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authorBjörn Gustavsson <[email protected]>2015-11-10 08:58:09 +0100
committerBjörn Gustavsson <[email protected]>2015-11-10 13:04:56 +0100
commite28fdaaad1c367bd073116fa0468ae22303189c2 (patch)
tree2560a14dc3d56e2c74164e53013ee9805af5ccde /lib/compiler/src
parent765df80e59c6d5397483518f6770c0fd3f9f9412 (diff)
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sys_pre_expand: Remove vestiges of variable usage tracking
Before the Core Erlang passes were introduced a long time ago, sys_pre_expand used to track used and new variables in order to do lambda lifting (i.e. transform funs into ordinary Erlang functions). Lambda lifting is now done in v3_kernel. Remove the few remaining vestiges of variable tracking in the comments and the code.
Diffstat (limited to 'lib/compiler/src')
-rw-r--r--lib/compiler/src/sys_pre_expand.erl55
1 files changed, 11 insertions, 44 deletions
diff --git a/lib/compiler/src/sys_pre_expand.erl b/lib/compiler/src/sys_pre_expand.erl
index aa1b04b631..e0c35d63e4 100644
--- a/lib/compiler/src/sys_pre_expand.erl
+++ b/lib/compiler/src/sys_pre_expand.erl
@@ -230,8 +230,6 @@ head(As, St) -> pattern_list(As, St).
%% {TransformedPattern,State'}
%%
-pattern({var,_,'_'}=Var, St) -> %Ignore anonymous variable.
- {Var,St};
pattern({var,_,_}=Var, St) ->
{Var,St};
pattern({char,_,_}=Char, St) ->
@@ -384,19 +382,19 @@ expr({block,Line,Es0}, St0) ->
{Es,St1} = exprs(Es0, St0),
{{block,Line,Es},St1};
expr({'if',Line,Cs0}, St0) ->
- {Cs,St1} = icr_clauses(Cs0, St0),
+ {Cs,St1} = clauses(Cs0, St0),
{{'if',Line,Cs},St1};
expr({'case',Line,E0,Cs0}, St0) ->
{E,St1} = expr(E0, St0),
- {Cs,St2} = icr_clauses(Cs0, St1),
+ {Cs,St2} = clauses(Cs0, St1),
{{'case',Line,E,Cs},St2};
expr({'receive',Line,Cs0}, St0) ->
- {Cs,St1} = icr_clauses(Cs0, St0),
+ {Cs,St1} = clauses(Cs0, St0),
{{'receive',Line,Cs},St1};
expr({'receive',Line,Cs0,To0,ToEs0}, St0) ->
{To,St1} = expr(To0, St0),
{ToEs,St2} = exprs(ToEs0, St1),
- {Cs,St3} = icr_clauses(Cs0, St2),
+ {Cs,St3} = clauses(Cs0, St2),
{{'receive',Line,Cs,To,ToEs},St3};
expr({'fun',Line,Body}, St) ->
fun_tq(Line, Body, St);
@@ -429,12 +427,11 @@ expr({call,Line,F,As0}, St0) ->
{{call,Line,Fun1,As1},St1};
expr({'try',Line,Es0,Scs0,Ccs0,As0}, St0) ->
{Es1,St1} = exprs(Es0, St0),
- {Scs1,St2} = icr_clauses(Scs0, St1),
- {Ccs1,St3} = icr_clauses(Ccs0, St2),
+ {Scs1,St2} = clauses(Scs0, St1),
+ {Ccs1,St3} = clauses(Ccs0, St2),
{As1,St4} = exprs(As0, St3),
{{'try',Line,Es1,Scs1,Ccs1,As1},St4};
expr({'catch',Line,E0}, St0) ->
- %% Catch exports no new variables.
{E,St1} = expr(E0, St0),
{{'catch',Line,E},St1};
expr({match,Line,P0,E0}, St0) ->
@@ -455,21 +452,6 @@ expr_list([E0|Es0], St0) ->
{[E|Es],St2};
expr_list([], St) -> {[],St}.
-%% icr_clauses([Clause], State) -> {[TransformedClause],State'}
-%% Be very careful here to return the variables that are really used
-%% and really new.
-
-icr_clauses([], St) -> {[],St};
-icr_clauses(Clauses, St) -> icr_clauses2(Clauses, St).
-
-icr_clauses2([{clause,Line,H0,G0,B0}|Cs0], St0) ->
- {H,St1} = head(H0, St0),
- {G,St2} = guard(G0, St1),
- {B,St3} = exprs(B0, St2),
- {Cs,St4} = icr_clauses2(Cs0, St3),
- {[{clause,Line,H,G,B}|Cs],St4};
-icr_clauses2([], St) -> {[],St}.
-
%% lc_tq(Line, Qualifiers, State) ->
%% {[TransQual],State'}
@@ -485,16 +467,9 @@ lc_tq(Line, [{b_generate,Lg,P0,G0}|Qs0], St0) ->
{Qs1,St3} = lc_tq(Line, Qs0, St2),
{[{b_generate,Lg,P1,G1}|Qs1],St3};
lc_tq(Line, [F0 | Qs0], St0) ->
- case erl_lint:is_guard_test(F0) of
- true ->
- {F1,St1} = guard_test(F0, St0),
- {Qs1,St2} = lc_tq(Line, Qs0, St1),
- {[F1|Qs1],St2};
- false ->
- {F1,St1} = expr(F0, St0),
- {Qs1,St2} = lc_tq(Line, Qs0, St1),
- {[F1 | Qs1],St2}
- end;
+ {F1,St1} = expr(F0, St0),
+ {Qs1,St2} = lc_tq(Line, Qs0, St1),
+ {[F1|Qs1],St2};
lc_tq(_Line, [], St0) ->
{[],St0}.
@@ -526,7 +501,7 @@ fun_tq(L, {function,M,F,A}, St) when is_atom(M), is_atom(F), is_integer(A) ->
fun_tq(Lf, {function,_,_,_}=ExtFun, St) ->
{{'fun',Lf,ExtFun},St};
fun_tq(Lf, {clauses,Cs0}, St0) ->
- {Cs1,St1} = fun_clauses(Cs0, St0),
+ {Cs1,St1} = clauses(Cs0, St0),
{Fname,St2} = new_fun_name(St1),
%% Set dummy values for Index and Uniq -- the real values will
%% be assigned by beam_asm.
@@ -534,18 +509,10 @@ fun_tq(Lf, {clauses,Cs0}, St0) ->
{{'fun',Lf,{clauses,Cs1},{Index,Uniq,Fname}},St2}.
fun_tq(Line, Cs0, St0, Name) ->
- {Cs1,St1} = fun_clauses(Cs0, St0),
+ {Cs1,St1} = clauses(Cs0, St0),
{Fname,St2} = new_fun_name(St1, Name),
{{named_fun,Line,Name,Cs1,{0,0,Fname}},St2}.
-fun_clauses([{clause,L,H0,G0,B0}|Cs0], St0) ->
- {H,St1} = head(H0, St0),
- {G,St2} = guard(G0, St1),
- {B,St3} = exprs(B0, St2),
- {Cs,St4} = fun_clauses(Cs0, St3),
- {[{clause,L,H,G,B}|Cs],St4};
-fun_clauses([], St) -> {[],St}.
-
%% new_fun_name(State) -> {FunName,State}.
new_fun_name(St) ->