when running the analyzer on real projects. We'll keep the change to
AnalysisManager.cpp in r82198 so that -fobjc-gc analyzes code
correctly in both GC and non-GC modes, although this may emit two
diagnostics for each bug in some cases (a better solution will come
later).
llvm-svn: 82201
pruning of diagnostics that may be emitted multiple times. This is
accomplished by adding FoldingSet profiling support to PathDiagnostic,
and then having BugReporter record what diagnostics have been issued.
This was motived to a serious bug introduced by moving the
'divide-by-zero' checking outside of GRExprEngine into a separate
'Checker' class. When analyzing code using the '-fobjc-gc' option, a
given function would be analyzed twice, but the second time various
"internal checks" would be disabled to avoid emitting multiple
diagnostics (e.g., "null dereference") for the same issue. The
problem is that such checks also effect path pruning and don't just
emit diagnostics. This resulted in an assertion failure involving a
real divide-by-zero in some analyzed code where we would get an
assertion failure in APInt because the 'DivZero' check was disabled
and didn't prune the logic that resulted in the divide-by-zero in the
analyzer.
The implemented solution is somewhat of a hack, and may not perform
extremely well. This will need to be cleaned up over time.
As a regression test, 'misc-ps.m' has been modified so that its tests
are run using -fobjc-gc to test this diagnostic pruning behavior.
llvm-svn: 82198
Here we implement this as a precondition within GRExprEngine, even though it is
related to how BasicStoreManager and RegionStoreManager model 'self'
differently. Putting this as a high-level precondition is more general, which is
why it isn't in RegionStore.cpp.
llvm-svn: 81378
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
'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
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
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
ValueManager::makeArrayIndex()/convertArrayIndex() methods. This
handles yet another crash case when reasoning about array indices of
different bitwidth and signedness.
llvm-svn: 75884
where we are comparing a symbolic value against itself, regardless of
the nature of that symbolic value.
This enhancement identified a case where RegionStoreManager is not
correctly symbolicating the values of the pointees of parameters. The
failing test is now in 'test/Analysis/misc-ps-region-store.m', with
that test file now (temporarily) marked XFAIL.
llvm-svn: 75521
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
and replace the 'clang-cc' option '-analyzer-store=basic-new-cast' with
'-analyzer-store=basic-old-cast'. We'll keep the old CastRegion implementation
around for a little while for regression testing.
llvm-svn: 75209
- 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
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
ElementRegion. I also removed 'ElementRegion::getArrayRegion',
although we may need to add this back.
This breaks a few test cases with RegionStore:
- 'array-struct.c' triggers an infinite recursion in RegionStoreManager. Need to investigate.
- misc-ps.m triggers a failure with RegionStoreManager as we now get the diagnostic:
'Line 159: Uninitialized or undefined return value returned to caller.'
There were a bunch of places that needed to be edit
RegionStoreManager, and we may not be passing all the correct 'element
types' down from GRExprEngine.
Zhongxing: When you get a chance, could you review this? I could have
easily screwed up something basic in RegionStoreManager.
llvm-svn: 70830
When the StoreManager doesn't reason well about pointer-arithmetic, propagate
the non-nullness constraint on a pointer value when performing pointer
arithmetic uisng ++/--.
llvm-svn: 69741
clients of the analyzer to designate custom assertion routines as "noreturn"
functions from the analyzer's perspective but not the compiler's.
llvm-svn: 68746
Ted Kremenek