Commit Graph

30 Commits

Author SHA1 Message Date
Devin Coughlin 4fba10c394 Revert "[analyzer] Re-apply r283093 "Add extra notes to ObjCDeallocChecker""
Revert:
r283662: [analyzer] Re-apply r283093 "Add extra notes to ObjCDeallocChecker"
r283660: [analyzer] Fix build error after r283660 - remove constexpr strings.

It was causing an internal build bot to fail. It looks like in some cases
adding an extra note can cause scan-build plist output to drop a diagnostic
altogether.

llvm-svn: 284317
2016-10-16 00:30:08 +00:00
Artem Dergachev 46209e1dd0 [analyzer] Re-apply r283093 "Add extra notes to ObjCDeallocChecker"
The parent commit (r283092) was reverted before and now finally landed.

llvm-svn: 283660
2016-10-08 10:53:00 +00:00
Vitaly Buka b3814f6f38 Revert "[analyzer] Add extra notes to ObjCDeallocChecker" as its depends on reverted r283092
This reverts commit r283093.

llvm-svn: 283181
2016-10-04 02:36:58 +00:00
Artem Dergachev 918602df8d [analyzer] Add extra notes to ObjCDeallocChecker
The report is now highlighting instance variables and properties
referenced by the warning message with the help of the
extra notes feature recently introduced in r283092.

Differential Revision: https://reviews.llvm.org/D24915

llvm-svn: 283093
2016-10-03 08:03:51 +00:00
Devin Coughlin 3d066e13d7 [analyzer] Add tests for Objective-C class properties
Add basic tests to ensure the analyzer has support for class properties. This
is a test-only change.

rdar://problem/25256807

llvm-svn: 268773
2016-05-06 18:24:50 +00:00
Devin Coughlin c239dd1349 [analyzer] Prefer accessor method in extension over category in CallEvent.
In ObjCMethodCall:getRuntimeDefinition(), if the method is an accessor in a
category, and it doesn't have a self declaration, first try to find the method
in a class extension. This works around a bug in Sema where multiple accessors
are synthesized for properties in class extensions that are redeclared in a
category. The implicit parameters are not filled in for the method on the
category, which causes a crash when trying to synthesize a getter for the
property in BodyFarm. The Sema bug is tracked as rdar://problem/25481164.

rdar://problem/25056531

llvm-svn: 265103
2016-04-01 03:24:13 +00:00
Devin Coughlin 7646ebe6f9 [analyzer] Use BodyFarm-synthesized body even when actual body available.
Change body autosynthesis to use the BodyFarm-synthesized body even when
an actual body exists. This enables the analyzer to use the simpler,
analyzer-provided body to model the behavior of the function rather than trying
to understand the actual body. Further, this makes the analyzer robust against
changes in headers that expose the implementations of those bodies.

rdar://problem/25145950

llvm-svn: 264687
2016-03-28 23:55:58 +00:00
Devin Coughlin 2b77c4603d [analyzer] Move ObjCDeallocChecker out of the alpha package.
It will now be on by default on Darwin.

rdar://problem/6927496

llvm-svn: 262524
2016-03-02 21:50:54 +00:00
Devin Coughlin ad9f53e959 [analyzer] Reapply r261917 with a fix.
This reapplies "[analyzer] Make ObjCDeallocChecker path sensitive." (r261917)
with a fix for an error on some bots about specializing a template
from another namespace.

llvm-svn: 261929
2016-02-25 21:15:16 +00:00
Devin Coughlin ea02bba5a1 Revert "[analyzer] Make ObjCDeallocChecker path sensitive."
This reverts commit r261917. It broke the bots.

llvm-svn: 261921
2016-02-25 19:13:43 +00:00
Devin Coughlin 88691c1fcb [analyzer] Make ObjCDeallocChecker path sensitive.
Convert the ObjCDeallocChecker to be path sensitive. The primary
motivation for this change is to prevent false positives when -dealloc calls
helper invalidation methods to release instance variables, but it additionally
improves precision when -dealloc contains control flow. It also reduces the need
for pattern matching. The check for missing -dealloc methods remains AST-based.

Part of rdar://problem/6927496

Differential Revision: http://reviews.llvm.org/D17511

llvm-svn: 261917
2016-02-25 18:55:24 +00:00
Devin Coughlin 069a1073dd [analyzer] Improve modeling of ObjC synthesized property setters.
When modeling a call to a setter for a property that is synthesized to be
backed by an instance variable, don't invalidate the entire instance
but rather only the storage for the updated instance variable itself.

This still doesn't model the effect of the setter completely. It doesn't
bind the set value to the ivar storage location because doing so would cause
the set value to escape, removing valuable diagnostics about potential
leaks of the value from the retain count checker.

llvm-svn: 261243
2016-02-18 19:13:30 +00:00
Devin Coughlin b7e810bdc1 [analyzer] Body farm: Look for property ivar in shadowing readwrite property.
After r251874, readonly properties that are shadowed by a readwrite property
in a class extension no longer have an instance variable, which caused the body
farm to not synthesize getters. Now, if a readonly property does not have an
instance variable look for a shadowing property and try to get the instance
variable from there.

rdar://problem/24060091

llvm-svn: 258886
2016-01-26 23:58:48 +00:00
Jordan Rose ad176b5e10 [analyzer] Add test for previous commit.
Again, this is being applied in a separate commit so that the previous commit
can be reverted while leaving the test in place.

rdar://problem/20335433

llvm-svn: 233593
2015-03-30 20:18:04 +00:00
Jordan Rose 3da3f8e045 [analyzer] Disable all retain count diagnostics on values that come from ivars.
This is imitating a pre-r228174 state where ivars are not considered tracked by
default, but with the addition that even ivars /with/ retain count information
(e.g. "[_ivar retain]; [ivar _release];") are not being tracked as well. This is
to ensure that we don't regress on values accessed through both properties and
ivars, which is what r228174 was trying to fix.

The issue occurs in code like this:

  [_contentView retain];
  [_contentView removeFromSuperview];
  [self addSubview:_contentView]; // invalidates 'self'
  [_contentView release];

In this case, the call to -addSubview: may change the value of self->_contentView,
and so the analyzer can't be sure that we didn't leak the original _contentView.
This is a correct conservative view of the world, but not a useful one. Until we
have a heuristic that allows us to not consider this a leak, not emitting a
diagnostic is our best bet.

This commit disables all of the ivar-related retain count tests, but does not
remove them to ensure that we don't crash trying to evaluate either valid or
erroneous code. The next commit will add a new test for the example above so
that this commit (and the previous one) can be reverted wholesale when a better
solution is implemented.

Rest of rdar://problem/20335433

llvm-svn: 233592
2015-03-30 20:18:00 +00:00
Jordan Rose 218772f87e [analyzer] Don't special-case ivars backing +0 properties.
Give up this checking in order to continue tracking that these values came from
direct ivar access, which will be important in the next commit.

Part of rdar://problem/20335433

llvm-svn: 233591
2015-03-30 20:17:47 +00:00
Jordan Rose 03ad616143 [analyzer] RetainCountChecker: Don't assume +0 for ivars backing readonly properties.
Similarly, don't assume +0 if the property's setter is manually implemented.
In both cases, if the property's ownership is explicitly written, then we /do/
assume the ivar has the same ownership.

rdar://problem/20218183

llvm-svn: 232849
2015-03-20 21:12:27 +00:00
Jordan Rose 58f8cc15c9 [analyzer] RetainCountChecker: CF properties are always manually retain-counted.
In theory we could assume a CF property is stored at +0 if there's not a custom
setter, but that's not really worth the complexity. What we do know is that a
CF property can't have ownership attributes, and so we shouldn't assume anything
about the ownership of the ivar.

rdar://problem/20076963

llvm-svn: 231553
2015-03-07 05:47:24 +00:00
Jordan Rose 000bac5e17 [analyzer] RetainCountChecker: don't try to track ivars known to be nil.
We expect in general that any nil value has no retain count information
associated with it; violating this results in unexpected state unification
/later/ when we decide to throw the information away. Unexpectedly caching
out can lead to an assertion failure or crash.

rdar://problem/19862648

llvm-svn: 229934
2015-02-19 23:57:04 +00:00
Jordan Rose cb5386cbfc [analyzer] RetainCountChecker: be forgiving when ivars are accessed directly.
A refinement of r204730, itself a refinement of r198953, to better handle
cases where an object is accessed both through a property getter and
through direct ivar access. An object accessed through a property should
always be treated as +0, i.e. not owned by the caller. However, an object
accessed through an ivar may be at +0 or at +1, depending on whether the
ivar is a strong reference. Outside of ARC, we don't always have that
information.

The previous attempt would clear out the +0 provided by a getter, but only
if that +0 hadn't already participated in other retain counting operations.
(That is, "self.foo" is okay, but "[[self.foo retain] autorelease]" is
problematic.) This turned out to not be good enough when our synthesized
getters get involved.

This commit drops the notion of "overridable" reference counting and instead
just tracks whether a value ever came from a (strong) ivar. If it has, we
allow one more release than we otherwise would. This has the added benefit
of being able to catch /some/ overreleases of instance variables, though
it's not likely to come up in practice.

We do still get some false negatives because we currently throw away
refcount state upon assigning a value into an ivar. We should probably
improve on that in the future, especially once we synthesize setters as
well as getters.

rdar://problem/18075108

llvm-svn: 228174
2015-02-04 19:24:52 +00:00
Jordan Rose b3ad07e0a6 [analyzer] Don't track retain counts of objects directly accessed through ivars.
A refinement of r198953 to handle cases where an object is accessed both through
a property getter and through direct ivar access. An object accessed through a
property should always be treated as +0, i.e. not owned by the caller. However,
an object accessed through an ivar may be at +0 or at +1, depending on whether
the ivar is a strong reference. Outside of ARC, we don't have that information,
so we just don't track objects accessed through ivars.

With this change, accessing an ivar directly will deliberately override the +0
provided by a getter, but only if the +0 hasn't participated in other retain
counting yet. That isn't perfect, but it's already unusual for people to be
mixing property access with direct ivar access. (The primary use case for this
is in setters, init methods, and -dealloc.)

Thanks to Ted for spotting a few mistakes in private review.

<rdar://problem/16333368>

llvm-svn: 204730
2014-03-25 17:10:58 +00:00
Jordan Rose ddf1966cc3 [analyzer] Tighten up sanity checks on Objective-C property getter synthesis.
If there are non-trivially-copyable types /other/ than C++ records, we
won't have a synthesized copy expression, but we can't just use a simple
load/return.

Also, add comments and shore up tests, making sure to test in both ARC
and non-ARC.

llvm-svn: 199869
2014-01-23 03:59:10 +00:00
Jordan Rose 1a866cd54b [analyzer] Model getters of known-@synthesized Objective-C properties.
...by synthesizing their body to be "return self->_prop;", with an extra
nudge to RetainCountChecker to still treat the value as +0 if we have no
other information.

This doesn't handle weak properties, but that's mostly correct anyway,
since they can go to nil at any time. This also doesn't apply to properties
whose implementations we can't see, since they may not be backed by an
ivar at all. And finally, this doesn't handle properties of C++ class type,
because we can't invoke the copy constructor. (Sema has actually done this
work already, but the AST it synthesizes is one the analyzer doesn't quite
handle -- it has an rvalue DeclRefExpr.)

Modeling setters is likely to be more difficult (since it requires
handling strong/copy), but not impossible.

<rdar://problem/11956898>

llvm-svn: 198953
2014-01-10 20:06:06 +00:00
Jordan Rose 7467f06533 [analyzer] RetainCountChecker: Clean up path notes for autorelease.
No functionality change.

<rdar://problem/13710586>

llvm-svn: 180075
2013-04-23 01:42:25 +00:00
Patrick Beard acfbe9e1f2 Added a new attribute, objc_root_class, which informs the compiler when a root class is intentionally declared.
The warning this inhibits, -Wobjc-root-class, is opt-in for now. However, all clang unit tests that would trigger
the warning have been updated to use -Wno-objc-root-class. <rdar://problem/7446698>

llvm-svn: 154187
2012-04-06 18:12:22 +00:00
Ted Kremenek e98d63a823 Adopt ExprEngine and checkers to ObjC property refactoring. Everything was working, but now diagnostics are aware of message expressions implied by uses of properties. Fixes <rdar://problem/9241180>.
llvm-svn: 150888
2012-02-18 20:53:30 +00:00
Jordy Rose c49ec53e29 [analyzer] Move the knowledge of whether or not GC is enabled for the current analysis from CFRefCount to ExprEngine.
Remove TransferFuncs from ExprEngine and AnalysisConsumer.

Demote RetainReleaseChecker to a regular checker, and give it the name osx.cocoa.RetainCount (class name change coming shortly). Update tests accordingly.

llvm-svn: 138998
2011-09-02 05:55:19 +00:00
Argyrios Kyrtzidis 6a1c760760 [analyzer] Run the ExprEngine depending on the CheckerManager having path-sensitive checkers.
llvm-svn: 126674
2011-02-28 19:49:17 +00:00
Argyrios Kyrtzidis add754a02e [analyzer] Fix crash when handling dot syntax on 'super'.
llvm-svn: 124376
2011-01-27 16:17:11 +00:00
Argyrios Kyrtzidis ffb08c46fa [analyzer] Handle the dot syntax for properties in the ExprEngine.
We translate property accesses to obj-c messages by simulating "loads" or "stores" to properties
using a pseudo-location SVal kind (ObjCPropRef).

Checkers can now reason about obj-c messages for both explicit message expressions and implicit
messages due to property accesses.

llvm-svn: 124161
2011-01-25 00:04:03 +00:00