From 3ed131a2708c4b44e5dba77ba923a3f3ae28f011 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Fri, 16 Jan 2015 12:49:31 +0100
Subject: Modernize lc_SUITE

Remove ?line macros. Run test cases in parallel.
---
 lib/compiler/test/lc_SUITE.erl | 59 +++++++++++++++++++++++-------------------
 1 file changed, 32 insertions(+), 27 deletions(-)

diff --git a/lib/compiler/test/lc_SUITE.erl b/lib/compiler/test/lc_SUITE.erl
index 398398a397..b40431c246 100644
--- a/lib/compiler/test/lc_SUITE.erl
+++ b/lib/compiler/test/lc_SUITE.erl
@@ -18,7 +18,6 @@
 %%
 -module(lc_SUITE).
 
--author('bjorn@erix.ericsson.se').
 -export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1, 
 	 init_per_group/2,end_per_group/2,
 	 init_per_testcase/2,end_per_testcase/2,
@@ -31,10 +30,16 @@ suite() -> [{ct_hooks,[ts_install_cth]}].
 
 all() -> 
     test_lib:recompile(?MODULE),
-    [basic, deeply_nested, no_generator, empty_generator, no_export].
+    [{group,p}].
 
 groups() -> 
-    [].
+    [{p,test_lib:parallel(),
+      [basic,
+       deeply_nested,
+       no_generator,
+       empty_generator,
+       no_export
+      ]}].
 
 init_per_suite(Config) ->
     Config.
@@ -59,34 +64,34 @@ end_per_testcase(Case, Config) when is_atom(Case), is_list(Config) ->
     ok.
 
 basic(Config) when is_list(Config) ->
-    ?line L0 = lists:seq(1, 10),
-    ?line L1 = my_map(fun(X) -> {x,X} end, L0),
-    ?line L1 = [{x,X} || X <- L0],
-    ?line L0 = my_map(fun({x,X}) -> X end, L1),
-    ?line [1,2,3,4,5] = [X || X <- L0, X < 6],
-    ?line [4,5,6] = [X || X <- L0, X > 3, X < 7],
-    ?line [] = [X || X <- L0, X > 32, X < 7],
-    ?line [1,3,5,7,9] = [X || X <- L0, odd(X)],
-    ?line [2,4,6,8,10] = [X || X <- L0, not odd(X)],
-    ?line [1,3,5,9] = [X || X <- L0, odd(X), X =/= 7],
-    ?line [2,4,8,10] = [X || X <- L0, not odd(X), X =/= 6],
+    L0 = lists:seq(1, 10),
+    L1 = my_map(fun(X) -> {x,X} end, L0),
+    L1 = [{x,X} || X <- L0],
+    L0 = my_map(fun({x,X}) -> X end, L1),
+    [1,2,3,4,5] = [X || X <- L0, X < 6],
+    [4,5,6] = [X || X <- L0, X > 3, X < 7],
+    [] = [X || X <- L0, X > 32, X < 7],
+    [1,3,5,7,9] = [X || X <- L0, odd(X)],
+    [2,4,6,8,10] = [X || X <- L0, not odd(X)],
+    [1,3,5,9] = [X || X <- L0, odd(X), X =/= 7],
+    [2,4,8,10] = [X || X <- L0, not odd(X), X =/= 6],
 
     %% Append is specially handled.
-    ?line [1,3,5,9,2,4,8,10] = [X || X <- L0, odd(X), X =/= 7] ++
+    [1,3,5,9,2,4,8,10] = [X || X <- L0, odd(X), X =/= 7] ++
 	[X || X <- L0, not odd(X), X =/= 6],
 
     %% Guards BIFs are evaluated in guard context. Weird, but true.
-    ?line [{a,b,true},{x,y,true,true}] = [X || X <- tuple_list(), element(3, X)],
+    [{a,b,true},{x,y,true,true}] = [X || X <- tuple_list(), element(3, X)],
 
     %% Filter expressions with andalso/orelse.
-    ?line "abc123" = alphanum("?abc123.;"),
+    "abc123" = alphanum("?abc123.;"),
 
     %% Error cases.
-    ?line [] = [{xx,X} || X <- L0, element(2, X) == no_no_no],
-    ?line {'EXIT',_} = (catch [X || X <- L1, list_to_atom(X) == dum]),
-    ?line [] = [X || X <- L1, X+1 < 2],
-    ?line {'EXIT',_} = (catch [X || X <- L1, odd(X)]),
-    ?line fc([x], catch [E || E <- id(x)]),
+    [] = [{xx,X} || X <- L0, element(2, X) == no_no_no],
+    {'EXIT',_} = (catch [X || X <- L1, list_to_atom(X) == dum]),
+    [] = [X || X <- L1, X+1 < 2],
+    {'EXIT',_} = (catch [X || X <- L1, odd(X)]),
+    fc([x], catch [E || E <- id(x)]),
     ok.
 
 tuple_list() ->
@@ -116,12 +121,12 @@ deeply_nested_1() ->
 	X16 <- [4],X17 <- [3],X18 <- [fun() -> X16+X17 end],X19 <- [2],X20 <- [1]].
 
 no_generator(Config) when is_list(Config) ->
-    ?line Seq = lists:seq(-10, 17),
-    ?line [no_gen_verify(no_gen(A, B), A, B) || A <- Seq, B <- Seq],
+    Seq = lists:seq(-10, 17),
+    [no_gen_verify(no_gen(A, B), A, B) || A <- Seq, B <- Seq],
 
     %% Literal expression, for coverage.
-    ?line [a] = [a || true],
-    ?line [a,b,c] = [a || true] ++ [b,c],
+    [a] = [a || true],
+    [a,b,c] = [a || true] ++ [b,c],
     ok.
 
 no_gen(A, B) ->    
@@ -174,7 +179,7 @@ no_gen_eval(Fun, Res) ->
 no_gen_one_more(A, B) -> A + 1 =:= B.
 
 empty_generator(Config) when is_list(Config) ->
-    ?line [] = [X || {X} <- [], (false or (X/0 > 3))],
+    [] = [X || {X} <- [], (false or (X/0 > 3))],
     ok.
 
 no_export(Config) when is_list(Config) ->
-- 
cgit v1.2.3


From eaa0596c7c6e33f21783aef5b44fb52db23fc9fe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Fri, 16 Jan 2015 12:59:30 +0100
Subject: lc_SUITE: Add shadow/1

---
 lib/compiler/test/lc_SUITE.erl | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/lib/compiler/test/lc_SUITE.erl b/lib/compiler/test/lc_SUITE.erl
index b40431c246..6b3472b37b 100644
--- a/lib/compiler/test/lc_SUITE.erl
+++ b/lib/compiler/test/lc_SUITE.erl
@@ -22,7 +22,7 @@
 	 init_per_group/2,end_per_group/2,
 	 init_per_testcase/2,end_per_testcase/2,
 	 basic/1,deeply_nested/1,no_generator/1,
-	 empty_generator/1,no_export/1]).
+	 empty_generator/1,no_export/1,shadow/1]).
 
 -include_lib("test_server/include/test_server.hrl").
 
@@ -38,7 +38,8 @@ groups() ->
        deeply_nested,
        no_generator,
        empty_generator,
-       no_export
+       no_export,
+       shadow
       ]}].
 
 init_per_suite(Config) ->
@@ -186,6 +187,18 @@ no_export(Config) when is_list(Config) ->
     [] = [ _X = a || false ] ++ [ _X = a || false ],
     ok.
 
+%% Test that variables in list comprehensions are
+%% correctly shadowed.
+
+shadow(Config) when is_list(Config) ->
+    Shadowed = nomatch,
+    _ = id(Shadowed),				%Eliminate warning.
+    L = [{Shadowed,Shadowed+1} || Shadowed <- lists:seq(7, 9)],
+    [{7,8},{8,9},{9,10}] = id(L),
+    [8,9] = id([Shadowed || {_,Shadowed} <- id(L),
+			    Shadowed < 10]),
+    ok.
+
 id(I) -> I.
     
 fc(Args, {'EXIT',{function_clause,[{?MODULE,_,Args,_}|_]}}) -> ok;
-- 
cgit v1.2.3


From 3f7ab0ea59deedd63da8dbaa9dbdbf5666294d6c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Fri, 16 Jan 2015 13:02:38 +0100
Subject: warnings_SUITE: Eliminate compiler warning for a shadowed variable

---
 lib/compiler/test/warnings_SUITE.erl | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/compiler/test/warnings_SUITE.erl b/lib/compiler/test/warnings_SUITE.erl
index be0348a92d..6e5a7d35e9 100644
--- a/lib/compiler/test/warnings_SUITE.erl
+++ b/lib/compiler/test/warnings_SUITE.erl
@@ -699,10 +699,10 @@ run(Config, Tests) ->
 %% Compiles a test module and returns the list of errors and warnings.
 
 run_test(Conf, Test0, Warnings) ->
-    Mod = "warnings_"++test_lib:uniq(),
-    Filename = Mod ++ ".erl",
+    Module = "warnings_"++test_lib:uniq(),
+    Filename = Module ++ ".erl",
     ?line DataDir = ?privdir,
-    Test = ["-module(", Mod, "). ", Test0],
+    Test = ["-module(", Module, "). ", Test0],
     ?line File = filename:join(DataDir, Filename),
     ?line Opts = [binary,export_all,return|Warnings],
     ?line ok = file:write_file(File, Test),
-- 
cgit v1.2.3


From 62c1dd9d9994367da43212f1b33c9e2dacb27e4b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Fri, 16 Jan 2015 07:02:54 +0100
Subject: core_lib: Teach is_var_used/2 to handle keys in map patterns

is_var_used/2 did not notice that variable keys in map patterns
were used, which could cause sys_core_fold to do unsafe
optimizations.
---
 lib/compiler/src/core_lib.erl     | 13 +++++++++----
 lib/compiler/test/match_SUITE.erl | 18 ++++++++++++++++--
 2 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/lib/compiler/src/core_lib.erl b/lib/compiler/src/core_lib.erl
index 0d95971f91..730e3a5317 100644
--- a/lib/compiler/src/core_lib.erl
+++ b/lib/compiler/src/core_lib.erl
@@ -236,10 +236,15 @@ vu_pat_seg_list(V, Ss, St) ->
 			end
 		end, St, Ss).
 
-vu_map_pairs(V, [#c_map_pair{val=Pat}|T], St0) ->
-    case vu_pattern(V, Pat, St0) of
-	{true,_}=St -> St;
-	St -> vu_map_pairs(V, T, St)
+vu_map_pairs(V, [#c_map_pair{key=Key,val=Pat}|T], St0) ->
+    case vu_expr(V, Key) of
+	true ->
+	    {true,false};
+	false ->
+	    case vu_pattern(V, Pat, St0) of
+		{true,_}=St -> St;
+		St -> vu_map_pairs(V, T, St)
+	    end
     end;
 vu_map_pairs(_, [], St) -> St.
 
diff --git a/lib/compiler/test/match_SUITE.erl b/lib/compiler/test/match_SUITE.erl
index e5aaf49d6f..1234197cd7 100644
--- a/lib/compiler/test/match_SUITE.erl
+++ b/lib/compiler/test/match_SUITE.erl
@@ -22,7 +22,8 @@
 	 init_per_group/2,end_per_group/2,
 	 pmatch/1,mixed/1,aliases/1,match_in_call/1,
 	 untuplify/1,shortcut_boolean/1,letify_guard/1,
-	 selectify/1,underscore/1,match_map/1,coverage/1]).
+	 selectify/1,underscore/1,match_map/1,map_vars_used/1,
+      coverage/1]).
 	 
 -include_lib("test_server/include/test_server.hrl").
 
@@ -36,7 +37,7 @@ groups() ->
     [{p,test_lib:parallel(),
       [pmatch,mixed,aliases,match_in_call,untuplify,
        shortcut_boolean,letify_guard,selectify,
-       underscore,match_map,coverage]}].
+       underscore,match_map,map_vars_used,coverage]}].
 
 
 init_per_suite(Config) ->
@@ -412,6 +413,19 @@ do_match_map(#s{map=#{key:=Val}}=S) ->
     %% Would crash with a 'badarg' exception.
     S#s{t=Val}.
 
+map_vars_used(Config) when is_list(Config) ->
+    {some,value} = do_map_vars_used(a, b, #{{a,b}=>42,v=>{some,value}}),
+    ok.
+
+do_map_vars_used(X, Y, Map) ->
+    case {X,Y} of
+	T ->
+	    %% core_lib:is_var_used/2 would not consider T used.
+	    #{T:=42,v:=Val} = Map,
+	    Val
+    end.
+
+
 coverage(Config) when is_list(Config) ->
     %% Cover beam_dead.
     ok = coverage_1(x, a),
-- 
cgit v1.2.3


From a1243173ed98d1006914337b94f28c9594bd8b02 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Thu, 15 Jan 2015 17:17:11 +0100
Subject: Fix handling of binary map keys in comprehensions

The translation of list comprehension with a map pattern
with a big literal binary as key such as:

  lc(L) ->
    [V || #{<<2:301>> := V} <- L].

would generate Core Erlang code where an unbound variable
were referenced:

  'lc'/1 =
    fun (L) ->
      letrec
        'lc$^0'/1 = fun (_cor4) ->
           case _cor4 of
             <[~{~<_cor1,V>}~|_cor3]> when 'true' ->
               let <_cor5> = apply 'lc$^0'/1(_cor3)
                 in [V|_cor5]
             <[_cor2|_cor3]> when 'true' ->
               apply 'lc$^0'/1(_cor3)
             <[]> when 'true' ->
               []
           end
      in let <_cor1> = #{#<2>(301,1,'integer',['unsigned'|['big']])}#
         in apply 'lc$^0'/1(L)

In the map pattern in the 'case' in the 'letrec', the key is the
variable '_cor1' which should be bound in the enclosing environment.

It is not.

There is binding of '_cor1', but in the wrong place (at the end of
the function). Because of the way v3_kernel translates letrecs,
the code *happens* to work.

The code will break if Core Erlang optimizations were strengthened
to more aggressively eliminate variable bindings that are not used,
or if the translation from Core Erlang to Kernel Erlang were changed.

Correct the translation so that '_cor1' is bound in the environment
enclosing the 'letrec':

  'lc'/1 =
    fun (L) ->
      let <_cor1> = #{#<2>(301,1,'integer',['unsigned'|['big']])}#
        in letrec
          'lc$^0'/1 = fun (_cor4) ->
            case _cor4 of
              <[~{~<_cor1,V>}~|_cor3]> when 'true' ->
                let <_cor5> = apply 'lc$^0'/1(_cor3)
                  in [V|_cor5]
              <[_cor2|_cor3]> when 'true' ->
                apply 'lc$^0'/1(_cor3)
              <[]> when 'true' ->
                []
            end
      in apply 'lc$^0'/1(L)

Unfortunately I was not able to come up with a test case that
demonstrates the bug.
---
 lib/compiler/src/v3_core.erl | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/lib/compiler/src/v3_core.erl b/lib/compiler/src/v3_core.erl
index 612660c2d6..b861de3bbb 100644
--- a/lib/compiler/src/v3_core.erl
+++ b/lib/compiler/src/v3_core.erl
@@ -105,7 +105,8 @@
 -record(iset,      {anno=#a{},var,arg}).
 -record(itry,      {anno=#a{},args,vars,body,evars,handler}).
 -record(ifilter,   {anno=#a{},arg}).
--record(igen,      {anno=#a{},acc_pat,acc_guard,skip_pat,tail,tail_pat,arg}).
+-record(igen,      {anno=#a{},ceps=[],acc_pat,acc_guard,
+		    skip_pat,tail,tail_pat,arg}).
 
 -type iapply()    :: #iapply{}.
 -type ibinary()   :: #ibinary{}.
@@ -1011,7 +1012,8 @@ fun_tq({_,_,Name}=Id, Cs0, L, St0, NameInfo) ->
 %% lc_tq(Line, Exp, [Qualifier], Mc, State) -> {LetRec,[PreExp],State}.
 %%  This TQ from Simon PJ pp 127-138.  
 
-lc_tq(Line, E, [#igen{anno=GAnno,acc_pat=AccPat,acc_guard=AccGuard,
+lc_tq(Line, E, [#igen{anno=GAnno,ceps=Ceps,
+		      acc_pat=AccPat,acc_guard=AccGuard,
                       skip_pat=SkipPat,tail=Tail,tail_pat=TailPat,
                       arg={Pre,Arg}}|Qs], Mc, St0) ->
     {Name,St1} = new_fun_name("lc", St0),
@@ -1046,7 +1048,7 @@ lc_tq(Line, E, [#igen{anno=GAnno,acc_pat=AccPat,acc_guard=AccGuard,
     Fun = #ifun{anno=LAnno,id=[],vars=[Var],clauses=Cs,fc=Fc},
     {#iletrec{anno=LAnno#a{anno=[list_comprehension|LA]},defs=[{{Name,1},Fun}],
               body=Pre ++ [#iapply{anno=LAnno,op=F,args=[Arg]}]},
-     [],St4};
+     Ceps,St4};
 lc_tq(Line, E, [#ifilter{}=Filter|Qs], Mc, St) ->
     filter_tq(Line, E, Filter, Mc, St, Qs, fun lc_tq/5);
 lc_tq(Line, E0, [], Mc0, St0) ->
@@ -1071,7 +1073,8 @@ bc_tq(Line, Exp, Qs0, _, St0) ->
 			    args=[Sz]}}] ++ BcPre,
     {E,Pre,St}.
 
-bc_tq1(Line, E, [#igen{anno=GAnno,acc_pat=AccPat,acc_guard=AccGuard,
+bc_tq1(Line, E, [#igen{anno=GAnno,ceps=Ceps,
+		       acc_pat=AccPat,acc_guard=AccGuard,
                        skip_pat=SkipPat,tail=Tail,tail_pat=TailPat,
                        arg={Pre,Arg}}|Qs], Mc, St0) ->
     {Name,St1} = new_fun_name("lbc", St0),
@@ -1109,7 +1112,7 @@ bc_tq1(Line, E, [#igen{anno=GAnno,acc_pat=AccPat,acc_guard=AccGuard,
     Fun = #ifun{anno=LAnno,id=[],vars=Vars,clauses=Cs,fc=Fc},
     {#iletrec{anno=LAnno#a{anno=[list_comprehension|LA]},defs=[{{Name,2},Fun}],
               body=Pre ++ [#iapply{anno=LAnno,op=F,args=[Arg,Mc]}]},
-     [],St4};
+     Ceps,St4};
 bc_tq1(Line, E, [#ifilter{}=Filter|Qs], Mc, St) ->
     filter_tq(Line, E, Filter, Mc, St, Qs, fun bc_tq1/5);
 bc_tq1(_, {bin,Bl,Elements}, [], AccVar, St0) ->
@@ -1245,8 +1248,9 @@ generator(Line, {generate,Lg,P0,E}, Gs, St0) ->
                                 ann_c_cons(LA, Skip, Tail)}
                        end,
     {Ce,Pre,St4} = safe(E, St3),
-    Gen = #igen{anno=#a{anno=GA},acc_pat=AccPat,acc_guard=Cg,skip_pat=SkipPat,
-                tail=Tail,tail_pat=#c_literal{anno=LA,val=[]},arg={Ceps++Pre,Ce}},
+    Gen = #igen{anno=#a{anno=GA},ceps=Ceps,
+		acc_pat=AccPat,acc_guard=Cg,skip_pat=SkipPat,
+                tail=Tail,tail_pat=#c_literal{anno=LA,val=[]},arg={Pre,Ce}},
     {Gen,St4};
 generator(Line, {b_generate,Lg,P,E}, Gs, St0) ->
     LA = lineno_anno(Line, St0),
-- 
cgit v1.2.3


From 1ef53ead19d5bd07caad4daa71b8fecf2fbcd2a6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Fri, 16 Jan 2015 15:06:53 +0100
Subject: sys_core_fold: Strengthen optimization of letrecs in effect context

We used to evaluate the body of a 'letrec' in value context, even
if the 'letrec' was being evaluated in effect context. In most
cases, the context does not matter because the body is usually
just an 'apply' which will never be optimized away.

However, in the case of incorrect code described in the previous
commit, it does matter. We can find such bad code by evaluating
the body in effect context. For example, if we have the following
incorrect code:

  letrec
    f/1 = fun(A) -> ... <use of Var> ...
    in let Var = <<2:301>>
       in apply(Arg)

If the letrec is evaluated in effect context, the code will be
reduced to:

  letrec
    f/1 = fun(A) -> ... <use of Var> ...
    in seq Var = <<2:301>> do apply(Arg)

Now Var will be unbound and a later compiler pass will crash to
ensure that the bad Core Erlang code is noticed.

Also add a test case to ensure that the compiler crashes if the
bug fixed in the previous commit re-surfaces.
---
 lib/compiler/src/sys_core_fold.erl |  2 +-
 lib/compiler/test/lc_SUITE.erl     | 21 +++++++++++++++++++--
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl
index 09716d0866..e079fc072a 100644
--- a/lib/compiler/src/sys_core_fold.erl
+++ b/lib/compiler/src/sys_core_fold.erl
@@ -313,7 +313,7 @@ expr(#c_letrec{defs=Fs0,body=B0}=Letrec, Ctxt, Sub) ->
     Fs1 = map(fun ({Name,Fb}) ->
 		      {Name,expr(Fb, {letrec,Ctxt}, Sub)}
 	      end, Fs0),
-    B1 = body(B0, value, Sub),
+    B1 = body(B0, Ctxt, Sub),
     Letrec#c_letrec{defs=Fs1,body=B1};
 expr(#c_case{}=Case0, Ctxt, Sub) ->
     %% Ideally, the compiler should only emit warnings when there is
diff --git a/lib/compiler/test/lc_SUITE.erl b/lib/compiler/test/lc_SUITE.erl
index 6b3472b37b..6c5b34498b 100644
--- a/lib/compiler/test/lc_SUITE.erl
+++ b/lib/compiler/test/lc_SUITE.erl
@@ -22,7 +22,8 @@
 	 init_per_group/2,end_per_group/2,
 	 init_per_testcase/2,end_per_testcase/2,
 	 basic/1,deeply_nested/1,no_generator/1,
-	 empty_generator/1,no_export/1,shadow/1]).
+	 empty_generator/1,no_export/1,shadow/1,
+	 effect/1]).
 
 -include_lib("test_server/include/test_server.hrl").
 
@@ -39,7 +40,8 @@ groups() ->
        no_generator,
        empty_generator,
        no_export,
-       shadow
+       shadow,
+       effect
       ]}].
 
 init_per_suite(Config) ->
@@ -199,6 +201,21 @@ shadow(Config) when is_list(Config) ->
 			    Shadowed < 10]),
     ok.
 
+effect(Config) when is_list(Config) ->
+    [{42,{a,b,c}}] =
+	do_effect(fun(F, L) ->
+			  [F({V1,V2}) ||
+			      #{<<1:500>>:=V1,<<2:301>>:=V2} <- L],
+			  ok
+		  end, id([#{},x,#{<<1:500>>=>42,<<2:301>>=>{a,b,c}}])),
+    ok.
+
+do_effect(Lc, L) ->
+    put(?MODULE, []),
+    F = fun(V) -> put(?MODULE, [V|get(?MODULE)]) end,
+    ok = Lc(F, L),
+    lists:reverse(erase(?MODULE)).
+
 id(I) -> I.
     
 fc(Args, {'EXIT',{function_clause,[{?MODULE,_,Args,_}|_]}}) -> ok;
-- 
cgit v1.2.3


From 3ebfb44a83fcfd506fe4e4925412a973a86474ed Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Wed, 21 Jan 2015 12:21:18 +0100
Subject: cerl_clauses: Fix indentation

---
 lib/compiler/src/cerl_clauses.erl | 46 +++++++++++++++++++--------------------
 1 file changed, 23 insertions(+), 23 deletions(-)

diff --git a/lib/compiler/src/cerl_clauses.erl b/lib/compiler/src/cerl_clauses.erl
index 87bd47c08b..ef74c5b76f 100644
--- a/lib/compiler/src/cerl_clauses.erl
+++ b/lib/compiler/src/cerl_clauses.erl
@@ -354,29 +354,29 @@ match(P, E, Bs) ->
 			    {false, Bs}
 		    end
 	    end;
-    map ->
-        %% The most we can do is to say "definitely no match" if a
-        %% map pattern is matched against non-map data.
-        case E of
-            any ->
-                {false, Bs};
-            _ ->
-                case type(E) of
-		    literal ->
-			case is_map(concrete(E)) of
-			    false ->
-				none;
-			    true ->
-				{false, Bs}
-			end;
-                    cons ->
-                        none;
-                    tuple ->
-                        none;
-                    _ ->
-                        {false, Bs}
-                end
-        end;
+	map ->
+	    %% The most we can do is to say "definitely no match" if a
+	    %% map pattern is matched against non-map data.
+	    case E of
+		any ->
+		    {false, Bs};
+		_ ->
+		    case type(E) of
+			literal ->
+			    case is_map(concrete(E)) of
+				false ->
+				    none;
+				true ->
+				    {false, Bs}
+			    end;
+			cons ->
+			    none;
+			tuple ->
+			    none;
+			_ ->
+			    {false, Bs}
+		    end
+	    end;
 	_ ->
 	    match_1(P, E, Bs)
     end.
-- 
cgit v1.2.3


From 142da57a6790e879f0e593f97cf5a65459693c34 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Tue, 20 Jan 2015 11:05:28 +0100
Subject: cerl: Make sure that we preserve the invariants for maps

Maps have certain invariants that must be preserved:

(1) A map as a pattern must be represented as #c_map{} record,
never as a literal. The reason is that the pattern '#{}' will
match any map, not just the empty map. The literal '#{}' will
only match the empty map.

(2) In a map pattern, the key must be a literal, a variable, or
data (list or tuple). Keys that are binaries or maps *must* be
represented as literals.

(3) Maps in expressions should be represented as literals if possible.
Nothing is broken if this invariant is broken, but the generated
code will be less efficient.

To preserve invariant (1), cerl:update_c_map/3 must never collapse
a map to a literal. To preserve invariant (3), cerl:update_c_map/3
must collapse a map to a literal if possible.

To preserve both invariants, we need a way for cerl:update_c_map/3 to
know whether the map is used as a pattern or as an expression. The
simplest way is to have an 'is_pat' boolean in the #c_map{} record
which is set when a #c_map{} record is initially created.

We also need to update core_parse.yrl to establish the invariants
in the same way as v3_core, to ensure that compiling from a
.core file will work even if all optimizations on Core Erlang are
disabled.
---
 lib/compiler/src/cerl.erl       | 26 +++++++++++++----
 lib/compiler/src/core_parse.hrl |  3 +-
 lib/compiler/src/core_parse.yrl | 64 +++++++++++++++++++++++++++++++++++------
 lib/compiler/src/v3_core.erl    |  2 +-
 4 files changed, 78 insertions(+), 17 deletions(-)

diff --git a/lib/compiler/src/cerl.erl b/lib/compiler/src/cerl.erl
index 7a2c3d70de..96c8e02542 100644
--- a/lib/compiler/src/cerl.erl
+++ b/lib/compiler/src/cerl.erl
@@ -123,11 +123,13 @@
 	 bitstr_flags/1,
 
 	 %% keep map exports here for now
+	 c_map_pattern/1,
 	 map_es/1,
 	 map_arg/1,
 	 update_c_map/3,
 	 c_map/1, is_c_map_empty/1,
 	 ann_c_map/2, ann_c_map/3,
+	 ann_c_map_pattern/2,
 	 map_pair_op/1,map_pair_key/1,map_pair_val/1,
 	 update_c_map_pair/4,
 	 c_map_pair/2,
@@ -1590,7 +1592,17 @@ map_arg(#c_map{arg=M}) ->
 -spec c_map([c_map_pair()]) -> c_map().
 
 c_map(Pairs) ->
-    #c_map{es=Pairs}.
+    ann_c_map([], Pairs).
+
+-spec c_map_pattern([c_map_pair()]) -> c_map().
+
+c_map_pattern(Pairs) ->
+    #c_map{es=Pairs, is_pat=true}.
+
+-spec ann_c_map_pattern([term()], [c_map_pair()]) -> c_map().
+
+ann_c_map_pattern(As, Pairs) ->
+    #c_map{anno=As, es=Pairs, is_pat=true}.
 
 -spec is_c_map_empty(c_map() | c_literal()) -> boolean().
 
@@ -1598,9 +1610,9 @@ is_c_map_empty(#c_map{ es=[] }) -> true;
 is_c_map_empty(#c_literal{val=M}) when is_map(M),map_size(M) =:= 0 -> true;
 is_c_map_empty(_) -> false.
 
--spec ann_c_map([term()], [cerl()]) -> c_map() | c_literal().
+-spec ann_c_map([term()], [c_map_pair()]) -> c_map() | c_literal().
 
-ann_c_map(As,Es) ->
+ann_c_map(As, Es) ->
     ann_c_map(As, #c_literal{val=#{}}, Es).
 
 -spec ann_c_map([term()], c_map() | c_literal(), [c_map_pair()]) -> c_map() | c_literal().
@@ -1648,10 +1660,12 @@ fold_map_pairs(As,[#c_map_pair{op=#c_literal{val=exact},key=Ck,val=Cv}=E|Es],M)
 fold_map_pairs(As,Es,M) ->
     #c_map{arg=#c_literal{val=M,anno=As}, es=Es, anno=As }.
 
-%-spec update_c_map(c_map() | c_literal(), [c_map_pair()]) -> c_map() | c_literal().
+-spec update_c_map(c_map(), cerl(), [cerl()]) -> c_map() | c_literal().
 
-update_c_map(Old,M,Es) ->
-    #c_map{arg=M, es = Es, anno = get_ann(Old)}.
+update_c_map(#c_map{is_pat=true}=Old, M, Es) ->
+    Old#c_map{arg=M, es=Es};
+update_c_map(#c_map{is_pat=false}=Old, M, Es) ->
+    ann_c_map(get_ann(Old), M, Es).
 
 map_pair_key(#c_map_pair{key=K}) -> K.
 map_pair_val(#c_map_pair{val=V}) -> V.
diff --git a/lib/compiler/src/core_parse.hrl b/lib/compiler/src/core_parse.hrl
index 4a00535360..7fd4a82e4e 100644
--- a/lib/compiler/src/core_parse.hrl
+++ b/lib/compiler/src/core_parse.hrl
@@ -72,7 +72,8 @@
 
 -record(c_map, {anno=[],
 		arg=#c_literal{val=#{}} :: cerl:c_var() | cerl:c_literal(),
-		es :: [cerl:c_map_pair()]}).
+		es :: [cerl:c_map_pair()],
+		is_pat=false :: boolean()}).
 
 -record(c_map_pair, {anno=[],
 	             op :: #c_literal{val::'assoc'} | #c_literal{val::'exact'},
diff --git a/lib/compiler/src/core_parse.yrl b/lib/compiler/src/core_parse.yrl
index a66ad4235f..716c03bc94 100644
--- a/lib/compiler/src/core_parse.yrl
+++ b/lib/compiler/src/core_parse.yrl
@@ -182,14 +182,14 @@ atomic_pattern -> atomic_literal : '$1'.
 tuple_pattern -> '{' '}' : c_tuple([]).
 tuple_pattern -> '{' anno_patterns '}' : c_tuple('$2').
 
-map_pattern -> '~' '{' '}' '~' : #c_map{es=[]}.
+map_pattern -> '~' '{' '}' '~' : c_map_pattern([]).
 map_pattern -> '~' '{' map_pair_patterns '}' '~' :
-		   #c_map{es=lists:sort('$3')}.
+		   c_map_pattern(lists:sort('$3')).
 
 map_pair_patterns -> map_pair_pattern : ['$1'].
 map_pair_patterns -> map_pair_pattern ',' map_pair_patterns : ['$1' | '$3'].
 
-map_pair_pattern -> '~' '<' anno_pattern ',' anno_pattern '>' :
+map_pair_pattern -> '~' '<' anno_expression ',' anno_pattern '>' :
 			#c_map_pair{op=#c_literal{val=exact},key='$3',val='$5'}.
 
 cons_pattern -> '[' anno_pattern tail_pattern :
@@ -284,10 +284,10 @@ tail_literal -> ',' literal tail_literal : #c_cons{hd='$2',tl='$3'}.
 tuple -> '{' '}' : c_tuple([]).
 tuple -> '{' anno_expressions '}' : c_tuple('$2').
 
-map_expr -> '~' '{' '}' '~' : #c_map{es=[]}.
-map_expr -> '~' '{' map_pairs '}' '~' : #c_map{es='$3'}.
-map_expr -> '~' '{' map_pairs '|' variable '}' '~' : #c_map{arg='$5',es='$3'}.
-map_expr -> '~' '{' map_pairs '|' map_expr '}' '~' : #c_map{arg='$5',es='$3'}.
+map_expr -> '~' '{' '}' '~' : c_map([]).
+map_expr -> '~' '{' map_pairs '}' '~' : c_map('$3').
+map_expr -> '~' '{' map_pairs '|' variable '}' '~' : ann_c_map([], '$5', '$3').
+map_expr -> '~' '{' map_pairs '|' map_expr '}' '~' : ann_c_map([], '$5', '$3').
 
 map_pairs -> map_pair : ['$1'].
 map_pairs -> map_pair ',' map_pairs : ['$1' | '$3'].
@@ -307,7 +307,7 @@ tail -> '|' anno_expression ']' : '$2'.
 tail -> ',' anno_expression tail : c_cons('$2', '$3').
 
 binary -> '#' '{' '}' '#' : #c_literal{val = <<>>}.
-binary -> '#' '{' segments '}' '#' : #c_binary{segments='$3'}.
+binary -> '#' '{' segments '}' '#' : make_binary('$3').
 
 segments -> segment ',' segments : ['$1' | '$3'].
 segments -> segment : ['$1'].
@@ -410,9 +410,55 @@ Erlang code.
 
 -include("core_parse.hrl").
 
--import(cerl, [c_cons/2,c_tuple/1]).
+-import(cerl, [ann_c_map/3,c_cons/2,c_map/1,c_map_pattern/1,c_tuple/1]).
 
 tok_val(T) -> element(3, T).
 tok_line(T) -> element(2, T).
 
+%% make_binary([#c_bitstr{}]) -> #c_binary{} | #c_literal{}
+%%  Create either #c_binary{} or #c_literal{} from the binary segments.
+%%  In certain contexts, such as keys for maps, only literals and
+%%  variables are allowed, so we must not create a #c_binary{}
+%%  record in those situation.
+%%
+%%  To keep this function simple, we use a crude heuristic. We will
+%%  assume that Core Erlang has been produced by core_pp. If the
+%%  segments *could* have been output from a literal binary by
+%%  core_pp, we will create a #c_literal{}. Otherwise we will create a
+%%  #c_binary{} record.
+
+make_binary(Segs) ->
+    try make_lit_bin(<<>>, Segs) of
+	Bs when is_bitstring(Bs) ->
+	    #c_literal{val=Bs}
+    catch
+	throw:impossible ->
+	    #c_binary{segments=Segs}
+    end.
+
+make_lit_bin(Acc, [#c_bitstr{val=I0,size=Sz0,unit=U0,type=Type0,flags=F0}|T]) ->
+    I = get_lit_val(I0),
+    Sz = get_lit_val(Sz0),
+    U = get_lit_val(U0),
+    Type = get_lit_val(Type0),
+    F = get_lit_val(F0),
+    if
+	is_integer(I), U =:= 1, Type =:= integer, F =:= [unsigned,big] ->
+	    ok;
+	true ->
+	    throw(impossible)
+    end,
+    if
+	Sz =< 8, T =:= [] ->
+	    <<Acc/binary,I:Sz>>;
+	Sz =:= 8 ->
+	    make_lit_bin(<<Acc/binary,I:8>>, T);
+	true ->
+	    throw(impossible)
+    end;
+make_lit_bin(Acc, []) -> Acc.
+
+get_lit_val(#c_literal{val=Val}) -> Val;
+get_lit_val(_) -> throw(impossible).
+
 %% vim: syntax=erlang
diff --git a/lib/compiler/src/v3_core.erl b/lib/compiler/src/v3_core.erl
index b861de3bbb..1d5eb85a1c 100644
--- a/lib/compiler/src/v3_core.erl
+++ b/lib/compiler/src/v3_core.erl
@@ -1638,7 +1638,7 @@ pattern({tuple,L,Ps}, St) ->
     {annotate_tuple(record_anno(L, St), Ps1, St),Eps,St1};
 pattern({map,L,Pairs}, St0) ->
     {Ps,Eps,St1} = pattern_map_pairs(Pairs, St0),
-    {#c_map{anno=lineno_anno(L, St1), es=Ps},Eps,St1};
+    {#c_map{anno=lineno_anno(L, St1),es=Ps,is_pat=true},Eps,St1};
 pattern({bin,L,Ps}, St) ->
     %% We don't create a #ibinary record here, since there is
     %% no need to hold any used/new annotations in a pattern.
-- 
cgit v1.2.3


From 1fcdcd50e9dc09c78259434ae7ba189e6a47ced4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Tue, 27 Jan 2015 07:49:12 +0100
Subject: core_parse: Always fold literal conses

v3_core is careful to always create literals whenever possible.

Correct core_parse so it, too, always creates literals out
of literal conses. With that correction, we can remove the
workaround in sys_core_fold (introduced in 26a5dea3cb5e101)
that handles non-literal flags in a binary.
---
 lib/compiler/src/core_parse.yrl    | 8 ++++----
 lib/compiler/src/sys_core_fold.erl | 8 --------
 2 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/lib/compiler/src/core_parse.yrl b/lib/compiler/src/core_parse.yrl
index 716c03bc94..849f801a11 100644
--- a/lib/compiler/src/core_parse.yrl
+++ b/lib/compiler/src/core_parse.yrl
@@ -193,12 +193,12 @@ map_pair_pattern -> '~' '<' anno_expression ',' anno_pattern '>' :
 			#c_map_pair{op=#c_literal{val=exact},key='$3',val='$5'}.
 
 cons_pattern -> '[' anno_pattern tail_pattern :
-		    #c_cons{hd='$2',tl='$3'}.
+		    c_cons('$2', '$3').
 
 tail_pattern -> ']' : #c_literal{val=[]}.
 tail_pattern -> '|' anno_pattern ']' : '$2'.
 tail_pattern -> ',' anno_pattern tail_pattern :
-		    #c_cons{hd='$2',tl='$3'}.
+		    c_cons('$2', '$3').
 
 binary_pattern -> '#' '{' '}' '#' : #c_binary{segments=[]}.
 binary_pattern -> '#' '{' segment_patterns '}' '#' : #c_binary{segments='$3'}.
@@ -206,7 +206,7 @@ binary_pattern -> '#' '{' segment_patterns '}' '#' : #c_binary{segments='$3'}.
 segment_patterns -> segment_pattern ',' segment_patterns : ['$1' | '$3'].
 segment_patterns -> segment_pattern : ['$1'].
 
-segment_pattern -> '#' '<' anno_pattern '>' '(' anno_patterns ')':
+segment_pattern -> '#' '<' anno_pattern '>' '(' anno_expressions ')':
 	case '$6' of
 	    [S,U,T,Fs] ->
 		#c_bitstr{val='$3',size=S,unit=U,type=T,flags=Fs};
@@ -279,7 +279,7 @@ cons_literal -> '[' literal tail_literal : c_cons('$2', '$3').
 
 tail_literal -> ']' : #c_literal{val=[]}.
 tail_literal -> '|' literal ']' : '$2'.
-tail_literal -> ',' literal tail_literal : #c_cons{hd='$2',tl='$3'}.
+tail_literal -> ',' literal tail_literal : c_cons('$2', '$3').
 
 tuple -> '{' '}' : c_tuple([]).
 tuple -> '{' anno_expressions '}' : c_tuple('$2').
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl
index e079fc072a..08b1c0d7b7 100644
--- a/lib/compiler/src/sys_core_fold.erl
+++ b/lib/compiler/src/sys_core_fold.erl
@@ -607,14 +607,6 @@ eval_binary_1([#c_bitstr{val=#c_literal{val=Val},size=#c_literal{val=Sz},
 	error:_ ->
 	    throw(impossible)
     end;
-eval_binary_1([#c_bitstr{val=#c_literal{},size=#c_literal{},
-			 unit=#c_literal{},type=#c_literal{},
-			 flags=#c_cons{}=Flags}=Bitstr|Ss], Acc0) ->
-    case cerl:fold_literal(Flags) of
-	#c_literal{} = Flags1 ->
-	    eval_binary_1([Bitstr#c_bitstr{flags=Flags1}|Ss], Acc0);
-	_ -> throw(impossible)
-    end;
 eval_binary_1([], Acc) -> Acc;
 eval_binary_1(_, _) -> throw(impossible).
 
-- 
cgit v1.2.3


From 4a3ad317ec6ebe02ad1ecc8a4132896c333ba742 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Tue, 20 Jan 2015 12:33:35 +0100
Subject: Strengthen and modernize compile_SUITE

When we compile from Core Erlang, do it with and without
Core Erlang optimizations to ensure that we are not dependent
on the optimizations always being run.
---
 lib/compiler/test/compile_SUITE.erl | 71 ++++++++++++++++++++++++-------------
 1 file changed, 47 insertions(+), 24 deletions(-)

diff --git a/lib/compiler/test/compile_SUITE.erl b/lib/compiler/test/compile_SUITE.erl
index 0ff03c4295..1c96abe017 100644
--- a/lib/compiler/test/compile_SUITE.erl
+++ b/lib/compiler/test/compile_SUITE.erl
@@ -748,42 +748,65 @@ env_1(Simple, Target) ->
 %% compile the generated Core Erlang files.
 
 core(Config) when is_list(Config) ->
-    ?line Dog = test_server:timetrap(test_server:minutes(5)),
-    ?line PrivDir = ?config(priv_dir, Config),
-    ?line Outdir = filename:join(PrivDir, "core"),
-    ?line ok = file:make_dir(Outdir),
+    PrivDir = ?config(priv_dir, Config),
+    Outdir = filename:join(PrivDir, "core"),
+    ok = file:make_dir(Outdir),
 
-    ?line Wc = filename:join(filename:dirname(code:which(?MODULE)), "*.beam"),
-    ?line TestBeams = filelib:wildcard(Wc),
-    ?line Abstr = [begin {ok,{Mod,[{abstract_code,
+    Wc = filename:join(filename:dirname(code:which(?MODULE)), "*.beam"),
+    TestBeams = filelib:wildcard(Wc),
+    Abstr = [begin {ok,{Mod,[{abstract_code,
 				    {raw_abstract_v1,Abstr}}]}} = 
 			     beam_lib:chunks(Beam, [abstract_code]),
 			 {Mod,Abstr} end || Beam <- TestBeams],
-    ?line Res = test_lib:p_run(fun(F) -> do_core(F, Outdir) end, Abstr),
-    ?line test_server:timetrap_cancel(Dog),
-    Res.
-
+    test_lib:p_run(fun(F) -> do_core(F, Outdir) end, Abstr).
     
 do_core({M,A}, Outdir) ->
     try
-	{ok,M,Core} = compile:forms(A, [to_core,report]),
-	CoreFile = filename:join(Outdir, atom_to_list(M)++".core"),
-	CorePP = core_pp:format(Core),
-	ok = file:write_file(CoreFile, CorePP),
-	case compile:file(CoreFile, [clint,from_core,binary]) of
-	    {ok,M,_} ->
-		ok = file:delete(CoreFile);
-	    Other ->
-		io:format("*** core_lint failure '~p' for ~s\n",
-			  [Other,CoreFile]),
-		error
-	end
-    catch Class:Error ->
+	do_core_1(M, A, Outdir)
+    catch
+	throw:{error,Error} ->
+	    io:format("*** compilation failure '~p' for module ~s\n",
+		      [Error,M]),
+	    error;
+	Class:Error ->
 	    io:format("~p: ~p ~p\n~p\n",
 		      [M,Class,Error,erlang:get_stacktrace()]),
 	    error
     end.
 
+do_core_1(M, A, Outdir) ->
+    {ok,M,Core0} = compile:forms(A, [to_core]),
+    CoreFile = filename:join(Outdir, atom_to_list(M)++".core"),
+    CorePP = core_pp:format(Core0),
+    ok = file:write_file(CoreFile, CorePP),
+
+    %% Parse the .core file and return the result as Core Erlang Terms.
+    Core = case compile:file(CoreFile, [report_errors,from_core,no_copt,to_core,binary]) of
+	       {ok,M,Core1} -> Core1;
+	       Other -> throw({error,Other})
+	   end,
+    ok = file:delete(CoreFile),
+
+    %% Compile as usual (including optimizations).
+    compile_forms(Core, [clint,from_core,binary]),
+
+    %% Don't optimize to test that we are not dependent
+    %% on the Core Erlang optmimization passes.
+    %% (Example of a previous bug: The core_parse pass
+    %% would not turn map literals into #c_literal{}
+    %% records; if sys_core_fold was run it would fix
+    %% that; if sys_core_fold was not run v3_kernel would
+    %% crash.)
+    compile_forms(Core, [clint,from_core,no_copt,binary]),
+
+    ok.
+
+compile_forms(Forms, Opts) ->
+    case compile:forms(Forms, [report_errors|Opts]) of
+	{ok,[],_} ->  ok;
+	Other -> throw({error,Other})
+    end.
+
 %% Compile to Beam assembly language (.S) and then try to
 %% run .S through the compiler again.
 
-- 
cgit v1.2.3


From 440c54f6a6b78015e8c8e0c7d16ad3cbb3d22147 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Tue, 27 Jan 2015 13:42:31 +0100
Subject: core_pp: Correct printing of map literals

A map key in a pattern would be incorrectly pretty-printed.
As an example, the pattern in:

  x() ->
    #{ #{ a => 3 } := 42 } = X.

would be pretty-printed as:

    <~{~<~{~<'a',3>}~,42>}~

instead of:

    <~{~<~{::<'a',3>}~,42>}~

When this problem has been corrected, the workaround for it in
cerl:ann_c_map/3 can be removed. The workaround was not harmless,
as it would cause the following map update to incorrectly succeed:

  (#{})#{a:=1}
---
 lib/compiler/src/cerl.erl       | 12 ------------
 lib/compiler/src/core_pp.erl    | 10 ++++++++--
 lib/compiler/test/map_SUITE.erl |  6 ++++++
 3 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/lib/compiler/src/cerl.erl b/lib/compiler/src/cerl.erl
index 96c8e02542..705c87539e 100644
--- a/lib/compiler/src/cerl.erl
+++ b/lib/compiler/src/cerl.erl
@@ -1617,18 +1617,6 @@ ann_c_map(As, Es) ->
 
 -spec ann_c_map([term()], c_map() | c_literal(), [c_map_pair()]) -> c_map() | c_literal().
 
-ann_c_map(As,#c_literal{val=Mval}=M,Es) when is_map(Mval), map_size(Mval) =:= 0 ->
-    Pairs = [[Ck,Cv]||#c_map_pair{key=Ck,val=Cv}<-Es],
-    IsLit = lists:foldl(fun(Pair,Res) ->
-		Res andalso is_lit_list(Pair)
-	end, true, Pairs),
-    Fun = fun(Pair) -> [K,V] = lit_list_vals(Pair), {K,V} end,
-    case IsLit of
-	false ->
-	    #c_map{arg=M, es=Es, anno=As };
-	true ->
-	    #c_literal{anno=As, val=maps:from_list(lists:map(Fun, Pairs))}
-	end;
 ann_c_map(As,#c_literal{val=M},Es) when is_map(M) ->
     fold_map_pairs(As,Es,M);
 ann_c_map(As,M,Es) ->
diff --git a/lib/compiler/src/core_pp.erl b/lib/compiler/src/core_pp.erl
index 03801a9b6d..01922c3fdf 100644
--- a/lib/compiler/src/core_pp.erl
+++ b/lib/compiler/src/core_pp.erl
@@ -184,12 +184,12 @@ format_1(#c_map{arg=Var,es=Es}, Ctxt) ->
     ];
 format_1(#c_map_pair{op=#c_literal{val=assoc},key=K,val=V}, Ctxt) ->
     ["::<",
-     format_hseq([K,V], ",", add_indent(Ctxt, 1), fun format/2),
+     format_map_pair(K, V, Ctxt),
      ">"
     ];
 format_1(#c_map_pair{op=#c_literal{val=exact},key=K,val=V}, Ctxt) ->
     ["~<",
-     format_hseq([K,V], ",", add_indent(Ctxt, 1), fun format/2),
+     format_map_pair(K, V, Ctxt),
      ">"
     ];
 format_1(#c_cons{hd=H,tl=T}, Ctxt) ->
@@ -448,6 +448,12 @@ format_list_tail(#c_cons{anno=[],hd=H,tl=T}, Ctxt) ->
 format_list_tail(Tail, Ctxt) ->
     ["|",format(Tail, add_indent(Ctxt, 1)),"]"].
 
+format_map_pair(K, V, Ctxt0) ->
+    Ctxt1 = add_indent(Ctxt0, 1),
+    Txt = format(K, set_class(Ctxt1, expr)),
+    Ctxt2 = add_indent(Ctxt0, width(Txt, Ctxt1)),
+    [Txt,",",format(V, Ctxt2)].
+
 indent(Ctxt) -> indent(Ctxt#ctxt.indent, Ctxt).
 
 indent(N, _) when N =< 0 -> "";
diff --git a/lib/compiler/test/map_SUITE.erl b/lib/compiler/test/map_SUITE.erl
index dbac61765b..bc5ae803c6 100644
--- a/lib/compiler/test/map_SUITE.erl
+++ b/lib/compiler/test/map_SUITE.erl
@@ -319,6 +319,12 @@ t_update_exact(Config) when is_list(Config) ->
     {'EXIT',{badarg,_}} = (catch M0#{42=>v1,42.0:=v2,42:=v3}),
     {'EXIT',{badarg,_}} = (catch <<>>#{nonexisting:=val}),
     {'EXIT',{badarg,_}} = (catch M0#{<<0:257>> := val}), %% limitation
+
+    %% A workaround for a bug allowed an empty map to be updated.
+    {'EXIT',{badarg,_}} = (catch (id(#{}))#{a:=1}),
+    {'EXIT',{badarg,_}} = (catch #{}#{a:=1}),
+    Empty = #{},
+    {'EXIT',{badarg,_}} = (catch Empty#{a:=1}),
     ok.
 
 t_update_values(Config) when is_list(Config) ->
-- 
cgit v1.2.3


From 25603134a658a64d5b024fe1668d9db6f331b2e2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Tue, 27 Jan 2015 09:16:07 +0100
Subject: Move grouping of map constructions from v3_core to v3_kernel

When translating a function with map construction:

  f(A) ->
    B = b,
    C = c,
    #{A=>1,B=>2,C=>3}.

v3_core would break apart the map construction into three
parts because of the way the map instructions in BEAM work --
variable keys need to be in their own instruction.

In the example, constant propagation will turn two of the
keys to literal keys. But the initial breaking apart will
not be undone, so there will still be three map constructions:

  'f'/1 =
    fun (_cor0) ->
      let <_cor3> = ~{::<_cor0,1>}~
	in let <_cor4> = ~{::<'b',2>|_cor3}~
	  in ~{::<'c',3>|_cor4}~

It would be possible to complicate the sys_core_fold pass
to regroup map operations so that we would get:

  'f'/1 =
    fun (_cor0) ->
      let <_cor3> = ~{::<_cor0,1>}~
        in ~{::<'b',2>,::<'c',3>|_cor3}~

A simpler way that allows to simplify the translation is
to skip the grouping in v3_core and translate the function
to:

  'f'/1 =
    fun (_cor0) ->
      ~{::<_cor0,1>,::<'b',2>,::<'c',3>}~

We will then let v3_kernel do the grouping while translating
from Core Erlang to Kernel Erlang.
---
 lib/compiler/src/v3_core.erl   |  75 +++++++++--------------------
 lib/compiler/src/v3_kernel.erl | 106 +++++++++++++++++++++++------------------
 2 files changed, 82 insertions(+), 99 deletions(-)

diff --git a/lib/compiler/src/v3_core.erl b/lib/compiler/src/v3_core.erl
index 1d5eb85a1c..a9b54005d1 100644
--- a/lib/compiler/src/v3_core.erl
+++ b/lib/compiler/src/v3_core.erl
@@ -536,7 +536,7 @@ expr({tuple,L,Es0}, St0) ->
     A = record_anno(L, St1),
     {annotate_tuple(A, Es1, St1),Eps,St1};
 expr({map,L,Es0}, St0) ->
-    map_build_pair_chain(#c_literal{val=#{}},Es0,lineno_anno(L,St0),St0);
+    map_build_pairs(#c_literal{val=#{}}, Es0, lineno_anno(L, St0), St0);
 expr({map,L,M0,Es0}, St0) ->
     try expr_map(M0,Es0,lineno_anno(L, St0),St0) of
 	{_,_,_}=Res -> Res
@@ -779,66 +779,35 @@ expr_map(M0,Es0,A,St0) ->
 		    Fc = fail_clause([Fpat], A, #c_literal{val=badarg}),
 		    {#icase{anno=#a{anno=A},args=[M1],clauses=Cs,fc=Fc},Mps,St3};
 		{_,_} ->
-		    {M2,Eps,St2} = map_build_pair_chain(M1,Es0,A,St1),
+		    {M2,Eps,St2} = map_build_pairs(M1, Es0, A, St1),
 		    {M2,Mps++Eps,St2}
 	    end;
 	false -> throw({bad_map,bad_map})
     end.
 
-%% Group continuous literal blocks and single variables, i.e.
-%% M0#{ a := 1, b := V1, K1 := V2, K2 := 42}
-%% becomes equivalent to
-%% M1 = M0#{ a := 1, b := V1 },
-%% M2 = M1#{ K1 := V1 },
-%% M3 = M2#{ K2 := 42 }
-
-map_build_pair_chain(M,Es,A,St) ->
-    %% hack, remove iset if only literal
-    case map_build_pair_chain(M,Es,A,St,[]) of
-	{_,[#iset{arg=#c_literal{}=Val}],St1} -> {Val,[],St1};
-	Normal -> Normal
+map_build_pairs(Map0, Es0, Ann, St0) ->
+    {Es,Pre,St1} = map_build_pairs_1(Es0, St0),
+    case ann_c_map(Ann, Map0, Es) of
+	#c_literal{}=Map ->
+	    {Map,[],St1};
+	#c_map{}=Map ->
+	    {Var,St2} = new_var(St1),
+	    {Var,Pre++[#iset{var=Var,arg=Map}],St2}
     end.
 
-map_build_pair_chain(M0,[],_,St,Mps) ->
-    {M0,Mps,St};
-map_build_pair_chain(M0,Es0,A,St0,Mps) ->
-    % group continuous literal blocks
-    % Anno = #a{anno=[compiler_generated]},
-    % order is important, we need to reverse the literals
-    case map_pair_block(Es0,[],[],St0) of
-	{{CesL,EspL},{[],[]},Es1,St1} ->
-	    {MVar,St2} = new_var(St1),
-	    Pre = [#iset{var=MVar, arg=ann_c_map(A,M0,reverse(CesL))}],
-	    map_build_pair_chain(MVar,Es1,A,St2,Mps++EspL++Pre);
-	{{[],[]},{CesV,EspV},Es1,St1} ->
-	    {MVar,St2} = new_var(St1),
-	    Pre = [#iset{var=MVar, arg=#c_map{arg=M0,es=CesV, anno=A}}],
-	    map_build_pair_chain(MVar,Es1,A,St2,Mps ++ EspV++Pre);
-	{{CesL,EspL},{CesV,EspV},Es1,St1} ->
-	    {MVarL,St2} = new_var(St1),
-	    {MVarV,St3} = new_var(St2),
-	    Pre = [#iset{var=MVarL, arg=ann_c_map(A,M0,reverse(CesL))},
-		   #iset{var=MVarV, arg=#c_map{arg=MVarL,es=CesV,anno=A}}],
-	    map_build_pair_chain(MVarV,Es1,A,St3,Mps++EspL++EspV++Pre)
-    end.
-
-map_pair_block([{Op,L,K0,V0}|Es],Ces,Esp,St0) ->
-    {K,Ep0,St1} = safe(K0, St0),
-    {V,Ep1,St2} = safe(V0, St1),
-    A = lineno_anno(L, St2),
-    Pair0 = map_op_to_c_map_pair(Op),
-    Pair1 = Pair0#c_map_pair{anno=A,key=K,val=V},
-    case cerl:is_literal(K) of
-	true ->
-	    map_pair_block(Es,[Pair1|Ces],Ep0 ++ Ep1 ++ Esp,St2);
-	false ->
-	    {{Ces,Esp},{[Pair1],Ep0++Ep1},Es,St2}
-    end;
-map_pair_block([],Ces,Esp,St) ->
-    {{Ces,Esp},{[],[]},[],St}.
+map_build_pairs_1([{Op0,L,K0,V0}|Es], St0) ->
+    {K,Pre0,St1} = safe(K0, St0),
+    {V,Pre1,St2} = safe(V0, St1),
+    {Pairs,Pre2,St3} = map_build_pairs_1(Es, St2),
+    As = lineno_anno(L, St3),
+    Op = map_op(Op0),
+    Pair = cerl:ann_c_map_pair(As, Op, K, V),
+    {[Pair|Pairs],Pre0++Pre1++Pre2,St3};
+map_build_pairs_1([], St) ->
+    {[],[],St}.
 
-map_op_to_c_map_pair(map_field_assoc) -> #c_map_pair{op=#c_literal{val=assoc}};
-map_op_to_c_map_pair(map_field_exact) -> #c_map_pair{op=#c_literal{val=exact}}.
+map_op(map_field_assoc) -> #c_literal{val=assoc};
+map_op(map_field_exact) -> #c_literal{val=exact}.
 
 is_valid_map_src(#c_literal{val = M}) when is_map(M) -> true;
 is_valid_map_src(#c_var{})  -> true;
diff --git a/lib/compiler/src/v3_kernel.erl b/lib/compiler/src/v3_kernel.erl
index 6504351c02..72e7a39333 100644
--- a/lib/compiler/src/v3_kernel.erl
+++ b/lib/compiler/src/v3_kernel.erl
@@ -521,62 +521,76 @@ is_valid_map_src(#k_var{}) -> true;
 is_valid_map_src(_) -> false.
 
 map_split_pairs(A, Var, Ces, Sub, St0) ->
-    %% two steps
-    %% 1. force variables
-    %% 2. remove multiples
-    Pairs0 = [{Op,K,V} || #c_map_pair{op=#c_literal{val=Op},key=K,val=V} <- Ces],
+    %% 1. Force variables.
+    %% 2. Group adjacent pairs with literal keys.
+    %% 3. Within each such group, remove multiple assignments to the same key.
+    %% 4. Partition each group according to operator ('=>' and ':=').
+    Pairs0 = [{Op,K,V} ||
+		 #c_map_pair{op=#c_literal{val=Op},key=K,val=V} <- Ces],
     {Pairs,Esp,St1} = foldr(fun
 	    ({Op,K0,V0}, {Ops,Espi,Sti0}) when Op =:= assoc; Op =:= exact ->
 		{K,Eps1,Sti1} = atomic(K0, Sub, Sti0),
 		{V,Eps2,Sti2} = atomic(V0, Sub, Sti1),
 		{[{Op,K,V}|Ops],Eps1 ++ Eps2 ++ Espi,Sti2}
 	end, {[],[],St0}, Pairs0),
-
-    case map_group_pairs(Pairs) of
-	{Assoc,[]} ->
-	    Kes = [#k_map_pair{key=K,val=V}||{_,{assoc,K,V}} <- Assoc],
-	    {#k_map{anno=A,op=assoc,var=Var,es=Kes},Esp,St1};
-	{[],Exact} ->
-	    Kes = [#k_map_pair{key=K,val=V}||{_,{exact,K,V}} <- Exact],
-	    {#k_map{anno=A,op=exact,var=Var,es=Kes},Esp,St1};
-	{Assoc,Exact} ->
-	    Kes1 = [#k_map_pair{key=K,val=V}||{_,{assoc,K,V}} <- Assoc],
-	    {Mvar,Em,St2} = force_atomic(#k_map{anno=A,op=assoc,var=Var,es=Kes1},St1),
-	    Kes2 = [#k_map_pair{key=K,val=V}||{_,{exact,K,V}} <- Exact],
-	    {#k_map{anno=A,op=exact,var=Mvar,es=Kes2},Esp ++ Em,St2}
-
+    map_split_pairs_1(A, Var, Pairs, Esp, St1).
+
+map_split_pairs_1(A, Map0, [{Op,Key,Val}|Pairs1]=Pairs0, Esp0, St0) ->
+    {Map1,Em,St1} = force_atomic(Map0, St0),
+    case Key of
+	#k_var{} ->
+	    %% Don't combine variable keys with other keys.
+	    Kes = [#k_map_pair{key=Key,val=Val}],
+	    Map = #k_map{anno=A,op=Op,var=Map1,es=Kes},
+	    map_split_pairs_1(A, Map, Pairs1, Esp0 ++ Em, St1);
+	_ ->
+	    %% Literal key. Split off all literal keys.
+	    {L,Pairs} = splitwith(fun({_,#k_var{},_}) -> false;
+				     ({_,_,_}) -> true
+				  end, Pairs0),
+	    {Map,Esp,St2} = map_group_pairs(A, Map1, L, Esp0 ++ Em, St1),
+	    map_split_pairs_1(A, Map, Pairs, Esp, St2)
+    end;
+map_split_pairs_1(_, Map, [], Esp, St0) ->
+    {Map,Esp,St0}.
+
+map_group_pairs(A, Var, Pairs0, Esp, St0) ->
+    Pairs = map_remove_dup_keys(Pairs0),
+    Assoc = [#k_map_pair{key=K,val=V} || {_,{assoc,K,V}} <- Pairs],
+    Exact = [#k_map_pair{key=K,val=V} || {_,{exact,K,V}} <- Pairs],
+    case {Assoc,Exact} of
+	{[_|_],[]} ->
+	    {#k_map{anno=A,op=assoc,var=Var,es=Assoc},Esp,St0};
+	{[],[_|_]} ->
+	    {#k_map{anno=A,op=exact,var=Var,es=Exact},Esp,St0};
+	{[_|_],[_|_]} ->
+	    Map = #k_map{anno=A,op=assoc,var=Var,es=Assoc},
+	    {Mvar,Em,St1} = force_atomic(Map, St0),
+	    {#k_map{anno=A,op=exact,var=Mvar,es=Exact},Esp ++ Em,St1}
     end.
 
-%% Group map by Assoc operations and Exact operations
-
-map_group_pairs(Es) ->
-    Groups = dict:to_list(map_group_pairs(Es,dict:new())),
-    partition(fun({_,{Op,_,_}}) -> Op =:= assoc end, Groups).
-
-map_group_pairs([{assoc,K,V}|Es0],Used0) ->
-    Used1 = case map_key_is_used(K,Used0) of
-	{ok, {assoc,_,_}} -> map_key_set_used(K,{assoc,K,V},Used0);
-	{ok, {exact,_,_}} -> map_key_set_used(K,{exact,K,V},Used0);
-	_                 -> map_key_set_used(K,{assoc,K,V},Used0)
-    end,
-    map_group_pairs(Es0,Used1);
-map_group_pairs([{exact,K,V}|Es0],Used0) ->
-    Used1 = case map_key_is_used(K,Used0) of
-	{ok, {assoc,_,_}} -> map_key_set_used(K,{assoc,K,V},Used0);
-	{ok, {exact,_,_}} -> map_key_set_used(K,{exact,K,V},Used0);
-	_                 -> map_key_set_used(K,{exact,K,V},Used0)
-    end,
-    map_group_pairs(Es0,Used1);
-map_group_pairs([],Used) ->
-    Used.
+map_remove_dup_keys(Es) ->
+    dict:to_list(map_remove_dup_keys(Es, dict:new())).
 
-map_key_set_used(K,How,Used) ->
-    dict:store(map_key_clean(K),How,Used).
-
-map_key_is_used(K,Used) ->
-    dict:find(map_key_clean(K),Used).
+map_remove_dup_keys([{assoc,K0,V}|Es0],Used0) ->
+    K = map_key_clean(K0),
+    Op = case dict:find(K, Used0) of
+	     {ok,{exact,_,_}} -> exact;
+	     _                -> assoc
+	 end,
+    Used1 = dict:store(K, {Op,K0,V}, Used0),
+    map_remove_dup_keys(Es0, Used1);
+map_remove_dup_keys([{exact,K0,V}|Es0],Used0) ->
+    K = map_key_clean(K0),
+    Op = case dict:find(K, Used0) of
+	     {ok,{assoc,_,_}} -> assoc;
+	     _                -> exact
+	 end,
+    Used1 = dict:store(K, {Op,K0,V}, Used0),
+    map_remove_dup_keys(Es0, Used1);
+map_remove_dup_keys([], Used) -> Used.
 
-%% Be explicit instead of using set_kanno(K,[])
+%% Be explicit instead of using set_kanno(K, []).
 map_key_clean(#k_var{name=V})    -> {var,V};
 map_key_clean(#k_literal{val=V}) -> {lit,V};
 map_key_clean(#k_int{val=V})     -> {lit,V};
-- 
cgit v1.2.3


From 70478d290046844b504c8fe0643e499009b735b4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Wed, 28 Jan 2015 15:26:52 +0100
Subject: cerl: Remove a clause in fold_map_pairs/3 that will never be reached

---
 lib/compiler/src/cerl.erl | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/lib/compiler/src/cerl.erl b/lib/compiler/src/cerl.erl
index 705c87539e..1a2957ee31 100644
--- a/lib/compiler/src/cerl.erl
+++ b/lib/compiler/src/cerl.erl
@@ -1644,9 +1644,7 @@ fold_map_pairs(As,[#c_map_pair{op=#c_literal{val=exact},key=Ck,val=Cv}=E|Es],M)
 	    end;
 	false ->
 	    #c_map{arg=#c_literal{val=M,anno=As}, es=[E|Es], anno=As }
-    end;
-fold_map_pairs(As,Es,M) ->
-    #c_map{arg=#c_literal{val=M,anno=As}, es=Es, anno=As }.
+    end.
 
 -spec update_c_map(c_map(), cerl(), [cerl()]) -> c_map() | c_literal().
 
-- 
cgit v1.2.3