diff options
Diffstat (limited to 'lib/compiler/src')
| -rw-r--r-- | lib/compiler/src/sys_core_fold.erl | 52 |
1 files changed, 35 insertions, 17 deletions
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index 102a6951e8..7f4184fd30 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -1130,11 +1130,23 @@ let_substs_1(Vs, #c_values{es=As}, Sub) -> let_substs_1([V], A, Sub) -> let_subst_list([V], [A], Sub); let_substs_1(Vs, A, _) -> {Vs,A,[]}. -let_subst_list([V|Vs0], [A|As0], Sub) -> +let_subst_list([V|Vs0], [A0|As0], Sub) -> {Vs1,As1,Ss} = let_subst_list(Vs0, As0, Sub), - case is_subst(A) of - true -> {Vs1,As1,sub_subst_var(V, A, Sub) ++ Ss}; - false -> {[V|Vs1],[A|As1],Ss} + case is_subst(A0) of + true -> + A = case is_compiler_generated(V) andalso + not is_compiler_generated(A0) of + true -> + %% Propagate the 'compiler_generated' annotation + %% along with the value. + Ann = [compiler_generated|cerl:get_ann(A0)], + cerl:set_ann(A0, Ann); + false -> + A0 + end, + {Vs1,As1,sub_subst_var(V, A, Sub) ++ Ss}; + false -> + {[V|Vs1],[A0|As1],Ss} end; let_subst_list([], [], _) -> {[],[],[]}. @@ -1900,8 +1912,8 @@ case_data_pat_alias(P, BindTo0, TypeSig, Bs0) -> %% Here we will need to actually build the data and bind %% it to the variable. {Type,Arity} = TypeSig, - Vars = make_vars([], Arity), Ann = [compiler_generated], + Vars = make_vars(Ann, Arity), Data = cerl:ann_make_data(Ann, Type, Vars), Bs = [{BindTo0,P},{P,Data}|Bs0], {Vars,Bs}; @@ -2393,8 +2405,9 @@ delay_build_1(Core0, TypeSig) -> try delay_build_expr(Core0, TypeSig) of Core -> {Type,Arity} = TypeSig, - Vars = make_vars([], Arity), - Data = cerl:ann_make_data([compiler_generated], Type, Vars), + Ann = [compiler_generated], + Vars = make_vars(Ann, Arity), + Data = cerl:ann_make_data(Ann, Type, Vars), {yes,Vars,Core,Data} catch throw:impossible -> @@ -2481,7 +2494,7 @@ opt_simple_let_2(Let0, Vs0, Arg0, Body, PrevBody, Ctxt, Sub) -> Arg1; false -> %% let <Var> = Arg in <OtherVar> ==> seq Arg OtherVar - Arg = maybe_suppress_warnings(Arg1, Vs0, PrevBody, Ctxt), + Arg = maybe_suppress_warnings(Arg1, Vs0, PrevBody), expr(#c_seq{arg=Arg,body=Body}, Ctxt, sub_new_preserve_types(Sub)) end; @@ -2489,7 +2502,7 @@ opt_simple_let_2(Let0, Vs0, Arg0, Body, PrevBody, Ctxt, Sub) -> %% No variables left. Body; {Vs,Arg1,#c_literal{}} -> - Arg = maybe_suppress_warnings(Arg1, Vs, PrevBody, Ctxt), + Arg = maybe_suppress_warnings(Arg1, Vs, PrevBody), E = case Ctxt of effect -> %% Throw away the literal body. @@ -2508,7 +2521,7 @@ opt_simple_let_2(Let0, Vs0, Arg0, Body, PrevBody, Ctxt, Sub) -> %% seq Arg BodyWithoutVar case is_any_var_used(Vs, Body) of false -> - Arg = maybe_suppress_warnings(Arg1, Vs, PrevBody, Ctxt), + Arg = maybe_suppress_warnings(Arg1, Vs, PrevBody), expr(#c_seq{arg=Arg,body=Body}, Ctxt, sub_new_preserve_types(Sub)); true -> @@ -2518,7 +2531,7 @@ opt_simple_let_2(Let0, Vs0, Arg0, Body, PrevBody, Ctxt, Sub) -> end end. -%% maybe_suppress_warnings(Arg, [#c_var{}], PreviousBody, Context) -> Arg' +%% maybe_suppress_warnings(Arg, [#c_var{}], PreviousBody) -> Arg' %% Try to suppress false warnings when a variable is not used. %% For instance, we don't expect a warning for useless building in: %% @@ -2529,10 +2542,7 @@ opt_simple_let_2(Let0, Vs0, Arg0, Body, PrevBody, Ctxt, Sub) -> %% referenced in the original unoptimized code. If they were, we will %% consider the warning false and suppress it. -maybe_suppress_warnings(Arg, _, _, effect) -> - %% Don't suppress any warnings in effect context. - Arg; -maybe_suppress_warnings(Arg, Vs, PrevBody, value) -> +maybe_suppress_warnings(Arg, Vs, PrevBody) -> case should_suppress_warning(Arg) of true -> Arg; %Already suppressed. @@ -2556,8 +2566,16 @@ suppress_warning([H|T]) -> true -> suppress_warning(cerl:data_es(H) ++ T); false -> - Arg = cerl:set_ann(H, [compiler_generated]), - cerl:c_seq(Arg, suppress_warning(T)) + %% Some other thing, such as a function call. + %% This cannot be the compiler's fault, so the + %% warning should not be suppressed. We must + %% be careful not to destroy tail-recursion. + case T of + [] -> + H; + [_|_] -> + cerl:c_seq(H, suppress_warning(T)) + end end end; suppress_warning([]) -> void(). |