Commit Graph

2462 Commits

Author SHA1 Message Date
Anna Zaks 30d4668774 [analyzer] Fix missed leak from MSVC specific allocation functions
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
2016-03-08 01:21:51 +00:00
Richard Smith 4f902c7ecc P0188R1: add support for standard [[fallthrough]] attribute. This is almost
exactly the same as clang's existing [[clang::fallthrough]] attribute, which
has been updated to have the same semantics. The one significant difference
is that [[fallthrough]] is ill-formed if it's not used immediately before a
switch label (even when -Wimplicit-fallthrough is disabled). To support that,
we now build a CFG of any function that uses a '[[fallthrough]];' statement
to check.

In passing, fix some bugs with our support for statement attributes -- in
particular, diagnose their use on declarations, rather than asserting.

llvm-svn: 262881
2016-03-08 00:32:55 +00:00
Devin Coughlin a1d9d75a88 [analyzer] Nullability: add option to not report on calls to system headers.
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
2016-03-05 01:32:43 +00:00
Devin Coughlin a604679897 [analyzer] Add diagnostic in ObjCDeallocChecker for use of -dealloc instead of -release.
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
2016-03-04 18:09:58 +00:00
Devin Coughlin 578a20a82e [analyzer] ObjCDeallocChecker: Only check for nil-out when type is retainable.
This fixes a crash when setting a property of struct type in -dealloc.

llvm-svn: 262659
2016-03-03 21:38:39 +00:00
Devin Coughlin 2b2f8996ce [analyzer] Move ObjCSuperDeallocChecker out of the alpha package.
It will now be on by default on Darwin.

rdar://problem/6953275

llvm-svn: 262526
2016-03-02 22:01:03 +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 dce8d8b3f1 [analyzer] Fix capitalization in ObjCSuperDeallocChecker diagnostic.
llvm-svn: 262520
2016-03-02 21:22:48 +00:00
Devin Coughlin 6d0c8a036e [analyzer] Update CheckObjCDealloc diagnostic for missing -dealloc.
Update the diagnostic for classes missing -dealloc to mention an instance
variable that needs to be released.

llvm-svn: 262277
2016-03-01 00:39:04 +00:00
Devin Coughlin 093594938b [analyzer] Teach CheckObjCDealloc about Block_release().
It now treats Block_release(b) as a release in addition to [b release].

llvm-svn: 262272
2016-02-29 23:57:10 +00:00
Devin Coughlin 3fc67e47e5 [analyzer] Don't treat calls to system headers as escaping in CheckObjCDealloc.
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
2016-02-29 21:44:08 +00:00
Devin Coughlin 896dffe752 [analyzer] Shorten ObjcSuperDeallocChecker diagnostics.
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
2016-02-26 00:47:42 +00:00
Devin Coughlin 591991c86f [analyzer] Warn on use of 'self' after call to to [super dealloc].
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
2016-02-25 23:36:52 +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 c289b74bd6 [analyzer] Find ObjC 'self' decl even when block captures local named 'self'.
When looking up the 'self' decl in block captures, make sure to find the actual
self declaration even when the block captures a local variable named 'self'.

rdar://problem/24751280

llvm-svn: 261703
2016-02-23 22:26:04 +00:00
Gabor Horvath d1abcf799e [analyzer] Improve pointer arithmetic checker.
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
2016-02-23 12:34:39 +00:00
Devin Coughlin eb6673cfed [analyzer] Detect duplicate [super dealloc] calls
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
2016-02-22 17:56:24 +00:00
Devin Coughlin 8d922aa746 [analyzer] Add checker callback for beginning of function.
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
2016-02-19 01:35:10 +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 982c42da64 [analyzer] Improve pattern matching in ObjCDealloc checker.
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
2016-02-11 22:13:20 +00:00
Devin Coughlin 480a0c00ca [analyzer] Avoid crash when attempting to evaluate binary operation on LazyCompoundVal.
Instead, return UnknownValue if either operand is a nonloc::LazyCompoundVal. This is a
spot fix for PR 24951.

rdar://problem/23682244

llvm-svn: 260066
2016-02-08 00:28:24 +00:00
Devin Coughlin 9165df129e [analyzer] Invalidate destination of std::copy() and std::copy_backward().
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
2016-02-07 16:55:44 +00:00
Devin Coughlin 38e0e2970c [analyzer] DeallocChecker: Don't warn on release of readonly assign property in dealloc.
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
2016-02-06 17:17:32 +00:00
Devin Coughlin 084e363517 [analyzer] Suppress localization diagnostics in debug classes and methods.
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
2016-02-05 04:22:15 +00:00
Yury Gribov 0826bf2211 Forgot to remove file in previous commit.
llvm-svn: 259647
2016-02-03 13:36:31 +00:00
Yury Gribov 8f7d8b6c32 [analyzer] AnalysisConsumer: print fully-qualified function name while displaying progress
-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
2016-02-03 13:35:33 +00:00
Artem Dergachev f8d0f18fac [analyzer] Use a wider integer type for an array index.
Avoids unexpected overflows while performing pointer arithmetics in 64-bit code.
Moreover, neither PointerDiffType nor 'int' can be used as a common array index
type because arrays may have size (and indexes) more than PTRDIFF_MAX but less
than SIZE_MAX.

Patch by Aleksei Sidorin!

Differential Revision: http://reviews.llvm.org/D16063

llvm-svn: 259345
2016-02-01 09:29:17 +00:00
Devin Coughlin 4be27d4db9 [analyzer] Make suppression of macro defensive checks work with -analyzer-eagerly-assume.
This is the default for the analyzer but the flag is added by the driver so
our suppression tests didn't cover this case.

llvm-svn: 259288
2016-01-30 01:59:33 +00:00
Devin Coughlin 07c451fa4a [analyzer] Suppress null reports from defensive checks in function-like macros.
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
2016-01-29 18:47:13 +00:00
Anna Zaks ad9e7ea6d7 [analyzer] Improve Nullability checker diagnostics
- 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
2016-01-29 18:43:15 +00:00
Devin Coughlin de21767a4d [analyzer] Suppress nullability warnings in copy, mutableCopy, and init families.
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
2016-01-28 22:23:34 +00:00
Devin Coughlin 3075134739 [analyzer] ObjCDeallocChecker: Only operate on classes with retained properties.
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
2016-01-27 01:41:58 +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
Devin Coughlin 4a330201ff [analyzer] Suppress nullability warning for defensive super initializer idiom.
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
2016-01-22 01:01:11 +00:00
Devin Coughlin 5a3843e506 [analyzer] Nullability: Look through implicit casts when suppressing warnings on return.
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
2016-01-18 18:53:33 +00:00
Artem Dergachev 91c45e8f46 [analyzer] Fix an off-by-one in evalIntegralCast()
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
2016-01-18 10:17:16 +00:00
Devin Coughlin 851da71c8f [analyzer] Check for return of nil in ObjC methods with nonnull return type.
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
2016-01-15 21:35:40 +00:00
Artem Dergachev 895242f9fb [analyzer] Provide .def-files and visitors for SVal/SymExpr/MemRegion, v2.
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
2016-01-15 15:22:05 +00:00
Artem Dergachev 26ec8acc84 Revert "[analyzer] Provide .def-files and visitors for SVal/SymExpr/MemRegion."
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
2016-01-13 15:52:25 +00:00
Artem Dergachev beb02b5b8f [analyzer] Provide .def-files and visitors for SVal/SymExpr/MemRegion.
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
2016-01-13 15:13:48 +00:00
Pierre Gousseau bdd9da14d6 [analyzer] Fix RangeConstraintManager's pinning of single value ranges.
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
2016-01-12 10:40:45 +00:00
Pierre Gousseau e961b445ad [analyzer] Evaluate integral casts as cast symbols if truncations are detected.
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
2016-01-12 10:07:56 +00:00
Yury Gribov 054873b0be AnalysisConsumer: use canonical decl for both lookup and store of
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
2016-01-11 09:38:48 +00:00
Anna Zaks 03f483353c [analyzer] Fix false warning about memory leak for QApplication::postEvent
According to Qt documentation Qt takes care of memory allocated for QEvent:
http://doc.qt.io/qt-4.8/qcoreapplication.html#postEvent

A patch by Evgeniy Dushistov!

Differential Revision: http://reviews.llvm.org/D14170

llvm-svn: 256887
2016-01-06 00:32:56 +00:00
Anna Zaks ac4c8a639c [analyzer] Suppress reports coming from std::__independent_bits_engine
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
2016-01-06 00:32:52 +00:00
Anna Zaks c9f16fe48c [analyzer] Don't report null dereferences on address_space annotated memory
llvm-svn: 256885
2016-01-06 00:32:49 +00:00
Devin Coughlin 3369867aa7 [analyzer] Handle another Android assert function.
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
2015-12-30 00:08:59 +00:00
Devin Coughlin 3ab8b2e7d4 [analyzer] Suppress nullability warning for _Nonnull locals zero-initialized by ObjC ARC.
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
2015-12-29 23:44:19 +00:00