | /* Nothing. */; ]]) -AT_CHECK([bison -o input.c input.y], 0, [], -[[input.y:4.9: warning: rule never reduced because of conflicts: e: /* empty */ +AT_BISON_CHECK([-o input.c input.y], 0, [], +[[input.y:4.9: warning: rule useless in parser due to conflicts [-Wother] +]]) + +AT_BISON_CHECK([-fcaret -o input.c input.y], 0, [], +[[input.y:4.9: warning: rule useless in parser due to conflicts [-Wother] + e: 'e' | /* Nothing. */; + ^ ]]) AT_CLEANUP @@ -49,20 +297,17 @@ AT_CLEANUP AT_SETUP([%nonassoc and eof]) +AT_BISON_OPTION_PUSHDEFS AT_DATA_GRAMMAR([input.y], [[ %{ #include #include #include +#include #define YYERROR_VERBOSE 1 -static void -yyerror (const char *msg) -{ - fprintf (stderr, "%s\n", msg); -} - +]AT_YYERROR_DEFINE[ /* The current argument. */ static const char *input; @@ -70,8 +315,7 @@ static int yylex (void) { static size_t toknum; - if (! (toknum <= strlen (input))) - abort (); + assert (toknum <= strlen (input)); return input[toknum++]; } @@ -92,32 +336,419 @@ main (int argc, const char *argv[]) return yyparse (); } ]]) +AT_BISON_OPTION_POPDEFS -# Specify the output files to avoid problems on different file systems. -AT_CHECK([bison -o input.c input.y]) +m4_pushdef([AT_NONASSOC_AND_EOF_CHECK], +[AT_BISON_CHECK([$1[ -o input.c input.y]]) AT_COMPILE([input]) +m4_pushdef([AT_EXPECTING], [m4_if($2, [correct], [[, expecting $end]])]) + AT_PARSER_CHECK([./input '0<0']) -# FIXME: This is an actual bug, but a new one, in the sense that -# no one has ever spotted it! The messages are *wrong*: there should -# be nothing there, it should be expected eof. AT_PARSER_CHECK([./input '0<0<0'], [1], [], - [syntax error, unexpected '<', expecting '<' or '>' + [syntax error, unexpected '<'AT_EXPECTING ]) AT_PARSER_CHECK([./input '0>0']) AT_PARSER_CHECK([./input '0>0>0'], [1], [], - [syntax error, unexpected '>', expecting '<' or '>' + [syntax error, unexpected '>'AT_EXPECTING ]) AT_PARSER_CHECK([./input '0<0>0'], [1], [], - [syntax error, unexpected '>', expecting '<' or '>' + [syntax error, unexpected '>'AT_EXPECTING ]) +m4_popdef([AT_EXPECTING])]) + +# Expected token list is missing. +AT_NONASSOC_AND_EOF_CHECK([], [[incorrect]]) + +# We must disable default reductions in inconsistent states in order to +# have an explicit list of all expected tokens. +AT_NONASSOC_AND_EOF_CHECK([[-Dlr.default-reduction=consistent]], + [[correct]]) + +# lr.default-reduction=consistent happens to work for this test case. +# However, for other grammars, lookahead sets can be merged for +# different left contexts, so it is still possible to have an incorrect +# expected list. Canonical LR is almost a general solution (that is, it +# can fail only when %nonassoc is used), so make sure it gives the same +# result as above. +AT_NONASSOC_AND_EOF_CHECK([[-Dlr.type=canonical-lr]], [[correct]]) + +# parse.lac=full is a completely general solution that does not require +# any of the above sacrifices. Of course, it does not extend the +# language-recognition power of LALR to (IE)LR, but it does ensure that +# the reported list of expected tokens matches what the given parser +# would have accepted in place of the unexpected token. +AT_NONASSOC_AND_EOF_CHECK([[-Dparse.lac=full]], [[correct]]) + +m4_popdef([AT_NONASSOC_AND_EOF_CHECK]) + AT_CLEANUP +## ------------------------------------------- ## +## parse.error=verbose and consistent errors. ## +## ------------------------------------------- ## + +AT_SETUP([[parse.error=verbose and consistent errors]]) + +m4_pushdef([AT_CONSISTENT_ERRORS_CHECK], [ + +AT_BISON_OPTION_PUSHDEFS([$1]) + +m4_pushdef([AT_YYLEX_PROTOTYPE], +[AT_SKEL_CC_IF([[int yylex (yy::parser::semantic_type *lvalp)]], + [[int yylex (YYSTYPE *lvalp)]])]) + +AT_SKEL_JAVA_IF([AT_DATA], [AT_DATA_GRAMMAR])([input.y], +[AT_SKEL_JAVA_IF([[ + +%code imports { + import java.io.IOException; +}]], [[ + +%code {]AT_SKEL_CC_IF([[ + #include ]], [[ + #include + #include + ]AT_YYERROR_DECLARE])[ + ]AT_YYLEX_PROTOTYPE[; + #define USE(Var) +} + +]AT_SKEL_CC_IF([[%defines]], [[%define api.pure]])])[ + +]$1[ + +%define parse.error verbose + +%% + +]$2[ + +]AT_SKEL_JAVA_IF([[%code lexer {]], [[%%]])[ + +/*--------. +| yylex. | +`--------*/]AT_SKEL_JAVA_IF([[ + +public String input = "]$3["; +public int index = 0; +public int yylex () +{ + if (index < input.length ()) + return input.charAt (index++); + else + return 0; +} +public Object getLVal () +{ + return new Integer(1); +}]], [[ + +]AT_YYLEX_PROTOTYPE[ +{ + static char const *input = "]$3["; + *lvalp = 1; + return *input++; +}]])[ +]AT_YYERROR_DEFINE[ +]AT_SKEL_JAVA_IF([[ +}; + +%%]])[ + +/*-------. +| main. | +`-------*/ +]AT_MAIN_DEFINE +]) + +AT_FULL_COMPILE([[input]]) + +m4_pushdef([AT_EXPECTING], [m4_if($5, [ab], [[, expecting 'a' or 'b']], + $5, [a], [[, expecting 'a']], + $5, [b], [[, expecting 'b']])]) + +AT_SKEL_JAVA_IF([AT_JAVA_PARSER_CHECK([[input]], [[0]]], + [AT_PARSER_CHECK([[./input]], [[1]]]), +[[]], +[[syntax error, unexpected ]$4[]AT_EXPECTING[ +]]) + +m4_popdef([AT_EXPECTING]) +m4_popdef([AT_YYLEX_PROTOTYPE]) +AT_BISON_OPTION_POPDEFS + +]) + +m4_pushdef([AT_PREVIOUS_STATE_GRAMMAR], +[[%nonassoc 'a'; + +start: consistent-error-on-a-a 'a' ; + +consistent-error-on-a-a: + 'a' default-reduction + | 'a' default-reduction 'a' + | 'a' shift + ; + +default-reduction: /*empty*/ ; +shift: 'b' ; + +// Provide another context in which all rules are useful so that this +// test case looks a little more realistic. +start: 'b' consistent-error-on-a-a 'c' ; +]]) + +m4_pushdef([AT_PREVIOUS_STATE_INPUT], [[a]]) + +# Unfortunately, no expected tokens are reported even though 'b' can be +# accepted. Nevertheless, the main point of this test is to make sure +# that at least the unexpected token is reported. In a previous version +# of Bison, it wasn't reported because the error is detected in a +# consistent state with an error action, and that case always triggered +# the simple "syntax error" message. +# +# The point isn't to test IELR here, but state merging happens to +# complicate this example. +AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr]], + [AT_PREVIOUS_STATE_GRAMMAR], + [AT_PREVIOUS_STATE_INPUT], + [[$end]], [[none]]) +AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr + %glr-parser]], + [AT_PREVIOUS_STATE_GRAMMAR], + [AT_PREVIOUS_STATE_INPUT], + [[$end]], [[none]]) +AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr + %language "c++"]], + [AT_PREVIOUS_STATE_GRAMMAR], + [AT_PREVIOUS_STATE_INPUT], + [[$end]], [[none]]) +AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr + %language "java"]], + [AT_PREVIOUS_STATE_GRAMMAR], + [AT_PREVIOUS_STATE_INPUT], + [[end of input]], [[none]]) + +# Even canonical LR doesn't foresee the error for 'a'! +AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr + %define lr.default-reduction consistent]], + [AT_PREVIOUS_STATE_GRAMMAR], + [AT_PREVIOUS_STATE_INPUT], + [[$end]], [[ab]]) +AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr + %define lr.default-reduction accepting]], + [AT_PREVIOUS_STATE_GRAMMAR], + [AT_PREVIOUS_STATE_INPUT], + [[$end]], [[ab]]) +AT_CONSISTENT_ERRORS_CHECK([[%define lr.type canonical-lr]], + [AT_PREVIOUS_STATE_GRAMMAR], + [AT_PREVIOUS_STATE_INPUT], + [[$end]], [[ab]]) + +# Only LAC gets it right. +AT_CONSISTENT_ERRORS_CHECK([[%define lr.type canonical-lr + %define parse.lac full]], + [AT_PREVIOUS_STATE_GRAMMAR], + [AT_PREVIOUS_STATE_INPUT], + [[$end]], [[b]]) +AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr + %define parse.lac full]], + [AT_PREVIOUS_STATE_GRAMMAR], + [AT_PREVIOUS_STATE_INPUT], + [[$end]], [[b]]) + +m4_popdef([AT_PREVIOUS_STATE_GRAMMAR]) +m4_popdef([AT_PREVIOUS_STATE_INPUT]) + +m4_pushdef([AT_USER_ACTION_GRAMMAR], +[[%nonassoc 'a'; + +// If $$ = 0 here, then we know that the 'a' destructor is being invoked +// incorrectly for the 'b' set in the semantic action below. All 'a' +// tokens are returned by yylex, which sets $$ = 1. +%destructor { + if (!$$) + fprintf (stderr, "Wrong destructor.\n"); +} 'a'; + +// Rather than depend on an inconsistent state to induce reading a +// lookahead as in the previous grammar, just assign the lookahead in a +// semantic action. That lookahead isn't needed before either error +// action is encountered. In a previous version of Bison, this was a +// problem as it meant yychar was not translated into yytoken before +// either error action. The second error action thus invoked a +// destructor that it selected according to the incorrect yytoken. The +// first error action would have reported an incorrect unexpected token +// except that, due to the bug described in the previous grammar, the +// unexpected token was not reported at all. +start: error-reduce consistent-error 'a' { USE ($][3); } ; + +error-reduce: + 'a' 'a' consistent-reduction consistent-error 'a' + { USE (($][1, $][2, $][5)); } +| 'a' error + { USE ($][1); } +; + +consistent-reduction: /*empty*/ { + assert (yychar == YYEMPTY); + yylval = 0; + yychar = 'b'; +} ; + +consistent-error: + 'a' { USE ($][1); } +| /*empty*/ %prec 'a' +; + +// Provide another context in which all rules are useful so that this +// test case looks a little more realistic. +start: 'b' consistent-error 'b' ; +]]) +m4_pushdef([AT_USER_ACTION_INPUT], [[aa]]) + +AT_CONSISTENT_ERRORS_CHECK([[]], + [AT_USER_ACTION_GRAMMAR], + [AT_USER_ACTION_INPUT], + [['b']], [[none]]) +AT_CONSISTENT_ERRORS_CHECK([[%glr-parser]], + [AT_USER_ACTION_GRAMMAR], + [AT_USER_ACTION_INPUT], + [['b']], [[none]]) +# No C++ or Java test because yychar cannot be manipulated by users. + +AT_CONSISTENT_ERRORS_CHECK([[%define lr.default-reduction consistent]], + [AT_USER_ACTION_GRAMMAR], + [AT_USER_ACTION_INPUT], + [['b']], [[none]]) + +# Canonical LR doesn't foresee the error for 'a'! +AT_CONSISTENT_ERRORS_CHECK([[%define lr.default-reduction accepting]], + [AT_USER_ACTION_GRAMMAR], + [AT_USER_ACTION_INPUT], + [[$end]], [[a]]) +AT_CONSISTENT_ERRORS_CHECK([[%define lr.type canonical-lr]], + [AT_USER_ACTION_GRAMMAR], + [AT_USER_ACTION_INPUT], + [[$end]], [[a]]) + +AT_CONSISTENT_ERRORS_CHECK([[%define parse.lac full]], + [AT_USER_ACTION_GRAMMAR], + [AT_USER_ACTION_INPUT], + [['b']], [[none]]) +AT_CONSISTENT_ERRORS_CHECK([[%define parse.lac full + %define lr.default-reduction accepting]], + [AT_USER_ACTION_GRAMMAR], + [AT_USER_ACTION_INPUT], + [[$end]], [[none]]) + +m4_popdef([AT_USER_ACTION_GRAMMAR]) +m4_popdef([AT_USER_ACTION_INPUT]) + +m4_popdef([AT_CONSISTENT_ERRORS_CHECK]) + +AT_CLEANUP + + + +## ------------------------------------------------------- ## +## LAC: %nonassoc requires splitting canonical LR states. ## +## ------------------------------------------------------- ## + +# This test case demonstrates that, when %nonassoc is used, canonical +# LR(1) parser table construction followed by conflict resolution +# without further state splitting is not always sufficient to produce a +# parser that can detect all syntax errors as soon as possible on one +# token of lookahead. However, LAC solves the problem completely even +# with minimal LR parser tables. + +AT_SETUP([[LAC: %nonassoc requires splitting canonical LR states]]) +AT_BISON_OPTION_PUSHDEFS +AT_DATA_GRAMMAR([[input.y]], +[[%code { + #include + ]AT_YYERROR_DECLARE[ + ]AT_YYLEX_DECLARE[ +} + +%error-verbose +%nonassoc 'a' + +%% + +start: + 'a' problem 'a' // First context. +| 'b' problem 'b' // Second context. +| 'c' reduce-nonassoc // Just makes reduce-nonassoc useful. +; + +problem: + look reduce-nonassoc +| look 'a' +| look 'b' +; + +// For the state reached after shifting the 'a' in these productions, +// lookahead sets are the same in both the first and second contexts. +// Thus, canonical LR reuses the same state for both contexts. However, +// the lookahead 'a' for the reduction "look: 'a'" later becomes an +// error action only in the first context. In order to immediately +// detect the syntax error on 'a' here for only the first context, this +// canonical LR state would have to be split into two states, and the +// 'a' lookahead would have to be removed from only one of the states. +look: + 'a' // Reduction lookahead set is always ['a', 'b']. +| 'a' 'b' +| 'a' 'c' // 'c' is forgotten as an expected token. +; + +reduce-nonassoc: %prec 'a'; + +%% +]AT_YYERROR_DEFINE[ +]AT_YYLEX_DEFINE(["aaa"])[ +]AT_MAIN_DEFINE +]) +AT_BISON_OPTION_POPDEFS + +# Show canonical LR's failure. +AT_BISON_CHECK([[-Dlr.type=canonical-lr -o input.c input.y]], + [[0]], [[]], +[[input.y: warning: 2 shift/reduce conflicts [-Wconflicts-sr] +]]) +AT_COMPILE([[input]]) +AT_PARSER_CHECK([[./input]], [[1]], [[]], +[[syntax error, unexpected 'a', expecting 'b' +]]) + +# It's corrected by LAC. +AT_BISON_CHECK([[-Dlr.type=canonical-lr -Dparse.lac=full \ + -o input.c input.y]], [[0]], [[]], +[[input.y: warning: 2 shift/reduce conflicts [-Wconflicts-sr] +]]) +AT_COMPILE([[input]]) +AT_PARSER_CHECK([[./input]], [[1]], [[]], +[[syntax error, unexpected 'a', expecting 'b' or 'c' +]]) + +# IELR is sufficient when LAC is used. +AT_BISON_CHECK([[-Dlr.type=ielr -Dparse.lac=full -o input.c input.y]], + [[0]], [[]], +[[input.y: warning: 2 shift/reduce conflicts [-Wconflicts-sr] +]]) +AT_COMPILE([[input]]) +AT_PARSER_CHECK([[./input]], [[1]], [[]], +[[syntax error, unexpected 'a', expecting 'b' or 'c' +]]) + +AT_CLEANUP + ## ------------------------- ## ## Unresolved SR Conflicts. ## ## ------------------------- ## @@ -132,9 +763,9 @@ AT_DATA([input.y], exp: exp OP exp | NUM; ]]) -AT_CHECK([bison -o input.c --report=all input.y], 0, [], -[input.y: conflicts: 1 shift/reduce -]) +AT_BISON_CHECK([-o input.c --report=all input.y], 0, [], +[[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr] +]]) # Check the contents of the report. AT_CHECK([cat input.output], [], @@ -165,7 +796,7 @@ exp (6) on left: 1 2, on right: 0 1 -state 0 +State 0 0 $accept: . exp $end 1 exp: . exp OP exp @@ -176,14 +807,14 @@ state 0 exp go to state 2 -state 1 +State 1 2 exp: NUM . $default reduce using rule 2 (exp) -state 2 +State 2 0 $accept: exp . $end 1 exp: exp . OP exp @@ -192,14 +823,14 @@ state 2 OP shift, and go to state 4 -state 3 +State 3 0 $accept: exp $end . $default accept -state 4 +State 4 1 exp: . exp OP exp 1 | exp OP . exp @@ -210,9 +841,9 @@ state 4 exp go to state 5 -state 5 +State 5 - 1 exp: exp . OP exp [$end, OP] + 1 exp: exp . OP exp 1 | exp OP exp . [$end, OP] OP shift, and go to state 4 @@ -240,7 +871,7 @@ AT_DATA([input.y], exp: exp OP exp | NUM; ]]) -AT_CHECK([bison -o input.c --report=all input.y]) +AT_BISON_CHECK([-o input.c --report=all input.y]) # Check the contents of the report. AT_CHECK([cat input.output], [], @@ -268,7 +899,7 @@ exp (6) on left: 1 2, on right: 0 1 -state 0 +State 0 0 $accept: . exp $end 1 exp: . exp OP exp @@ -279,14 +910,14 @@ state 0 exp go to state 2 -state 1 +State 1 2 exp: NUM . $default reduce using rule 2 (exp) -state 2 +State 2 0 $accept: exp . $end 1 exp: exp . OP exp @@ -295,14 +926,14 @@ state 2 OP shift, and go to state 4 -state 3 +State 3 0 $accept: exp $end . $default accept -state 4 +State 4 1 exp: . exp OP exp 1 | exp OP . exp @@ -313,9 +944,9 @@ state 4 exp go to state 5 -state 5 +State 5 - 1 exp: exp . OP exp [$end, OP] + 1 exp: exp . OP exp 1 | exp OP exp . [$end, OP] $default reduce using rule 1 (exp) @@ -326,6 +957,62 @@ state 5 AT_CLEANUP +## ---------------------- ## +## %precedence suffices. ## +## ---------------------- ## + +AT_SETUP([%precedence suffices]) + +AT_DATA([input.y], +[[%precedence "then" +%precedence "else" +%% +stmt: + "if" cond "then" stmt +| "if" cond "then" stmt "else" stmt +| "stmt" +; + +cond: + "exp" +; +]]) + +AT_BISON_CHECK([-o input.c input.y]) + +AT_CLEANUP + + +## ------------------------------ ## +## %precedence does not suffice. ## +## ------------------------------ ## + +AT_SETUP([%precedence does not suffice]) + +AT_DATA([input.y], +[[%precedence "then" +%precedence "else" +%% +stmt: + "if" cond "then" stmt +| "if" cond "then" stmt "else" stmt +| "stmt" +; + +cond: + "exp" +| cond "then" cond +; +]]) + +AT_BISON_CHECK([-o input.c input.y], 0, [], +[[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr] +input.y:12.3-18: warning: rule useless in parser due to conflicts [-Wother] +]]) + +AT_CLEANUP + + ## -------------------------------- ## ## Defaulted Conflicted Reduction. ## ## -------------------------------- ## @@ -336,13 +1023,13 @@ AT_CLEANUP # $end reduce using rule 3 (num) # $end [reduce using rule 4 (id)] # -# But when `reduce 3' is the default action, we'd produce: +# But when 'reduce 3' is the default action, we'd produce: # # $end [reduce using rule 4 (id)] # $default reduce using rule 3 (num) # # In this precise case (a reduction is masked by the default -# reduction), we make the `reduce 3' explicit: +# reduction), we make the 'reduce 3' explicit: # # $end reduce using rule 3 (num) # $end [reduce using rule 4 (id)] @@ -362,14 +1049,14 @@ id : '0'; %% ]]) -AT_CHECK([bison -o input.c --report=all input.y], 0, [], -[[input.y: conflicts: 1 reduce/reduce -input.y:4.6-8: warning: rule never reduced because of conflicts: id: '0' +AT_BISON_CHECK([-o input.c --report=all input.y], 0, [], +[[input.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr] +input.y:4.6-8: warning: rule useless in parser due to conflicts [-Wother] ]]) # Check the contents of the report. AT_CHECK([cat input.output], [], -[[Rules never reduced +[[Rules useless in parser due to conflicts 4 id: '0' @@ -408,7 +1095,7 @@ id (7) on left: 4, on right: 2 -state 0 +State 0 0 $accept: . exp $end 1 exp: . num @@ -423,7 +1110,7 @@ state 0 id go to state 4 -state 1 +State 1 3 num: '0' . [$end] 4 id: '0' . [$end] @@ -433,28 +1120,28 @@ state 1 $default reduce using rule 3 (num) -state 2 +State 2 0 $accept: exp . $end $end shift, and go to state 5 -state 3 +State 3 1 exp: num . $default reduce using rule 1 (exp) -state 4 +State 4 2 exp: id . $default reduce using rule 2 (exp) -state 5 +State 5 0 $accept: exp $end . @@ -479,10 +1166,9 @@ AT_DATA([input.y], exp: exp OP exp | NUM; ]]) -AT_CHECK([bison -o input.c input.y], 1, [], -[input.y: conflicts: 1 shift/reduce -input.y: expected 0 shift/reduce conflicts -]) +AT_BISON_CHECK([-o input.c input.y], 1, [], +[[input.y: error: shift/reduce conflicts: 1 found, 0 expected +]]) AT_CLEANUP @@ -499,7 +1185,7 @@ AT_DATA([input.y], exp: exp OP exp | NUM; ]]) -AT_CHECK([bison -o input.c input.y]) +AT_BISON_CHECK([-o input.c input.y]) AT_CLEANUP @@ -516,16 +1202,15 @@ AT_DATA([input.y], exp: exp OP exp | NUM; ]]) -AT_CHECK([bison -o input.c input.y], 1, [], -[input.y: conflicts: 1 shift/reduce -input.y: expected 2 shift/reduce conflicts -]) +AT_BISON_CHECK([-o input.c input.y], 1, [], +[[input.y: error: shift/reduce conflicts: 1 found, 2 expected +]]) AT_CLEANUP -## ------------------------------ ## -## %expect with reduce conflicts ## -## ------------------------------ ## +## ------------------------------- ## +## %expect with reduce conflicts. ## +## ------------------------------- ## AT_SETUP([%expect with reduce conflicts]) @@ -536,16 +1221,32 @@ program: a 'a' | a a; a: 'a'; ]]) -AT_CHECK([bison -o input.c input.y], 1, [], -[input.y: conflicts: 1 reduce/reduce -input.y: expected 0 reduce/reduce conflicts -]) +AT_BISON_CHECK([-o input.c input.y], 1, [], +[[input.y: error: reduce/reduce conflicts: 1 found, 0 expected +]]) AT_CLEANUP -## ------------------------------- ## -## %no-default-prec without %prec ## -## ------------------------------- ## +## ------------------------- ## +## %prec with user strings. ## +## ------------------------- ## + +AT_SETUP([%prec with user string]) + +AT_DATA([[input.y]], +[[%% +exp: + "foo" %prec "foo" +; +]]) + +AT_BISON_CHECK([-o input.c input.y]) +AT_CLEANUP + + +## -------------------------------- ## +## %no-default-prec without %prec. ## +## -------------------------------- ## AT_SETUP([%no-default-prec without %prec]) @@ -563,15 +1264,17 @@ e: e '+' e ; ]]) -AT_CHECK([bison -o input.c input.y], 0, [], -[[input.y: conflicts: 4 shift/reduce +AT_BISON_CHECK([-Wall -o input.c input.y], 0, [], +[[input.y: warning: 4 shift/reduce conflicts [-Wconflicts-sr] +input.y:1.1-5: warning: useless precedence and associativity for '+' [-Wprecedence] +input.y:2.1-5: warning: useless precedence and associativity for '*' [-Wprecedence] ]]) AT_CLEANUP -## ---------------------------- ## -## %no-default-prec with %prec ## -## ---------------------------- ## +## ----------------------------- ## +## %no-default-prec with %prec. ## +## ----------------------------- ## AT_SETUP([%no-default-prec with %prec]) @@ -589,13 +1292,13 @@ e: e '+' e %prec '+' ; ]]) -AT_CHECK([bison -o input.c input.y]) +AT_BISON_CHECK([-o input.c input.y]) AT_CLEANUP -## ---------------- ## -## %default-prec ## -## ---------------- ## +## --------------- ## +## %default-prec. ## +## --------------- ## AT_SETUP([%default-prec]) @@ -613,7 +1316,7 @@ e: e '+' e ; ]]) -AT_CHECK([bison -o input.c input.y]) +AT_BISON_CHECK([-o input.c input.y]) AT_CLEANUP @@ -636,7 +1339,7 @@ AT_DATA([[input.y]], start: resolved_conflict 'a' reported_conflicts 'a' ; -/* S/R conflict resolved as shift, so the state with item +/* S/R conflict resolved as reduce, so the state with item * (resolved_conflict: 'a' . unreachable1) and all it transition successors are * unreachable, and the associated production is useless. */ resolved_conflict: @@ -665,30 +1368,31 @@ reported_conflicts: ]]) -AT_CHECK([[bison --report=all input.y]], 0, [], -[[input.y: conflicts: 1 shift/reduce, 1 reduce/reduce -input.y:12.5-20: warning: rule never reduced because of conflicts: resolved_conflict: 'a' unreachable1 -input.y:20.5-20: warning: rule never reduced because of conflicts: unreachable1: 'a' unreachable2 -input.y:21.4: warning: rule never reduced because of conflicts: unreachable1: /* empty */ -input.y:25.13: warning: rule never reduced because of conflicts: unreachable2: /* empty */ -input.y:25.16: warning: rule never reduced because of conflicts: unreachable2: /* empty */ -input.y:31.5-7: warning: rule never reduced because of conflicts: reported_conflicts: 'a' -input.y:32.4: warning: rule never reduced because of conflicts: reported_conflicts: /* empty */ +AT_BISON_CHECK([[--report=all input.y]], 0, [], +[[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr] +input.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr] +input.y:12.5-20: warning: rule useless in parser due to conflicts [-Wother] +input.y:20.5-20: warning: rule useless in parser due to conflicts [-Wother] +input.y:21.4: warning: rule useless in parser due to conflicts [-Wother] +input.y:25.13: warning: rule useless in parser due to conflicts [-Wother] +input.y:25.16: warning: rule useless in parser due to conflicts [-Wother] +input.y:31.5-7: warning: rule useless in parser due to conflicts [-Wother] +input.y:32.4: warning: rule useless in parser due to conflicts [-Wother] ]]) AT_CHECK([[cat input.output]], 0, -[[Rules never reduced +[[Rules useless in parser due to conflicts 2 resolved_conflict: 'a' unreachable1 4 unreachable1: 'a' unreachable2 - 5 | /* empty */ + 5 | %empty - 6 unreachable2: /* empty */ - 7 | /* empty */ + 6 unreachable2: %empty + 7 | %empty 9 reported_conflicts: 'a' - 10 | /* empty */ + 10 | %empty State 4 conflicts: 1 shift/reduce @@ -702,17 +1406,17 @@ Grammar 1 start: resolved_conflict 'a' reported_conflicts 'a' 2 resolved_conflict: 'a' unreachable1 - 3 | /* empty */ + 3 | %empty 4 unreachable1: 'a' unreachable2 - 5 | /* empty */ + 5 | %empty - 6 unreachable2: /* empty */ - 7 | /* empty */ + 6 unreachable2: %empty + 7 | %empty 8 reported_conflicts: 'a' 9 | 'a' - 10 | /* empty */ + 10 | %empty Terminals, with rules where they appear @@ -738,12 +1442,12 @@ reported_conflicts (9) on left: 8 9 10, on right: 1 -state 0 +State 0 0 $accept: . start $end 1 start: . resolved_conflict 'a' reported_conflicts 'a' 2 resolved_conflict: . 'a' unreachable1 - 3 | . ['a'] + 3 | . %empty ['a'] $default reduce using rule 3 (resolved_conflict) @@ -753,33 +1457,33 @@ state 0 Conflict between rule 3 and token 'a' resolved as reduce (%left 'a'). -state 1 +State 1 0 $accept: start . $end $end shift, and go to state 3 -state 2 +State 2 1 start: resolved_conflict . 'a' reported_conflicts 'a' 'a' shift, and go to state 4 -state 3 +State 3 0 $accept: start $end . $default accept -state 4 +State 4 1 start: resolved_conflict 'a' . reported_conflicts 'a' 8 reported_conflicts: . 'a' 9 | . 'a' - 10 | . ['a'] + 10 | . %empty ['a'] 'a' shift, and go to state 5 @@ -788,7 +1492,7 @@ state 4 reported_conflicts go to state 6 -state 5 +State 5 8 reported_conflicts: 'a' . ['a'] 9 | 'a' . ['a'] @@ -798,20 +1502,34 @@ state 5 $default reduce using rule 8 (reported_conflicts) -state 6 +State 6 1 start: resolved_conflict 'a' reported_conflicts . 'a' 'a' shift, and go to state 7 -state 7 +State 7 1 start: resolved_conflict 'a' reported_conflicts 'a' . $default reduce using rule 1 (start) ]]) +AT_DATA([[input-keep.y]], +[[%define lr.keep-unreachable-state +]]) +AT_CHECK([[cat input.y >> input-keep.y]]) + +AT_BISON_CHECK([[input-keep.y]], 0, [], +[[input-keep.y: warning: 2 shift/reduce conflicts [-Wconflicts-sr] +input-keep.y: warning: 2 reduce/reduce conflicts [-Wconflicts-rr] +input-keep.y:22.4: warning: rule useless in parser due to conflicts [-Wother] +input-keep.y:26.16: warning: rule useless in parser due to conflicts [-Wother] +input-keep.y:32.5-7: warning: rule useless in parser due to conflicts [-Wother] +input-keep.y:33.4: warning: rule useless in parser due to conflicts [-Wother] +]]) + AT_CLEANUP @@ -845,9 +1563,9 @@ empty_c1: %prec 'c' ; empty_c2: %prec 'c' ; empty_c3: %prec 'd' ; ]]) -AT_CHECK([[bison --report=all -o input.c input.y]], 0, [], [ignore]) -AT_CHECK([[cat input.output | sed -n '/^state 0$/,/^state 1$/p']], 0, -[[state 0 +AT_BISON_CHECK([[--report=all -o input.c input.y]], 0, [], [ignore]) +AT_CHECK([[cat input.output | sed -n '/^State 0$/,/^State 1$/p']], 0, +[[State 0 0 $accept: . start $end 1 start: . 'a' @@ -858,14 +1576,14 @@ AT_CHECK([[cat input.output | sed -n '/^state 0$/,/^state 1$/p']], 0, 6 | . empty_c1 'c' 7 | . empty_c2 'c' 8 | . empty_c3 'c' - 9 empty_a: . ['a'] - 10 empty_b: . [] - 11 empty_c1: . [] - 12 empty_c2: . [] - 13 empty_c3: . ['c'] + 9 empty_a: . %empty ['a'] + 10 empty_b: . %empty [] + 11 empty_c1: . %empty [] + 12 empty_c2: . %empty [] + 13 empty_c3: . %empty ['c'] 'b' shift, and go to state 1 - + 'c' reduce using rule 13 (empty_c3) $default reduce using rule 9 (empty_a) @@ -883,7 +1601,7 @@ AT_CHECK([[cat input.output | sed -n '/^state 0$/,/^state 1$/p']], 0, Conflict between rule 13 and token 'c' resolved as reduce ('c' < 'd'). -state 1 +State 1 ]]) AT_CLEANUP @@ -921,9 +1639,9 @@ empty_c2: %prec 'c' ; empty_c3: %prec 'c' ; ]]) -AT_CHECK([[bison --report=all -o input.c input.y]], 0, [], [ignore]) -AT_CHECK([[cat input.output | sed -n '/^state 0$/,/^state 1$/p']], 0, -[[state 0 +AT_BISON_CHECK([[--report=all -o input.c input.y]], 0, [], [ignore]) +AT_CHECK([[cat input.output | sed -n '/^State 0$/,/^State 1$/p']], 0, +[[State 0 0 $accept: . start $end 1 start: . 'a' @@ -934,11 +1652,11 @@ AT_CHECK([[cat input.output | sed -n '/^state 0$/,/^state 1$/p']], 0, 6 | . empty_c1 'c' 7 | . empty_c2 'c' 8 | . empty_c3 'c' - 9 empty_a: . [] - 10 empty_b: . [] - 11 empty_c1: . [] - 12 empty_c2: . ['c'] - 13 empty_c3: . ['c'] + 9 empty_a: . %empty [] + 10 empty_b: . %empty [] + 11 empty_c1: . %empty [] + 12 empty_c2: . %empty ['c'] + 13 empty_c3: . %empty ['c'] 'a' error (nonassociative) 'b' error (nonassociative) @@ -959,6 +1677,150 @@ AT_CHECK([[cat input.output | sed -n '/^state 0$/,/^state 1$/p']], 0, Conflict between rule 11 and token 'c' resolved as an error (%nonassoc 'c'). -state 1 +State 1 ]]) AT_CLEANUP + + +## -------------------- ## +## %expect-rr non GLR. ## +## -------------------- ## + +AT_SETUP([[%expect-rr non GLR]]) + +AT_DATA([[1.y]], +[[%expect-rr 0 +%% +exp: 'a' +]]) + +AT_BISON_CHECK([[1.y]], [[0]], [], +[[1.y: warning: %expect-rr applies only to GLR parsers [-Wother] +]]) + +AT_DATA([[2.y]], +[[%expect-rr 1 +%% +exp: 'a' | 'a'; +]]) + +AT_BISON_CHECK([[2.y]], [[0]], [], +[[2.y: warning: %expect-rr applies only to GLR parsers [-Wother] +2.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr] +2.y:3.12-14: warning: rule useless in parser due to conflicts [-Wother] +]]) + +AT_CLEANUP + + +## ---------------------------------- ## +## -W versus %expect and %expect-rr. ## +## ---------------------------------- ## + +AT_SETUP([[-W versus %expect and %expect-rr]]) + +AT_DATA([[sr-rr.y]], +[[%glr-parser +%% +start: 'a' | A 'a' | B 'a' ; +A: ; +B: ; +]]) +AT_DATA([[sr.y]], +[[%glr-parser +%% +start: 'a' | A 'a' ; +A: ; +]]) +AT_DATA([[rr.y]], +[[%glr-parser +%% +start: A | B ; +A: ; +B: ; +]]) + +AT_BISON_CHECK([[sr-rr.y]], [[0]], [[]], +[[sr-rr.y: warning: 1 shift/reduce conflict [-Wconflicts-sr] +sr-rr.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr] +]]) +AT_BISON_CHECK([[-Wno-conflicts-sr sr-rr.y]], [[0]], [[]], +[[sr-rr.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr] +]]) +AT_BISON_CHECK([[-Wno-conflicts-rr sr-rr.y]], [[0]], [[]], +[[sr-rr.y: warning: 1 shift/reduce conflict [-Wconflicts-sr] +]]) + +[ +# This is piece of code is rather complex for a simple task: try every +# combinaison of (0 or 1 real SR) x (0 or 1 real RR) x (don't %expect +# or %expect 0, 1, or 2 SR) x (don't %expect-rr or %expect-rr 0, 1, or 2 +# RR). + +# Number and types of genuine conflicts in the grammar. +for gram in sr-rr sr rr; do + # Number of expected s/r conflicts. + for sr_exp_i in '' 0 1 2; do + # Number of expected r/r conflicts. + for rr_exp_i in '' 0 1 2; do + test -z "$sr_exp_i" && test -z "$rr_exp_i" && continue + + # Build grammar file. + sr_exp=0 + rr_exp=0 + file=$gram + directives= + if test -n "$sr_exp_i"; then + sr_exp=$sr_exp_i + file=$file-expect-$sr_exp + directives="%expect $sr_exp" + fi + if test -n "$rr_exp_i"; then + rr_exp=$rr_exp_i + file=$file-expect-rr-$rr_exp + directives="$directives %expect-rr $rr_exp" + fi + file=$file.y + echo "$directives" > $file + cat $gram.y >> $file + + # Number of found conflicts. + case $gram in + (sr) sr_count=1; rr_count=0;; + (rr) sr_count=0; rr_count=1;; + (sr-rr) sr_count=1; rr_count=1;; + esac + + # Update number of expected conflicts: if %expect is given then + # %expect-rr defaults to 0, and vice-versa. Leave empty if + # nothing expected. + case $sr_exp_i:$rr_exp_i in + ?:) rr_exp_i=0;; + :?) sr_exp_i=0;; + esac + + # Run tests. + if test $sr_count -eq $sr_exp && test $rr_count -eq $rr_exp; then + ]AT_BISON_CHECK([[-Wnone $file]])[ + ]AT_BISON_CHECK([[-Werror $file]])[ + else + { + if test -z "$sr_exp_i" && test "$sr_count" -ne 0; then + echo "warning: $sr_count shift/reduce conflicts" + elif test "$sr_exp_i" -ne "$sr_count"; then + echo "error: shift/reduce conflicts: $sr_count found, $sr_exp_i expected" + fi + if test -z "$rr_exp_i" && test "$rr_count" -ne 0; then + echo "warning: $rr_count reduce/reduce conflicts" + elif test "$rr_exp_i" -ne "$rr_count"; then + echo "error: reduce/reduce conflicts: $rr_count found, $rr_exp_i expected" + fi + } | sed -e "s/^/$file: /" > experr + ]AT_BISON_CHECK([[-Wnone $file]], [[1]], [[]], [[experr]])[ + ]AT_BISON_CHECK([[-Werror $file]], [[1]], [[]], [[experr]])[ + fi + done + done +done] + +AT_CLEANUP