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author | Hans Bolinder <hasse@erlang.org> | 2010-03-03 09:51:52 +0000 |
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committer | Erlang/OTP <otp@erlang.org> | 2010-03-03 09:51:52 +0000 |
commit | 67e5a5f8833a9d090e4e9920f29541870eba34f5 (patch) | |
tree | 0a2ba81c2372093091bc89ecae47a1081a7d4fa4 /lib | |
parent | f94ff4fb58b9db3926ce0fea2c0fb4b18b1823ca (diff) | |
download | otp-67e5a5f8833a9d090e4e9920f29541870eba34f5.tar.gz otp-67e5a5f8833a9d090e4e9920f29541870eba34f5.tar.bz2 otp-67e5a5f8833a9d090e4e9920f29541870eba34f5.zip |
OTP-8483 parsetools: yecc bug
Yecc failed to report reduce/reduce conflicts where one of the reductions
involved the root symbol. This bug has been fixed. (Thanks to Manolis
Papadakis.)
Diffstat (limited to 'lib')
-rw-r--r-- | lib/parsetools/src/yecc.erl | 16 | ||||
-rw-r--r-- | lib/parsetools/test/yecc_SUITE.erl | 28 |
2 files changed, 40 insertions, 4 deletions
diff --git a/lib/parsetools/src/yecc.erl b/lib/parsetools/src/yecc.erl index b8b2b2308c..7fb6aae31a 100644 --- a/lib/parsetools/src/yecc.erl +++ b/lib/parsetools/src/yecc.erl @@ -1582,6 +1582,11 @@ find_action_conflicts2(Rs, Cxt0) -> find_reduce_reduce([R], Cxt) -> {R, Cxt}; +find_reduce_reduce([accept=A, #reduce{}=R | Rs], Cxt0) -> + Confl = conflict(R, A, Cxt0), + St = conflict_error(Confl, Cxt0#cxt.yecc), + Cxt = Cxt0#cxt{yecc = St}, + find_reduce_reduce([R | Rs], Cxt); find_reduce_reduce([#reduce{head = Categ1, prec = {P1, _}}=R1, #reduce{head = Categ2, prec = {P2, _}}=R2 | Rs], Cxt0) -> #cxt{res = Res0, yecc = St0} = Cxt0, @@ -1773,6 +1778,8 @@ add_conflict(Conflict, St) -> case Conflict of {Symbol, StateN, _, {reduce, _, _, _}} -> St#yecc{reduce_reduce = [{StateN,Symbol} |St#yecc.reduce_reduce]}; + {Symbol, StateN, _, {accept, _}} -> + St#yecc{reduce_reduce = [{StateN,Symbol} |St#yecc.reduce_reduce]}; {Symbol, StateN, _, {shift, _, _}} -> St#yecc{shift_reduce = [{StateN,Symbol} | St#yecc.shift_reduce]}; {_Symbol, _StateN, {one_level_up, _, _}, _Confl} -> @@ -1791,6 +1798,8 @@ conflict(#reduce{rule_nmbr = RuleNmbr1}, NewAction, Cxt) -> #cxt{terminal = Symbol, state_n = N, yecc = St} = Cxt, {R1, RuleLine1, RuleN1} = rule(RuleNmbr1, St), Confl = case NewAction of + accept -> + {accept, St#yecc.rootsymbol}; #reduce{rule_nmbr = RuleNmbr2} -> {R2, RuleLine2, RuleN2} = rule(RuleNmbr2, St), {reduce, R2, RuleN2, RuleLine2}; @@ -1830,7 +1839,10 @@ format_conflict({Symbol, N, Reduce, Confl}) -> {shift, NewState, Sym} -> io_lib:fwrite(<<" shift to state ~w, adding right " "sisters to ~s.">>, - [NewState, format_symbol(Sym)]) + [NewState, format_symbol(Sym)]); + {accept, Rootsymbol} -> + io_lib:fwrite(<<" reduce to rootsymbol ~s.">>, + [format_symbol(Rootsymbol)]) end, [S1, S2, S3]. @@ -2078,7 +2090,7 @@ output_action(St0, State, Terminal, #shift{state = NewState}, IsFirst, _SI) -> output_action(St0, State, Terminal, accept, IsFirst, _SI) -> St10 = delim(St0, IsFirst), St = fwrite(St10, - <<"yeccpars2_~w(_S, ~s, _Ss, Stack, _T, _Ts, _Tzr) ->\n">>, + <<"yeccpars2_~w(_S, ~s, _Ss, Stack, _T, _Ts, _Tzr) ->\n">>, [State, quoted_atom(Terminal)]), fwrite(St, <<" {ok, hd(Stack)}">>, []); output_action(St, _State, _Terminal, nonassoc, _IsFirst, _SI) -> diff --git a/lib/parsetools/test/yecc_SUITE.erl b/lib/parsetools/test/yecc_SUITE.erl index b5da414f7b..2e287f413a 100644 --- a/lib/parsetools/test/yecc_SUITE.erl +++ b/lib/parsetools/test/yecc_SUITE.erl @@ -44,7 +44,7 @@ empty/1, prec/1, yeccpre/1, lalr/1, old_yecc/1, other_examples/1, bugs/1, - otp_5369/1, otp_6362/1, otp_7945/1, + otp_5369/1, otp_6362/1, otp_7945/1, otp_8483/1, improvements/1, otp_7292/1, otp_7969/1]). @@ -1284,7 +1284,7 @@ other_examples(Config) when is_list(Config) -> ok. bugs(suite) -> - [otp_5369, otp_6362, otp_7945]. + [otp_5369, otp_6362, otp_7945, otp_8483]. otp_5369(doc) -> "OTP-5369. A bug in parse_and_scan reported on erlang questions."; @@ -1486,6 +1486,30 @@ otp_7945(Config) when is_list(Config) -> ?line {error,_} = erl_parse:parse([{atom,3,foo},{'.',2,9,9}]), ok. +otp_8483(doc) -> + "OTP-8483. reduce/accept conflict"; +otp_8483(suite) -> []; +otp_8483(Config) when is_list(Config) -> + Dir = ?privdir, + Input = filename:join(Dir, "bug.yrl"), + + Bug1 = <<"Nonterminals elem seq. + Terminals 'foo'. + Rootsymbol elem. + elem -> 'foo'. + elem -> seq. + seq -> elem. + seq -> seq elem.">>, + ?line ok = file:write_file(Input, Bug1), + Ret = [return, {report, true}], + ?line {error,[{_,[{none,yecc,{conflict,_}}, + {none,yecc,{conflict,_}}, + {none,yecc,{conflict,_}}]}], + [{_,[{none,yecc,{conflicts,1,3}}]}]} = + yecc:file(Input, Ret), + file:delete(Input), + ok. + improvements(suite) -> [otp_7292, otp_7969]. |