diff options
Diffstat (limited to 'lib/compiler/src/sys_core_fold.erl')
| -rw-r--r-- | lib/compiler/src/sys_core_fold.erl | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index 4068d60ec4..37006cd8ce 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -2493,7 +2493,7 @@ 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; @@ -2501,7 +2501,7 @@ 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. @@ -2520,7 +2520,7 @@ 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 -> @@ -2530,7 +2530,7 @@ 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: %% @@ -2541,10 +2541,7 @@ 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. @@ -2568,8 +2565,16 @@ 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(). |