Previously, this code discarded the result of CheckPlaceholderExpr for
non-matrix subexpressions. Not only is this wasteful, but it was creating a
Warc-repeated-use-of-weak false-positive on the attached testcase, since the
discarded expression was still registered as a use of the weak property.
rdar://66162246
Differential revision: https://reviews.llvm.org/D87102
This reverts r365382 (git commit 8b1becf2e3)
Appears to regress this semi-reduced fragment of valid code from windows
SDK headers:
#define InterlockedIncrement64 _InterlockedIncrement64
extern "C" __int64 InterlockedIncrement64(__int64 volatile *Addend);
#pragma intrinsic(_InterlockedIncrement64)
unsigned __int64 InterlockedIncrement(unsigned __int64 volatile *Addend) {
return (unsigned __int64)(InterlockedIncrement64)((volatile __int64 *)Addend);
}
Found on a buildbot here, but no mail was sent due to it already being
red:
http://lab.llvm.org:8011/builders/sanitizer-windows/builds/48067
llvm-svn: 365393
of an auto"
This commit changed the initializer expression passed into
initialization (stripping off an enclosing pair of parentheses or
braces) and subtly changing the meaning of programs, typically by
inserting bogus calls to copy constructors.
See the added testcase in test/SemaCXX/cxx1y-init-captures.cpp for an
example of the breakage.
llvm-svn: 359066
variable during auto type deduction, use the rewritten initializer when
performing initialization of the variable.
This silences spurious -Warc-repeated-use-of-weak warnings that are
issued when the initializer uses a weak ObjC pointer.
Differential Revision: https://reviews.llvm.org/D55662
llvm-svn: 350917
placeholder expressions while an unevaluated context is still on the
expression evaluation context stack.
This prevents recordUseOfWeek from being called when a weak variable is
used as an operand of a decltype or a typeof expression and fixes
spurious -Warc-repeated-use-of-weak warnings.
rdar://problem/45742525
Differential Revision: https://reviews.llvm.org/D55662
llvm-svn: 350887
-Warc-repeated-use-of-weak may trigger a segmentation fault when the Decl
being checked is outside of a function scope, leaving the current function
info pointer null. This adds a check before using the function info.
llvm-svn: 333471
Summary: -Warc-repeated-use-of-weak should produce the same warnings with -fobjc-weak as it does with -objc-arc. Also check for ObjCWeak along with ObjCAutoRefCount when recording the use of an evaluated weak variable. Add a -fobjc-weak run to the existing arc-repeated-weak test case and adapt it slightly to work in both modes.
Reviewers: rsmith, doug.gregor, jordan_rose, rjmccall
Reviewed By: rjmccall
Subscribers: arphaman, rjmccall, cfe-commits
Differential Revision: https://reviews.llvm.org/D31005
llvm-svn: 299011
IsExact shouldn't be set to true in WeakObjectProfileTy::getBaseInfo
when the receiver is a class because having a class as the receiver
doesn't guarantee that the Base is exact.
This is a follow-up to r263818.
rdar://problem/25208167
llvm-svn: 264025
The crash occurs in WeakObjectProfileTy::getBaseInfo when getBase() is
called on an ObjCPropertyRefExpr object whose receiver is an interface.
This commit fixes the crash by checking the type of the receiver and
setting IsExact to true if it is an interface.
rdar://problem/25208167
Differential Revision: http://reviews.llvm.org/D18268
llvm-svn: 263818
When we are in a implementation, we check the global method pool whether there were category
methods with the same selector. If there were none (common case) we don't need to do lookups for
overridden methods again.
Note that for an interface method (if we don't encounter its implementation), it is considered that
it overrides methods that were declared before it, not for category methods introduced after it.
This is tradeoff in favor of performance, since it is expensive to do lookups in case there was a
category, and moving the global method pool to ASTContext (so we can check it) would increase complexity.
rdar://13508196
llvm-svn: 179654
This reverts commit r179436.
Due to caching, it was possible that we could miss overridden methods that
were introduced by categories later on.
Along with reverting the commit I also included a test case that would have caught this.
llvm-svn: 179547
Previously, the warning would erroneously fire on this:
for (Test *a in someArray)
use(a.weakProp);
...because it looks like the same property is being accessed over and over.
However, clearly this is not the case. We now ignore loops like this for
local variables, but continue to warn if the base object is a parameter,
global variable, or instance variable, on the assumption that these are
not repeatedly usually assigned to within loops.
Additionally, do-while loops where the condition is 'false' are not really
loops at all; usually they're just used for semicolon-swallowing macros or
using "break" like "goto".
<rdar://problem/12578785&12578849>
llvm-svn: 166942
This is a "safe" pattern, or at least one that cannot be helped by using
a strong local variable. However, if the single read is within a loop,
it should /always/ be treated as potentially dangerous.
<rdar://problem/12437490>
llvm-svn: 165719
Previously, [foo weakProp] was not being treated the same as foo.weakProp.
Now, for every explicit message send, we check if it's a property access,
and if so, if the property is weak. Then for every assignment of a
message, we have to do the same thing again.
This is a potentially expensive increase because determining whether a
method is a property accessor requires searching through the methods it
overrides. However, without it -Warc-repeated-use-of-weak will miss cases
from people who prefer not to use dot syntax. If this turns out to be
too expensive, we can try caching the result somewhere, or even lose
precision by not checking superclass methods. The warning is off-by-default,
though.
<rdar://problem/12407765>
llvm-svn: 165718
Like properties, loading from a weak ivar twice in the same function can
give you inconsistent results if the object is deallocated between the
two loads. It is safer to assign to a strong local variable and use that.
Second half of <rdar://problem/12280249>.
llvm-svn: 164855
The motivating example:
if (self.weakProp)
use(self.weakProp);
As with any non-atomic test-then-use, it is possible a weak property to be
non-nil at the 'if', but be deallocated by the time it is used. The correct
way to write this example is as follows:
id tmp = self.weakProp;
if (tmp)
use(tmp);
The warning is controlled by -Warc-repeated-use-of-receiver, and uses the
property name and base to determine if the same property on the same object
is being accessed multiple times. In cases where the base is more
complicated than just a single Decl (e.g. 'foo.bar.weakProp'), it picks a
Decl for some degree of uniquing and reports the problem under a subflag,
-Warc-maybe-repeated-use-of-receiver. This gives a way to tune the
aggressiveness of the warning for a particular project.
The warning is not on by default because it is not flow-sensitive and thus
may have a higher-than-acceptable rate of false positives, though it is
less noisy than -Wreceiver-is-weak. On the other hand, it will not warn
about some cases that may be legitimate issues that -Wreceiver-is-weak
will catch, and it does not attempt to reason about methods returning weak
values.
Even though this is not a real "analysis-based" check I've put the bug
emission code in AnalysisBasedWarnings for two reasons: (1) to run on
every kind of code body (function, method, block, or lambda), and (2) to
suggest that it may be enhanced by flow-sensitive analysis in the future.
The second (smaller) half of this work is to extend it to weak locals
and weak ivars. This should use most of the same infrastructure.
Part of <rdar://problem/12280249>
llvm-svn: 164854
Erik Pilkington