RegionStore already lazily abstracted the contents of arrays and structs, when
doing an assignment from one array/struct to another we did an explicit
element-wise copy, which resulted in a loss of laziness and huge performance
problem when analyzing many code bases.
Now RegionStoreManager handles such assignments using a new SVal could
'LazyCompoundSVal', which basically means the value of a given struct or array
(a MemRegion*) in a specific state (GRState). When we do a load from a field
whose encompassing struct binds to a LazyCompoundSVal, we essentially do a field
lookup in the original structure. This means we have essentially zero copying of
data for structs/arrays and everything stays lazy.
llvm-svn: 78268
constant value. If the UnaryOperator has location type, create the
constant with int type and pointer width.
This fixes the bug that all pointer increments 'p++' evaluated to Unknown.
llvm-svn: 78147
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
could cause false positives if any the subexpressions had side-effects. These
initializers weren't evaluated because the StoreManager would need to handle
them, but that's an orthogonal problem of whether or not the StoreManager can
handle the binding.
llvm-svn: 77361
TryEvaluateBool instead of using a raw 'int'. This avoids any
confusion of how 'int' converts to bool, and makes the resultant code
easier to read.
Condense a bunch of 'addSuccessor()' calls in 'if ... else' to use the
ternary operator instead.
llvm-svn: 76947
Educate GRExprEngine::VisitGraph() about 'PreStmt'.
Mark the constructor of 'PostStmt' to be explicit, preventing implicit
conversions and the selection of the wrong 'generateNode' method in
GRStmtNodeBuilder.
Constify a bunch of arguments, which falls out of the changes to ProgramPoint.
llvm-svn: 76809
'Checker' interface. An updated test case illustrates that after calling a
function with the 'nonnull' attribute we now register the fact that the passed
pointer must be non-null. This retention of information was not possible with
the previously used GRSimpleAPICheck interface.
llvm-svn: 76797
Ted Kremenek