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
instead preferring to use the a region's actual type when creating
symbols and using the QualType passed to Retrieve for implicit
casting. This preprocessor logic is temporary; eventually we will
either remove region casts or keep them.
Temporarily toggle (via preprocessor directives) that SymbolicRegions
with heap storage are not undefined, but instead should be
symbolicated. If we want to model that a SymbolicRegion is
uninitialized, we can explicitly model that by binding UndefinedVal to
that region. It turns out that we want to treat most heap objects as
being defined, not the other way around.
llvm-svn: 76720
to SValuator::EvalCast. In the process, the StoreManagers now use this new cast
machinery, and the hack in GRExprEngine::EvalBind to handle implicit casts
involving OSAtomicCompareAndSwap and friends has been removed (and replaced with
logic closer to the logic specific to those functions).
llvm-svn: 76641
-refactor logic for retrieving bindings from VarDecls into
RegionStoreManager::RetrieveVar()
- improve RegionStoreManager::CastRetrievedVal() and SimpleSValuate::EvalCastNL
to better handle casts of values of the same canonical type as well as
casts of LocAsInteger values.
llvm-svn: 76516
pointers.
Enhanced RegionStoreManager::Retrieve() to handle automatic casts when the
loaded value is different from the requested value. This should be refined over
time, but essentially we should always symbolicate locations as locations, and
convert them to non-locations on demand.
These changes now cause 'misc-ps.m' to pass again.
llvm-svn: 76497
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
ValueManager::makeArrayIndex()/convertArrayIndex() methods. This
handles yet another crash case when reasoning about array indices of
different bitwidth and signedness.
llvm-svn: 75884
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
(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
ValueManager::getRegionValueSymbolVal() with unguarded calls to
ValueManager::getRegionValueSymbolValOrUnknown(). This changes centralizes the
decision of what values to symbolicate in SymbolManager rather than having it
scatter in RegionStoreManager.
llvm-svn: 74730
pass misc-ps.m. Currently RegionStore/BasicStore don't do any special reasoning
about clang-style vectors, so we should return UnknownVal (in all cases) when
accessing their values via an array.
llvm-svn: 74660
unknown for it.
Mark the super region of a live region as live, if the live region is pointed
to by a live pointer variable.
These fixes xfail_regionstore_wine_crash.c.
llvm-svn: 74524
Remove ASTContext parameter from DeclContext's methods. This change cascaded down to other Decl's methods and changes to call sites started "escalating".
Timings using pre-tokenized "cocoa.h" showed only a ~1% increase in time run between and after this commit.
llvm-svn: 74506
GRTransferFuncs had the conflated role of both constructing SVals (symbolic
expressions) as well as handling checker-specific logic. Now SValuator has the
role of constructing SVals from expressions and GRTransferFuncs just handles
checker-specific logic. The motivation is by separating these two concepts we
will be able to much more easily create richer constraint-generating logic
without coupling it to the main checker transfer function logic.
We now have one implementation of SValuator: SimpleSValuator.
SimpleSValuator is essentially the SVal-related logic that was in GRSimpleVals
(which is removed in this patch). This includes the logic for EvalBinOp,
EvalCast, etc. Because SValuator has a narrower role than the old
GRTransferFuncs, the interfaces are much simpler, and so is the implementation
of SimpleSValuator compared to GRSimpleVals. I also did a line-by-line review of
SVal-related logic in GRSimpleVals and cleaned it up while moving it over to
SimpleSValuator.
As a consequence of removing GRSimpleVals, there is no longer a
'-checker-simple' option. The '-checker-cfref' did everything that option did
but also ran the retain/release checker. Of course a user may not always wish to
run the retain/release checker, nor do we wish core analysis logic buried in the
checker-specific logic. The next step is to refactor the logic in CFRefCount.cpp
to separate out these pieces into the core analysis engine.
llvm-svn: 74229
- Change implementation of MemRegion::hasStackStorage()/hasHeapStorage() to use
'getMemorySpace()'. This avoids a double traversal up the region hierarchy
and is simpler.
- Add MemRegion::hasHeapOrStackStorage() as a slightly more efficient
alternative to 'hasStackStorage() || hasHeapStorage()'.
llvm-svn: 73977
Ted Kremenek