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-rw-r--r--lib/compiler/src/beam_bool.erl75
-rw-r--r--lib/compiler/test/guard_SUITE.erl18
2 files changed, 63 insertions, 30 deletions
diff --git a/lib/compiler/src/beam_bool.erl b/lib/compiler/src/beam_bool.erl
index 5a4621dc37..a452d30b61 100644
--- a/lib/compiler/src/beam_bool.erl
+++ b/lib/compiler/src/beam_bool.erl
@@ -126,44 +126,53 @@ bopt_block(Reg, Fail, OldIs, [{block,Bl0}|Acc0], St0) ->
%% There was a reference to a boolean expression
%% from inside a protected block (try/catch), to
%% a boolean expression outside.
- throw:protected_barrier ->
+ throw:protected_barrier ->
failed;
- %% The 'xor' operator was used. We currently don't
- %% find it worthwile to translate 'xor' operators
- %% (the code would be clumsy).
- throw:'xor' ->
+ %% The 'xor' operator was used. We currently don't
+ %% find it worthwile to translate 'xor' operators
+ %% (the code would be clumsy).
+ throw:'xor' ->
failed;
- %% The block does not contain a boolean expression,
- %% but only a call to a guard BIF.
- %% For instance: ... when element(1, T) ->
- throw:not_boolean_expr ->
+ %% The block does not contain a boolean expression,
+ %% but only a call to a guard BIF.
+ %% For instance: ... when element(1, T) ->
+ throw:not_boolean_expr ->
failed;
- %% The block contains a 'move' instruction that could
- %% not be handled.
- throw:move ->
+ %% The block contains a 'move' instruction that could
+ %% not be handled.
+ throw:move ->
failed;
- %% The optimization is not safe. (A register
- %% used by the instructions following the
- %% optimized code is either not assigned a
- %% value at all or assigned a different value.)
- throw:all_registers_not_killed ->
+ %% The optimization is not safe. (A register
+ %% used by the instructions following the
+ %% optimized code is either not assigned a
+ %% value at all or assigned a different value.)
+ throw:all_registers_not_killed ->
failed;
- throw:registers_used ->
+ throw:registers_used ->
failed;
- %% A protected block refered to the value
- %% returned by another protected block,
- %% probably because the Core Erlang code
- %% used nested try/catches in the guard.
- %% (v3_core never produces nested try/catches
- %% in guards, so it must have been another
- %% Core Erlang translator.)
- throw:protected_violation ->
+ %% A protected block refered to the value
+ %% returned by another protected block,
+ %% probably because the Core Erlang code
+ %% used nested try/catches in the guard.
+ %% (v3_core never produces nested try/catches
+ %% in guards, so it must have been another
+ %% Core Erlang translator.)
+ throw:protected_violation ->
+ failed;
+
+ %% Failed to work out the live registers for a GC
+ %% BIF. For example, if the number of live registers
+ %% needed to be 4 because {x,3} was a source register,
+ %% but {x,2} was not known to be initialized, this
+ %% exception would be thrown.
+ throw:gc_bif_alloc_failure ->
failed
+
end
end.
@@ -665,10 +674,16 @@ put_reg_1(V, [], I) -> [{I,V}].
fetch_reg(V, [{I,V}|_]) -> {x,I};
fetch_reg(V, [_|SRs]) -> fetch_reg(V, SRs).
-live_regs(Regs) ->
- foldl(fun ({I,_}, _) ->
- I
- end, -1, Regs)+1.
+live_regs([{_,reserved}|_]) ->
+ %% We are not sure that this register is initialized, so we must
+ %% abort the optimization.
+ throw(gc_bif_alloc_failure);
+live_regs([{I,_}]) ->
+ I+1;
+live_regs([{_,_}|Regs]) ->
+ live_regs(Regs);
+live_regs([]) ->
+ 0.
%%%
diff --git a/lib/compiler/test/guard_SUITE.erl b/lib/compiler/test/guard_SUITE.erl
index eb205d09a7..34bfdeb1e5 100644
--- a/lib/compiler/test/guard_SUITE.erl
+++ b/lib/compiler/test/guard_SUITE.erl
@@ -1556,6 +1556,24 @@ bad_constants(Config) when is_list(Config) ->
bad_guards(Config) when is_list(Config) ->
if erlang:float(self()); true -> ok end,
+
+ fc(catch bad_guards_1(1, [])),
+ fc(catch bad_guards_1(1, [2])),
+ fc(catch bad_guards_1(atom, [2])),
+
+ fc(catch bad_guards_2(#{a=>0,b=>0}, [])),
+ fc(catch bad_guards_2(#{a=>0,b=>0}, [x])),
+ fc(catch bad_guards_2(not_a_map, [x])),
+ fc(catch bad_guards_2(42, [x])),
+ ok.
+
+%% beam_bool used to produce GC BIF instructions whose
+%% Live operands included uninitialized registers.
+
+bad_guards_1(X, [_]) when {{X}}, -X ->
+ ok.
+
+bad_guards_2(M, [_]) when M#{a := 0, b => 0}, map_size(M) ->
ok.
%% Call this function to turn off constant propagation.