Due to the previously added overflow checks, we can have a retain/release
relation that is one directional. This occurs specifically when we run into an
additive overflow causing us to drop state in only one direction. If that
occurs, we should bail and not optimize that retain/release instead of
asserting.
Apologies for the size of the testcase. It is necessary to cause the additive
cfg overflow to trigger.
rdar://15377890
llvm-svn: 194083
The reason that I am turning off this optimization is that there is an
additional case where a block can escape that has come up. Specifically, this
occurs when a block is used in a scope outside of its current scope.
This can cause a captured retainable object pointer whose life is preserved by
the objc_retainBlock to be deallocated before the block is invoked.
An example of the code needed to trigger the bug is:
----
\#import <Foundation/Foundation.h>
int main(int argc, const char * argv[]) {
void (^somethingToDoLater)();
{
NSObject *obj = [NSObject new];
somethingToDoLater = ^{
[obj self]; // Crashes here
};
}
NSLog(@"test.");
somethingToDoLater();
return 0;
}
----
In the next commit, I remove all the dead code that results from this.
Once I put in the fixing commit I will bring back the tests that I deleted in
this commit.
rdar://14802782.
rdar://14868830.
llvm-svn: 189869
I fixed the aforementioned problems that came up on some of the linux boxes.
Major thanks to Nick Lewycky for his help debugging!
rdar://14590914
llvm-svn: 188122
This reverts commit r187941.
The commit was passing on my os x box, but it is failing on some non-osx
platforms. I do not have time to look into it now, so I am reverting and will
recommit after I figure this out.
llvm-svn: 187946
This is the first patch in a series of 3 patches which clean up how we create
runtime function declarations in the ARC optimizer when they do not exist
already in the IR.
Currently we have a bunch of duplicated code in ObjCARCOpts, ObjCARCContract
that does this. This patch refactors that code into a separate class called
ARCRuntimeEntryPoints which lazily creates the declarations for said
entrypoints.
The next two patches will consist of the work of refactoring
ObjCARCContract/ObjCARCOpts to use this new code.
llvm-svn: 185740
This is apart of a series of patches to encapsulate PtrState.RRI and
make PtrState.RRI a private field of PtrState.
*NOTE* This is actually the second commit in the patch stream. I should
have put this note on the first such commit r184528.
llvm-svn: 184532
In the presense of a block being initialized, the frontend will emit the
objc_retain on the original pointer and the release on the pointer loaded from
the alloca. The optimizer will through the provenance analysis realize that the
two are related (albiet different), but since we only require KnownSafe in one
direction, will match the inner retain on the original pointer with the guard
release on the original pointer. This is fixed by ensuring that in the presense
of allocas we only unconditionally remove pointers if both our retain and our
release are KnownSafe (i.e. we are KnownSafe in both directions) since we must
deal with the possibility that the frontend will emit what (to the optimizer)
appears to be unbalanced retain/releases.
An example of the miscompile is:
%A = alloca
retain(%x)
retain(%x) <--- Inner Retain
store %x, %A
%y = load %A
... DO STUFF ...
release(%y)
call void @use(%x)
release(%x) <--- Guarding Release
getting optimized to:
%A = alloca
retain(%x)
store %x, %A
%y = load %A
... DO STUFF ...
release(%y)
call void @use(%x)
rdar://13750319
llvm-svn: 181743
This makes the statistics gathering completely independent of the actual
optimization occuring, preventing any sort of bleeding over from occuring.
Additionally, it simplifies a switch statement in the non-statistic gathering case.
llvm-svn: 181719
the things, and renames it to CBindingWrapping.h. I also moved
CBindingWrapping.h into Support/.
This new file just contains the macros for defining different wrap/unwrap
methods.
The calls to those macros, as well as any custom wrap/unwrap definitions
(like for array of Values for example), are put into corresponding C++
headers.
Doing this required some #include surgery, since some .cpp files relied
on the fact that including Wrap.h implicitly caused the inclusion of a
bunch of other things.
This also now means that the C++ headers will include their corresponding
C API headers; for example Value.h must include llvm-c/Core.h. I think
this is harmless, since the C API headers contain just external function
declarations and some C types, so I don't believe there should be any
nasty dependency issues here.
llvm-svn: 180881
Turning retains into retainRV calls disrupts the data flow analysis in
ObjCARCOpts. Thus we move it as late as we can by moving it into
ObjCARCContract.
We leave in the conversion from retainRV -> retain in ObjCARCOpt since
it enables the dataflow analysis.
rdar://10813093
llvm-svn: 180698
