diff options
| -rw-r--r-- | lib/stdlib/src/erl_lint.erl | 166 | ||||
| -rw-r--r-- | lib/stdlib/test/erl_lint_SUITE.erl | 109 |
2 files changed, 199 insertions, 76 deletions
diff --git a/lib/stdlib/src/erl_lint.erl b/lib/stdlib/src/erl_lint.erl index 269e4b34cf..49f1f3a6ee 100644 --- a/lib/stdlib/src/erl_lint.erl +++ b/lib/stdlib/src/erl_lint.erl @@ -2065,8 +2065,8 @@ expr({'receive',Line,Cs,To,ToEs}, Vt, St0) -> {Cvt,St3} = icrt_clauses(Cs, Vt, St2), %% Csvts = [vtnew(Tevt, Vt)|Cvt], %This is just NEW variables! Csvts = [Tevt|Cvt], - {Rvt,St4} = icrt_export(Csvts, Vt, {'receive',Line}, St3), - {vtmerge([Tvt,Tevt,Rvt]),St4}; + Rvt = icrt_export(Csvts, Vt, {'receive',Line}), + {vtmerge([Tvt,Tevt,Rvt]),St3}; expr({'fun',Line,Body}, Vt, St) -> %%No one can think funs export! case Body of @@ -2177,21 +2177,20 @@ expr({'try',Line,Es,Scs,Ccs,As}, Vt, St0) -> %% passes cannot handle exports in combination with 'after'. {Evt0,St1} = exprs(Es, Vt, St0), TryLine = {'try',Line}, - Uvt = vtunsafe(vtnames(vtnew(Evt0, Vt)), TryLine, []), - Evt1 = vtupdate(Uvt, vtsubtract(Evt0, Uvt)), + Uvt = vtunsafe(TryLine, Evt0, Vt), + Evt1 = vtupdate(Uvt, Evt0), {Sccs,St2} = icrt_clauses(Scs++Ccs, TryLine, vtupdate(Evt1, Vt), St1), Rvt0 = Sccs, - Rvt1 = vtupdate(vtunsafe(vtnames(vtnew(Rvt0, Vt)), TryLine, []), Rvt0), + Rvt1 = vtupdate(vtunsafe(TryLine, Rvt0, Vt), Rvt0), Evt2 = vtmerge(Evt1, Rvt1), {Avt0,St} = exprs(As, vtupdate(Evt2, Vt), St2), - Avt1 = vtupdate(vtunsafe(vtnames(vtnew(Avt0, Vt)), TryLine, []), Avt0), + Avt1 = vtupdate(vtunsafe(TryLine, Avt0, Vt), Avt0), Avt = vtmerge(Evt2, Avt1), {Avt,St}; expr({'catch',Line,E}, Vt, St0) -> %% No new variables added, flag new variables as unsafe. - {Evt,St1} = expr(E, Vt, St0), - Uvt = vtunsafe(vtnames(vtnew(Evt, Vt)), {'catch',Line}, []), - {vtupdate(Uvt,vtupdate(Evt, Vt)),St1}; + {Evt,St} = expr(E, Vt, St0), + {vtupdate(vtunsafe({'catch',Line}, Evt, Vt), Evt),St}; expr({match,_Line,P,E}, Vt, St0) -> {Evt,St1} = expr(E, Vt, St0), {Pvt,Bvt,St2} = pattern(P, vtupdate(Evt, Vt), St1), @@ -2204,9 +2203,8 @@ expr({op,Line,Op,L,R}, Vt, St0) when Op =:= 'orelse'; Op =:= 'andalso' -> {Evt1,St1} = expr(L, Vt, St0), Vt1 = vtupdate(Evt1, Vt), {Evt2,St2} = expr(R, Vt1, St1), - Vt2 = vtmerge(Evt2, Vt1), - {Vt3,St3} = icrt_export([Vt1,Vt2], Vt1, {Op,Line}, St2), - {vtmerge(Evt1, Vt3),St3}; + Evt3 = vtupdate(vtunsafe({Op,Line}, Evt2, Vt1), Evt2), + {vtmerge(Evt1, Evt3),St2}; expr({op,_Line,_Op,L,R}, Vt, St) -> expr_list([L,R], Vt, St); %They see the same variables %% The following are not allowed to occur anywhere! @@ -2946,11 +2944,12 @@ check_local_opaque_types(St) -> dict:fold(FoldFun, St, Ts). %% icrt_clauses(Clauses, In, ImportVarTable, State) -> -%% {NewVts,State}. +%% {UpdVt,State}. icrt_clauses(Cs, In, Vt, St0) -> {Csvt,St1} = icrt_clauses(Cs, Vt, St0), - icrt_export(Csvt, Vt, In, St1). + UpdVt = icrt_export(Csvt, Vt, In), + {UpdVt,St1}. %% icrt_clauses(Clauses, ImportVarTable, State) -> %% {NewVts,State}. @@ -2960,26 +2959,73 @@ icrt_clauses(Cs, Vt, St) -> icrt_clause({clause,_Line,H,G,B}, Vt0, St0) -> {Hvt,Binvt,St1} = head(H, Vt0, St0), - Vt1 = vtupdate(Hvt, vtupdate(Binvt, Vt0)), - {Gvt,St2} = guard(G, Vt1, St1), + Vt1 = vtupdate(Hvt, Binvt), + {Gvt,St2} = guard(G, vtupdate(Vt1, Vt0), St1), Vt2 = vtupdate(Gvt, Vt1), - {Bvt,St3} = exprs(B, Vt2, St2), + {Bvt,St3} = exprs(B, vtupdate(Vt2, Vt0), St2), {vtupdate(Bvt, Vt2),St3}. -icrt_export(Csvt, Vt, In, St) -> - Vt1 = vtmerge(Csvt), - All = ordsets:subtract(vintersection(Csvt), vtnames(Vt)), - Some = ordsets:subtract(vtnames(Vt1), vtnames(Vt)), - Xvt = vtexport(All, In, []), - Evt = vtunsafe(ordsets:subtract(Some, All), In, Xvt), - Unused = vtmerge([unused_vars(Vt0, Vt, St) || Vt0 <- Csvt]), - %% Exported and unsafe variables may be unused: - Uvt = vtmerge(Evt, Unused), - %% Make exported and unsafe unused variables unused in subsequent code: - Vt2 = vtmerge(Uvt, vtsubtract(Vt1, Uvt)), - %% Forget about old variables which were not used: - Vt3 = vtmerge(vtnew(Vt2, Vt), vt_no_unused(vtold(Vt2, Vt))), - {Vt3,St}. +icrt_export(Vts, Vt, {Tag,Attrs}) -> + {_File,Loc} = loc(Attrs), + icrt_export(lists:merge(Vts), Vt, {Tag,Loc}, length(Vts), []). + +icrt_export([{V,{{export,_},_,_}}|Vs0], [{V,{{export,_}=S0,_,Ls}}|Vt], + In, I, Acc) -> + %% V was an exported variable and has been used in an expression in at least + %% one clause. Its state needs to be merged from all clauses to silence any + %% exported var warning already emitted. + {VVs,Vs} = lists:partition(fun ({K,_}) -> K =:= V end, Vs0), + S = foldl(fun ({_,{S1,_,_}}, AccS) -> merge_state(AccS, S1) end, S0, VVs), + icrt_export(Vs, Vt, In, I, [{V,{S,used,Ls}}|Acc]); +icrt_export([{V,_}|Vs0], [{V,{_,_,Ls}}|Vt], In, I, Acc) -> + %% V was either unsafe or bound and has now been reused. It may also have + %% been an export but as it was not matched by the previous clause, it means + %% it has been changed to 'bound' in at least one clause because it was used + %% in a pattern. + Vs = lists:dropwhile(fun ({K,_}) -> K =:= V end, Vs0), + icrt_export(Vs, Vt, In, I, [{V,{bound,used,Ls}}|Acc]); +icrt_export([{V1,_}|_]=Vs, [{V2,_}|Vt], In, I, Acc) when V1 > V2 -> + %% V2 was already in scope and has not been reused in any clause. + icrt_export(Vs, Vt, In, I, Acc); +icrt_export([{V,_}|_]=Vs0, Vt, In, I, Acc) -> + %% V is a new variable. + {VVs,Vs} = lists:partition(fun ({K,_}) -> K =:= V end, Vs0), + F = fun ({_,{S,U,Ls}}, {AccI,AccS0,AccLs0}) -> + AccS = case {S,AccS0} of + {{unsafe,_},{unsafe,_}} -> + %% V was found unsafe in a previous clause, mark + %% it as unsafe for the whole parent expression. + {unsafe,In}; + {{unsafe,_},_} -> + %% V was unsafe in a clause, keep that state and + %% generalize it to the whole expression if it + %% is found unsafe in another one. + S; + _ -> + %% V is either bound or exported, keep original + %% state. + AccS0 + end, + AccLs = case U of + used -> AccLs0; + unused -> merge_lines(AccLs0, Ls) + end, + {AccI + 1,AccS,AccLs} + end, + %% Initial state is exported from the current expression. + {Count,S1,Ls} = foldl(F, {0,{export,In},[]}, VVs), + S = case Count of + I -> + %% V was found in all clauses, keep computed state. + S1; + _ -> + %% V was not bound in some clauses, mark as unsafe. + {unsafe,In} + end, + U = case Ls of [] -> used; _ -> unused end, + icrt_export(Vs, Vt, In, I, [{V,{S,U,Ls}}|Acc]); +icrt_export([], _, _, _, Acc) -> + reverse(Acc). handle_comprehension(E, Qs, Vt0, St0) -> {Vt1, Uvt, St1} = lc_quals(Qs, Vt0, St0), @@ -3077,7 +3123,8 @@ fun_clauses(Cs, Vt, St) -> {Cvt,St1} = fun_clause(C, Vt, St0), {vtmerge(Cvt, Bvt0),St1} end, {[],St#lint{recdef_top = false}}, Cs), - {vt_no_unused(vtold(Bvt, Vt)),St2#lint{recdef_top = OldRecDef}}. + Uvt = vt_no_unsafe(vt_no_unused(vtold(Bvt, Vt))), + {Uvt,St2#lint{recdef_top = OldRecDef}}. fun_clause({clause,_Line,H,G,B}, Vt0, St0) -> {Hvt,Binvt,St1} = head(H, Vt0, [], St0), % No imported pattern variables @@ -3191,19 +3238,24 @@ pat_binsize_var(V, Line, Vt, Bvt, St) -> %% exported vars are probably safe, warn only if warn_export_vars is %% set. -expr_var(V, Line, Vt, St0) -> +expr_var(V, Line, Vt, St) -> case orddict:find(V, Vt) of {ok,{bound,_Usage,Ls}} -> - {[{V,{bound,used,Ls}}],St0}; + {[{V,{bound,used,Ls}}],St}; {ok,{{unsafe,In},_Usage,Ls}} -> {[{V,{bound,used,Ls}}], - add_error(Line, {unsafe_var,V,In}, St0)}; + add_error(Line, {unsafe_var,V,In}, St)}; {ok,{{export,From},_Usage,Ls}} -> - {[{V,{bound,used,Ls}}], - exported_var(Line, V, From, St0)}; + case is_warn_enabled(export_vars, St) of + true -> + {[{V,{bound,used,Ls}}], + add_warning(Line, {exported_var,V,From}, St)}; + false -> + {[{V,{{export,From},used,Ls}}],St} + end; error -> {[{V,{bound,used,[Line]}}], - add_error(Line, {unbound_var,V}, St0)} + add_error(Line, {unbound_var,V}, St)} end. exported_var(Line, V, From, St) -> @@ -3267,17 +3319,12 @@ vtupdate(Uvt, Vt0) -> {S, merge_used(U1, U2), merge_lines(L1, L2)} end, Uvt, Vt0). -%% vtexport([Variable], From, VarTable) -> VarTable. -%% vtunsafe([Variable], From, VarTable) -> VarTable. -%% Add the variables to VarTable either as exported from From or as unsafe. - -vtexport(Vs, {InTag,FileLine}, Vt0) -> - {_File,Line} = loc(FileLine), - vtupdate([{V,{{export,{InTag,Line}},unused,[]}} || V <- Vs], Vt0). +%% vtunsafe(From, UpdVarTable, VarTable) -> UnsafeVarTable. +%% Return all new variables in UpdVarTable as unsafe. -vtunsafe(Vs, {InTag,FileLine}, Vt0) -> +vtunsafe({Tag,FileLine}, Uvt, Vt) -> {_File,Line} = loc(FileLine), - vtupdate([{V,{{unsafe,{InTag,Line}},unused,[]}} || V <- Vs], Vt0). + [{V,{{unsafe,{Tag,Line}},U,Ls}} || {V,{_,U,Ls}} <- vtnew(Uvt, Vt)]. %% vtmerge(VarTable, VarTable) -> VarTable. %% Merge two variables tables generating a new vartable. Give priority to @@ -3330,8 +3377,6 @@ vtsubtract(New, Old) -> vtold(New, Old) -> orddict:filter(fun (V, _How) -> orddict:is_key(V, Old) end, New). -vtnames(Vt) -> [ V || {V,_How} <- Vt ]. - vt_no_unsafe(Vt) -> [V || {_,{S,_U,_L}}=V <- Vt, case S of {unsafe,_} -> false; @@ -3340,29 +3385,6 @@ vt_no_unsafe(Vt) -> [V || {_,{S,_U,_L}}=V <- Vt, vt_no_unused(Vt) -> [V || {_,{_,U,_L}}=V <- Vt, U =/= unused]. -%% vunion(VarTable1, VarTable2) -> [VarName]. -%% vunion([VarTable]) -> [VarName]. -%% vintersection(VarTable1, VarTable2) -> [VarName]. -%% vintersection([VarTable]) -> [VarName]. -%% Union/intersection of names of vars in VarTable. - --ifdef(NOTUSED). -vunion(Vs1, Vs2) -> ordsets:union(vtnames(Vs1), vtnames(Vs2)). - -vunion(Vss) -> foldl(fun (Vs, Uvs) -> - ordsets:union(vtnames(Vs), Uvs) - end, [], Vss). - -vintersection(Vs1, Vs2) -> ordsets:intersection(vtnames(Vs1), vtnames(Vs2)). --endif. - -vintersection([Vs]) -> - vtnames(Vs); %Boundary conditions!!! -vintersection([Vs|Vss]) -> - ordsets:intersection(vtnames(Vs), vintersection(Vss)); -vintersection([]) -> - []. - %% copy_expr(Expr, Line) -> Expr. %% Make a copy of Expr converting all line numbers to Line. diff --git a/lib/stdlib/test/erl_lint_SUITE.erl b/lib/stdlib/test/erl_lint_SUITE.erl index 5d189006a1..049ca8e963 100644 --- a/lib/stdlib/test/erl_lint_SUITE.erl +++ b/lib/stdlib/test/erl_lint_SUITE.erl @@ -42,6 +42,7 @@ unused_vars_warn_rec/1, unused_vars_warn_fun/1, unused_vars_OTP_4858/1, + unused_unsafe_vars_warn/1, export_vars_warn/1, shadow_vars/1, unused_import/1, @@ -97,7 +98,7 @@ groups() -> [{unused_vars_warn, [], [unused_vars_warn_basic, unused_vars_warn_lc, unused_vars_warn_rec, unused_vars_warn_fun, - unused_vars_OTP_4858]}, + unused_vars_OTP_4858, unused_unsafe_vars_warn]}, {on_load, [], [on_load_successful, on_load_failing]}]. init_per_suite(Config) -> @@ -729,6 +730,48 @@ unused_vars_OTP_4858(Config) when is_list(Config) -> ?line [] = run(Config, Ts), ok. +unused_unsafe_vars_warn(Config) when is_list(Config) -> + Ts = [{unused_unsafe1, + <<"t1() -> + UnusedVar1 = unused1, + try + UnusedVar2 = unused2 + catch + _:_ -> + ok + end, + ok. + ">>, + [warn_unused_vars], + {warnings,[{2,erl_lint,{unused_var,'UnusedVar1'}}, + {4,erl_lint,{unused_var,'UnusedVar2'}}]}}, + {unused_unsafe2, + <<"t2() -> + try + X = 1 + catch + _:_ -> ok + end. + ">>, + [warn_unused_vars], + {warnings,[{3,erl_lint,{unused_var,'X'}}]}}, + {unused_unsafe2, + <<"t3(X, Y) -> + X andalso Y. + ">>, + [warn_unused_vars], + []}, + {unused_unsafe4, + <<"t4() -> + _ = (catch X = X = 1), + _ = case ok of _ -> fun() -> ok end end, + fun (X) -> X end. + ">>, + [warn_unused_vars], + []}], + run(Config, Ts), + ok. + export_vars_warn(doc) -> "Warnings for exported variables"; export_vars_warn(suite) -> []; @@ -807,7 +850,19 @@ export_vars_warn(Config) when is_list(Config) -> [], {error,[{9,erl_lint,{unbound_var,'B'}}], [{9,erl_lint,{exported_var,'Y',{'receive',2}}}, - {10,erl_lint,{shadowed_var,'B',generate}}]}} + {10,erl_lint,{shadowed_var,'B',generate}}]}}, + + {exp4, + <<"t(X) -> + if true -> Z = X end, + case X of + 1 -> Z; + 2 -> X + end, + Z = X. + ">>, + [], + {warnings,[{7,erl_lint,{exported_var,'Z',{'if',2}}}]}} ], ?line [] = run(Config, Ts), ok. @@ -831,8 +886,15 @@ shadow_vars(Config) when is_list(Config) -> ">>, [nowarn_shadow_vars], {error,[{9,erl_lint,{unbound_var,'B'}}], - [{9,erl_lint,{exported_var,'Y',{'receive',2}}}]}}], - + [{9,erl_lint,{exported_var,'Y',{'receive',2}}}]}}, + {shadow2, + <<"t() -> + _ = (catch MS = MS = 1), % MS used unsafe + _ = case ok of _ -> fun() -> ok end end, + fun (MS) -> MS end. % MS not shadowed here + ">>, + [], + []}], ?line [] = run(Config, Ts), ok. @@ -957,6 +1019,45 @@ unsafe_vars(Config) when is_list(Config) -> [warn_unused_vars], {errors,[{3,erl_lint,{unsafe_var,'X',{'if',2}}}, {4,erl_lint,{unsafe_var,'X',{'if',2}}}], + []}}, + {unsafe8, + <<"t8(X) -> + case X of _ -> catch _Y = 1 end, + _Y." + >>, + [], + {errors,[{3,erl_lint,{unsafe_var,'_Y',{'catch',2}}}], + []}}, + {unsafe9, + <<"t9(X) -> + case X of + 1 -> + catch A = 1, % unsafe only here + B = 1, + C = 1, + D = 1; + 2 -> + A = 2, + % B not bound here + C = 2, + catch D = 2; % unsafe in two clauses + 3 -> + A = 3, + B = 3, + C = 3, + catch D = 3; % unsafe in two clauses + 4 -> + A = 4, + B = 4, + C = 4, + D = 4 + end, + {A,B,C,D}." + >>, + [], + {errors,[{24,erl_lint,{unsafe_var,'A',{'catch',4}}}, + {24,erl_lint,{unsafe_var,'B',{'case',2}}}, + {24,erl_lint,{unsafe_var,'D',{'case',2}}}], []}} ], ?line [] = run(Config, Ts), |