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-rw-r--r--lib/compiler/src/sys_core_fold.erl27
-rw-r--r--lib/compiler/src/v3_core.erl26
-rw-r--r--lib/compiler/test/float_SUITE.erl12
-rw-r--r--lib/compiler/test/match_SUITE.erl26
-rw-r--r--lib/compiler/test/num_bif_SUITE.erl14
-rw-r--r--lib/compiler/test/warnings_SUITE.erl17
6 files changed, 79 insertions, 43 deletions
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl
index 068478496b..6202f07479 100644
--- a/lib/compiler/src/sys_core_fold.erl
+++ b/lib/compiler/src/sys_core_fold.erl
@@ -1,19 +1,19 @@
%%
%% %CopyrightBegin%
-%%
-%% Copyright Ericsson AB 1999-2009. All Rights Reserved.
-%%
+%%
+%% Copyright Ericsson AB 1999-2010. All Rights Reserved.
+%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
-%%
+%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
-%%
+%%
%% %CopyrightEnd%
%%
%% Purpose : Constant folding optimisation for Core
@@ -602,15 +602,23 @@ count_bits_1(Int, Bits) -> count_bits_1(Int bsr 64, Bits+64).
%% a rewritten expression consisting of a sequence of
%% the arguments only is returned.
-useless_call(effect, #c_call{module=#c_literal{val=Mod},
+useless_call(effect, #c_call{anno=Anno,
+ module=#c_literal{val=Mod},
name=#c_literal{val=Name},
args=Args}=Call) ->
A = length(Args),
case erl_bifs:is_safe(Mod, Name, A) of
false ->
case erl_bifs:is_pure(Mod, Name, A) of
- true -> add_warning(Call, result_ignored);
- false -> ok
+ true ->
+ case member(result_not_wanted, Anno) of
+ false ->
+ add_warning(Call, result_ignored);
+ true ->
+ ok
+ end;
+ false ->
+ ok
end,
no;
true ->
@@ -2806,7 +2814,8 @@ format_error({no_effect,{erlang,F,A}}) ->
end,
flatten(io_lib:format(Fmt, Args));
format_error(result_ignored) ->
- "the result of the expression is ignored";
+ "the result of the expression is ignored "
+ "(suppress the warning by assigning the expression to the _ variable)";
format_error(useless_building) ->
"a term is constructed, but never used";
format_error(bin_opt_alias) ->
diff --git a/lib/compiler/src/v3_core.erl b/lib/compiler/src/v3_core.erl
index 4ac2196d79..b2f0ac75c7 100644
--- a/lib/compiler/src/v3_core.erl
+++ b/lib/compiler/src/v3_core.erl
@@ -128,6 +128,7 @@
-record(core, {vcount=0 :: non_neg_integer(), %Variable counter
fcount=0 :: non_neg_integer(), %Function counter
in_guard=false :: boolean(), %In guard or not.
+ wanted=true :: boolean(), %Result wanted or not.
opts :: [compile:option()], %Options.
es=[] :: [error()], %Errors.
ws=[] :: [warning()], %Warnings.
@@ -580,10 +581,14 @@ expr({'fun',L,{function,F,A},{_,_,_}=Id}, St) ->
{#c_var{anno=Lanno++[{id,Id}],name={F,A}},[],St};
expr({'fun',L,{clauses,Cs},Id}, St) ->
fun_tq(Id, Cs, L, St);
-expr({call,L,{remote,_,M,F},As0}, St0) ->
+expr({call,L,{remote,_,M,F},As0}, #core{wanted=Wanted}=St0) ->
{[M1,F1|As1],Aps,St1} = safe_list([M,F|As0], St0),
Lanno = lineno_anno(L, St1),
- {#icall{anno=#a{anno=Lanno},module=M1,name=F1,args=As1},Aps,St1};
+ Anno = case Wanted of
+ false -> [result_not_wanted|Lanno];
+ true -> Lanno
+ end,
+ {#icall{anno=#a{anno=Anno},module=M1,name=F1,args=As1},Aps,St1};
expr({call,Lc,{atom,Lf,F},As0}, St0) ->
{As1,Aps,St1} = safe_list(As0, St0),
Op = #c_var{anno=lineno_anno(Lf, St1),name={F,length(As1)}},
@@ -596,23 +601,28 @@ expr({call,L,FunExp,As0}, St0) ->
expr({match,L,P0,E0}, St0) ->
%% First fold matches together to create aliases.
{P1,E1} = fold_match(E0, P0),
- {E2,Eps,St1} = novars(E1, St0),
+ St1 = case P1 of
+ {var,_,'_'} -> St0#core{wanted=false};
+ _ -> St0
+ end,
+ {E2,Eps,St2} = novars(E1, St1),
+ St3 = St2#core{wanted=St0#core.wanted},
P2 = try
- pattern(P1, St1)
+ pattern(P1, St3)
catch
throw:Thrown ->
Thrown
end,
- {Fpat,St2} = new_var(St1),
+ {Fpat,St4} = new_var(St3),
Fc = fail_clause([Fpat], c_tuple([#c_literal{val=badmatch},Fpat])),
- Lanno = lineno_anno(L, St2),
+ Lanno = lineno_anno(L, St4),
case P2 of
nomatch ->
- St = add_warning(L, nomatch, St2),
+ St = add_warning(L, nomatch, St4),
{#icase{anno=#a{anno=Lanno},
args=[E2],clauses=[],fc=Fc},Eps,St};
Other when not is_atom(Other) ->
- {#imatch{anno=#a{anno=Lanno},pat=P2,arg=E2,fc=Fc},Eps,St2}
+ {#imatch{anno=#a{anno=Lanno},pat=P2,arg=E2,fc=Fc},Eps,St4}
end;
expr({op,_,'++',{lc,Llc,E,Qs},More}, St0) ->
%% Optimise '++' here because of the list comprehension algorithm.
diff --git a/lib/compiler/test/float_SUITE.erl b/lib/compiler/test/float_SUITE.erl
index 3d2dbf47e9..07779ddd5a 100644
--- a/lib/compiler/test/float_SUITE.erl
+++ b/lib/compiler/test/float_SUITE.erl
@@ -1,19 +1,19 @@
%%
%% %CopyrightBegin%
-%%
-%% Copyright Ericsson AB 2002-2009. All Rights Reserved.
-%%
+%%
+%% Copyright Ericsson AB 2002-2010. All Rights Reserved.
+%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
-%%
+%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
-%%
+%%
%% %CopyrightEnd%
%%
-module(float_SUITE).
@@ -41,7 +41,7 @@ float_sub(A)->
float_mul(0, _, _)->
ok;
float_mul(Iter, A, B) when is_float(A), is_float(B) ->
- A*B,
+ _ = A*B,
float_mul(Iter-1, A, B).
%% Thanks to Mikael Pettersson and Tobias Lindahl (HiPE).
diff --git a/lib/compiler/test/match_SUITE.erl b/lib/compiler/test/match_SUITE.erl
index 20969c0b26..9c4687efa1 100644
--- a/lib/compiler/test/match_SUITE.erl
+++ b/lib/compiler/test/match_SUITE.erl
@@ -1,19 +1,19 @@
%%
%% %CopyrightBegin%
-%%
-%% Copyright Ericsson AB 2004-2009. All Rights Reserved.
-%%
+%%
+%% Copyright Ericsson AB 2004-2010. All Rights Reserved.
+%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
-%%
+%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
-%%
+%%
%% %CopyrightEnd%
%%
-module(match_SUITE).
@@ -21,14 +21,14 @@
-export([all/1,
pmatch/1,mixed/1,aliases/1,match_in_call/1,
untuplify/1,shortcut_boolean/1,letify_guard/1,
- selectify/1]).
+ selectify/1,underscore/1]).
-include("test_server.hrl").
all(suite) ->
test_lib:recompile(?MODULE),
[pmatch,mixed,aliases,match_in_call,untuplify,shortcut_boolean,
- letify_guard,selectify].
+ letify_guard,selectify,underscore].
pmatch(Config) when is_list(Config) ->
?line ok = doit(1),
@@ -352,4 +352,16 @@ sel_same_value2(V) when V =:= 42; V =:= 43 ->
sel_same_value2(_) ->
error.
+underscore(Config) when is_list(Config) ->
+ case Config of
+ [] ->
+ %% Assignment to _ at the end of a construct.
+ _ = length(Config);
+ [_|_] ->
+ %% Assignment to _ at the end of a construct.
+ _ = list_to_tuple(Config)
+ end,
+ _ = is_list(Config),
+ ok.
+
id(I) -> I.
diff --git a/lib/compiler/test/num_bif_SUITE.erl b/lib/compiler/test/num_bif_SUITE.erl
index c246f56611..912f7366dd 100644
--- a/lib/compiler/test/num_bif_SUITE.erl
+++ b/lib/compiler/test/num_bif_SUITE.erl
@@ -1,19 +1,19 @@
%%
%% %CopyrightBegin%
-%%
-%% Copyright Ericsson AB 2004-2009. All Rights Reserved.
-%%
+%%
+%% Copyright Ericsson AB 2004-2010. All Rights Reserved.
+%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
-%%
+%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
-%%
+%%
%% %CopyrightEnd%
%%
-module(num_bif_SUITE).
@@ -166,7 +166,7 @@ t_list_to_float_safe(Config) when is_list(Config) ->
t_list_to_float_risky(Config) when is_list(Config) ->
?line Many_Ones = lists:duplicate(25000, $1),
- ?line list_to_float("2."++Many_Ones),
+ ?line _ = list_to_float("2."++Many_Ones),
?line {'EXIT', {badarg, _}} = (catch list_to_float("2"++Many_Ones)),
ok.
@@ -186,7 +186,7 @@ t_list_to_integer(Config) when is_list(Config) ->
%% Bignums.
?line 123456932798748738738 = list_to_integer("123456932798748738738"),
- ?line list_to_integer(lists:duplicate(2000, $1)),
+ ?line _ = list_to_integer(lists:duplicate(2000, $1)),
ok.
%% Tests round/1.
diff --git a/lib/compiler/test/warnings_SUITE.erl b/lib/compiler/test/warnings_SUITE.erl
index 6e60ab88cb..5ed8836c70 100644
--- a/lib/compiler/test/warnings_SUITE.erl
+++ b/lib/compiler/test/warnings_SUITE.erl
@@ -1,19 +1,19 @@
%%
%% %CopyrightBegin%
-%%
-%% Copyright Ericsson AB 2003-2009. All Rights Reserved.
-%%
+%%
+%% Copyright Ericsson AB 2003-2010. All Rights Reserved.
+%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
-%%
+%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
-%%
+%%
%% %CopyrightEnd%
%%
-module(warnings_SUITE).
@@ -375,7 +375,12 @@ effect(Config) when is_list(Config) ->
comp_op ->
X =:= 2;
cookie ->
- erlang:get_cookie()
+ erlang:get_cookie();
+ result_ignore ->
+ _ = list_to_integer(X);
+ warn_lc_4 ->
+ %% No warning because of assignment to _.
+ [_ = abs(Z) || Z <- [1,2,3]]
end,
ok.
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-15 15:02:35 +0000