This change was a lot bigger than I originally anticipated; among
other things it requires us storing more information in the CFG to
record what block-level expressions need to be evaluated as lvalues.
The big change is that CFGBlocks no longer contain Stmt*'s by
CFGElements. Currently CFGElements just wrap Stmt*, but they also
store a bit indicating whether the block-level expression should be
evalauted as an lvalue. DeclStmts involving the initialization of a
reference require us treating the initialization expression as an
lvalue, even though that information isn't recorded in the AST.
Conceptually this change isn't that complicated, but it required
bubbling up the data through the CFGBuilder, to GRCoreEngine, and
eventually to GRExprEngine.
The addition of CFGElement is also useful for when we want to handle
more control-flow constructs or other data we want to keep in the CFG
that isn't represented well with just a block of statements.
In GRExprEngine, this patch introduces logic for evaluating the
lvalues of references, which currently retrieves the internal "pointer
value" that the reference represents. EvalLoad does a two stage load
to catch null dereferences involving an invalid reference (although
this could possibly be caught earlier during the initialization of a
reference).
Symbols are currently symbolicated using the reference type, instead
of a pointer type, and special handling is required creating
ElementRegions that layer on SymbolicRegions (see the changes to
RegionStoreManager).
Along the way, the DeadStoresChecker also silences warnings involving
dead stores to references. This was the original change I introduced
(which I wrote test cases for) that I realized caused GRExprEngine to
crash.
llvm-svn: 91501
Remove isPod() from DenseMapInfo, splitting it out to its own
isPodLike type trait. This is a generally useful type trait for
more than just DenseMap, and we really care about whether something
acts like a pod, not whether it really is a pod.
llvm-svn: 91422
now, don't construct CFGs that contain C++ try/catch statements, and
have GRExprEngine abort a path if it encounters a C++ construct it
doesn't understand (which is mostly everything at this point).
llvm-svn: 91389
Otherwise, even when real evaluation occurs, the previous fake auto
transitions would still be in the destination set, causing fake state
bifurcation.
llvm-svn: 90967
by the test case in PR 5627. Essentially we shouldn't clear the
ExplodedNodeSet where we deposit newly constructed nodes if that set
is the 'Dst' set passed in. It is not okay to clear that set because
it may already contain nodes.
llvm-svn: 90931
- Refactor the MemRegion hierarchy to distinguish between different StackSpaceRegions for locals and parameters.
- VarRegions for "captured" variables now have the BlockDataRegion as their super region (except those passed by reference)
- Add transfer function support to GRExprEngine for BlockDeclRefExprs.
This change also supports analyzing blocks as an analysis entry point
(top-of-the-stack), which required pushing more context-sensitivity
around in the MemRegion hierarchy via the use of LocationContext
objects. Functionally almost everything is the same, except we track
LocationContexts in a few more areas and StackSpaceRegions now refer
to a StackFrameContext object. In the future we will need to modify
MemRegionManager to allow multiple StackSpaceRegions in flight at once
(for the analysis of multiple stack frames).
llvm-svn: 90809
handler to this interface.
GRExprEngine::CheckerEvalCall() will return true if one of the checkers has
processed the node. In the future this might return void when we have some
default checker.
llvm-svn: 90755
we don't need to use the DoneEvaluation hack when check for
ObjCMessageExpr.
PreVisitObjCMessageExpr() only checks for undefined receiver or arguments.
Add checker interface EvalNilReceiver(). This is a 'once-and-done' interface.
llvm-svn: 90296
the set of variables "captured" by a block. Until the analysis gets
more sophisticated, for now we stop the retain count tracking of any
objects (transitively) referenced by these variables.
llvm-svn: 89929
This required two changes:
1) Added 'getReferencedgetReferencedBlockVars()' to AnalysisContext so
that clients can iterate over the "captured" variables in a block.
2) Modified LiveVariables to take an AnalysisContext& in its
constructor and to call getReferencedgetReferencedBlockVars() when it
processes a BlockExpr*.
llvm-svn: 89924
'BlockDataRegion' to distinguish between the code associated with a
block (which is represented by 'BlockTextRegion') and an instance of a
block, which includes both code and data. 'BlockDataRegion' has an
associated LocationContext, which can be used to eventually model the
lifetime of a block object once LocationContexts can represent scopes
(and iterations around a loop, etc.).
llvm-svn: 89900
only stop processing the checkers after all the nodes for a current
check have been processed. This (I believe) handles the case where
PredSet (the input nodes) contains more than one node due to state
bifurcation. Zhongxing: can you review this?
llvm-svn: 89882
initial transition of the nil-receiver checker to the Checker
interface as done in r89745. Some important changes include:
1) We consolidate the BugType object used for nil receiver bug
reports, and don't include the type of the returned value in the
BugType (which would be wrong if a nil receiver bug was reported more
than once)
2) Added a new (temporary) flag to CheckerContext: DoneEvauating.
This is used by GRExprEngine when evaluating message expressions to
not continue evaluating the message expression if this flag is set.
This flag is currently set by the nil receiver checker. This is an
intermediate solution to allow the nil-receiver checker to properly
work as a plug-in outside of GRExprEngine. Basically, this flag
indicates that the entire message expression has been evaluated, not
just a precondition (which is what the nil-receiver checker does).
This flag *should not* be repurposed for general use, but just to pull
more things out of GRExprEngine that already in there as we devise a
better interface in the Checker class.
3) Cleaned up the logic in the nil-receiver checker, making the
control-flow a lot easier to read.
llvm-svn: 89804
along the way. Important changes:
1) To generate a sink node, use GenerateSink(); GenerateNode() is for
generating regular transitions. This makes the API clearer and also
allows us to use the 'bool' option to GenerateNode() for a different
purpose.
2) GenerateNode() now automatically adds the generated node to the
destination ExplodedNodeSet (autotransition) unless the client
specifies otherwise with a bool flag. Several checkers did not call
'addTransition()' after calling 'GenerateNode()', causing the
simulation path to be prematurely culled when a non-fail stop bug was
encountered.
3) Add variants of GenerateNode()/GenerateSink() that take neither a
Stmt* or a GRState*; most callers of GenerateNode() just pass in the
same Stmt* as provided when the CheckerContext object is created; we
can just use that the majority of the time. This cleanup also allows
us to potentially coelesce the APIs for evaluating branches and
end-of-paths (which currently directly use builders).
4) addTransition() no longer needs to be called except for a few
cases. We now have a variant of addTransition() that takes a
GRState*; this allows one to propagate the updated state without
caring about generating a new node explicitly. This nicely cleaned up
a bunch of cases that called autoTransition() with a bunch of
conditional logic surround the call (that common logic has now been
swallowed up by addTransition() itself).
llvm-svn: 89707
sugared types. The basic problem is that our qualifier accessors
(getQualifiers, getCVRQualifiers, isConstQualified, etc.) only look at
the current QualType and not at any qualifiers that come from sugared
types, meaning that we won't see these qualifiers through, e.g.,
typedefs:
typedef const int CInt;
typedef CInt Self;
Self.isConstQualified() currently returns false!
Various bugs (e.g., PR5383) have cropped up all over the front end due
to such problems. I'm addressing this problem by splitting each
qualifier accessor into two versions:
- the "local" version only returns qualifiers on this particular
QualType instance
- the "normal" version that will eventually combine qualifiers from this
QualType instance with the qualifiers on the canonical type to
produce the full set of qualifiers.
This commit adds the local versions and switches a few callers from
the "normal" version (e.g., isConstQualified) over to the "local"
version (e.g., isLocalConstQualified) when that is the right thing to
do, e.g., because we're printing or serializing the qualifiers. Also,
switch a bunch of
Context.getCanonicalType(T1).getUnqualifiedType() == Context.getCanonicalType(T2).getQualifiedType()
expressions over to
Context.hasSameUnqualifiedType(T1, T2)
llvm-svn: 88969
* Add a load type to GRExprEngine::EvalLoad().
* When retrieve from 'theValue' of OSAtomic funcitions, use the type of the
region instead of the argument expression as the load type.
* Then we can convert CastRetrievedSVal to a pure assertion. In the future
we can let all Retrieve() methods simply return SVal.
llvm-svn: 88888
- Eliminates many calls to std::string.c_str()
- Fixes an invalid read in ReturnStackAddressChecker due to an unsafe call to
StringRef.data() which doesn't guarantee null-termination.
llvm-svn: 88779
Zhongxing Xu