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-rw-r--r--lib/compiler/src/Makefile1
-rw-r--r--lib/compiler/src/compile.erl7
-rw-r--r--lib/compiler/src/compiler.app.src1
-rw-r--r--lib/compiler/src/sys_core_bsm.erl355
-rw-r--r--lib/compiler/src/sys_core_fold.erl297
5 files changed, 368 insertions, 293 deletions
diff --git a/lib/compiler/src/Makefile b/lib/compiler/src/Makefile
index 59b80ade5d..f06b8b9ec3 100644
--- a/lib/compiler/src/Makefile
+++ b/lib/compiler/src/Makefile
@@ -83,6 +83,7 @@ MODULES = \
core_scan \
erl_bifs \
rec_env \
+ sys_core_bsm \
sys_core_dsetel \
sys_core_fold \
sys_core_fold_lists \
diff --git a/lib/compiler/src/compile.erl b/lib/compiler/src/compile.erl
index c6e61d543e..d05b8a9530 100644
--- a/lib/compiler/src/compile.erl
+++ b/lib/compiler/src/compile.erl
@@ -718,8 +718,10 @@ core_passes() ->
| kernel_passes()].
kernel_passes() ->
- %% Destructive setelement/3 optimization and core lint.
- [{pass,sys_core_dsetel},
+ %% Optimizations that must be done after all other optimizations.
+ [{pass,sys_core_bsm},
+ {iff,dcbsm,{listing,"core_bsm"}},
+ {pass,sys_core_dsetel},
{iff,dsetel,{listing,"dsetel"}},
{iff,clint,?pass(core_lint_module)},
@@ -1919,6 +1921,7 @@ pre_load() ->
erl_lint,
erl_parse,
erl_scan,
+ sys_core_bsm,
sys_core_dsetel,
sys_core_fold,
v3_codegen,
diff --git a/lib/compiler/src/compiler.app.src b/lib/compiler/src/compiler.app.src
index 3961b2af86..d4b4d4da04 100644
--- a/lib/compiler/src/compiler.app.src
+++ b/lib/compiler/src/compiler.app.src
@@ -58,6 +58,7 @@
core_lib,
erl_bifs,
rec_env,
+ sys_core_bsm,
sys_core_dsetel,
sys_core_fold,
sys_core_fold_lists,
diff --git a/lib/compiler/src/sys_core_bsm.erl b/lib/compiler/src/sys_core_bsm.erl
new file mode 100644
index 0000000000..3e04cc33df
--- /dev/null
+++ b/lib/compiler/src/sys_core_bsm.erl
@@ -0,0 +1,355 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2017. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%% http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+%% Purpose : Optimize bit syntax matching.
+
+
+-module(sys_core_bsm).
+-export([module/2,format_error/1]).
+
+-include("core_parse.hrl").
+-import(lists, [member/2,nth/2,reverse/1,usort/1]).
+
+-spec module(cerl:c_module(), [compile:option()]) -> {'ok', cerl:c_module()}.
+
+module(#c_module{defs=Ds0}=Mod, Opts) ->
+ {Ds,Ws0} = function(Ds0, [], []),
+ case member(bin_opt_info, Opts) of
+ false ->
+ {ok,Mod#c_module{defs=Ds}};
+ true ->
+ Ws1 = [make_warning(Where, What) || {Where,What} <- Ws0],
+ Ws = usort(Ws1),
+ {ok,Mod#c_module{defs=Ds},Ws}
+ end.
+
+function([{#c_var{name={F,Arity}}=Name,B0}|Fs], FsAcc, Ws0) ->
+ try cerl_trees:mapfold(fun bsm_an/2, Ws0, B0) of
+ {B,Ws} ->
+ function(Fs, [{Name,B}|FsAcc], Ws)
+ catch
+ Class:Error ->
+ Stack = erlang:get_stacktrace(),
+ io:fwrite("Function: ~w/~w\n", [F,Arity]),
+ erlang:raise(Class, Error, Stack)
+ end;
+function([], Fs, Ws) ->
+ {reverse(Fs),Ws}.
+
+-type error() :: atom().
+-spec format_error(error()) -> nonempty_string().
+
+format_error(bin_opt_alias) ->
+ "INFO: the '=' operator will prevent delayed sub binary optimization";
+format_error(bin_partition) ->
+ "INFO: matching non-variables after a previous clause matching a variable "
+ "will prevent delayed sub binary optimization";
+format_error(bin_left_var_used_in_guard) ->
+ "INFO: a variable to the left of the binary pattern is used in a guard; "
+ "will prevent delayed sub binary optimization";
+format_error(bin_argument_order) ->
+ "INFO: matching anything else but a plain variable to the left of "
+ "binary pattern will prevent delayed sub binary optimization; "
+ "SUGGEST changing argument order";
+format_error(bin_var_used) ->
+ "INFO: using a matched out sub binary will prevent "
+ "delayed sub binary optimization";
+format_error(orig_bin_var_used_in_guard) ->
+ "INFO: using the original binary variable in a guard will prevent "
+ "delayed sub binary optimization";
+format_error(bin_var_used_in_guard) ->
+ "INFO: using a matched out sub binary in a guard will prevent "
+ "delayed sub binary optimization".
+
+
+%%%
+%%% Annotate bit syntax matching to faciliate optimization in further passes.
+%%%
+
+bsm_an(Core0, Ws0) ->
+ case bsm_an(Core0) of
+ {ok,Core} ->
+ {Core,Ws0};
+ {ok,Core,W} ->
+ {Core,[W|Ws0]}
+ end.
+
+bsm_an(#c_case{arg=#c_var{}=V}=Case) ->
+ bsm_an_1([V], Case);
+bsm_an(#c_case{arg=#c_values{es=Es}}=Case) ->
+ bsm_an_1(Es, Case);
+bsm_an(Other) ->
+ {ok,Other}.
+
+bsm_an_1(Vs, #c_case{clauses=Cs}=Case) ->
+ case bsm_leftmost(Cs) of
+ none -> {ok,Case};
+ Pos -> bsm_an_2(Vs, Cs, Case, Pos)
+ end.
+
+bsm_an_2(Vs, Cs, Case, Pos) ->
+ case bsm_nonempty(Cs, Pos) of
+ true -> bsm_an_3(Vs, Cs, Case, Pos);
+ false -> {ok,Case}
+ end.
+
+bsm_an_3(Vs, Cs, Case, Pos) ->
+ try
+ bsm_ensure_no_partition(Cs, Pos),
+ {ok,bsm_do_an(Vs, Pos, Cs, Case)}
+ catch
+ throw:{problem,Where,What} ->
+ {ok,Case,{Where,What}}
+ end.
+
+bsm_do_an(Vs0, Pos, Cs0, Case) ->
+ case nth(Pos, Vs0) of
+ #c_var{name=Vname}=V0 ->
+ Cs = bsm_do_an_var(Vname, Pos, Cs0, []),
+ V = bsm_annotate_for_reuse(V0),
+ Bef = lists:sublist(Vs0, Pos-1),
+ Aft = lists:nthtail(Pos, Vs0),
+ case Bef ++ [V|Aft] of
+ [_] ->
+ Case#c_case{arg=V,clauses=Cs};
+ Vs ->
+ Case#c_case{arg=#c_values{es=Vs},clauses=Cs}
+ end;
+ _ ->
+ Case
+ end.
+
+bsm_do_an_var(V, S, [#c_clause{pats=Ps,guard=G,body=B0}=C0|Cs], Acc) ->
+ case nth(S, Ps) of
+ #c_var{name=VarName} ->
+ case core_lib:is_var_used(V, G) of
+ true -> bsm_problem(C0, orig_bin_var_used_in_guard);
+ false -> ok
+ end,
+ case core_lib:is_var_used(VarName, G) of
+ true -> bsm_problem(C0, bin_var_used_in_guard);
+ false -> ok
+ end,
+ B1 = bsm_maybe_ctx_to_binary(VarName, B0),
+ B = bsm_maybe_ctx_to_binary(V, B1),
+ C = C0#c_clause{body=B},
+ bsm_do_an_var(V, S, Cs, [C|Acc]);
+ #c_alias{}=P ->
+ case bsm_could_match_binary(P) of
+ false ->
+ bsm_do_an_var(V, S, Cs, [C0|Acc]);
+ true ->
+ bsm_problem(C0, bin_opt_alias)
+ end;
+ P ->
+ case bsm_could_match_binary(P) andalso bsm_is_var_used(V, G, B0) of
+ false ->
+ bsm_do_an_var(V, S, Cs, [C0|Acc]);
+ true ->
+ bsm_problem(C0, bin_var_used)
+ end
+ end;
+bsm_do_an_var(_, _, [], Acc) -> reverse(Acc).
+
+bsm_annotate_for_reuse(#c_var{anno=Anno}=Var) ->
+ Var#c_var{anno=[reuse_for_context|Anno]}.
+
+bsm_is_var_used(V, G, B) ->
+ core_lib:is_var_used(V, G) orelse core_lib:is_var_used(V, B).
+
+bsm_maybe_ctx_to_binary(V, B) ->
+ case core_lib:is_var_used(V, B) andalso not previous_ctx_to_binary(V, B) of
+ false ->
+ B;
+ true ->
+ #c_seq{arg=#c_primop{name=#c_literal{val=bs_context_to_binary},
+ args=[#c_var{name=V}]},
+ body=B}
+ end.
+
+previous_ctx_to_binary(V, Core) ->
+ case Core of
+ #c_seq{arg=#c_primop{name=#c_literal{val=bs_context_to_binary},
+ args=[#c_var{name=V}]}} ->
+ true;
+ _ ->
+ false
+ end.
+
+%% bsm_leftmost(Cs) -> none | ArgumentNumber
+%% Find the leftmost argument that does binary matching. Return
+%% the number of the argument (1-N).
+
+bsm_leftmost(Cs) ->
+ bsm_leftmost_1(Cs, none).
+
+bsm_leftmost_1([#c_clause{pats=Ps}|Cs], Pos) ->
+ bsm_leftmost_2(Ps, Cs, 1, Pos);
+bsm_leftmost_1([], Pos) -> Pos.
+
+bsm_leftmost_2(_, Cs, Pos, Pos) ->
+ bsm_leftmost_1(Cs, Pos);
+bsm_leftmost_2([#c_binary{}|_], Cs, N, _) ->
+ bsm_leftmost_1(Cs, N);
+bsm_leftmost_2([_|Ps], Cs, N, Pos) ->
+ bsm_leftmost_2(Ps, Cs, N+1, Pos);
+bsm_leftmost_2([], Cs, _, Pos) ->
+ bsm_leftmost_1(Cs, Pos).
+
+%% bsm_nonempty(Cs, Pos) -> true|false
+%% Check if at least one of the clauses matches a non-empty
+%% binary in the given argument position.
+%%
+bsm_nonempty([#c_clause{pats=Ps}|Cs], Pos) ->
+ case nth(Pos, Ps) of
+ #c_binary{segments=[_|_]} ->
+ true;
+ _ ->
+ bsm_nonempty(Cs, Pos)
+ end;
+bsm_nonempty([], _ ) -> false.
+
+%% bsm_ensure_no_partition(Cs, Pos) -> ok (exception if problem)
+%% We must make sure that matching is not partitioned between
+%% variables like this:
+%% foo(<<...>>) -> ...
+%% foo(<Variable>) when ... -> ...
+%% foo(<Any non-variable pattern>) ->
+%% If there is such partition, we are not allowed to reuse the binary variable
+%% for the match context.
+%%
+%% Also, arguments to the left of the argument that is matched
+%% against a binary, are only allowed to be simple variables, not
+%% used in guards. The reason is that we must know that the binary is
+%% only matched in one place (i.e. there must be only one bs_start_match2
+%% instruction emitted).
+
+bsm_ensure_no_partition(Cs, Pos) ->
+ bsm_ensure_no_partition_1(Cs, Pos, before).
+
+%% Loop through each clause.
+bsm_ensure_no_partition_1([#c_clause{pats=Ps,guard=G}|Cs], Pos, State0) ->
+ State = bsm_ensure_no_partition_2(Ps, Pos, G, simple_vars, State0),
+ case State of
+ 'after' ->
+ bsm_ensure_no_partition_after(Cs, Pos);
+ _ ->
+ ok
+ end,
+ bsm_ensure_no_partition_1(Cs, Pos, State);
+bsm_ensure_no_partition_1([], _, _) -> ok.
+
+%% Loop through each pattern for this clause.
+bsm_ensure_no_partition_2([#c_binary{}=Where|_], 1, _, Vstate, State) ->
+ case State of
+ before when Vstate =:= simple_vars -> within;
+ before -> bsm_problem(Where, Vstate);
+ within when Vstate =:= simple_vars -> within;
+ within -> bsm_problem(Where, Vstate)
+ end;
+bsm_ensure_no_partition_2([#c_alias{}=Alias|_], 1, N, Vstate, State) ->
+ %% Retrieve the real pattern that the alias refers to and check that.
+ P = bsm_real_pattern(Alias),
+ bsm_ensure_no_partition_2([P], 1, N, Vstate, State);
+bsm_ensure_no_partition_2([_|_], 1, _, _Vstate, before=State) ->
+ %% No binary matching yet - therefore no partition.
+ State;
+bsm_ensure_no_partition_2([P|_], 1, _, Vstate, State) ->
+ case bsm_could_match_binary(P) of
+ false ->
+ %% If clauses can be freely arranged (Vstate =:= simple_vars),
+ %% a clause that cannot match a binary will not partition the clause.
+ %% Example:
+ %%
+ %% a(Var, <<>>) -> ...
+ %% a(Var, []) -> ...
+ %% a(Var, <<B>>) -> ...
+ %%
+ %% But if the clauses can't be freely rearranged, as in
+ %%
+ %% b(Var, <<X>>) -> ...
+ %% b(1, 2) -> ...
+ %%
+ %% we do have a problem.
+ %%
+ case Vstate of
+ simple_vars -> State;
+ _ -> bsm_problem(P, Vstate)
+ end;
+ true ->
+ %% The pattern P *may* match a binary, so we must update the state.
+ %% (P must be a variable.)
+ case State of
+ within -> 'after';
+ 'after' -> 'after'
+ end
+ end;
+bsm_ensure_no_partition_2([#c_var{name=V}|Ps], N, G, Vstate, S) ->
+ case core_lib:is_var_used(V, G) of
+ false ->
+ bsm_ensure_no_partition_2(Ps, N-1, G, Vstate, S);
+ true ->
+ bsm_ensure_no_partition_2(Ps, N-1, G, bin_left_var_used_in_guard, S)
+ end;
+bsm_ensure_no_partition_2([_|Ps], N, G, _, S) ->
+ bsm_ensure_no_partition_2(Ps, N-1, G, bin_argument_order, S).
+
+bsm_ensure_no_partition_after([#c_clause{pats=Ps}=C|Cs], Pos) ->
+ case nth(Pos, Ps) of
+ #c_var{} ->
+ bsm_ensure_no_partition_after(Cs, Pos);
+ _ ->
+ bsm_problem(C, bin_partition)
+ end;
+bsm_ensure_no_partition_after([], _) -> ok.
+
+bsm_could_match_binary(#c_alias{pat=P}) -> bsm_could_match_binary(P);
+bsm_could_match_binary(#c_cons{}) -> false;
+bsm_could_match_binary(#c_tuple{}) -> false;
+bsm_could_match_binary(#c_literal{val=Lit}) -> is_bitstring(Lit);
+bsm_could_match_binary(_) -> true.
+
+bsm_real_pattern(#c_alias{pat=P}) -> bsm_real_pattern(P);
+bsm_real_pattern(P) -> P.
+
+bsm_problem(Where, What) ->
+ throw({problem,Where,What}).
+
+make_warning(Core, Term) ->
+ case should_suppress_warning(Core) of
+ true ->
+ ok;
+ false ->
+ Anno = cerl:get_ann(Core),
+ Line = get_line(Anno),
+ File = get_file(Anno),
+ {File,[{Line,?MODULE,Term}]}
+ end.
+
+should_suppress_warning(Core) ->
+ Ann = cerl:get_ann(Core),
+ member(compiler_generated, Ann).
+
+get_line([Line|_]) when is_integer(Line) -> Line;
+get_line([_|T]) -> get_line(T);
+get_line([]) -> none.
+
+get_file([{file,File}|_]) -> File;
+get_file([_|T]) -> get_file(T);
+get_file([]) -> "no_file". % should not happen
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl
index 3673a339f6..cbf6e256f7 100644
--- a/lib/compiler/src/sys_core_fold.erl
+++ b/lib/compiler/src/sys_core_fold.erl
@@ -71,7 +71,7 @@
-export([module/2,format_error/1]).
-import(lists, [map/2,foldl/3,foldr/3,mapfoldl/3,all/2,any/2,
- reverse/1,reverse/2,member/2,nth/2,flatten/1,
+ reverse/1,reverse/2,member/2,flatten/1,
unzip/1,keyfind/3]).
-import(cerl, [ann_c_cons/3,ann_c_map/3,ann_c_tuple/2]).
@@ -107,7 +107,6 @@
{'ok', cerl:c_module(), [_]}.
module(#c_module{defs=Ds0}=Mod, Opts) ->
- put(bin_opt_info, member(bin_opt_info, Opts)),
put(no_inline_list_funcs, not member(inline_list_funcs, Opts)),
case get(new_var_num) of
undefined -> put(new_var_num, 0);
@@ -116,7 +115,6 @@ module(#c_module{defs=Ds0}=Mod, Opts) ->
init_warnings(),
Ds1 = [function_1(D) || D <- Ds0],
erase(no_inline_list_funcs),
- erase(bin_opt_info),
{ok,Mod#c_module{defs=Ds1},get_warnings()}.
function_1({#c_var{name={F,Arity}}=Name,B0}) ->
@@ -383,10 +381,8 @@ expr(#c_case{}=Case0, Ctxt, Sub) ->
warn_no_clause_match(Case1, Case),
Expr = eval_case(Case, Sub),
case move_case_into_arg(Case, Sub) of
- impossible ->
- bsm_an(Expr);
- Other ->
- Other
+ impossible -> Expr;
+ Other -> Other
end;
Other ->
expr(Other, Ctxt, Sub)
@@ -2943,15 +2939,8 @@ update_types(Expr, Pat, #sub{t=Tdb0}=Sub) ->
Tdb = update_types_1(Expr, Pat, Tdb0),
Sub#sub{t=Tdb}.
-update_types_1(#c_var{name=V,anno=Anno}, Pat, Types) ->
- case member(reuse_for_context, Anno) of
- true ->
- %% If a variable has been marked for reuse of binary context,
- %% optimizations based on type information are unsafe.
- kill_types(V, Types);
- false ->
- update_types_2(V, Pat, Types)
- end;
+update_types_1(#c_var{name=V}, Pat, Types) ->
+ update_types_2(V, Pat, Types);
update_types_1(_, _, Types) -> Types.
update_types_2(V, [#c_tuple{}=P], Types) ->
@@ -2994,253 +2983,6 @@ copy_type(_, _, Tdb) -> Tdb.
void() -> #c_literal{val=ok}.
-%%%
-%%% Annotate bit syntax matching to faciliate optimization in further passes.
-%%%
-
-bsm_an(#c_case{arg=#c_var{}=V}=Case) ->
- bsm_an_1([V], Case);
-bsm_an(#c_case{arg=#c_values{es=Es}}=Case) ->
- bsm_an_1(Es, Case);
-bsm_an(Other) -> Other.
-
-bsm_an_1(Vs, #c_case{clauses=Cs}=Case) ->
- case bsm_leftmost(Cs) of
- none -> Case;
- Pos -> bsm_an_2(Vs, Cs, Case, Pos)
- end.
-
-bsm_an_2(Vs, Cs, Case, Pos) ->
- case bsm_nonempty(Cs, Pos) of
- true -> bsm_an_3(Vs, Cs, Case, Pos);
- false -> Case
- end.
-
-bsm_an_3(Vs, Cs, Case, Pos) ->
- try
- bsm_ensure_no_partition(Cs, Pos),
- bsm_do_an(Vs, Pos, Cs, Case)
- catch
- throw:{problem,Where,What} ->
- add_bin_opt_info(Where, What),
- Case
- end.
-
-bsm_do_an(Vs0, Pos, Cs0, Case) ->
- case nth(Pos, Vs0) of
- #c_var{name=Vname}=V0 ->
- Cs = bsm_do_an_var(Vname, Pos, Cs0, []),
- V = bsm_annotate_for_reuse(V0),
- Bef = lists:sublist(Vs0, Pos-1),
- Aft = lists:nthtail(Pos, Vs0),
- case Bef ++ [V|Aft] of
- [_] ->
- Case#c_case{arg=V,clauses=Cs};
- Vs ->
- Case#c_case{arg=#c_values{es=Vs},clauses=Cs}
- end;
- _ ->
- Case
- end.
-
-bsm_do_an_var(V, S, [#c_clause{pats=Ps,guard=G,body=B0}=C0|Cs], Acc) ->
- case nth(S, Ps) of
- #c_var{name=VarName} ->
- case core_lib:is_var_used(V, G) of
- true -> bsm_problem(C0, orig_bin_var_used_in_guard);
- false -> ok
- end,
- case core_lib:is_var_used(VarName, G) of
- true -> bsm_problem(C0, bin_var_used_in_guard);
- false -> ok
- end,
- B1 = bsm_maybe_ctx_to_binary(VarName, B0),
- B = bsm_maybe_ctx_to_binary(V, B1),
- C = C0#c_clause{body=B},
- bsm_do_an_var(V, S, Cs, [C|Acc]);
- #c_alias{}=P ->
- case bsm_could_match_binary(P) of
- false ->
- bsm_do_an_var(V, S, Cs, [C0|Acc]);
- true ->
- bsm_problem(C0, bin_opt_alias)
- end;
- P ->
- case bsm_could_match_binary(P) andalso bsm_is_var_used(V, G, B0) of
- false ->
- bsm_do_an_var(V, S, Cs, [C0|Acc]);
- true ->
- bsm_problem(C0, bin_var_used)
- end
- end;
-bsm_do_an_var(_, _, [], Acc) -> reverse(Acc).
-
-bsm_annotate_for_reuse(#c_var{anno=Anno}=Var) ->
- case member(reuse_for_context, Anno) of
- false -> Var#c_var{anno=[reuse_for_context|Anno]};
- true -> Var
- end.
-
-bsm_is_var_used(V, G, B) ->
- core_lib:is_var_used(V, G) orelse core_lib:is_var_used(V, B).
-
-bsm_maybe_ctx_to_binary(V, B) ->
- case core_lib:is_var_used(V, B) andalso not previous_ctx_to_binary(V, B) of
- false ->
- B;
- true ->
- #c_seq{arg=#c_primop{name=#c_literal{val=bs_context_to_binary},
- args=[#c_var{name=V}]},
- body=B}
- end.
-
-previous_ctx_to_binary(V, Core) ->
- case Core of
- #c_seq{arg=#c_primop{name=#c_literal{val=bs_context_to_binary},
- args=[#c_var{name=V}]}} ->
- true;
- _ ->
- false
- end.
-
-%% bsm_leftmost(Cs) -> none | ArgumentNumber
-%% Find the leftmost argument that does binary matching. Return
-%% the number of the argument (1-N).
-
-bsm_leftmost(Cs) ->
- bsm_leftmost_1(Cs, none).
-
-bsm_leftmost_1([#c_clause{pats=Ps}|Cs], Pos) ->
- bsm_leftmost_2(Ps, Cs, 1, Pos);
-bsm_leftmost_1([], Pos) -> Pos.
-
-bsm_leftmost_2(_, Cs, Pos, Pos) ->
- bsm_leftmost_1(Cs, Pos);
-bsm_leftmost_2([#c_binary{}|_], Cs, N, _) ->
- bsm_leftmost_1(Cs, N);
-bsm_leftmost_2([_|Ps], Cs, N, Pos) ->
- bsm_leftmost_2(Ps, Cs, N+1, Pos);
-bsm_leftmost_2([], Cs, _, Pos) ->
- bsm_leftmost_1(Cs, Pos).
-
-%% bsm_nonempty(Cs, Pos) -> true|false
-%% Check if at least one of the clauses matches a non-empty
-%% binary in the given argument position.
-%%
-bsm_nonempty([#c_clause{pats=Ps}|Cs], Pos) ->
- case nth(Pos, Ps) of
- #c_binary{segments=[_|_]} ->
- true;
- _ ->
- bsm_nonempty(Cs, Pos)
- end;
-bsm_nonempty([], _ ) -> false.
-
-%% bsm_ensure_no_partition(Cs, Pos) -> ok (exception if problem)
-%% We must make sure that matching is not partitioned between
-%% variables like this:
-%% foo(<<...>>) -> ...
-%% foo(<Variable>) when ... -> ...
-%% foo(<Any non-variable pattern>) ->
-%% If there is such partition, we are not allowed to reuse the binary variable
-%% for the match context.
-%%
-%% Also, arguments to the left of the argument that is matched
-%% against a binary, are only allowed to be simple variables, not
-%% used in guards. The reason is that we must know that the binary is
-%% only matched in one place (i.e. there must be only one bs_start_match2
-%% instruction emitted).
-
-bsm_ensure_no_partition(Cs, Pos) ->
- bsm_ensure_no_partition_1(Cs, Pos, before).
-
-%% Loop through each clause.
-bsm_ensure_no_partition_1([#c_clause{pats=Ps,guard=G}|Cs], Pos, State0) ->
- State = bsm_ensure_no_partition_2(Ps, Pos, G, simple_vars, State0),
- case State of
- 'after' ->
- bsm_ensure_no_partition_after(Cs, Pos);
- _ ->
- ok
- end,
- bsm_ensure_no_partition_1(Cs, Pos, State);
-bsm_ensure_no_partition_1([], _, _) -> ok.
-
-%% Loop through each pattern for this clause.
-bsm_ensure_no_partition_2([#c_binary{}=Where|_], 1, _, Vstate, State) ->
- case State of
- before when Vstate =:= simple_vars -> within;
- before -> bsm_problem(Where, Vstate);
- within when Vstate =:= simple_vars -> within;
- within -> bsm_problem(Where, Vstate)
- end;
-bsm_ensure_no_partition_2([#c_alias{}=Alias|_], 1, N, Vstate, State) ->
- %% Retrieve the real pattern that the alias refers to and check that.
- P = bsm_real_pattern(Alias),
- bsm_ensure_no_partition_2([P], 1, N, Vstate, State);
-bsm_ensure_no_partition_2([_|_], 1, _, _Vstate, before=State) ->
- %% No binary matching yet - therefore no partition.
- State;
-bsm_ensure_no_partition_2([P|_], 1, _, Vstate, State) ->
- case bsm_could_match_binary(P) of
- false ->
- %% If clauses can be freely arranged (Vstate =:= simple_vars),
- %% a clause that cannot match a binary will not partition the clause.
- %% Example:
- %%
- %% a(Var, <<>>) -> ...
- %% a(Var, []) -> ...
- %% a(Var, <<B>>) -> ...
- %%
- %% But if the clauses can't be freely rearranged, as in
- %%
- %% b(Var, <<X>>) -> ...
- %% b(1, 2) -> ...
- %%
- %% we do have a problem.
- %%
- case Vstate of
- simple_vars -> State;
- _ -> bsm_problem(P, Vstate)
- end;
- true ->
- %% The pattern P *may* match a binary, so we must update the state.
- %% (P must be a variable.)
- case State of
- within -> 'after';
- 'after' -> 'after'
- end
- end;
-bsm_ensure_no_partition_2([#c_var{name=V}|Ps], N, G, Vstate, S) ->
- case core_lib:is_var_used(V, G) of
- false ->
- bsm_ensure_no_partition_2(Ps, N-1, G, Vstate, S);
- true ->
- bsm_ensure_no_partition_2(Ps, N-1, G, bin_left_var_used_in_guard, S)
- end;
-bsm_ensure_no_partition_2([_|Ps], N, G, _, S) ->
- bsm_ensure_no_partition_2(Ps, N-1, G, bin_argument_order, S).
-
-bsm_ensure_no_partition_after([#c_clause{pats=Ps}=C|Cs], Pos) ->
- case nth(Pos, Ps) of
- #c_var{} ->
- bsm_ensure_no_partition_after(Cs, Pos);
- _ ->
- bsm_problem(C, bin_partition)
- end;
-bsm_ensure_no_partition_after([], _) -> ok.
-
-bsm_could_match_binary(#c_alias{pat=P}) -> bsm_could_match_binary(P);
-bsm_could_match_binary(#c_cons{}) -> false;
-bsm_could_match_binary(#c_tuple{}) -> false;
-bsm_could_match_binary(#c_literal{val=Lit}) -> is_bitstring(Lit);
-bsm_could_match_binary(_) -> true.
-
-bsm_real_pattern(#c_alias{pat=P}) -> bsm_real_pattern(P);
-bsm_real_pattern(P) -> P.
-
-bsm_problem(Where, What) ->
- throw({problem,Where,What}).
%%%
%%% Handling of warnings.
@@ -3249,12 +2991,6 @@ bsm_problem(Where, What) ->
init_warnings() ->
put({?MODULE,warnings}, []).
-add_bin_opt_info(Core, Term) ->
- case get(bin_opt_info) of
- true -> add_warning(Core, Term);
- false -> ok
- end.
-
add_warning(Core, Term) ->
case should_suppress_warning(Core) of
true ->
@@ -3376,28 +3112,7 @@ format_error(result_ignored) ->
format_error(invalid_call) ->
"invalid function call";
format_error(useless_building) ->
- "a term is constructed, but never used";
-format_error(bin_opt_alias) ->
- "INFO: the '=' operator will prevent delayed sub binary optimization";
-format_error(bin_partition) ->
- "INFO: matching non-variables after a previous clause matching a variable "
- "will prevent delayed sub binary optimization";
-format_error(bin_left_var_used_in_guard) ->
- "INFO: a variable to the left of the binary pattern is used in a guard; "
- "will prevent delayed sub binary optimization";
-format_error(bin_argument_order) ->
- "INFO: matching anything else but a plain variable to the left of "
- "binary pattern will prevent delayed sub binary optimization; "
- "SUGGEST changing argument order";
-format_error(bin_var_used) ->
- "INFO: using a matched out sub binary will prevent "
- "delayed sub binary optimization";
-format_error(orig_bin_var_used_in_guard) ->
- "INFO: using the original binary variable in a guard will prevent "
- "delayed sub binary optimization";
-format_error(bin_var_used_in_guard) ->
- "INFO: using a matched out sub binary in a guard will prevent "
- "delayed sub binary optimization".
+ "a term is constructed, but never used".
-ifdef(DEBUG).
%% In order for simplify_let/2 to work correctly, the list of