From 0f222d55ce46358aa7891ea482655937daaf8b52 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Wed, 18 May 2016 06:21:34 +0200
Subject: beam_type: Correct handling of setelement/3

We must be careful how we treat the type info for the result of:

  setelement(Index, Tuple, NewValue)

If Tuple had type information, the result of setelement/3 (in x(0))
would be assigned the same type information. But that is not safe
for:

  setelement(1, Tuple, NewValue)

since the type for the first element will be changed.

Therefore, we must take care to remove the type information for
the first element of the tuple if might have been modified by
setelement/3.
---
 lib/compiler/test/beam_type_SUITE.erl | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

(limited to 'lib/compiler/test/beam_type_SUITE.erl')

diff --git a/lib/compiler/test/beam_type_SUITE.erl b/lib/compiler/test/beam_type_SUITE.erl
index 8d5c0190ed..063a27ad8d 100644
--- a/lib/compiler/test/beam_type_SUITE.erl
+++ b/lib/compiler/test/beam_type_SUITE.erl
@@ -21,7 +21,7 @@
 
 -export([all/0,suite/0,groups/0,init_per_suite/1,end_per_suite/1,
 	 init_per_group/2,end_per_group/2,
-	 integers/1,coverage/1,booleans/1]).
+	 integers/1,coverage/1,booleans/1,setelement/1]).
 
 suite() -> [{ct_hooks,[ts_install_cth]}].
 
@@ -33,7 +33,8 @@ groups() ->
     [{p,[parallel],
       [integers,
        coverage,
-       booleans
+       booleans,
+       setelement
       ]}].
 
 init_per_suite(Config) ->
@@ -94,5 +95,11 @@ do_booleans(B) ->
 	no -> no
     end.
 
+setelement(_Config) ->
+    T0 = id({a,42}),
+    {a,_} = T0,
+    {b,_} = setelement(1, T0, b),
+    ok.
+
 id(I) ->
     I.
-- 
cgit v1.2.3


From 121cc9ba61e44e9c47d831d837dfb0f0b2d81990 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Tue, 17 May 2016 07:09:59 +0200
Subject: beam_type: Eliminate crash

The following code:

simple() ->
    case try 0 after [] end of
	0 -> college;
	1 -> 0
    end.

would crash the compiler like this:

crash reason: {case_clause,
    {'EXIT',
        {function_clause,
            [{beam_type,simplify_select_val_int,
                 [{select,select_val,
                      {x,0},
                      {f,7},
                      [{integer,1},{f,9},{integer,0},{f,8}]},
                  0],
                 [{file,"beam_type.erl"},{line,169}]},
             {beam_type,simplify_basic_1,3,
                 [{file,"beam_type.erl"},{line,155}]},
             {beam_type,opt,3,[{file,"beam_type.erl"},{line,57}]},
             {beam_type,function,1,[{file,"beam_type.erl"},{line,36}]},
             {beam_type,'-module/2-lc$^0/1-0-',1,
                 [{file,"beam_type.erl"},{line,30}]},
             {beam_type,module,2,[{file,"beam_type.erl"},{line,30}]},
             {compile,'-select_passes/2-anonymous-2-',2,
                 [{file,"compile.erl"},{line,521}]},
             {compile,'-internal_comp/4-anonymous-1-',2,
                 [{file,"compile.erl"},{line,306}]}]}}}

The root cause is that the type representation is not well-defined.

Integers could be represented in three different ways:

  integer
  {integer,{1,10}}
  {integer,0}

However, only the first two forms were handled.

To avoid similar problems in the future:

* Make the type representation stricter. Make sure that integers are
  only represented as 'integer' or {integer,{Min,Max}}.

* Call verify_type/1 whenever a new type is added (not only when
  merging types) to ensure that only the supported types are added
  to the type database).

(ERL-150)
---
 lib/compiler/test/beam_type_SUITE.erl | 29 +++++++++++++++++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)

(limited to 'lib/compiler/test/beam_type_SUITE.erl')

diff --git a/lib/compiler/test/beam_type_SUITE.erl b/lib/compiler/test/beam_type_SUITE.erl
index 063a27ad8d..69e2f1838d 100644
--- a/lib/compiler/test/beam_type_SUITE.erl
+++ b/lib/compiler/test/beam_type_SUITE.erl
@@ -21,7 +21,8 @@
 
 -export([all/0,suite/0,groups/0,init_per_suite/1,end_per_suite/1,
 	 init_per_group/2,end_per_group/2,
-	 integers/1,coverage/1,booleans/1,setelement/1]).
+	 integers/1,coverage/1,booleans/1,setelement/1,cons/1,
+	 tuple/1]).
 
 suite() -> [{ct_hooks,[ts_install_cth]}].
 
@@ -34,7 +35,9 @@ groups() ->
       [integers,
        coverage,
        booleans,
-       setelement
+       setelement,
+       cons,
+       tuple
       ]}].
 
 init_per_suite(Config) ->
@@ -56,6 +59,8 @@ integers(_Config) ->
     a = do_integers_2(<<0:1>>),
     {'EXIT',{{case_clause,-1},_}} = (catch do_integers_2(<<1:1>>)),
 
+    college = do_integers_3(),
+
     ok.
 
 do_integers_1(B0) ->
@@ -72,6 +77,12 @@ do_integers_2(Bin) ->
 	1 -> b
     end.
 
+do_integers_3() ->
+    case try 0 after [] end of
+	0 -> college;
+	1 -> 0
+    end.
+
 coverage(_Config) ->
     {'EXIT',{badarith,_}} = (catch id(1) bsl 0.5),
     {'EXIT',{badarith,_}} = (catch id(2.0) bsl 2),
@@ -101,5 +112,19 @@ setelement(_Config) ->
     {b,_} = setelement(1, T0, b),
     ok.
 
+cons(_Config) ->
+    [did] = cons(assigned, did),
+    ok.
+
+cons(assigned, Instrument) ->
+    [Instrument] = [did].
+
+tuple(_Config) ->
+    {'EXIT',{{badmatch,{necessary}},_}} = (catch do_tuple()),
+    ok.
+
+do_tuple() ->
+    {0, _} = {necessary}.
+
 id(I) ->
     I.
-- 
cgit v1.2.3