This reverts commit r284335.
It appears to be causing test-suite compile-time and execution-time
performance measurements to take longer than expected on several bots.
This is surprising, because r284335 is a static-analyzer-only change.
llvm-svn: 284340
Add additional checking to MallocChecker to avoid crashing when memory
routines have unexpected numbers of arguments. You wouldn't expect to see much
of this in normal code (-Wincompatible-library-redeclaration warns on this),
but, for example, CMake tests can generate these.
This is PR30616.
rdar://problem/28631974
llvm-svn: 284335
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
AST matchers are useful for the analyzer's checkers.
More patches on particular checkers shall follow.
This is the first time clang binary gets linked to ASTMatchers.
The binary size increase for the clang executable would be
+0.5% in release mode, +2% in debug mode.
Differential Revision: https://reviews.llvm.org/D25429
llvm-svn: 284112
On macOS (but not iOS), if an ObjC property has no setter, the nib-loading code
for an IBOutlet is documented as directly setting the backing ivar without
retaining the value -- even if the property is 'retain'.
This resulted in false positives from the DeallocChecker for code that did not
release such ivars in -dealloc.
To avoid these false positives, treat IBOutlet ivars that back a property
without a setter as having an unknown release requirement in macOS.
rdar://problem/28507353
llvm-svn: 284084
The problem that caused the msvc crash has been indentified and fixed
in the previous commit. This patch contains the rest of r283092.
llvm-svn: 283584
Define PathDiagnosticNotePiece. The next commit would be able to address the
BugReport class code that is pointed to by the msvc crash message.
llvm-svn: 283566
Returns when calling an inline function should not be merged in the ExplodedGraph unless they are same.
Differential Revision: https://reviews.llvm.org/D25326
llvm-svn: 283554
Currently if the path diagnostic consumer (e.g HTMLDiagnostics and PlistDiagnostics) do not support cross file diagnostics then the path diagnostic report is silently omitted in the case of cross file diagnostics. The patch adds a little verbosity to Clang in this case.
The patch also adds help entry for the "--analyzer-output" driver option.
llvm-svn: 283499
Logical short-circuit operators now act like other branch conditions.
If the symbolic value of the left-hand side is not known to be true or false
(based on the previous execution path), the "Assuming" event piece is added
in order to explain that the analyzer is adding a new assumption.
Additionally, when the assumption is made against the right-hand side of
the logical operator (i.e. when the operator itself acts as a condition
in another CFG terminator), the "Assuming..." piece is written out for the
right-hand side of the operator rather than for the whole operator.
This allows expression-specific diagnostic message text to be constructed.
Differential Revision: https://reviews.llvm.org/D25092
llvm-svn: 283302
In the analyzer's path-sensitive reports, when a report goes through a branch
and the branch condition cannot be decided to be definitely true or false
(based on the previous execution path), an event piece is added that tells the
user that a new assumption is added upon the symbolic value of the branch
condition. For example, "Assuming 'a' is equal to 3".
The text of the assumption is hand-crafted in various manners depending on
the AST expression. If the AST expression is too complex and the text of
the assumption fails to be constructed, the event piece is omitted.
This causes loss of information and misunderstanding of the report.
Do not omit the event piece even if the expression is too complex;
add a piece with a generic text instead.
Differential Revision: https://reviews.llvm.org/D23300
llvm-svn: 283301
Highlight code clones referenced by the warning message with the help of
the extra notes feature recently introduced in r283092.
Change warning text to more clang-ish. Remove suggestions from the copy-paste
error checker diagnostics, because currently our suggestions are strictly 50%
wrong (we do not know which of the two code clones contains the error), and
for that reason we should not sound as if we're actually suggesting this.
Hopefully a better solution would bring them back.
Make sure the suspicious clone pair structure always mentions
the correct variable for the second clone.
Differential Revision: https://reviews.llvm.org/D24916
llvm-svn: 283094
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
These diagnostics are separate from the path-sensitive engine's path notes,
and can be added manually on top of path-sensitive or path-insensitive reports.
The new note diagnostics would appear as note:-diagnostic on console and
as blue bubbles in scan-build. In plist files they currently do not appear,
because format needs to be discussed with plist file users.
The analyzer option "-analyzer-config notes-as-events=true" would convert
notes to normal path notes, and put them at the beginning of the path.
This is a temporary hack to show the new notes in plist files.
A few checkers would be updated in subsequent commits,
including tests for this new feature.
Differential Revision: https://reviews.llvm.org/D24278
llvm-svn: 283092
Example:
switch (x) {
int a; // <- This is unreachable but needed
case 1:
a = ...
Differential Revision: https://reviews.llvm.org/D24905
llvm-svn: 282574
This option behaves in a similar spirit as -save-temps and writes
internal llvm statistics in json format to a file.
Differential Revision: https://reviews.llvm.org/D24820
llvm-svn: 282426
The class BodyFarm creates bodies for
OSAtomicCompareAndSwap*, objc_atomicCompareAndSwap*, dispatch_sync*, dispatch_once*
and for them the flag isBodyAutosynthesized is set to true.
This diff
1. makes AnalysisConsumer::HandleCode skip the autosynthesized code
2. replaces assert(LCtx->getParent()) in RetainCountChecker::checkEndFunction
by assert(!LCtx->inTopFrame()) (minor cleanup)
Test plan: make -j8 check-clang-analysis
Differential revision: https://reviews.llvm.org/D24792
llvm-svn: 282293
This checker should find the calls to blocking functions (for example: sleep, getc, fgets,read,recv etc.) inside a critical section. When sleep(x) is called while a mutex is held, other threads cannot lock the same mutex. This might take some time, leading to bad performance or even deadlock.
Example:
mutex_t m;
void f() {
sleep(1000); // Error: sleep() while m is locked! [f() is called from foobar() while m is locked]
// do some work
}
void foobar() {
lock(m);
f();
unlock(m);
}
A patch by zdtorok (Zoltán Dániel Török)!
Differential Revision: https://reviews.llvm.org/D21506
llvm-svn: 282011
ArrayBoundChecker did not detect out of bounds memory access errors in case an
array was allocated by the new expression. This patch resolves this issue.
Patch by Daniel Krupp!
Differential Revision: https://reviews.llvm.org/D24307
llvm-svn: 281934
AST may contain intermediate ParenExpr nodes
between MemberExpr and ArrayToPointerDecay.
This diff adjusts the check in ExprEngine::VisitMemberExpr accordingly.
Test plan: make -j8 check-clang-analysis
Differential revision: https://reviews.llvm.org/D24484
llvm-svn: 281373
For ObjC type parameter, we used to have TypedefType that is canonicalized to
id or the bound type. We can't represent "T <protocol>" and thus will lose
the type information in the following example:
@interface MyMutableDictionary<KeyType, ObjectType> : NSObject
- (void)setObject:(ObjectType)obj forKeyedSubscript:(KeyType <NSCopying>)key;
@end
MyMutableDictionary<NSString *, NSString *> *stringsByString;
NSNumber *n1, *n2;
stringsByString[n1] = n2;
--> no warning on type mismatch of the key.
To fix the problem, we introduce a new type ObjCTypeParamType that supports
a list of protocol qualifiers.
We create ObjCTypeParamType for ObjCTypeParamDecl when we create
ObjCTypeParamDecl. We also substitute ObjCTypeParamType instead of TypedefType
on an ObjCTypeParamDecl.
rdar://24619481
rdar://25060179
Differential Revision: http://reviews.llvm.org/D23080
llvm-svn: 281358
This patch also introduces AnalysisOrderChecker which is intended for testing
of callback call correctness.
Differential Revision: https://reviews.llvm.org/D23804
llvm-svn: 280367
Some FileIDs that may be used by PlistDiagnostics were not added while building
a list of pieces. This caused assertion violation in GetFID() function.
This patch adds some missing FileIDs to avoid the assertion. It also contains
small refactoring of PlistDiagnostics::FlushDiagnosticsImpl().
Patch by Aleksei Sidorin, Ilya Palachev.
Differential Revision: https://reviews.llvm.org/D22090
llvm-svn: 280360
Fix a crash when relexing the underlying memory buffer to find incorrect
arguments to NSLocalizedString(). With precompiled headers, the raw
buffer may be NULL. Instead, use the source manager to get the buffer,
which will lazily create the buffer for precompiled headers.
rdar://problem/27429091
llvm-svn: 280174
This replaces the old approach of fingerprinting every AST node into a string,
which avoided collisions and was simple to implement, but turned out to be
extremely ineffective with respect to both performance and memory.
The collisions are now dealt with in a separate pass, which no longer causes
performance problems because collisions are rare.
Patch by Raphael Isemann!
Differential Revision: https://reviews.llvm.org/D22515
llvm-svn: 279378
We should ignore paren casts when making sure that the semantic expression
in a PseudoObjectExpr for an ObjC getter is a message send.
This has no other intended functionality change.
Adding a test for this exposed an interesting issue in another test case
that only manifests under ARC. trackNullOrUndefValue() is not properly
suppressing for nil values that are the result of nil propagation from a nil
receiver when the nil is returned from a function. I've added a FIXME for that
missing suppression.
rdar://problem/27290568
llvm-svn: 279181
The original clone checker tries to find copy-pasted code that is exactly
identical to the original code, up to minor details.
As an example, if the copy-pasted code has all references to variable 'a'
replaced with references to variable 'b', it is still considered to be
an exact clone.
The new check finds copy-pasted code in which exactly one variable seems
out of place compared to the original code, which likely indicates
a copy-paste error (a variable was forgotten to be renamed in one place).
Patch by Raphael Isemann!
Differential Revision: https://reviews.llvm.org/D23314
llvm-svn: 279056
This reverts commit r279003 as it breaks some of our buildbots (e.g.
clang-cmake-aarch64-quick, clang-x86_64-linux-selfhost-modules).
The error is in OpenMP/teams_distribute_simd_ast_print.cpp:
clang: /home/buildslave/buildslave/clang-cmake-aarch64-quick/llvm/include/llvm/ADT/DenseMap.h:527:
bool llvm::DenseMapBase<DerivedT, KeyT, ValueT, KeyInfoT, BucketT>::LookupBucketFor(const LookupKeyT&, const BucketT*&) const
[with LookupKeyT = clang::Stmt*; DerivedT = llvm::DenseMap<clang::Stmt*, long unsigned int>;
KeyT = clang::Stmt*; ValueT = long unsigned int;
KeyInfoT = llvm::DenseMapInfo<clang::Stmt*>;
BucketT = llvm::detail::DenseMapPair<clang::Stmt*, long unsigned int>]:
Assertion `!KeyInfoT::isEqual(Val, EmptyKey) && !KeyInfoT::isEqual(Val, TombstoneKey) &&
"Empty/Tombstone value shouldn't be inserted into map!"' failed.
llvm-svn: 279045
This patch is to implement sema and parsing for 'teams distribute simd’ pragma.
This patch is originated by Carlo Bertolli.
Differential Revision: https://reviews.llvm.org/D23528
llvm-svn: 279003
This new checker tries to find execution paths on which implicit integral casts
cause definite loss of information: a certainly-negative integer is converted
to an unsigned integer, or an integer is definitely truncated to fit into
a smaller type.
Being implicit, such casts are likely to produce unexpected results.
Patch by Daniel Marjamäki!
Differential Revision: https://reviews.llvm.org/D13126
llvm-svn: 278941
Like SymbolConjured, SymbolMetadata also needs to be uniquely
identified by the moment of its birth.
Such moments are coded by the (Statement, LocationContext, Block count) triples.
Each such triple represents the moment of analyzing a statement with a certain
call backtrace, with corresponding CFG block having been entered a given amount
of times during analysis of the current code body.
The LocationContext information was accidentally omitted for SymbolMetadata,
which leads to reincarnation of SymbolMetadata upon re-entering a code body
with a different backtrace; the new symbol is incorrectly unified with
the old symbol, which leads to unsound assumptions.
Patch by Alexey Sidorin!
Differential Revision: https://reviews.llvm.org/D21978
llvm-svn: 278937
Change the retain count checker to treat CoreFoundation-style "CV"-prefixed
reference types from CoreVideo similarly to CoreGraphics types. With this
change, we treat CVFooRetain() on a CVFooRef type as a retain. CVFooRelease()
APIs are annotated as consuming their parameter, so this change prevents false
positives about incorrect decrements of reference counts.
<rdar://problem/27116090>
llvm-svn: 278382
Both -analyze-function and -analyzer-display-progress now share the same
convention for naming functions, which allows discriminating between
methods with the same name in different classes, C++ overloads, and also
presents Objective-C instance and class methods in the convenient notation.
This also allows looking up the name for the particular function you're trying
to restrict analysis to in the -analyzer-display-progress output,
in case it was not instantly obvious.
Differential Revision: https://reviews.llvm.org/D22856
llvm-svn: 278018
This patch adds a command line option to list the checkers that were enabled
by analyzer-checker and not disabled by -analyzer-disable-checker.
It can be very useful to debug long command lines when it is not immediately
apparent which checkers are turned on and which checkers are turned off.
Differential Revision: https://reviews.llvm.org/D23060
llvm-svn: 278006
Dynamic casts are handled relatively well by the static analyzer.
BaseToDerived casts however are treated conservatively. This can cause some
false positives with the NewDeleteLeaks checker.
This patch alters the behavior of BaseToDerived casts. In case a dynamic cast
would succeed use the same semantics. Otherwise fall back to the conservative
approach.
Differential Revision: https://reviews.llvm.org/D23014
llvm-svn: 277989
Correct two comments that do not match the current behavior of the checker.
A patch by Alexander Droste!
Differential Revision: https://reviews.llvm.org/D22670
llvm-svn: 277547
Add new APIs that require localized strings and remove two APIs that were
incorrectly marked as requiring a user-facing string.
A patch by Kulpreet Chilana!
Differential Revision: https://reviews.llvm.org/D22926
llvm-svn: 277273
Currently Clang use int32 to represent sampler_t, which have been a source of issue for some backends, because in some backends sampler_t cannot be represented by int32. They have to depend on kernel argument metadata and use IPA to find the sampler arguments and global variables and transform them to target specific sampler type.
This patch uses opaque pointer type opencl.sampler_t* for sampler_t. For each use of file-scope sampler variable, it generates a function call of __translate_sampler_initializer. For each initialization of function-scope sampler variable, it generates a function call of __translate_sampler_initializer.
Each builtin library can implement its own __translate_sampler_initializer(). Since the real sampler type tends to be architecture dependent, allowing it to be initialized by a library function simplifies backend design. A typical implementation of __translate_sampler_initializer could be a table lookup of real sampler literal values. Since its argument is always a literal, the returned pointer is known at compile time and easily optimized to finally become some literal values directly put into image read instructions.
This patch is partially based on Alexey Sotkin's work in Khronos Clang (3d4eec6162).
Differential Revision: https://reviews.llvm.org/D21567
llvm-svn: 277024
This patch adds the CloneDetector class which allows searching source code
for clones.
For every statement or group of statements within a compound statement,
CloneDetector computes a hash value, and finds clones by detecting
identical hash values.
This initial patch only provides a simple hashing mechanism
that hashes the kind of each sub-statement.
This patch also adds CloneChecker - a simple static analyzer checker
that uses CloneDetector to report copy-pasted code.
Patch by Raphael Isemann!
Differential Revision: https://reviews.llvm.org/D20795
llvm-svn: 276782
Summary:
This patch moves the MPIFunctionClassifier header to `clang/include/clang/StaticAnalyzer/Checkers`,
in order to make it accessible in other parts of the architecture.
Reviewers: dcoughlin, zaks.anna
Subscribers: alexfh, cfe-commits
Patch by Alexander Droste!
Differential Revision: https://reviews.llvm.org/D22671
llvm-svn: 276639
Remove some FIXMEs in the surrounding code,
which have been addressed long time ago
by introducing checker-specific tags.
Differential Revision: https://reviews.llvm.org/D22622
llvm-svn: 276557
This checker checks copy and move assignment operators whether they are
protected against self-assignment. Since C++ core guidelines discourages
explicit checking for `&rhs==this` in general we take a different approach: in
top-frame analysis we branch the exploded graph for two cases, where &rhs==this
and &rhs!=this and let existing checkers (e.g. unix.Malloc) do the rest of the
work. It is important that we check all copy and move assignment operator in top
frame even if we checked them already since self-assignments may happen
undetected even in the same translation unit (e.g. using random indices for an
array what may or may not be the same).
This reapplies r275820 after fixing a string-lifetime issue discovered by the
bots.
A patch by Ádám Balogh!
Differential Revision: https://reviews.llvm.org/D19311
llvm-svn: 276365
This checker checks copy and move assignment operators whether they are
protected against self-assignment. Since C++ core guidelines discourages
explicit checking for `&rhs==this` in general we take a different approach: in
top-frame analysis we branch the exploded graph for two cases, where &rhs==this
and &rhs!=this and let existing checkers (e.g. unix.Malloc) do the rest of the
work. It is important that we check all copy and move assignment operator in top
frame even if we checked them already since self-assignments may happen
undetected even in the same translation unit (e.g. using random indices for an
array what may or may not be the same).
A patch by Ádám Balogh!
Differential Revision: https://reviews.llvm.org/D19311
llvm-svn: 275820
This patch adds a new AST node: ObjCAvailabilityCheckExpr, and teaches the
Parser and Sema to generate it. This node represents an availability check of
the form:
@available(macos 10.10, *);
Which will eventually compile to a runtime check of the host's OS version. This
is the first patch of the feature I proposed here:
http://lists.llvm.org/pipermail/cfe-dev/2016-July/049851.html
Differential Revision: https://reviews.llvm.org/D22171
llvm-svn: 275654
This patch is to implement sema and parsing for 'target parallel for simd' pragma.
Differential Revision: http://reviews.llvm.org/D22096
llvm-svn: 275365
This encourages checkers to make logical decisions depending on
value of which region was the symbol under consideration
introduced to denote.
A similar technique is already used in a couple of checkers;
they were modified to call the new method.
Differential Revision: http://reviews.llvm.org/D22242
llvm-svn: 275290
This proposed patch adds crude handling of atomics to the static analyzer.
Rather than ignore AtomicExprs, as we now do, this patch causes the analyzer
to escape the arguments. This is imprecise -- and we should model the
expressions fully in the future -- but it is less wrong than ignoring their
effects altogether.
This is rdar://problem/25353187
Differential Revision: http://reviews.llvm.org/D21667
llvm-svn: 274816
The analyzer does not model C++ temporary destructors completely and so
reports false alarms about leaks of memory allocated by the internals of
shared_ptr:
std::shared_ptr<int> p(new int(1));
p = nullptr; // 'Potential leak of memory pointed to by field __cntrl_'
This patch suppresses all diagnostics where the end of the path is inside
a method in std::shared_ptr.
It also reorganizes the tests for suppressions in the C++ standard library
to use a separate simulated header for library functions with bugs
that were deliberately inserted to test suppression. This will prevent
other tests from using these as models.
rdar://problem/23652766
llvm-svn: 274691
Summary: This patch is an implementation of sema and parsing for the OpenMP composite pragma 'distribute simd'.
Differential Revision: http://reviews.llvm.org/D22007
llvm-svn: 274604
Summary: This patch is an implementation of sema and parsing for the OpenMP composite pragma 'distribute parallel for simd'.
Differential Revision: http://reviews.llvm.org/D21977
llvm-svn: 274530
Replace inheriting constructors implementation with new approach, voted into
C++ last year as a DR against C++11.
Instead of synthesizing a set of derived class constructors for each inherited
base class constructor, we make the constructors of the base class visible to
constructor lookup in the derived class, using the normal rules for
using-declarations.
For constructors, UsingShadowDecl now has a ConstructorUsingShadowDecl derived
class that tracks the requisite additional information. We create shadow
constructors (not found by name lookup) in the derived class to model the
actual initialization, and have a new expression node,
CXXInheritedCtorInitExpr, to model the initialization of a base class from such
a constructor. (This initialization is special because it performs real perfect
forwarding of arguments.)
In cases where argument forwarding is not possible (for inalloca calls,
variadic calls, and calls with callee parameter cleanup), the shadow inheriting
constructor is not emitted and instead we directly emit the initialization code
into the caller of the inherited constructor.
Note that this new model is not perfectly compatible with the old model in some
corner cases. In particular:
* if B inherits a private constructor from A, and C uses that constructor to
construct a B, then we previously required that A befriends B and B
befriends C, but the new rules require A to befriend C directly, and
* if a derived class has its own constructors (and so its implicit default
constructor is suppressed), it may still inherit a default constructor from
a base class
llvm-svn: 274049
[OpenMP] Initial implementation of parse and sema for composite pragma 'distribute parallel for'
This patch is an initial implementation for #distribute parallel for.
The main differences that affect other pragmas are:
The implementation of 'distribute parallel for' requires blocking of the associated loop, where blocks are "distributed" to different teams and iterations within each block are scheduled to parallel threads within each team. To implement blocking, sema creates two additional worksharing directive fields that are used to pass the team assigned block lower and upper bounds through the outlined function resulting from 'parallel'. In this way, scheduling for 'for' to threads can use those bounds.
As a consequence of blocking, the stride of 'distribute' is not 1 but it is equal to the blocking size. This is returned by the runtime and sema prepares a DistIncrExpr variable to hold that value.
As a consequence of blocking, the global upper bound (EnsureUpperBound) expression of the 'for' is not the original loop upper bound (e.g. in for(i = 0 ; i < N; i++) this is 'N') but it is the team-assigned block upper bound. Sema creates a new expression holding the calculation of the actual upper bound for 'for' as UB = min(UB, PrevUB), where UB is the loop upper bound, and PrevUB is the team-assigned block upper bound.
llvm-svn: 273884
http://reviews.llvm.org/D21564
This patch is an initial implementation for #distribute parallel for.
The main differences that affect other pragmas are:
The implementation of 'distribute parallel for' requires blocking of the associated loop, where blocks are "distributed" to different teams and iterations within each block are scheduled to parallel threads within each team. To implement blocking, sema creates two additional worksharing directive fields that are used to pass the team assigned block lower and upper bounds through the outlined function resulting from 'parallel'. In this way, scheduling for 'for' to threads can use those bounds.
As a consequence of blocking, the stride of 'distribute' is not 1 but it is equal to the blocking size. This is returned by the runtime and sema prepares a DistIncrExpr variable to hold that value.
As a consequence of blocking, the global upper bound (EnsureUpperBound) expression of the 'for' is not the original loop upper bound (e.g. in for(i = 0 ; i < N; i++) this is 'N') but it is the team-assigned block upper bound. Sema creates a new expression holding the calculation of the actual upper bound for 'for' as UB = min(UB, PrevUB), where UB is the loop upper bound, and PrevUB is the team-assigned block upper bound.
llvm-svn: 273705
During the core analysis, ExplodedNodes are added to the
ExplodedGraph, and those nodes are cached for deduplication purposes.
After core analysis, reports are generated. Here, trimmed copies of
the ExplodedGraph are made. Since the ExplodedGraph has already been
deduplicated, there is no need to deduplicate again.
This change makes it possible to add ExplodedNodes to an
ExplodedGraph without the overhead of deduplication. "Uncached" nodes
also cannot be iterated over, but none of the report generation code
attempts to iterate over all nodes. This change reduces the analysis
time of a large .C file from 3m43.941s to 3m40.256s (~1.6% speedup).
It should slightly reduce memory consumption. Gains should be roughly
proportional to the number (and path length) of static analysis
warnings.
This patch enables future work that should remove the need for an
InterExplodedGraphMap inverse map. I plan on using the (now unused)
ExplodedNode link to connect new nodes to the original nodes.
http://reviews.llvm.org/D21229
llvm-svn: 273572
Like with SenTestCase, subclasses of XCTestCase follow a "tear down" idiom to
release instance variables and so typically do not release ivars in -dealloc.
This commit applies the existing special casing for SenTestCase to XCTestCase
as well.
rdar://problem/25884696
llvm-svn: 273441
Teach trackNullOrUndefValue() how to properly look through PseudoObjectExprs
to find the underlying semantic method call for property getters. This fixes a
crash when looking through class property getters that I introduced in r265839.
rdar://problem/26796666
llvm-svn: 273340
classes.
MSVC actively uses unqualified lookup in dependent bases, lookup at the
instantiation point (non-dependent names may be resolved on things
declared later) etc. and all this stuff is the main cause of
incompatibility between clang and MSVC.
Clang tries to emulate MSVC behavior but it may fail in many cases.
clang could store lexed tokens for member functions definitions within
ClassTemplateDecl for later parsing during template instantiation.
It will allow resolving many possible issues with lookup in dependent
base classes and removing many already existing MSVC-specific
hacks/workarounds from the clang code.
llvm-svn: 272774
This is a speculative attempt to fix the compiler error: "list initialization inside
member initializer list or non-static data member initializer is not implemented" with
r272529.
llvm-svn: 272530
This commit adds a static analysis checker to verify the correct usage of the MPI API in C
and C++. This version updates the reverted r271981 to fix a memory corruption found by the
ASan bots.
Three path-sensitive checks are included:
- Double nonblocking: Double request usage by nonblocking calls without intermediate wait
- Missing wait: Nonblocking call without matching wait.
- Unmatched wait: Waiting for a request that was never used by a nonblocking call
Examples of how to use the checker can be found at https://github.com/0ax1/MPI-Checker
A patch by Alexander Droste!
Reviewers: zaks.anna, dcoughlin
Differential Revision: http://reviews.llvm.org/D21081
llvm-svn: 272529
Rehashing the ExplodedNode table is very expensive. The hashing
itself is expensive, and the general activity of iterating over the
hash table is highly cache unfriendly. Instead, we guess at the
eventual size by using the maximum number of steps allowed. This
generally avoids a rehash. It is possible that we still need to
rehash if the backlog of work that is added to the worklist
significantly exceeds the number of work items that we process. Even
if we do need to rehash in that scenario, this change is still a
win, as we still have fewer rehashes that we would have prior to
this change.
For small work loads, this will increase the memory used. For large
work loads, it will somewhat reduce the memory used. Speed is
significantly increased. A large .C file took 3m53.812s to analyze
prior to this change. Now it takes 3m38.976s, for a ~6% improvement.
http://reviews.llvm.org/D20933
llvm-svn: 272394
Second try at reapplying
"[analyzer] Add checker for correct usage of MPI API in C and C++."
Special thanks to Dan Liew for helping test the fix for the template
specialization compiler error with gcc.
The original patch is by Alexander Droste!
Differential Revision: http://reviews.llvm.org/D12761
llvm-svn: 271977
Reapply r271907 with a fix for the compiler error with gcc about specializing
clang::ento::ProgramStateTrait in a different namespace.
Differential Revision: http://reviews.llvm.org/D12761
llvm-svn: 271914
This commit adds a static analysis checker to check for the correct usage of the
MPI API in C and C++.
3 path-sensitive checks are included:
- Double nonblocking: Double request usage by nonblocking calls
without intermediate wait.
- Missing wait: Nonblocking call without matching wait.
- Unmatched wait: Waiting for a request that was never used by a
nonblocking call.
Examples of how to use the checker can be found
at https://github.com/0ax1/MPI-Checker
Reviewers: zaks.anna
A patch by Alexander Droste!
Differential Revision: http://reviews.llvm.org/D12761
llvm-svn: 271907
Summary:
This patch is to add parsing and sema support for `target update` directive. Support for the `to` and `from` clauses will be added by a different patch. This patch also adds support for other clauses that are already implemented upstream and apply to `target update`, e.g. `device` and `if`.
This patch is based on the original post by Kelvin Li.
Reviewers: hfinkel, carlo.bertolli, kkwli0, arpith-jacob, ABataev
Subscribers: caomhin, cfe-commits
Differential Revision: http://reviews.llvm.org/D15944
llvm-svn: 270878
Summary:
Leaking a stack address via a static variable refers to it in the diagnostic as a 'global'. This patch corrects the diagnostic for static variables.
Patch by Phil Camp, SN Systems
Reviewers: dcoughlin, zaks.anna
Subscribers: xazax.hun, cfe-commits
Differential Revision: http://reviews.llvm.org/D19866
Patch by Phil Camp
llvm-svn: 270849
The function strcmp() can return any value, not just {-1,0,1} : "The strcmp(const char *s1, const char *s2) function returns an integer greater than, equal to, or less than zero, accordingly as the string pointed to by s1 is greater than, equal to, or less than the string pointed to by s2." [C11 7.24.4.2p3]
https://llvm.org/bugs/show_bug.cgi?id=23790http://reviews.llvm.org/D16317
llvm-svn: 270154
Fix a crash in the generics checker where DynamicTypePropagation tries
to get the superclass of a root class.
This is a spot-fix for a deeper issue where the checker makes assumptions
that may not hold about subtyping between the symbolically-tracked type of
a value and the compile-time types of a cast on that value.
I've added a TODO to address the underlying issue.
rdar://problem/26086914
llvm-svn: 269227
If an address of a field is passed through a const pointer,
the whole structure's base region should receive the
TK_PreserveContents trait and avoid invalidation.
Additionally, include a few FIXME tests shown up during testing.
Differential Revision: http://reviews.llvm.org/D19057
llvm-svn: 267413
Update the nullability checker to allow an explicit cast to nonnull to
suppress a warning on an assignment of nil to a nonnull:
id _Nonnull x = (id _Nonnull)nil; // no-warning
This suppression as already possible for diagnostics on returns and
function/method arguments.
rdar://problem/25381178
llvm-svn: 266219
Treat a _Nonnull ivar that is nil as an invariant violation in a similar
fashion to how a nil _Nonnull parameter is treated as a precondition violation.
This avoids warning on defensive returns of nil on defensive internal
checks, such as the following common idiom:
@class InternalImplementation
@interface PublicClass {
InternalImplementation * _Nonnull _internal;
}
-(id _Nonnull)foo;
@end
@implementation PublicClass
-(id _Nonnull)foo {
if (!_internal)
return nil; // no-warning
return [_internal foo];
}
@end
rdar://problem/24485171
llvm-svn: 266157
The nullability checker can sometimes miss detecting nullability precondition
violations in inlined functions because the binding for the parameter
that violated the precondition becomes dead before the return:
int * _Nonnull callee(int * _Nonnull p2) {
if (!p2)
// p2 becomes dead here, so binding removed.
return 0; // warning here because value stored in p2 is symbolic.
else
return p2;
}
int *caller(int * _Nonnull p1) {
return callee(p1);
}
The fix, which is quite blunt, is to not warn about null returns in inlined
methods/functions. This won’t lose much coverage for ObjC because the analyzer
always analyzes each ObjC method at the top level in addition to inlined. It
*will* lose coverage for C — but there aren’t that many codebases with C
nullability annotations.
rdar://problem/25615050
llvm-svn: 266109
Don't emit a path note marking the return site if the return statement does not
have a valid location. This fixes an assertion failure I introduced in r265839.
llvm-svn: 266031
Teach trackNullOrUndefValue() how to look through PseudoObjectExprs to find
the underlying method call for property getters. This makes over-suppression
of 'return nil' in getters consistent with the similar over-suppression for
method and function calls.
rdar://problem/24437252
llvm-svn: 265839
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
In case the (uniqueing) location of the diagnostic is in a line that only
contains whitespaces there was an assertion fail during issue hash generation.
Unfortunately I am unable to reproduce this error with the built in checkers,
so no there is no failing test case with this patch. It would be possible to
write a debug checker for that purpuse but it does not worth the effort.
Differential Revision: http://reviews.llvm.org/D18210
llvm-svn: 264851
Change the nullability checker to not warn along paths where null is returned from
a method with a non-null return type, even when the diagnostic for this return
has been suppressed. This prevents warning from methods with non-null return types
that inline methods that themselves return nil but that suppressed the diagnostic.
Also change the PreconditionViolated state component to be called "InvariantViolated"
because it is set when a post-condition is violated, as well.
rdar://problem/25393539
llvm-svn: 264647
The -dealloc method in CIFilter is highly unusual in that it will release
instance variables belonging to its *subclasses* if the variable name
starts with "input" or backs a property whose name starts with "input".
Subclasses should not release these ivars in their own -dealloc method --
doing so could result in an over release.
Before this commit, the DeallocChecker would warn about missing releases for
such "input" properties -- which could cause users of the analyzer to add
over releases to silence the warning.
To avoid this, DeallocChecker now treats CIFilter "input-prefixed" ivars
as MustNotReleaseDirectly and so will not require a release. Further, it
will now warn when such an ivar is directly released in -dealloc.
rdar://problem/25364901
llvm-svn: 264463
The range here isn't over references, so using `auto &` here incites a
copy. Switching to `auto *` would do, but we might as well list an
explicit type for clarity.
Found by -Wrange-loop-analysis.
llvm-svn: 264071
Add the wide character strdup variants (wcsdup, _wcsdup) and the MSVC
version of alloca (_alloca) and other differently named function used
by the Malloc checker.
A patch by Alexander Riccio!
Differential Revision: http://reviews.llvm.org/D17688
llvm-svn: 262894
Add an -analyzer-config 'nullability:NoDiagnoseCallsToSystemHeaders' option to
the nullability checker. When enabled, this option causes the analyzer to not
report about passing null/nullable values to functions and methods declared
in system headers.
This option is motivated by the observation that large projects may have many
nullability warnings. These projects may find warnings about nullability
annotations that they have explicitly added themselves higher priority to fix
than warnings on calls to system libraries.
llvm-svn: 262763
In dealloc methods, the analyzer now warns when -dealloc is called directly on
a synthesized retain/copy ivar instead of -release. This is intended to find mistakes of
the form:
- (void)dealloc {
[_ivar dealloc]; // Mistaken call to -dealloc instead of -release
[super dealloc];
}
rdar://problem/16227989
llvm-svn: 262729
This prevents false negatives when a -dealloc method, for example, removes itself as
as an observer with [[NSNotificationCenter defaultCenter] removeObserver:self]. It is
unlikely that passing 'self' to a system header method will release 'self''s instance
variables, so this is unlikely to produce false positives.
A challenge here is that while CheckObjCDealloc no longer treats these calls as
escaping, the rest of the analyzer still does. In particular, this means that loads
from the same instance variable before and after a call to a system header will
result in different symbols being loaded by the region store. To account for this,
the checker now treats different ivar symbols with the same instance and ivar decl as
the same for the purpose of release checking and more eagerly removes a release
requirement when an instance variable is assumed to be nil. This was not needed before
because when an ivar escaped its release requirement was always removed -- now the
requirement is not removed for calls to system headers.
llvm-svn: 262261
Change "use of 'self' after it has been freed with call to [super dealloc]" to
"use of 'self' after it has been deallocated" and "use of instance variable
'_ivar' after the instance has been freed with call to [super dealloc]" to
"use of instance variable '_ivar' after 'self' has been deallocated".
llvm-svn: 261945
Referring to 'self' after a call to [super dealloc] is a use-after-free in
Objective-C because NSObject's -dealloc frees the memory pointed to by self.
This patch extends the ObjCSuperDeallocChecker to catch this error.
rdar://problem/6953275
Differential Revision: http://reviews.llvm.org/D17528
llvm-svn: 261935
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
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
This patch is intended to improve pointer arithmetic checker.
From now on it only warns when the pointer arithmetic is likely to cause an
error. For example when the pointer points to a single object, or an array of
derived types.
Differential Revision: http://reviews.llvm.org/D14203
llvm-svn: 261632
Add an alpha path checker that warns about duplicate calls to [super dealloc].
This will form the foundation of a checker that will detect uses of
'self' after calling [super dealloc].
Part of rdar://problem/6953275.
Based on a patch by David Kilzer!
Differential Revision: http://reviews.llvm.org/D5238
llvm-svn: 261545
Add a checker callback that is called when the analyzer starts analyzing a
function either at the top level or when inlined. This will be used by a
follow-on patch making the DeallocChecker path sensitive.
Differential Revision: http://reviews.llvm.org/D17418
llvm-svn: 261293
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
r260925 introduced a version of the *trim methods which is preferable
when trimming a single kind of character. Update all users in clang.
llvm-svn: 260927
Look through PseudoObjectExpr and OpaqueValueExprs when scanning for
release-like operations. This commit also adds additional tests in anticipation
of re-writing this as a path-sensitive checker.
llvm-svn: 260608
Now that the libcpp implementations of these methods has a branch that doesn't call
memmove(), the analyzer needs to invalidate the destination for these methods explicitly.
rdar://problem/23575656
llvm-svn: 260043
It is common for the ivars for read-only assign properties to always be stored retained,
so don't warn for a release in dealloc for the ivar backing these properties.
llvm-svn: 259998
If the class or method name case-insensitively contains the term "debug",
suppress warnings about string constants flowing to user-facing UI APIs.
llvm-svn: 259875
Summary:
This patch adds parsing + sema for the target parallel for directive along with testcases.
Reviewers: ABataev
Differential Revision: http://reviews.llvm.org/D16759
llvm-svn: 259654
-analyzer-display progress option prints only function names which may be ambiguous. This patch forces AnalysisConsumer to print fully-qualified function names.
Patch by Alex Sidorin!
Differential Revision: http://reviews.llvm.org/D16804
llvm-svn: 259646
These sets perform linear searching in small mode so it is never a good
idea to use SmallSize/N bigger than 32.
Differential Revision: http://reviews.llvm.org/D16705
llvm-svn: 259284
We already do this for case splits introduced as a result of defensive null
checks in functions and methods, so do the same for function-like macros.
rdar://problem/19640441
llvm-svn: 259222
- Include the position of the argument on which the nullability is violated
- Differentiate between a 'method' and a 'function' in the message wording
- Test for the error message text in the tests
- Fix a bug with setting 'IsDirectDereference' which resulted in regular dereferences assumed to have call context.
llvm-svn: 259221
PropertyMap used to map IdentifierInfo (name of the property) to
ObjcPropertyDecl *. Now that a class property can have the same name as
an instance property, we change PropertyMap to map a pair <IdentifierInfo *,
unsigned> to ObjcPropertyDecl *.
Also update a few places from iterating over instance_properties to
iterating over all properties.
rdar://23891898
llvm-svn: 259119
There are multiple, common idioms of defensive nil-checks in copy,
mutableCopy, and init methods in ObjC. The analyzer doesn't currently have the
capability to distinguish these idioms from true positives, so suppress all
warnings about returns in those families. This is a pretty blunt suppression
that we should improve later.
rdar://problem/24395811
llvm-svn: 259099
Previously the ObjC Dealloc Checker only checked classes with ivars, not
retained properties, which caused three bugs:
- False positive warnings about a missing -dealloc method in classes with only
ivars.
- Missing warnings about a missing -dealloc method on classes with only
properties.
- Missing warnings about an over-released or under-released ivar associated with
a retained property in classes with only properties.
The fix is to check only classes with at least one retained synthesized
property.
This also exposed a bug when reporting an over-released or under-released
property that did not contain a synthesize statement. The checker tried to
associate the warning with an @synthesize statement that did not exist, which
caused an assertion failure in debug builds. The fix is to fall back to the
@property statement in this case.
A patch by David Kilzer!
Part of rdar://problem/6927496
Differential Revision: http://reviews.llvm.org/D5023
llvm-svn: 258896
Summary:
This patch is provided in preparation for removing autoconf on 1/26. The proposal to remove autoconf on 1/26 was discussed on the llvm-dev thread here: http://lists.llvm.org/pipermail/llvm-dev/2016-January/093875.html
"This is the way [autoconf] ends
Not with a bang but a whimper."
-T.S. Eliot
Reviewers: chandlerc, grosbach, bob.wilson, echristo
Subscribers: klimek, cfe-commits
Differential Revision: http://reviews.llvm.org/D16472
llvm-svn: 258862
Summary:
This patch adds parsing + sema for the target parallel directive and its clauses along with testcases.
Reviewers: ABataev
Differential Revision: http://reviews.llvm.org/D16553
Rebased to current trunk and updated test cases.
llvm-svn: 258832
All current properties are instance properties.
This is the second patch in a series of patches to support class properties
in addition to instance properties in objective-c.
rdar://23891898
llvm-svn: 258824
This patch adds a small utility to match function calls. This utility abstracts away the mutable keywords and the lazy initialization and caching logic of identifiers from the checkers. The SimpleStreamChecker is ported over this utility within this patch to show the reduction of code and to test this change.
Differential Revision: http://reviews.llvm.org/D15921
llvm-svn: 258572
A common idiom in Objective-C initializers is for a defensive nil-check on the
result of a call to a super initializer:
if (self = [super init]) {
...
}
return self;
To avoid warning on this idiom, the nullability checker now suppress diagnostics
for returns of nil on syntactic 'return self' even in initializers with non-null
return types.
llvm-svn: 258461
In r256567 I changed the nullability checker to suppress warnings about returning a null
value from a function/method with a non-null return type when the type of the returned
expression is itself nonnull. This enables the programmer to silence nullability warnings
by casting to _Nonnull:
return (SomeObject * _Nonnull)nil;
Unfortunately, under ObjC automated reference counting, Sema adds implicit casts to
_Nonnull to return expressions of nullable or unspecified types in functions with
non-null function/method return types. With r256567, these casts cause all nullability
warnings for returns of reference-counted types to be suppressed under ARC, leading to
false negatives.
This commit updates the nullability checker to look through implicit casts before
determining the type of the returned expression. It also updates the tests to turn on
ARC for the nullability_nullonly.mm testfile and adds a new testfile to test when ARC
is turned off.
rdar://problem/24200117
llvm-svn: 258061
Make sure that we do not add SymbolCast at the very boundary of
the range in which the cast would not certainly happen.
Differential Revision: http://reviews.llvm.org/D16178
llvm-svn: 258039
Update NullabilityChecker so that it checks return statements in ObjC methods.
Previously it was returning early because methods do not have a function type.
Also update detection of violated parameter _Nonnull preconditions to handle
ObjC methods.
rdar://problem/24200560
llvm-svn: 257938
Provide separate visitor templates for the three hierarchies, and also
the `FullSValVisitor' class, which is a union of all three visitors.
Additionally, add a particular example visitor, `SValExplainer', in order to
test the visitor templates. This visitor is capable of explaining the SVal,
SymExpr, or MemRegion in a natural language.
Compared to the reverted r257605, this fixes the test that used to fail
on some triples, and fixes build failure under -fmodules.
Differential Revision: http://reviews.llvm.org/D15448
llvm-svn: 257893
This reverts commit r257605.
The test fails on architectures that use unsigned int as size_t.
SymbolManager.h fails with compile errors on some platforms.
llvm-svn: 257608
Provide separate visitor templates for the three hierarchies, and also
the `FullSValVisitor' class, which is a union of all three visitors.
Additionally, add a particular example visitor, `SValExplainer', in order to
test the visitor templates. This visitor is capable of explaining the SVal,
SymExpr, or MemRegion in a natural language.
Differential Revision: http://reviews.llvm.org/D15448
llvm-svn: 257605
The purpose of these changes is to simplify introduction of definition files
for the three hierarchies.
1. For every sub-class C of these classes, its kind in the relevant enumeration
is changed to "CKind" (or C##Kind in preprocessor-ish terms), eg:
MemRegionKind -> MemRegionValKind
RegionValueKind -> SymbolRegionValueKind
CastSymbolKind -> SymbolCastKind
SymIntKind -> SymIntExprKind
2. MemSpaceRegion used to be inconsistently used as both an abstract base and
a particular region. This region class is now an abstract base and no longer
occupies GenericMemSpaceRegionKind. Instead, a new class, CodeSpaceRegion,
is introduced for handling the unique use case for MemSpaceRegion as
"the generic memory space" (when it represents a memory space that holds all
executable code).
3. BEG_ prefixes in memory region kind ranges are renamed to BEGIN_ for
consisitency with symbol kind ranges.
4. FunctionTextRegion and BlockTextRegion are renamed to FunctionCodeRegion and
BlockCodeRegion, respectively. The term 'code' is less jargony than 'text' and
we already refer to BlockTextRegion as a 'code region' in BlockDataRegion.
Differential Revision: http://reviews.llvm.org/D16062
llvm-svn: 257598
In {CG,}ExprConstant.cpp, we weren't treating vector splats properly.
This patch makes us treat splats more properly.
Additionally, this patch adds a new cast kind which allows a bool->int
cast to result in -1 or 0, instead of 1 or 0 (for true and false,
respectively), so we can sanely model OpenCL bool->int casts in the AST.
Differential Revision: http://reviews.llvm.org/D14877
llvm-svn: 257559
This fix a bug in RangeSet::pin causing single value ranges to be considered non conventionally ordered.
Differential Revision: http://reviews.llvm.org/D12901
llvm-svn: 257467
The current workaround for truncations not being modelled is that the evaluation of integer to integer casts are simply bypassed and so the original symbol is used as the new casted symbol (cf SimpleSValBuilder::evalCastFromNonLoc).
This lead to the issue described in PR25078, as the RangeConstraintManager associates ranges with symbols.
The new evalIntegralCast method added by this patch wont bypass the cast if it finds the range of the symbol to be greater than the maximum value of the target type.
The fix to RangeSet::pin mentioned in the initial review will be committed separately.
Differential Revision: http://reviews.llvm.org/D12901
llvm-svn: 257464
visited decls.
Due to redeclarations, the function may have different declarations used
in CallExpr and in the definition. However, we need to use a unique
declaration for both store and lookup in VisitedCallees. This patch
fixes issues with analysis in topological order. A simple test is
included.
Patch by Alex Sidorin!
Differential Revision: http://reviews.llvm.org/D15410
llvm-svn: 257318
The analyzer reports a shift by a negative value in the constructor. The bug can
be easily triggered by calling std::random_shuffle on a vector
(<rdar://problem/19658126>).
(The shift by a negative value is reported because __w0_ gets constrained to
63 by the conditions along the path:__w0_ < _WDt && __w0_ >= _WDt-1,
where _WDt is 64. In normal execution, __w0_ is not 63, it is 1 and there is
no overflow. The path is infeasible, but the analyzer does not know about that.)
llvm-svn: 256886
Android's assert can call both the __assert and __assert2 functions under the cover, but
the NoReturnFunctionChecker does not handle the latter. This commit fixes that.
A patch by Yury Gribov!
Differential Revision: http://reviews.llvm.org/D15810
llvm-svn: 256605
Prevent the analyzer from warning when a _Nonnnull local variable is implicitly
zero-initialized because of Objective-C automated reference counting. This avoids false
positives in cases where a _Nonnull local variable cannot be initialized with an
initialization expression, such as:
NSString * _Nonnull s; // no-warning
@autoreleasepool {
s = ...;
}
The nullability checker will still warn when a _Nonnull local variable is explicitly
initialized with nil.
This suppression introduces the potential for false negatives if the local variable
is used before it is assigned a _Nonnull value. Based on a discussion with Anna Zaks,
Jordan Rose, and John McCall, I've added a FIXME to treat implicitly zero-initialized
_Nonnull locals as uninitialized in Sema's UninitializedValues analysis to avoid these
false negatives.
rdar://problem/23522311
llvm-svn: 256603
The nullability checker currently allows casts to suppress warnings when a nil
literal is passed as an argument to a parameter annotated as _Nonnull:
foo((NSString * _Nonnull)nil); // no-warning
It does so by suppressing the diagnostic when the *type* of the argument expression
is _Nonnull -- even when the symbolic value returned is known to be nil.
This commit updates the nullability checker to similarly honor such casts in the analogous
scenario when nil is returned from a function with a _Nonnull return type:
return (NSString * _Nonnull)nil; // no-warning
This commit also normalizes variable naming between the parameter and return cases and
adds several tests demonstrating the limitations of this suppression mechanism (such as
when nil is cast to _Nonnull and then stored into a local variable without a nullability
qualifier). These tests are marked with FIXMEs.
rdar://problem/23176782
llvm-svn: 256567
Use getRedeclContext() instead of a manually-written loop and fix a comment.
A patch by Aleksei Sidorin!
Differential Revision: http://reviews.llvm.org/D15794
llvm-svn: 256524