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authorBjörn Gustavsson <[email protected]>2010-03-18 08:45:03 +0100
committerBjörn Gustavsson <[email protected]>2010-03-26 08:09:26 +0100
commit0320836d1b58438ef4467832b00306672d22f8d6 (patch)
tree6953fb68c2c04e162ecb7e5cd9a568a43ceacddf
parente74235df989995f5bd2b66b7102857446ff10d11 (diff)
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Consistently rewrite an inlined function_clause exception to case_clause
A function_clause exception is generated by jumping to a func_info/3 instruction at the beginning of the function. The x registers are assumed to contain the arguments for the function. That means that a func_info/3 instruction copied from another function (or even from the same function if not at the top level) will not work, so it must be replaced with an instruction that generates a case_clause exception. In Core Erlang, a func_info/3 instruction is represented as a the primop match_fail({function_clause,Arg1,...ArgN}). The current mechanism that is supposed to replace the primop match_fail(function_clause) with match_fail(case_clause) will fail to do that in the following circumstances: 1. If the inliner has inlined a function into itself. Fix that by having the inliner clear the function_name annotations on all match_fail primops in functions that are inlined. (To simplify doing that, the annotation is now on the primop node itself and not on the 'function_clause' atom inside it.) 2. If the inliner has rewritten the tuple node in the primop node to a literal (when inlining a function call with literal arguments), v3_kernel would not recognize the match_fail(function_clause) primop and would not rewrite it. Fix it by making v3_kernel smarter. Also simplify the "old" inliner (sys_core_inline) to only clear the function_name annotations instead of rewriting function_clause execptions to case_clause execptions itself.
-rw-r--r--lib/compiler/src/cerl_inline.erl32
-rw-r--r--lib/compiler/src/sys_core_inline.erl12
-rw-r--r--lib/compiler/src/v3_core.erl22
-rw-r--r--lib/compiler/src/v3_kernel.erl66
4 files changed, 88 insertions, 44 deletions
diff --git a/lib/compiler/src/cerl_inline.erl b/lib/compiler/src/cerl_inline.erl
index 191efa3032..f4eaa17e72 100644
--- a/lib/compiler/src/cerl_inline.erl
+++ b/lib/compiler/src/cerl_inline.erl
@@ -1429,17 +1429,26 @@ inline(E, #app{opnds = Opnds, ctxt = Ctxt, loc = L}, Ren, Env, S) ->
{E, S};
true ->
%% Create local bindings for the parameters to their
- %% respective operand structures from the app-structure, and
- %% visit the body in the context saved in the structure.
+ %% respective operand structures from the app-structure.
{Rs, Ren1, Env1, S1} = bind_locals(Vs, Opnds, Ren, Env, S),
- {E1, S2} = i(fun_body(E), Ctxt, Ren1, Env1, S1),
+
+ %% function_clause exceptions that have been inlined
+ %% into another function (or even into the same function)
+ %% will not work properly. The v3_kernel pass will
+ %% take care of it, but we will need to help it by
+ %% removing any function_name annotations on match_fail
+ %% primops that we inline.
+ E1 = kill_function_name_anns(fun_body(E)),
+
+ %% Visit the body in the context saved in the structure.
+ {E2, S2} = i(E1, Ctxt, Ren1, Env1, S1),
%% Create necessary bindings and/or set flags.
- {E2, S3} = make_let_bindings(Rs, E1, S2),
+ {E3, S3} = make_let_bindings(Rs, E2, S2),
%% Lastly, flag the application as inlined, since the inlining
%% attempt was not aborted before we reached this point.
- {E2, st__set_app_inlined(L, S3)}
+ {E3, st__set_app_inlined(L, S3)}
end.
%% For the (possibly renamed) argument variables to an inlined call,
@@ -2370,6 +2379,19 @@ kill_id_anns([A | As]) ->
kill_id_anns([]) ->
[].
+kill_function_name_anns(Body) ->
+ F = fun(P) ->
+ case type(P) of
+ primop ->
+ Ann = get_ann(P),
+ Ann1 = lists:keydelete(function_name, 1, Ann),
+ set_ann(P, Ann1);
+ _ ->
+ P
+ end
+ end,
+ cerl_trees:map(F, Body).
+
%% =====================================================================
%% General utilities
diff --git a/lib/compiler/src/sys_core_inline.erl b/lib/compiler/src/sys_core_inline.erl
index 06696e5950..c644b9e015 100644
--- a/lib/compiler/src/sys_core_inline.erl
+++ b/lib/compiler/src/sys_core_inline.erl
@@ -41,11 +41,9 @@
-module(sys_core_inline).
-%%-compile({inline,{match_fail_fun,0}}).
-
-export([module/2]).
--import(lists, [member/2,map/2,foldl/3,mapfoldl/3]).
+-import(lists, [member/2,map/2,foldl/3,mapfoldl/3,keydelete/3]).
-include("core_parse.hrl").
@@ -178,11 +176,9 @@ weight_func(_Core, Acc) -> Acc + 1.
%% function_clause match_fail (if they have one).
match_fail_fun() ->
- fun (#c_primop{name=#c_literal{val=match_fail},
- args=[#c_tuple{es=[#c_literal{val=function_clause}|As]}]}=P) ->
- Fail = #c_tuple{es=[#c_literal{val=case_clause},
- #c_tuple{es=As}]},
- P#c_primop{args=[Fail]};
+ fun (#c_primop{anno=Anno0,name=#c_literal{val=match_fail}}=P) ->
+ Anno = keydelete(function_name, 1, Anno0),
+ P#c_primop{anno=Anno};
(Other) -> Other
end.
diff --git a/lib/compiler/src/v3_core.erl b/lib/compiler/src/v3_core.erl
index 8b04969b05..4ac2196d79 100644
--- a/lib/compiler/src/v3_core.erl
+++ b/lib/compiler/src/v3_core.erl
@@ -1542,17 +1542,21 @@ new_vars_1(N, Anno, St0, Vs) when N > 0 ->
new_vars_1(0, _, St, Vs) -> {Vs,St}.
function_clause(Ps, Name) ->
- fail_clause(Ps, c_tuple([#c_literal{anno=[{name,Name}],
- val=function_clause}|Ps])).
-function_clause(Ps, Anno, Name) ->
- fail_clause(Ps, ann_c_tuple(Anno,
- [#c_literal{anno=[{name,Name}],
- val=function_clause}|Ps])).
-
-fail_clause(Pats, A) ->
+ function_clause(Ps, [], Name).
+
+function_clause(Ps, LineAnno, Name) ->
+ FcAnno = [{function_name,Name}],
+ fail_clause(Ps, FcAnno,
+ ann_c_tuple(LineAnno, [#c_literal{val=function_clause}|Ps])).
+
+fail_clause(Pats, Arg) ->
+ fail_clause(Pats, [], Arg).
+
+fail_clause(Pats, Anno, Arg) ->
#iclause{anno=#a{anno=[compiler_generated]},
pats=Pats,guard=[],
- body=[#iprimop{anno=#a{},name=#c_literal{val=match_fail},args=[A]}]}.
+ body=[#iprimop{anno=#a{anno=Anno},name=#c_literal{val=match_fail},
+ args=[Arg]}]}.
ubody(B, St) -> uexpr(B, [], St).
diff --git a/lib/compiler/src/v3_kernel.erl b/lib/compiler/src/v3_kernel.erl
index f1215e8a35..974c64a8bc 100644
--- a/lib/compiler/src/v3_kernel.erl
+++ b/lib/compiler/src/v3_kernel.erl
@@ -80,7 +80,8 @@
-export([module/2,format_error/1]).
--import(lists, [map/2,foldl/3,foldr/3,mapfoldl/3,splitwith/2,member/2,keymember/3]).
+-import(lists, [map/2,foldl/3,foldr/3,mapfoldl/3,splitwith/2,member/2,
+ keymember/3,keyfind/3]).
-import(ordsets, [add_element/2,del_element/2,union/2,union/1,subtract/2]).
-compile({nowarn_deprecated_function, {erlang,hash,2}}).
@@ -408,7 +409,7 @@ expr(#c_call{anno=A,module=M0,name=F0,args=Cargs}, Sub, St0) ->
{Call,Ap,St}
end;
expr(#c_primop{anno=A,name=#c_literal{val=match_fail},args=Cargs0}, Sub, St0) ->
- Cargs = translate_match_fail(Cargs0, Sub, St0),
+ Cargs = translate_match_fail(Cargs0, Sub, A, St0),
%% This special case will disappear.
{Kargs,Ap,St} = atomic_list(Cargs, Sub, St0),
Ar = length(Cargs),
@@ -435,32 +436,53 @@ expr(#c_catch{anno=A,body=Cb}, Sub, St0) ->
%% Handle internal expressions.
expr(#ireceive_accept{anno=A}, _Sub, St) -> {#k_receive_accept{anno=A},[],St}.
-%% Translate a function_clause to case_clause if it has been moved into
-%% another function.
-translate_match_fail([#c_tuple{es=[#c_literal{anno=A0,
- val=function_clause}|As]}]=Args,
- Sub,
- #kern{ff=FF}) ->
- A = case A0 of
- [{name,{Func0,Arity0}}] ->
- [{name,{get_fsub(Func0, Arity0, Sub),Arity0}}];
- _ ->
- A0
- end,
- case {A,FF} of
- {[{name,Same}],Same} ->
+%% Translate a function_clause exception to a case_clause exception if
+%% it has been moved into another function. (A function_clause exception
+%% will not work correctly if it is moved into another function, or
+%% even if it is invoked not from the top level in the correct function.)
+translate_match_fail(Args, Sub, Anno, St) ->
+ case Args of
+ [#c_tuple{es=[#c_literal{val=function_clause}|As]}] ->
+ translate_match_fail_1(Anno, Args, As, Sub, St);
+ [#c_literal{val=Tuple}] when is_tuple(Tuple) ->
+ %% The inliner may have created a literal out of
+ %% the original #c_tuple{}.
+ case tuple_to_list(Tuple) of
+ [function_clause|As0] ->
+ As = [#c_literal{val=E} || E <- As0],
+ translate_match_fail_1(Anno, Args, As, Sub, St);
+ _ ->
+ Args
+ end;
+ _ ->
+ %% Not a function_clause exception.
+ Args
+ end.
+
+translate_match_fail_1(Anno, Args, As, Sub, #kern{ff=FF}) ->
+ AnnoFunc = case keyfind(function_name, 1, Anno) of
+ false ->
+ none; %Force rewrite.
+ {function_name,{Name,Arity}} ->
+ {get_fsub(Name, Arity, Sub),Arity}
+ end,
+ case {AnnoFunc,FF} of
+ {Same,Same} ->
%% Still in the correct function.
Args;
- {[{name,{F,_}}],F} ->
+ {{F,_},F} ->
%% Still in the correct function.
Args;
_ ->
- %% Inlining has probably moved the function_clause into another
- %% function (where it will not work correctly).
- %% Rewrite to a case_clause.
+ %% Wrong function or no function_name annotation.
+ %%
+ %% The inliner has copied the match_fail(function_clause)
+ %% primop from another function (or from another instance of
+ %% the current function). match_fail(function_clause) will
+ %% only work at the top level of the function it was originally
+ %% defined in, so we will need to rewrite it to a case_clause.
[#c_tuple{es=[#c_literal{val=case_clause},#c_tuple{es=As}]}]
- end;
-translate_match_fail(Args, _, _) -> Args.
+ end.
%% call_type(Module, Function, Arity) -> call | bif | apply | error.
%% Classify the call.