diff options
| -rw-r--r-- | lib/compiler/src/sys_core_fold.erl | 152 | ||||
| -rw-r--r-- | lib/compiler/test/core_fold_SUITE.erl | 6 | ||||
| -rw-r--r-- | lib/compiler/test/match_SUITE.erl | 7 |
3 files changed, 89 insertions, 76 deletions
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index 09716d0866..f4f5c3f361 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -1338,9 +1338,12 @@ eval_element(Call, #c_literal{val=Pos}, #c_var{name=V}, Types) {ok,#c_tuple{es=Elements}} -> if 1 =< Pos, Pos =< length(Elements) -> - case lists:nth(Pos, Elements) of - #c_alias{var=Alias} -> Alias; - Res -> Res + El = lists:nth(Pos, Elements), + try + pat_to_expr(El) + catch + throw:impossible -> + Call end; true -> eval_failure(Call, badarg) @@ -2040,17 +2043,18 @@ case_opt_args([], Cs, _Sub, _LitExpr, Acc) -> %% Try to expand one argument to several arguments (if tuple/list) %% or to remove a literal argument. %% -case_opt_arg(E0, Sub, Cs, LitExpr) -> +case_opt_arg(E0, Sub, Cs0, LitExpr) -> E = maybe_replace_var(E0, Sub), case cerl:is_data(E) of false -> - {error,Cs}; + {error,Cs0}; true -> + Cs = case_opt_nomatch(E, Cs0, LitExpr), case cerl:data_type(E) of {atomic,_} -> - case_opt_lit(E, Cs, LitExpr); + case_opt_lit(E, Cs); _ -> - case_opt_data(E, Cs, LitExpr) + case_opt_data(E, Cs) end end. @@ -2113,8 +2117,26 @@ coerce_to_data(C) -> coerce_to_data(cerl:alias_pat(C)) end. -%% case_opt_lit(Literal, Clauses0, LitExpr) -> -%% {ok,[],Clauses} | error +%% case_opt_nomatch(E, Clauses, LitExpr) -> Clauses' +%% Remove all clauses that cannot possibly match. + +case_opt_nomatch(E, [{[P|_],C,_,_}=Current|Cs], LitExpr) -> + case cerl_clauses:match(P, E) of + none -> + %% The pattern will not match the case expression. Remove + %% the clause. Unless the entire case expression is a + %% literal, also emit a warning. + case LitExpr of + false -> add_warning(C, nomatch_clause_type); + true -> ok + end, + case_opt_nomatch(E, Cs, LitExpr); + _ -> + [Current|case_opt_nomatch(E, Cs, LitExpr)] + end; +case_opt_nomatch(_, [], _) -> []. + +%% case_opt_lit(Literal, Clauses0) -> {ok,[],Clauses} | error %% The current part of the case expression is a literal. That %% means that we will know at compile-time whether a clause %% will match, and we can remove the corresponding pattern from @@ -2123,68 +2145,48 @@ coerce_to_data(C) -> %% The only complication is if the literal is a binary. Binary %% pattern matching is tricky, so we will give up in that case. -case_opt_lit(Lit, Cs0, LitExpr) -> - Cs1 = case_opt_lit_1(Lit, Cs0, LitExpr), - try case_opt_lit_2(Lit, Cs1) of +case_opt_lit(Lit, Cs0) -> + try case_opt_lit_1(Lit, Cs0) of Cs -> {ok,[],Cs} catch throw:impossible -> - {error,Cs1} + {error,Cs0} end. -case_opt_lit_1(E, [{[P|_],C,_,_}=Current|Cs], LitExpr) -> - case cerl_clauses:match(P, E) of - none -> - %% The pattern will not match the literal. Remove the clause. - %% Unless the entire case expression is a literal, also - %% emit a warning. - case LitExpr of - false -> add_warning(C, nomatch_clause_type); - true -> ok - end, - case_opt_lit_1(E, Cs, LitExpr); - _ -> - [Current|case_opt_lit_1(E, Cs, LitExpr)] - end; -case_opt_lit_1(_, [], _) -> []. - -case_opt_lit_2(E, [{[P|Ps],C,PsAcc,Bs0}|Cs]) -> - %% Non-matching clauses have already been removed in case_opt_lit_1/3. +case_opt_lit_1(E, [{[P|Ps],C,PsAcc,Bs0}|Cs]) -> + %% Non-matching clauses have already been removed + %% in case_opt_nomatch/3. case cerl_clauses:match(P, E) of {true,Bs} -> %% The pattern matches the literal. Remove the pattern %% and update the bindings. - [{Ps,C,PsAcc,Bs++Bs0}|case_opt_lit_2(E, Cs)]; + [{Ps,C,PsAcc,Bs++Bs0}|case_opt_lit_1(E, Cs)]; {false,_} -> %% Binary literal and pattern. We are not sure whether %% the pattern will match. throw(impossible) end; -case_opt_lit_2(_, []) -> []. +case_opt_lit_1(_, []) -> []. %% case_opt_data(Expr, Clauses0, LitExpr) -> {ok,Exprs,Clauses} -case_opt_data(E, Cs0, LitExpr) -> +case_opt_data(E, Cs0) -> Es = cerl:data_es(E), - Cs = case_opt_data_1(Cs0, Es, - {cerl:data_type(E),cerl:data_arity(E)}, - LitExpr), - {ok,Es,Cs}. - -case_opt_data_1([{[P|Ps0],C,PsAcc,Bs0}|Cs], Es, TypeSig, LitExpr) -> - case case_data_pat(P, TypeSig) of - {ok,Ps1,Bs1} -> - [{Ps1++Ps0,C,PsAcc,Bs1++Bs0}| - case_opt_data_1(Cs, Es, TypeSig,LitExpr)]; - error -> - case LitExpr of - false -> add_warning(C, nomatch_clause_type); - true -> ok - end, - case_opt_data_1(Cs, Es, TypeSig, LitExpr) - end; -case_opt_data_1([], _, _, _) -> []. + TypeSig = {cerl:data_type(E),cerl:data_arity(E)}, + try case_opt_data_1(Cs0, Es, TypeSig) of + Cs -> + {ok,Es,Cs} + catch + throw:impossible -> + {error,Cs0} + end. + +case_opt_data_1([{[P|Ps0],C,PsAcc,Bs0}|Cs], Es, TypeSig) -> + {ok,Ps1,Bs1} = case_data_pat(P, TypeSig), + [{Ps1++Ps0,C,PsAcc,Bs1++Bs0}| + case_opt_data_1(Cs, Es, TypeSig)]; +case_opt_data_1([], _, _) -> []. %% case_data_pat(Pattern, Type, Arity) -> {ok,[Pattern],[{AliasVar,Pat}]} | error. @@ -2193,12 +2195,7 @@ case_data_pat(P, TypeSig) -> false -> case_data_pat_var(P, TypeSig); true -> - case {cerl:data_type(P),cerl:data_arity(P)} of - TypeSig -> - {ok,cerl:data_es(P),[]}; - {_,_} -> - error - end + {ok,cerl:data_es(P),[]} end. %% case_data_pat_var(Pattern, {DataType,ArityType}) -> @@ -2218,35 +2215,38 @@ case_data_pat_var(P, {Type,Arity}=TypeSig) -> alias -> V = cerl:alias_var(P), Apat = cerl:alias_pat(P), - case case_data_pat(Apat, TypeSig) of - {ok,Ps,Bs} -> - {ok,Ps,[{V,cerl:ann_make_data(Ann, Type, unalias_pat_list(Ps))}|Bs]}; - error -> - error - end; - _ -> - error + {ok,Ps,Bs} = case_data_pat(Apat, TypeSig), + {ok,Ps,[{V,cerl:ann_make_data(Ann, Type, + pat_to_expr_list(Ps))}|Bs]} end. -%% unalias_pat(Pattern) -> Pattern. -%% Remove all the aliases in a pattern but using the alias variables -%% instead of the values. We KNOW they will be bound. +%% pat_to_expr(Pattern) -> Expression. +%% Convert a pattern to an expression if possible. We KNOW that +%% all variables in the pattern will be bound. +%% +%% Throw an 'impossible' exception if a map or (non-literal) +%% binary is encountered. Trying to use a map pattern as an +%% expression is incorrect, while rebuilding a potentially +%% huge binary in an expression would be wasteful. -unalias_pat(P) -> - case cerl:is_c_alias(P) of - true -> +pat_to_expr(P) -> + case cerl:type(P) of + alias -> cerl:alias_var(P); - false -> + var -> + P; + _ -> case cerl:is_data(P) of false -> - P; + %% Map or binary. + throw(impossible); true -> - Es = unalias_pat_list(cerl:data_es(P)), + Es = pat_to_expr_list(cerl:data_es(P)), cerl:update_data(P, cerl:data_type(P), Es) end end. -unalias_pat_list(Ps) -> [unalias_pat(P) || P <- Ps]. +pat_to_expr_list(Ps) -> [pat_to_expr(P) || P <- Ps]. make_vars(A, Max) -> make_vars(A, 1, Max). diff --git a/lib/compiler/test/core_fold_SUITE.erl b/lib/compiler/test/core_fold_SUITE.erl index 6a7036d728..9c7e97a1bf 100644 --- a/lib/compiler/test/core_fold_SUITE.erl +++ b/lib/compiler/test/core_fold_SUITE.erl @@ -60,6 +60,12 @@ t_element(Config) when is_list(Config) -> X = make_ref(), ?line X = id(element(1, {X,y,z})), ?line b = id(element(2, {a,b,c,d})), + (fun() -> + case {a,#{k=>X}} of + {a,#{k:=X}}=Tuple -> + #{k:=X} = id(element(2, Tuple)) + end + end)(), %% No optimization, but should work. Tuple = id({x,y,z}), diff --git a/lib/compiler/test/match_SUITE.erl b/lib/compiler/test/match_SUITE.erl index e5aaf49d6f..1e778dca24 100644 --- a/lib/compiler/test/match_SUITE.erl +++ b/lib/compiler/test/match_SUITE.erl @@ -406,12 +406,19 @@ underscore(Config) when is_list(Config) -> match_map(Config) when is_list(Config) -> Map = #{key=>{x,y},ignore=>anything}, #s{map=Map,t={x,y}} = do_match_map(#s{map=Map}), + {a,#{k:={a,b,c}}} = do_match_map_2(#{k=>{a,b,c}}), ok. do_match_map(#s{map=#{key:=Val}}=S) -> %% Would crash with a 'badarg' exception. S#s{t=Val}. +do_match_map_2(Map) -> + case {a,Map} of + {a,#{k:=_}}=Tuple -> + Tuple + end. + coverage(Config) when is_list(Config) -> %% Cover beam_dead. ok = coverage_1(x, a), |