summaryrefslogtreecommitdiffstats
path: root/clang/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp
Commit message (Collapse)AuthorAgeFilesLines
* [analyzer] Improve Nullability checker diagnosticsAnna Zaks2016-01-291-32/+60
| | | | | | | | | - 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
* [analyzer] NullabilityChecker: Remove unused isReturnSelf() function.Devin Coughlin2016-01-281-16/+0
| | | | | | | Remove the now-unused isReturnSelf() function so we don't get a compiler warning. Apologies for not doing this in r259099. llvm-svn: 259118
* [analyzer] Suppress nullability warnings in copy, mutableCopy, and init ↵Devin Coughlin2016-01-281-11/+10
| | | | | | | | | | | | | | 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
* [analyzer] Suppress nullability warning for defensive super initializer idiom.Devin Coughlin2016-01-221-4/+33
| | | | | | | | | | | | | | | 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
* [analyzer] Nullability: Look through implicit casts when suppressing ↵Devin Coughlin2016-01-181-1/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | 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
* [analyzer] Check for return of nil in ObjC methods with nonnull return type.Devin Coughlin2016-01-151-20/+20
| | | | | | | | | | | | 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
* [analyzer] Suppress nullability warning for _Nonnull locals zero-initialized ↵Devin Coughlin2015-12-291-1/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | 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
* [analyzer] Nullability: allow cast to _Nonnull to suppress warning about ↵Devin Coughlin2015-12-291-12/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | returning nil. 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
* [analyzer] Pass value expression for inlined defensive checks when binding ↵Devin Coughlin2015-11-241-1/+30
| | | | | | | | | | | | | | | | null to nonnull. The nullability checker was not suppressing false positives resulting from inlined defensive checks when null was bound to a nonnull variable because it was passing the entire bind statement rather than the value expression to trackNullOrUndefValue(). This commit changes that checker to synactically match on the bind statement to extract the value expression so it can be passed to trackNullOrUndefValue(). rdar://problem/23575439 llvm-svn: 254007
* [analyzer] Add generateErrorNode() APIs to CheckerContext.Devin Coughlin2015-09-161-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The analyzer trims unnecessary nodes from the exploded graph before reporting path diagnostics. However, in some cases it can trim all nodes (including the error node), leading to an assertion failure (see https://llvm.org/bugs/show_bug.cgi?id=24184). This commit addresses the issue by adding two new APIs to CheckerContext to explicitly create error nodes. Unless the client provides a custom tag, these APIs tag the node with the checker's tag -- preventing it from being trimmed. The generateErrorNode() method creates a sink error node, while generateNonFatalErrorNode() creates an error node for a path that should continue being explored. The intent is that one of these two methods should be used whenever a checker creates an error node. This commit updates the checkers to use these APIs. These APIs (unlike addTransition() and generateSink()) do not take an explicit Pred node. This is because there are not any error nodes in the checkers that were created with an explicit different than the default (the CheckerContext's Pred node). It also changes generateSink() to require state and pred nodes (previously these were optional) to reduce confusion. Additionally, there were several cases where checkers did check whether a generated node could be null; we now explicitly check for null in these places. This commit also includes a test case written by Ying Yi as part of http://reviews.llvm.org/D12163 (that patch originally addressed this issue but was reverted because it introduced false positive regressions). Differential Revision: http://reviews.llvm.org/D12780 llvm-svn: 247859
* [Static Analyzer] Nullability checker optimization.Gabor Horvath2015-09-141-1/+6
| | | | | | Differential Revision: http://reviews.llvm.org/D12848 llvm-svn: 247612
* [Static Analyzer] Moving nullability checkers to a top level package.Gabor Horvath2015-09-141-10/+27
| | | | | | Differential Revision: http://reviews.llvm.org/D12852 llvm-svn: 247590
* [Static Analyzer] Fixed a typo in a diagnostic message.Gabor Horvath2015-09-111-1/+1
| | | | llvm-svn: 247444
* [Static Analyzer] Minor cleanups for the nullability checker.Gabor Horvath2015-09-111-46/+40
| | | | | | Differential Revision: http://reviews.llvm.org/D12619 llvm-svn: 247423
* [Static Analyzer] Remove sinks from nullability checks.Gabor Horvath2015-09-031-26/+146
| | | | | | Differential Revision: http://reviews.llvm.org/D12445 llvm-svn: 246818
* [Static Analyzer] Make NonNullParamChecker emit implicit null dereference ↵Gabor Horvath2015-08-271-1/+4
| | | | | | | | events. Differential Revision: http://reviews.llvm.org/D11433 llvm-svn: 246182
* [Static Analyzer] Checks to catch nullability related issues.Gabor Horvath2015-08-261-0/+838
Differential Revision: http://reviews.llvm.org/D11468 llvm-svn: 246105
OpenPOWER on IntegriCloud