when creating symbolic values, we distinguish between location and non-location
values. For location values, we create a symbolic region instead of a
loc::SymbolVal.
llvm-svn: 68373
Zhongxing and I discussed by email.
Main changes:
- Removed SymIntConstraintVal and SymIntConstraint
- Added SymExpr as a parent class to SymbolData, SymSymExpr, SymIntExpr
- Added nonloc::SymExprVal to wrap SymExpr
- SymbolRef is now just a typedef of 'const SymbolData*'
- Bunch of minor code cleanups in how some methods were invoked (no functionality change)
This changes are part of a long-term plan to have full symbolic expression
trees. This will be useful for lazily evaluating complicated expressions.
llvm-svn: 67731
SVal::GetRValueSymbolVal do the checking if we can symbolicate a type instead of
having BasicStoreManager do it (which wasn't always doing the check
consistently). Having this check in SVal::GetRValueSymbolVal keeps the check in
one centralized place.
llvm-svn: 67245
- Store bindings using a MemRegion -> SVal binding instead of VarDecl -> SVal
binding. This mirrors some of the idea of RegionStore, but is far simpler and
not nearly as functional. This leads to some code simplification and
some potential for some minor precision hacks.
Along the way...
- constify the use of MemRegion* in a few places
- add operator<<(llvm::raw_ostream, const MemRegion*)
llvm-svn: 66163
do the symblic regions associated with them and we need them to be typed.
Current SymbolicRegion::getRValueType() method is very restricting. It may be
modified when we are more clear about what could be the types of symblic
regions.
BasicConstraintManager::Assume() is changed due to that now SymblicRegion is a
subclass of SubRegion.
llvm-svn: 63844
their associated APIs. We no longer need separate SymbolData objects
for fields, variables, etc. Instead, we now associated symbols with
the "rvalue" of a MemRegion (i.e., the value stored at that region).
Now we only have two kinds of SymbolData objects: SymbolRegionRValue
and SymbolConjured.
This cleanup also makes the distinction between a SymbolicRegion and a
symbolic value that is a location much clearer. A SymbolicRegion
represents a chunk of symbolic memory, while a symbolic location is
just a "pointer" with different possible values. Without any specific
knowledge, a symbolic location resolves (i.e., via a dereference) to a
SymbolicRegion. In the future, when we do better alias reasoning, a
symbolic location can become an alias for another location, thus
merging the constraints on the referred SymbolicRegion with the other
region.
llvm-svn: 62769
* Now Bind() methods take and return GRState* because binding could
also alter GDM.
* No variables are initialized except those declared with initial
values.
* failed C test cases are due to bugs in RemoveDeadBindings(),
which removes constraints that is still alive. This will be fixed in later
patch.
* default value of array and struct regions will be implemented in later patch.
llvm-svn: 61274
- Overhauled the notion of "types" for TypedRegions. We now distinguish between the "lvalue" of a region (via getLValueRegion()) and the "rvalue" of a region (va getRValueRegion()). Since a region represents a chunk of memory it has both, but we were conflating these concepts in some cases, leading to some insidious bugs.
- Removed AnonPointeeType, partially because it is unused and because it doesn't have a clear notion of lvalue vs rvalue type. We can add it back once there is a need for it and we can resolve its role with these concepts.
StoreManager:
- Overhauled StoreManager::CastRegion. It expects an *lvalue* type for a region. This is actually what motivated the overhaul to the MemRegion type mechanism. It also no longer returns an SVal; we can just return a MemRegion*.
- BasicStoreManager::CastRegion now overlays an "AnonTypedRegion" for pointer-pointer casts. This matches with the MemRegion changes.
- Similar changes to RegionStore, except I've added a bunch of FIXMEs where it wasn't 100% clear where we should use TypedRegion::getRValueRegion() or TypedRegion::getLValueRegion().
AuditCFNumberCreate check:
- Now blasts through AnonTypedRegions that may layer the original memory region, thus checking if the actually memory block is of the appropriate type. This change was needed to work with the changes to StoreManager::CastRegion.
GRExprEngine::VisitCast:
- Conform to the new interface of StoreManager::CastRegion.
Tests:
- None of the analysis tests fail now for using the "basic store".
- Disabled the tests 'array-struct.c' and 'rdar-6442306-1.m' pending further testing and bug fixing.
llvm-svn: 60995
GRExprEngine (VisitCast):
- When using StoreManager::CastRegion, always use the state and value it returns to generate the next node. Failure to do so means that region values returned that don't require the state to be modified will get ignored.
MemRegion:
- Tighten the interface for ElementRegion. Now ElementRegion can only be created with a super region that is a 'TypedRegion' instead of any MemRegion. Code in BasicStoreManager/RegionStoreManager already assumed this, but it would result in a dynamic assertion check (and crash) rather than just having the compiler forbid the construction of such regions.
- Added ElementRegion::getArrayRegion() to return the 'typed version' of an ElementRegion's super region.
- Removed bogus assertion in ElementRegion::getType() that assumed that the super region was an AnonTypedRegion. All that matters is that it is a TypedRegion, which is now true all the time by design.
BasicStore:
- Modified getLValueElement() to check if the 'array' region is a TypedRegion before creating an ElementRegion. This conforms to the updated interface for ElementRegion.
RegionStore:
- In ArrayToPointer() gracefully handle things we don't reason about, and only create an ElementRegion if the array region is indeed a TypedRegion.
llvm-svn: 60990
- RegionView and RegionViewMap is introduced to assist back-mapping from
super region to subregions.
- GDM is used to carry RegionView information.
- AnonTypedRegion is added to represent a typed region introduced by pointer
casting. Later AnonTypedRegion can be used in other similar cases, e.g.,
malloc()'ed region.
- The specific conversion is delegated to store manager.
llvm-svn: 59382
BindDecl better describes what the function does:
- Bind the VarDecl to its memory region
- Bind the memory region to some initial value.
llvm-svn: 58359
- GRExprEngine::VisitCompoundLiteral...
(1) visits the initializer list (generating ExplodedNodes)
(2) creates a CompoundMemRegion for the literal
(3) creates a new state with the bound literal values using
GRStateManager::BindCompoundLiteral
- GRStateManager::BindCompoundLiteral simply calls
StoreManager::BindCompoundLiteral to get a new store and returns a persistent
GRState with that store.
- BasicStore::BindCompoundLiteral simply returns the same store, as it
doesn't handle field sensitivity
- RegionStore::BindCompoundLiteral currently fires an assert (pending discussion
of how to best implement mappings for CompoundLiteralRegion).
llvm-svn: 58277
GRExprEngine::VisitCast() so that other parts of the analyzer can be ignorant.
When we cast "array of type T" to "pointer to T", we get the loc::MemRegionVal
corresponding to the array variable. This is sufficient for BasicStore, but not
for RegionStore. RegionStore should get the element region for the first array
element in the cast. So next comes to the revamping of transfer functions for
different store model.
llvm-svn: 57897
- Added new region "SymbolicRegion", which maps symbol values to the region domain.
- Enhanced BasicStore::getFieldLValue() to return a FieldRegion (using SymbolicRegion)
- Added some utility methods to GRState for fetch svals from the store.
- Fixed regression in CheckNSError (we weren't getting the value bound to the parameter)
llvm-svn: 57717
Zhongxing Xu