diff options
| -rw-r--r-- | lib/compiler/src/sys_core_fold.erl | 23 | ||||
| -rw-r--r-- | lib/compiler/test/core_fold_SUITE.erl | 28 |
2 files changed, 36 insertions, 15 deletions
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index d73060fb7e..f3f315935a 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -2422,16 +2422,10 @@ move_let_into_expr(#c_let{vars=InnerVs0,body=InnerBody0}=Inner, Outer#c_let{vars=OuterVs,arg=Arg, body=Inner#c_let{vars=InnerVs,arg=OuterBody,body=InnerBody}}; move_let_into_expr(#c_let{vars=Lvs0,body=Lbody0}=Let, - #c_case{arg=Cexpr0,clauses=[Ca0,Cb0|Cs]}=Case, Sub0) -> - %% Test if there are no more clauses than Ca0 and Cb0, or if - %% Cb0 is guaranteed to match. - TwoClauses = Cs =:= [] orelse - case Cb0 of - #c_clause{pats=[#c_var{}],guard=#c_literal{val=true}} -> true; - _ -> false - end, - case {TwoClauses,is_failing_clause(Ca0),is_failing_clause(Cb0)} of - {true,false,true} -> + #c_case{arg=Cexpr0,clauses=[Ca0|Cs0]}=Case, Sub0) -> + case not is_failing_clause(Ca0) andalso + are_all_failing_clauses(Cs0) of + true -> %% let <Lvars> = case <Case-expr> of %% <Cpats> -> <Clause-body>; %% <OtherCpats> -> erlang:error(...) @@ -2467,8 +2461,8 @@ move_let_into_expr(#c_let{vars=Lvs0,body=Lbody0}=Let, body=Lbody}, Ca = Ca0#c_clause{pats=CaPats,guard=G,body=B}, - Cb = clause(Cb0, Cexpr, value, Sub0), - Case#c_case{arg=Cexpr,clauses=[Ca,Cb]} + Cs = [clause(C, Cexpr, value, Sub0) || C <- Cs0], + Case#c_case{arg=Cexpr,clauses=[Ca|Cs]} catch nomatch -> %% This is not a defeat. The code will eventually @@ -2476,7 +2470,7 @@ move_let_into_expr(#c_let{vars=Lvs0,body=Lbody0}=Let, %% optimizations done in this module. impossible end; - {_,_,_} -> impossible + false -> impossible end; move_let_into_expr(#c_let{vars=Lvs0,body=Lbody0}=Let, #c_seq{arg=Sarg0,body=Sbody0}=Seq, Sub0) -> @@ -2499,6 +2493,9 @@ move_let_into_expr(#c_let{vars=Lvs0,body=Lbody0}=Let, body=Lbody}}; move_let_into_expr(_Let, _Expr, _Sub) -> impossible. +are_all_failing_clauses(Cs) -> + all(fun is_failing_clause/1, Cs). + is_failing_clause(#c_clause{body=B}) -> will_fail(B). diff --git a/lib/compiler/test/core_fold_SUITE.erl b/lib/compiler/test/core_fold_SUITE.erl index 0097e28d4d..262967d03d 100644 --- a/lib/compiler/test/core_fold_SUITE.erl +++ b/lib/compiler/test/core_fold_SUITE.erl @@ -26,7 +26,8 @@ unused_multiple_values_error/1,unused_multiple_values/1, multiple_aliases/1,redundant_boolean_clauses/1, mixed_matching_clauses/1,unnecessary_building/1, - no_no_file/1,configuration/1,supplies/1]). + no_no_file/1,configuration/1,supplies/1, + redundant_stack_frame/1]). -export([foo/0,foo/1,foo/2,foo/3]). @@ -45,7 +46,8 @@ groups() -> unused_multiple_values_error,unused_multiple_values, multiple_aliases,redundant_boolean_clauses, mixed_matching_clauses,unnecessary_building, - no_no_file,configuration,supplies]}]. + no_no_file,configuration,supplies, + redundant_stack_frame]}]. init_per_suite(Config) -> @@ -527,4 +529,26 @@ supplies(_Config) -> do_supplies(#{1 := Value}) when byte_size(Value), byte_size(kg) -> working. +redundant_stack_frame(_Config) -> + {1,2} = do_redundant_stack_frame(#{x=>1,y=>2}), + {'EXIT',{{badkey,_,x},_}} = (catch do_redundant_stack_frame(#{y=>2})), + {'EXIT',{{badkey,_,y},_}} = (catch do_redundant_stack_frame(#{x=>1})), + ok. + +do_redundant_stack_frame(Map) -> + %% There should not be a stack frame for this function. + X = case Map of + #{x := X0} -> + X0; + #{} -> + erlang:error({badkey, Map, x}) + end, + Y = case Map of + #{y := Y0} -> + Y0; + #{} -> + erlang:error({badkey, Map, y}) + end, + {X, Y}. + id(I) -> I. |