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authorErlang/OTP <[email protected]>2009-12-14 12:54:41 +0000
committerErlang/OTP <[email protected]>2009-12-14 12:54:41 +0000
commit47b882a585b5a226bd00b5125bac948ba9268c7f (patch)
tree16b9b5e3e572e13c16db227af0397a644541d9f1
parent76623933ce8b95f3be52c06311374370e94f1348 (diff)
parent88efa63b733b627934fb7eec6236c71d7acfe082 (diff)
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Merge branch 'bg/compiler-bopt-bug' into ccase/r13b04_dev
* bg/compiler-bopt-bug: beam_bool: Fix generation of code that does not validate Fix crash in beam_bool OTP-8338 Using complex boolean expressions in ifs could cause the compiler to either crash or teminate with an internal error. (Thanks to Simon Cornish.)
-rw-r--r--lib/compiler/src/beam_bool.erl27
-rw-r--r--lib/compiler/test/andor_SUITE.erl66
2 files changed, 79 insertions, 14 deletions
diff --git a/lib/compiler/src/beam_bool.erl b/lib/compiler/src/beam_bool.erl
index d8c201a194..dcc6ad4c7c 100644
--- a/lib/compiler/src/beam_bool.erl
+++ b/lib/compiler/src/beam_bool.erl
@@ -123,6 +123,12 @@ bopt_block(Reg, Fail, OldIs, [{block,Bl0}|Acc0], St0) ->
throw:mixed ->
failed;
+ %% There was a reference to a boolean expression
+ %% from inside a protected block (try/catch), to
+ %% a boolean expression outside.
+ 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).
@@ -167,7 +173,7 @@ bopt_block(Reg, Fail, OldIs, [{block,Bl0}|Acc0], St0) ->
%% whether the optimized code is guaranteed to work in the same
%% way as the original code.
%%
-%% Throws an exception if the optmization is not safe.
+%% Throw an exception if the optimization is not safe.
%%
ensure_opt_safe(Bl, NewCode, OldIs, Fail, PreceedingCode, St) ->
%% Here are the conditions that must be true for the
@@ -184,10 +190,10 @@ ensure_opt_safe(Bl, NewCode, OldIs, Fail, PreceedingCode, St) ->
%% by the code that follows.
%%
%% 3. Any register that is assigned a value in the optimized
- %% code must be UNUSED or KILLED in the following code.
- %% (Possible future improvement: Registers that are known
- %% to be assigned the SAME value in the original and optimized
- %% code don't need to be unused in the following code.)
+ %% code must be UNUSED or KILLED in the following code
+ %% (because the register might be assigned the wrong value,
+ %% and even if the value is right it might no longer be
+ %% assigned on *all* paths leading to its use).
InitInPreceeding = initialized_regs(PreceedingCode),
@@ -304,6 +310,8 @@ dst_regs([{set,[D],_,{bif,_,{f,_}}}|Is], Acc) ->
dst_regs(Is, [D|Acc]);
dst_regs([{set,[D],_,{alloc,_,{gc_bif,_,{f,_}}}}|Is], Acc) ->
dst_regs(Is, [D|Acc]);
+dst_regs([{set,[D],_,move}|Is], Acc) ->
+ dst_regs(Is, [D|Acc]);
dst_regs([_|Is], Acc) ->
dst_regs(Is, Acc);
dst_regs([], Acc) -> ordsets:from_list(Acc).
@@ -414,11 +422,10 @@ bopt_good_args([A|As], Regs) ->
bopt_good_args([], _) -> ok.
bopt_good_arg({Tag,_}=X, Regs) when Tag =:= x; Tag =:= tmp ->
- case gb_trees:get(X, Regs) of
- any -> ok;
- _Other ->
- %%io:format("not any: ~p: ~p\n", [X,_Other]),
- throw(mixed)
+ case gb_trees:lookup(X, Regs) of
+ {value,any} -> ok;
+ {value,_} -> throw(mixed);
+ none -> throw(protected_barrier)
end;
bopt_good_arg(_, _) -> ok.
diff --git a/lib/compiler/test/andor_SUITE.erl b/lib/compiler/test/andor_SUITE.erl
index 34609a49f2..a460d54239 100644
--- a/lib/compiler/test/andor_SUITE.erl
+++ b/lib/compiler/test/andor_SUITE.erl
@@ -20,13 +20,14 @@
-export([all/1,
t_case/1,t_and_or/1,t_andalso/1,t_orelse/1,inside/1,overlap/1,
- combined/1,in_case/1]).
+ combined/1,in_case/1,before_and_inside_if/1]).
-include("test_server.hrl").
all(suite) ->
test_lib:recompile(?MODULE),
- [t_case,t_and_or,t_andalso,t_orelse,inside,overlap,combined,in_case].
+ [t_case,t_and_or,t_andalso,t_orelse,inside,overlap,combined,in_case,
+ before_and_inside_if].
t_case(Config) when is_list(Config) ->
%% We test boolean cases almost but not quite like cases
@@ -380,6 +381,65 @@ in_case_1_guard(LenUp, LenDw, LenN, Rotation, Count) ->
false -> loop
end.
+before_and_inside_if(Config) when is_list(Config) ->
+ ?line no = before_and_inside_if([a], [b], delete),
+ ?line no = before_and_inside_if([a], [b], x),
+ ?line no = before_and_inside_if([a], [], delete),
+ ?line no = before_and_inside_if([a], [], x),
+ ?line no = before_and_inside_if([], [], delete),
+ ?line yes = before_and_inside_if([], [], x),
+ ?line yes = before_and_inside_if([], [b], delete),
+ ?line yes = before_and_inside_if([], [b], x),
+
+ ?line {ch1,ch2} = before_and_inside_if_2([a], [b], blah),
+ ?line {ch1,ch2} = before_and_inside_if_2([a], [b], xx),
+ ?line {ch1,ch2} = before_and_inside_if_2([a], [], blah),
+ ?line {ch1,ch2} = before_and_inside_if_2([a], [], xx),
+ ?line {no,no} = before_and_inside_if_2([], [b], blah),
+ ?line {no,no} = before_and_inside_if_2([], [b], xx),
+ ?line {ch1,no} = before_and_inside_if_2([], [], blah),
+ ?line {no,ch2} = before_and_inside_if_2([], [], xx),
+ ok.
+
+%% Thanks to Simon Cornish and Kostis Sagonas.
+%% Used to crash beam_bool.
+before_and_inside_if(XDo1, XDo2, Do3) ->
+ Do1 = (XDo1 =/= []),
+ Do2 = (XDo2 =/= []),
+ if
+ %% This expression occurs in a try/catch (protected)
+ %% block, which cannot refer to variables outside of
+ %% the block that are boolean expressions.
+ Do1 =:= true;
+ Do1 =:= false, Do2 =:= false, Do3 =:= delete ->
+ no;
+ true ->
+ yes
+ end.
+
+%% Thanks to Simon Cornish.
+%% Used to generate code that would not set {y,0} on
+%% all paths before its use (and therefore fail
+%% validation by the beam_validator).
+before_and_inside_if_2(XDo1, XDo2, Do3) ->
+ Do1 = (XDo1 =/= []),
+ Do2 = (XDo2 =/= []),
+ CH1 = if Do1 == true;
+ Do1 == false,Do2==false,Do3 == blah ->
+ ch1;
+ true ->
+ no
+ end,
+ CH2 = if Do1 == true;
+ Do1 == false,Do2==false,Do3 == xx ->
+ ch2;
+ true ->
+ no
+ end,
+ {CH1,CH2}.
+
+%% Utilities.
+
check(V1, V0) ->
if V1 /= V0 ->
io:fwrite("error: ~w.\n", [V1]),
@@ -393,5 +453,3 @@ echo(X) ->
X.
id(I) -> I.
-
-