diff options
Diffstat (limited to 'lib/compiler')
| -rw-r--r-- | lib/compiler/src/sys_core_fold.erl | 43 | ||||
| -rw-r--r-- | lib/compiler/test/core_fold_SUITE.erl | 14 |
2 files changed, 38 insertions, 19 deletions
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index 52d6dfe184..b7422318b2 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -2031,9 +2031,9 @@ case_opt(Arg, Cs0, Sub) -> case_opt_args([A0|As0], Cs0, Sub, LitExpr, Acc) -> case case_opt_arg(A0, Sub, Cs0, LitExpr) of - error -> + {error,Cs1} -> %% Nothing to be done. Move on to the next argument. - Cs = [{Ps,C,[P|PsAcc],Bs} || {[P|Ps],C,PsAcc,Bs} <- Cs0], + Cs = [{Ps,C,[P|PsAcc],Bs} || {[P|Ps],C,PsAcc,Bs} <- Cs1], case_opt_args(As0, Cs, Sub, LitExpr, [A0|Acc]); {ok,As1,Cs} -> %% The argument was either expanded (from tuple/list) or @@ -2052,7 +2052,7 @@ case_opt_arg(E0, Sub, Cs, LitExpr) -> E = maybe_replace_var(E0, Sub), case cerl:is_data(E) of false -> - error; + {error,Cs}; true -> case cerl:data_type(E) of {atomic,_} -> @@ -2102,35 +2102,44 @@ maybe_replace_var_1(E, #sub{t=Tdb}) -> %% pattern matching is tricky, so we will give up in that case. case_opt_lit(Lit, Cs0, LitExpr) -> - try case_opt_lit_1(Cs0, Lit, LitExpr) of + Cs1 = case_opt_lit_1(Lit, Cs0, LitExpr), + try case_opt_lit_2(Lit, Cs1) of Cs -> {ok,[],Cs} catch throw:impossible -> - error + {error,Cs1} end. -case_opt_lit_1([{[P|Ps],C,PsAcc,Bs0}|Cs], E, LitExpr) -> +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 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(Cs, E, LitExpr); {true,Bs} -> %% The pattern matches the literal. Remove the pattern %% and update the bindings. - [{Ps,C,PsAcc,Bs++Bs0}|case_opt_lit_1(Cs, E, LitExpr)]; + [{Ps,C,PsAcc,Bs++Bs0}|case_opt_lit_2(E, Cs)]; {false,_} -> %% Binary literal and pattern. We are not sure whether %% the pattern will match. throw(impossible) end; -case_opt_lit_1([], _, _) -> []. +case_opt_lit_2(_, []) -> []. %% case_opt_data(Expr, Clauses0, LitExpr) -> {ok,Exprs,Clauses} diff --git a/lib/compiler/test/core_fold_SUITE.erl b/lib/compiler/test/core_fold_SUITE.erl index 9c986576d5..6a7036d728 100644 --- a/lib/compiler/test/core_fold_SUITE.erl +++ b/lib/compiler/test/core_fold_SUITE.erl @@ -23,7 +23,7 @@ t_element/1,setelement/1,t_length/1,append/1,t_apply/1,bifs/1, eq/1,nested_call_in_case/1,guard_try_catch/1,coverage/1, unused_multiple_values_error/1,unused_multiple_values/1, - multiple_aliases/1,redundant_boolean_clauses/1]). + multiple_aliases/1,redundant_boolean_clauses/1,mixed_matching_clauses/1]). -export([foo/0,foo/1,foo/2,foo/3]). @@ -40,7 +40,7 @@ groups() -> [t_element,setelement,t_length,append,t_apply,bifs, eq,nested_call_in_case,guard_try_catch,coverage, unused_multiple_values_error,unused_multiple_values, - multiple_aliases,redundant_boolean_clauses]}]. + multiple_aliases,redundant_boolean_clauses,mixed_matching_clauses]}]. init_per_suite(Config) -> @@ -373,5 +373,15 @@ redundant_boolean_clauses(Config) when is_list(Config) -> true -> yes end. +mixed_matching_clauses(Config) when is_list(Config) -> + 0 = case #{} of + #{} -> 0; + a -> 1 + end, + 0 = case <<>> of + <<>> -> 0; + a -> 1 + end, + ok. id(I) -> I. |