Split it to two checkers, one for undefined size,
the other for zero size, so that we don't need to query the size
when emitting the bug report.
llvm-svn: 85895
by Zhongxing Xu. RemoveDeadBindings() would falsely prune
SymbolicRegions from the store that wrapped derived symbols whose
liveness could only be determined after scanning the store.
llvm-svn: 85484
RegionStoreManager::Retrieve() that was intended to handle conflated uses of pointers as integers.
It turns out this isn't needed, and resulted in inconsistent behavior when creating symbolic values on the following test case in 'tests/Analysis/misc-ps.m':
typedef struct _BStruct { void *grue; } BStruct;
void testB_aux(void *ptr);
void testB(BStruct *b) {
{
int *__gruep__ = ((int *)&((b)->grue));
int __gruev__ = *__gruep__;
testB_aux(__gruep__);
}
{
int *__gruep__ = ((int *)&((b)->grue));
int __gruev__ = *__gruep__;
if (~0 != __gruev__) {}
}
}
When the code was analyzed with '-arch x86_64', the value assigned to '__gruev__' be would be a
symbolic integer, but for '-arch i386' the value assigned to '__gruev__' would be a symbolic region
(a blob of memory). With this change the value created is always a symbolic integer.
Since the code being removed was added to support analysis of code calling
OSAtomicCompareAndSwapXXX(), I also modified 'test/Analysis/NSString.m' to analyze the code in both
'-arch i386' and '-arch x86_64', and also added some complementary test cases to test the presence
of leaks when using OSAtomicCompareAndSwap32Barrier()/OSAtomicCompareAndSwap64Barrier() instead of
just their absence. This code change reveals that previously both RegionStore and BasicStore were
handling these cases wrong, and would never cause the analyzer to emit a leak in these cases (false
negatives). Now RegionStore gets it right, but BasicStore still gets it wrong (and hence it has been
disabled temporarily for this test case).
llvm-svn: 84163
'CVPixelBufferCreateWithPlanarBytes()' and
'CVPixelBufferCreateWithBytes' (Core Video API) can indirectly release
a pixel buffer object via a callback.
This fixes <rdar://problem/7283567>.
llvm-svn: 84064
adding assert
This fix required a few changes:
SimpleSValuator:
- Eagerly replace a symbolic value with its constant value in EvalBinOpNN
when it is constrained to a constant. This allows us to better constant fold
values along a path.
- Handle trivial case of '<', '>' comparison of pointers when the two pointers
are exactly the same.
RegionStoreManager:
llvm-svn: 83358
identified with a false positive reported by Thomas Clement. This
involved doing another rewrite of
RegionStoreManager::RemoveDeadBindings(), which phrases the entire
problem of scanning for dead regions as a graph exploration problem.
It is more methodic than the previous implementation.
llvm-svn: 83053
are only specially treated by RegionStore::InvalidateRegion() when
their super region is also invalidated. When this isn't the case,
conjure a new symbol for a FieldRegion. Thanks to Zhongxing Xu and
Daniel Dunbar for pointing out this issue.
llvm-svn: 83043
<rdar://problem/6914474> checker doesn't realize that variable might
have been assigned if a pointer to that variable was passed to another
function via a structure
The problem here was the RegionStoreManager::InvalidateRegion didn't
invalidate the bindings of invalidated regions. This required a
rewrite of this method using a worklist.
As part of this fix, changed ValueManager::getConjuredSymbolVal() to
require a 'void*' SymbolTag argument. This tag is used to
differentiate two different symbols created at the same location.
llvm-svn: 82920
The issue was a discrepancy between how RegionStoreManager::Bind() and
RegionStoreManager::Retrieve() derived the "key" for the first element
of a symbolic region.
llvm-svn: 82680
integer pointer. For now just invalidate the fields of the struct.
This addresses: <rdar://problem/7185607> [RegionStore] support invalidation of bit fields using integer assignment
llvm-svn: 82492
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
to statically type various methods in SValuator/GRState as required either a
defined value or a defined-but-possibly-unknown value. This leads to various
logic cleanups in GRExprEngine, and lets the compiler enforce via type checking
our assumptions about what symbolic values are possibly undefined and what are
not.
Along the way, clean up some of the static analyzer diagnostics regarding the uses of uninitialized values.
llvm-svn: 81579
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
fixing <rdar://problem/7152619>. Along the way, merge test cases in
'test/Analysis/rdar-6539791.c' into 'test/Analysis/retain-release.m'.
llvm-svn: 79499
with array accesses. In the process, refactor some common logic in
RetrieveElement() and RetrieveField() into RetrieveFieldOrElementCommon().
llvm-svn: 78349
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
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
'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
'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
functions that return a value. I was going to buffer the whole lot
up, but it should be easier to review if I check them in
incrementally. Most of the forth coming changes either add a return
value, or make it impossible to return, or alter the return type.
llvm-svn: 76605
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
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
are not explicitly marked as not accepting NULL pointers. This check illustrates
how we need more refactoring in the custom-check logic.
llvm-svn: 75570
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
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
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
RegionStore needs to know the type of alloca region.
* RegionStoreManager::EvalBinOp() now converts the alloca region to its first
element region, as what is done to symbolic region.
llvm-svn: 72164
This patch isn't quite ideal in that it eliminates the warning for
constructs like "int a = {1};", where the braces are in fact redundant.
However, that would have required a bunch of refactoring, and it's
much less likely to cause confusion compared to redundant nested braces.
llvm-svn: 71939
cf_returns_retained. Currently this attribute can now be applied to any
Objective-C method or C function that returns a pointer or Objective-C object
type.
Modify the tablegen definition of diagnostic 'warn_attribute_wrong_decl_type' to
expect that the diagnostics infrastructure will add quotes around the attribute
name when appropriate. Alonq with this change, I modified the places where this
warning is issued to passed the attribute's IdentifierInfo* instead of having a
hard-coded C constant string.
llvm-svn: 71718
generation when EvalObjCMessageExpr() did not resolve the
ObjCInterfaceDecl* for a receiver when the receiver's symbolic value
wasn't being explicitly tracked.
llvm-svn: 71685
array region, set its default value to conjured symbol. When retrieving its
element, create new region value symbol for the element.
Also fix some 80 columns violations.
llvm-svn: 71548
where an owned one is expected. Also add preliminary checking for
returning a positive retain count object in GC mode where an owned GC
object is expected.
llvm-svn: 71388
implicitly be changed to unsigned values in GRSimpleVals.cpp. This can happen
when the comparison involves logic in specialized transfer functions (e.g.,
OSAtomicCompareAndSwap).
llvm-svn: 71200
- Update the old StoreManager::CastRegion to strip off 'ElementRegions' when
casting to void* (Zhongxing: please validate)
- Pass-by-reference argument invalidation logic in CFRefCount.cpp:
- Strip ElementRegions when the ElementRegion is just a 'raw data' view
on top of the underlying typed region.
llvm-svn: 71094
- add a static function getTypeWidth(), which computes the width of a type
with the help of TargetInfo.
- no-outofbounds.c now passes for region store.
llvm-svn: 71080
'objc_ownership_cfretain' -> 'cf_ownership_retain'
'objc_ownership_cfrelease' -> 'cf_ownership_release'
Motivation: Core Foundation objects can be used in isolation from Objective-C,
and this forces users to reason about the separate semantics of CF objects. More
Sema support pending.
llvm-svn: 70884
return type and the selector. This is inconsistent with C functions
(where such attributes would be placed on the return type, not the the
FunctionDecl), and is inconsistent with what people are use to seeing.
llvm-svn: 70878
'ElementRegion' on top of the VarRegion for 'x'. This causes the test
case xfail_wine_crash.c to now pass for BasicStoreManager. It doesn't
crash for RegionStoreManager either, but reports a bogus unintialized
value warning.
llvm-svn: 70832
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
- Don't layer TypedViewRegions on top of any region except
SymbolicRegions and AllocaRegions. This follows from my offline
discussion within Zhongxing about how TypedViewRegions really only
represent memory getting re-appropriated for a new purpose.
Fallout from this change:
- Move test case from xfail_rdar_6440393.m to misc-ps-64.m
(it now passes).
- test/Analysis/fields.c now fails for region store (crash).
Marking XFAIL.
- test/Analysis/rdar-6441136-region.c now fails (only runs with region store).
Marking XFAIL.
Diagnosis: The analyzer now correctly identifies an early out-of-bounds memory
access then the one flagged:
rdar-6541136-region.c:17:3: warning: Load or store into an out-of-bound memory position.
*p = 1;
^~
Changing the line:
char *p = (void*) &wonky[1];
to
char *p = (void*) &wonky[0];
(which should delay the buffer overrun) causes region store to crash, probably
because it expects a TypedViewRegion.
- test/Analysis/casts.c (region store) now fails (crash).
Marking XFAIL.
llvm-svn: 70565
applied to ObjCMethodDecls, not just parameters. This allows one to specific
side-effects on the receiver of a message expression. No checker support yet.
llvm-svn: 70505
appear between the return type and the selector. This is a separate code path
from regular attribute processing, as we only want to (a) accept only a specific
set of attributes in this place and (b) want to distinguish to clients the
context in which an attribute was added to an ObjCMethodDecl.
Currently, the attribute 'objc_ownership_returns' is the only attribute that
uses this new feature. Shortly I will add a warning for 'objc_ownership_returns'
to be placed at the end of a method declaration.
llvm-svn: 70504
This fixes <rdar://problem/6839489> 10A345: Clang does not warm about mismatched returns (void return from a bool function)
Will implement -Wreturn-type, -Wno-return-type in another commit.
llvm-svn: 70492
as 'objc_ownership_cfretain' except that the method acts like a CFRetain instead
of a [... retain] (important in GC modes). Checker support is wired up, but
currently only for Objective-C message expressions (not function calls).
llvm-svn: 70218
to the checker yet, but essentially it allows a user to specify that an
Objective-C method or C function increments the reference count of a passed
object.
llvm-svn: 70005
up to the checker yet, but essentially it allows a user to specify that an
Objective-C method or C function returns an owned an Objective-C object.
llvm-svn: 70001
- Fix summary lookup for class methods to now use the (optional)
ObjCInterfaceDecl associated with a message expression. This removes a
long-standing FIXME.
- Partial fix for <rdar://problem/6062730> by stop tracking objects that
are passed to [NSObject performSelector]. These methods are often used
for delegates, which the analyzer doesn't reason about well yet.
llvm-svn: 69982
extend the number of objects tracked by the retain/release checker by assuming
that all class and instance methods should follow Cocoa object "getter" and
"alloc/new" conventions.
llvm-svn: 69908
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
ProgramPoints all the way through to GRCoreEngine.
NSString.m now fails with RegionStoreManager because of the void** cast.
Disabling use of region store for that test for now.
llvm-svn: 68845
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
"The attached patch generates warnings of cases where an ObjC message is sent to
a nil object and the size of return type of that message is larger than the size
of void pointer. This may result in undefined return values as described in PR
2718. The patch also includes test cases."
llvm-svn: 68585
<rdar://problem/6704930> involving SimpleConstraintManager not reasoning well
about symbolic constraint values involving arithmetic operators.
llvm-svn: 67534
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
Ted Kremenek