ObjCSelfInitChecker stashes information in the GDM to persist it across
function calls; it is stored in pre-call checks and retrieved post-call.
The post-call check is supposed to clear out the stored state, but was
failing to do so in cases where the call did not have a symbolic return
value.
This was actually causing the inappropriate cache-out from r163361.
Per discussion with Anna, we should never actually cache out when
assuming the receiver of an Objective-C message is non-nil, because
we guarded that node generation by checking that the state has changed.
Therefore, the only states that could reach this exact ExplodedNode are
ones that should have merged /before/ making this assumption.
r163361 has been reverted and the test case removed, since it won't
actually test anything interesting now.
llvm-svn: 163449
with at least one subtle bug in MacOSXKeyChainAPIChecker where the
calling the method was a substitute for assuming a symbolic value
was null (which is not the case).
We still keep ConstraintManager::getSymVal(), but we use that as
an optimization in SValBuilder and ProgramState::getSVal() to
constant-fold SVals. This is only if the ConstraintManager can
provide us with that information, which is no longer a requirement.
As part of this, introduce a default implementation of
ConstraintManager::getSymVal() which returns null.
For Checkers, introduce ConstraintManager::isNull(), which queries
the state to see if the symbolic value is constrained to be a null
value. It does this without assuming it has been implicitly constant
folded.
llvm-svn: 163428
While the check itself should count 0-based for the parameter index,
the diagnostic should be 1-based (first, second, third, not start at 0).
Fixes <rdar://problem/12249569>.
llvm-svn: 163375
are used in EH code. Right now the CFG doesn't support exceptions well,
so we need this hack to avoid bogus dead store warnings.
Fixes <rdar://problem/12147586>
llvm-svn: 163353
CXXDestructorCall now has a flag for when it is a base destructor call.
Other kinds of destructor calls (locals, fields, temporaries, and 'delete')
all behave as "whole-object" destructors and do not behave differently
from one another (specifically, in these cases we /should/ try to
devirtualize a call to a virtual destructor).
This was causing crashes in both our internal buildbot, the crash still
being tracked in PR13765, and some of the crashes being tracked in PR13763,
due to a assertion failure. (The behavior under -Asserts happened to be
correct anyway.)
Adding this knowledge also allows our DynamicTypePropagation checker to do
a bit less work; the special rules about virtual method calls during a
destructor only require extra handling during base destructors.
llvm-svn: 163348
Any future exceptions need to go INSIDE the test that checks if the
IdentifierInfo is non-null!
No functionality change. Thanks for the review, Ted.
llvm-svn: 163067
Previously, we preferred to get a result type by looking at the callee's
declared result type. This allowed us to handlereferences, which are
represented in the AST as lvalues of their pointee type. (That is, a call
to a function returning 'int &' has type 'int' and value kind 'lvalue'.)
However, this results in us preferring the original type of a function
over a casted type. This is a problem when a function pointer is casted
to another type, because the conjured result value will have the wrong
type. AdjustedReturnValueChecker is supposed to handle this, but still
doesn't handle the case where there is no "original function" at all,
i.e. where the callee is unknown.
Now, we instead look at the call expression's value kind (lvalue, xvalue,
or prvalue), and adjust the expr's type accordingly. This will have no
effect when the function is inlined, and will conjure the value that will
actually be used when it is not.
This makes AdjustedReturnValueChecker /nearly/ unnecessary; unfortunately,
the cases where it would still be useful are where we need to cast the
result of an inlined function or a checker-evaluated function, and in these
cases we don't know what we're casting /from/ by the time we can do post-
call checks. In light of that, remove AdjustedReturnValueChecker, which
was already not checking quite a few calls.
llvm-svn: 163065
Fixes a hard-to-reach crash when calling a non-member overloaded operator
with arguments that may be callbacks.
Future-proofing: don't make the same assumption in MallocSizeofChecker.
Aside from possibly respecting attributes in the future, it might be
possible to call 'malloc' through a function pointer.
I audited all other uses of FunctionDecl::getIdentifier() in the analyzer;
they all now correctly test to see if the identifier is present before
using it.
llvm-svn: 163012
inlined function.
This resolves retain count checker false positives that are caused by
inlining ObjC and other methods. Essentially, if we are passing an
object to a method with "delegate" in the selector or a function pointer
as another argument, we should stop tracking the other parameters/return
value as far as the retain count checker is concerned.
llvm-svn: 162876
This heuristic addresses the case when a pointer (or ref) is passed
to a function, which initializes the variable (or sets it to something
other than '0'). On the branch where the inlined function does not
set the value, we report use of undefined value (or NULL pointer
dereference). The access happens in the caller and the path
through the callee would get pruned away with regular path pruning. To
solve this issue, we previously disabled diagnostic pruning completely
on undefined and null pointer dereference checks, which entailed very
verbose diagnostics in most cases. Furthermore, not all of the
undef value checks had the diagnostic pruning disabled.
This patch implements the following heuristic: if we pass a pointer (or
ref) to the region (on which the error is reported) into a function and
it's value is either undef or 'NULL' (and is a pointer), do not prune
the function.
llvm-svn: 162863
In C++, objects being returned on the stack are actually copy-constructed into
the return value. That means that when a temporary is returned, it still has
to be destroyed, i.e. the returned expression will be wrapped in an
ExprWithCleanups node. Our "returning stack memory" checker needs to look
through this node to see if we really are returning an object by value.
PR13722
llvm-svn: 162817
This helper function (in the clang::ento::bugreporter namespace) may add more
than one visitor, but conceptually it's tracking a single use of a null or
undefined value and should do so as best it can.
Also, the BugReport parameter has been made a reference to underscore that
it is non-optional.
llvm-svn: 162720
This allows us to better reason about status objects, like Clang's own
llvm::Optional (when its contents are trivially destructible), which are
often intended to be passed around by value.
We still don't inline constructors for temporaries in the general case.
<rdar://problem/11986434>
llvm-svn: 162681
This code has been added a while ago and removing it does not trigger
any test failures. The false positives it was trying to suppress are
probably handled by other logic (ex: special handling of delegates).
llvm-svn: 162529
With inlining, retain count checker starts tracking 'self' through the
init methods. The analyser results were too noisy if the developer
did not follow 'self = [super init]' pattern (which is common
especially in older code bases) - we reported self init anti-pattern AND
possible use-after-free. This patch teaches the retain count
checker to assume that [super init] does not fail when it's not consumed
by another expression. This silences the retain count warning that warns
about possibility of use-after-free when init fails, while preserving
all the other checking on 'self'.
llvm-svn: 162508
The checker adds assumptions that the return values from the known APIs
are non-nil. Teach the checker about NSArray/NSMutableArray/NSOrderedSet
objectAtIndex, objectAtIndexedSubscript.
llvm-svn: 162398
Also rename 'getCurrentBlockCounter()' to 'blockCount()'.
This ripples a bunch of code simplifications; mostly aesthetic,
but makes the code a bit tighter.
llvm-svn: 162349
No need to have the "get", the word "conjure" is a verb too!
Getting a conjured symbol is the same as conjuring one up.
This shortening is largely cosmetic, but just this simple changed
cleaned up a handful of lines, making them less verbose.
llvm-svn: 162348
Generating a sink is significantly different behavior from generating a
normal node, and a simple boolean parameter can be rather opaque. Per
offline discussion with Anna, adding new generation methods is the
clearest way to communicate intent.
No functionality change.
llvm-svn: 162215
This was once an adapter class between callbacks that had CheckerContexts
and those that don't, but for a while now it's essentially just been a
wrapper around a ProgramPointTag. We can just pass the tag around instead.
No functionality change.
llvm-svn: 162155
This is analogous to our handling of pointer dereferences: if we
dereference a pointer that may or may not be null, we assume it's non-null
from then on.
While some implementations of C++ (including ours) allow you to call a
non-virtual method through a null pointer of object type, it is technically
disallowed by the C++ standard, and should not prune out any real paths in
practice.
[class.mfct.non-static]p1: A non-static member function may be called
for an object of its class type, or for an object of a class derived
from its class type...
(a null pointer value does not refer to an object)
We can also make the same assumption about function pointers.
llvm-svn: 161992
This is the other half of C++11 [class.cdtor]p4 (the destructor side
was added in r161915). This also fixes an issue with post-call checks
where the 'this' value was already being cleaned out of the state, thus
being omitted from a reconstructed CXXConstructorCall.
llvm-svn: 161981
C++11 [class.cdtor]p4: When a virtual function is called directly or
indirectly from a constructor or from a destructor, including during
the construction or destruction of the class’s non-static data members,
and the object to which the call applies is the object under
construction or destruction, the function called is the final overrider
in the constructor's or destructor's class and not one overriding it in
a more-derived class.
llvm-svn: 161915
The autorelease pool has not been implemented completely: we were adding
the autoreleased symbols to the state, but never looking at them. Until
we have a complete implementation, remove the overhead and comment out
the unused code.
llvm-svn: 161821
to set/get/remove the RefBinding.
No functional change here. Having these setter and getter methods will
make it much easier when replacing the underlining representation of
RefBindings (I just went through the exercise). It makes the code more
readable as well.
llvm-svn: 161820
This check is also accessible through the debug.ExprInspection checker.
Like clang_analyzer_eval, you can use it to test the analyzer engine's
current state; the argument should be true or false to indicate whether or
not you expect the function to be inlined.
When used in the positive case (clang_analyzer_checkInlined(true)), the
analyzer prints the message "TRUE" if the function is ever inlined. However,
clang_analyzer_checkInlined(false) should never print a message; this asserts
that there should be no paths on which the current function is inlined, but
then there are no paths on which to print a message! (If the assertion is
violated, the message "FALSE" will be printed.)
This asymmetry comes from the fact that the only other chance to print a
message is when the function is analyzed as a top-level function. However,
when we do that, we can't be sure it isn't also inlined elsewhere (such as
in a recursive function, or if we want to analyze in both general or
specialized cases). Rather than have all checkInlined calls have an appended,
meaningless "FALSE" or "TOP-LEVEL" case, there is just no message printed.
void clang_analyzer_checkInlined(int);
For debugging purposes only!
llvm-svn: 161708
Dmitri Gribenko