pointers. Most logic cares first about whether or not a region is
symbolic, and second if represents code. This should fix a series of
silent corner case bugs (as well as simplify a bunch of code).
llvm-svn: 80335
implicit cast logic in RegionStoreManager to BasicStoreManager. This involved
moving CastRetriedVal from RegionStoreManager to StoreManager.
llvm-svn: 80026
made to RegionStore (and related classes) in order to handle some
analyzer failures involving casts and manipulation of symbolic memory.
The root of the change is in StoreManager::CastRegion(). Instead of
using ad hoc heuristics to decide when to layer an ElementRegion on a
casted MemRegion, we now always layer an ElementRegion when the cast
type is different than the original type of the region. This carries
the current cast information associated with a region around without
resorting to the error prone recording of "casted types" in GRState.
Along with this new policy of layering ElementRegions, I added a new
algorithm to strip away existing ElementRegions when they simply
represented casts of a base memory object. This algorithm computes
the raw "byte offset" that an ElementRegion represents from the base
region, and allows the new ElementRegion to be based off that offset.
The added benefit is that this naturally handles a series of casts of
a MemRegion without building up a set of redundant ElementRegions
(thus canonicalizing the region view).
Other related changes that cascaded from this one (as tests were
failing in RegionStore):
- Revamped RegionStoreManager::InvalidateRegion() to completely remove
all bindings and default values from a region and all subregions.
Now invalidated fields are not bound directly to new symbolic
values; instead the base region has a "default" symbol value from
which "derived symbols" can be created. The main advantage of this
approach is that it allows us to invalidate a region hierarchy and
then lazily instantiate new values no matter how deep the hierarchy
went (i.e., regardless of the number of field accesses,
e.g. x->f->y->z->...). The previous approach did not do this.
- Slightly reworked RegionStoreManager::RemoveDeadBindings() to also
incorporate live symbols and live regions that do not have direct
bindings but also have "default values" used for lazy instantiation.
The changes to 'InvalidateRegion' revealed that these were necessary
in order to achieve lazy instantiation of values in the region store
with those bindings being removed too early.
- The changes to InvalidateRegion() and RemoveDeadBindings() revealed
a serious bug in 'getSubRegionMap()' where not all region -> subregion
relationships involved in actually bindings (explicit and implicit)
were being recorded. This has been fixed by using a worklist algorithm
to iteratively fill in the region map.
- Added special support to RegionStoreManager::Bind()/Retrieve() to handle
OSAtomicCompareAndSwap in light of the new 'CastRegion' changes and the
layering of ElementRegions.
- Fixed a bug in SymbolReaper::isLive() where derived symbols were not
being marked live if the symbol they were derived from was also live.
This fix was critical for getting lazy instantiation in RegionStore
to work.
- Tidied up the implementation of ValueManager::getXXXSymbolVal() methods
to use SymbolManager::canSymbolicate() to decide whether or not a
symbol should be symbolicated.
- 'test/Analysis/misc-ps-xfail.m' now passes; that test case has been
moved to 'test/Analysis/misc-ps.m'.
- Tweaked some pretty-printing of MemRegions, and implemented
'ElementRegion::getRawOffset()' for use with the CastRegion changes.
llvm-svn: 77782
Type::getAsReferenceType() -> Type::getAs<ReferenceType>()
Type::getAsRecordType() -> Type::getAs<RecordType>()
Type::getAsPointerType() -> Type::getAs<PointerType>()
Type::getAsBlockPointerType() -> Type::getAs<BlockPointerType>()
Type::getAsLValueReferenceType() -> Type::getAs<LValueReferenceType>()
Type::getAsRValueReferenceType() -> Type::getAs<RValueReferenceType>()
Type::getAsMemberPointerType() -> Type::getAs<MemberPointerType>()
Type::getAsReferenceType() -> Type::getAs<ReferenceType>()
Type::getAsTagType() -> Type::getAs<TagType>()
And remove Type::getAsReferenceType(), etc.
This change is similar to one I made a couple weeks ago, but that was partly
reverted pending some additional design discussion. With Doug's pending smart
pointer changes for Types, it seemed natural to take this approach.
llvm-svn: 77510
in StoreManager to RegionStoreManager, and create a special, highly reduced
version in BasicStoreManager.
These changes are in preparation for future RegionStore-specific changes to
InvalidateRegion.
llvm-svn: 77483
'cast type' of a region to invalidate its binding. This only occurs
when using RegionStoreManager, as it records the cast type. I'm
currently considering removing the notion of a cast type (see
comments in code).
llvm-svn: 76719
until Doug Gregor's Type smart pointer code lands (or more discussion occurs).
These methods just call the new Type::getAs<XXX> methods, so we still have
reduced implementation redundancy. Having explicit getAsXXXType() methods makes
it easier to set breakpoints in the debugger.
llvm-svn: 76193
This method is intended to eventually replace the individual
Type::getAsXXXType<> methods.
The motivation behind this change is twofold:
1) Reduce redundant implementations of Type::getAsXXXType() methods. Most of
them are basically copy-and-paste.
2) By centralizing the implementation of the getAs<Type> logic we can more
smoothly move over to Doug Gregor's proposed canonical type smart pointer
scheme.
Along with this patch:
a) Removed 'Type::getAsPointerType()'; now clients use getAs<PointerType>.
b) Removed 'Type::getAsBlockPointerTypE()'; now clients use getAs<BlockPointerType>.
llvm-svn: 76098
This patch causes:
- StoreManager::InvalidateRegion() to not used the casted type of a region if
it would cause a pointer type to be invalidated as a non-pointer type.
- Pushes RegionStore::RetrieveElement() further by handling retrievals from
symbolic arrays that have been invalidated. This uses the new SymbolDerived
construct that was recently introduced.
The result is that the failing test in misc-ps-region-store-x86_64.m now passes.
Both misc-ps-region-store-x86_64.m and misc-ps-region-store-i386.m contain a
test case that motivated this change.
llvm-svn: 75730
invalidate the region correctly. It uses the cast-to type to invalidate
the region when available. To avoid invalid cast-to type like 'void*' or 'id',
region store now only records non-generic casts of regions.
llvm-svn: 75580
CodeTextRegions can only be casted to FunctionPointer or BlockPointerTypes. This
simply isn't true. We can handle bogus operations on CodeTextRegions (e.g, an
array access) elsewhere.
llvm-svn: 75285
- Refactor logic that creates ElementRegions into a help method 'MakeElementRegion'.
- Fix crash due to not handling StringRegions. Casts of StringRegions now
result in a new ElementRegion layered on the original StringRegion.
llvm-svn: 74867
(its superclass). This will allow us to experiment with using the new CastRegion
with BasicStoreManager, and gradually phase out the old implementation.
llvm-svn: 74851
TypedRegion. While we plan on removing this code at some point, it serves as a
good reference implementation for use with BasicStore until we are sure the new
CastRegion logic (in RegionStore.cpp) is correct.
llvm-svn: 74559
- Update the old StoreManager::CastRegion to strip off 'ElementRegions' when
casting to void* (Zhongxing: please validate)
- Pass-by-reference argument invalidation logic in CFRefCount.cpp:
- Strip ElementRegions when the ElementRegion is just a 'raw data' view
on top of the underlying typed region.
llvm-svn: 71094
'ElementRegion' on top of the VarRegion for 'x'. This causes the test
case xfail_wine_crash.c to now pass for BasicStoreManager. It doesn't
crash for RegionStoreManager either, but reports a bogus unintialized
value warning.
llvm-svn: 70832
- Don't layer TypedViewRegions on top of any region except
SymbolicRegions and AllocaRegions. This follows from my offline
discussion within Zhongxing about how TypedViewRegions really only
represent memory getting re-appropriated for a new purpose.
Fallout from this change:
- Move test case from xfail_rdar_6440393.m to misc-ps-64.m
(it now passes).
- test/Analysis/fields.c now fails for region store (crash).
Marking XFAIL.
- test/Analysis/rdar-6441136-region.c now fails (only runs with region store).
Marking XFAIL.
Diagnosis: The analyzer now correctly identifies an early out-of-bounds memory
access then the one flagged:
rdar-6541136-region.c:17:3: warning: Load or store into an out-of-bound memory position.
*p = 1;
^~
Changing the line:
char *p = (void*) &wonky[1];
to
char *p = (void*) &wonky[0];
(which should delay the buffer overrun) causes region store to crash, probably
because it expects a TypedViewRegion.
- test/Analysis/casts.c (region store) now fails (crash).
Marking XFAIL.
llvm-svn: 70565
into StoreManager::CastRegion. Both methods were practically identical, and this
is core logic that is common to all StoreManagers since it defines the basic
invariants of the abstract memory model.
llvm-svn: 69730
Zhongxing Xu