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authorBjörn Gustavsson <[email protected]>2016-10-02 14:21:13 +0200
committerBjörn Gustavsson <[email protected]>2016-10-27 08:14:08 +0200
commit89bf3f5bef9d9f5fb4a0003d6da028900d0f32fc (patch)
treef57230b970f903a7490c79bf9729c1483cb06300
parent9be10412e1837aac339a284f2b01cfc112778180 (diff)
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Don't copy funs into guards
Funs must not be created in guards. The instruction for creating a fun clobbers all X registers, which is a bad thing to do in a guard.
-rw-r--r--lib/compiler/src/sys_core_fold.erl8
-rw-r--r--lib/compiler/test/guard_SUITE.erl13
2 files changed, 20 insertions, 1 deletions
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl
index 5e1602cb5b..4922953407 100644
--- a/lib/compiler/src/sys_core_fold.erl
+++ b/lib/compiler/src/sys_core_fold.erl
@@ -1130,7 +1130,13 @@ clause_1(#c_clause{guard=G0,body=B0}=Cl, Ps1, Cexpr, Ctxt, Sub1) ->
%%
%% case A of NewVar when true -> ...
%%
- sub_set_var(Var, Cexpr, Sub2);
+ case cerl:is_c_fname(Cexpr) of
+ false ->
+ sub_set_var(Var, Cexpr, Sub2);
+ true ->
+ %% We must not copy funs, and especially not into guards.
+ Sub2
+ end;
_ ->
Sub2
end,
diff --git a/lib/compiler/test/guard_SUITE.erl b/lib/compiler/test/guard_SUITE.erl
index 6302f82f29..429d6b79e0 100644
--- a/lib/compiler/test/guard_SUITE.erl
+++ b/lib/compiler/test/guard_SUITE.erl
@@ -87,6 +87,7 @@ misc(Config) when is_list(Config) ->
{ok,buf,<<>>} = get_data({o,true,0}, 42, buf),
{ok,buf,<<>>} = get_data({o,false,0}, 0, buf),
error = get_data({o,false,0}, 42, buf),
+
ok.
@@ -343,6 +344,11 @@ complex_semicolon(Config) when is_list(Config) ->
ok = csemi7(#{a=>1}, 3, 3),
ok = csemi7(#{a=>1, b=>3}, 0, 0),
+ %% 8: Make sure that funs cannot be copied into guards.
+ ok = csemi8(true),
+ error = csemi8(false),
+ error = csemi8(42),
+
ok.
csemi1(Type, Val) when is_list(Val), Type == float;
@@ -457,6 +463,13 @@ csemi6(_, _) -> error.
csemi7(A, B, C) when A#{a:=B} > #{a=>1}; abs(C) > 2 -> ok;
csemi7(_, _, _) -> error.
+csemi8(Together) ->
+ case fun csemi8/1 of
+ Typically when Together; Typically, Together -> ok;
+ _ -> error
+ end.
+
+
comma(Config) when is_list(Config) ->
%% ',' combinations of literal true/false.