Author: dcoughlin
Date: Wed Apr 13 12:59:24 2016
New Revision: 266219
URL: http://llvm.org/viewvc/llvm-project?rev=266219&view=rev
Log:
[analyzer] Nullability: Suppress diagnostic on bind with cast.
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
Modified:
cfe/trunk/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp
cfe/trunk/test/Analysis/nullability.mm
Modified: cfe/trunk/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp?rev=266219&r1=266218&r2=266219&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp Wed Apr 13
12:59:24 2016
@@ -1103,26 +1103,48 @@ void NullabilityChecker::checkBind(SVal
ValNullability = getNullabilityAnnotation(Sym->getType());
Nullability LocNullability = getNullabilityAnnotation(LocType);
+
+ // If the type of the RHS expression is nonnull, don't warn. This
+ // enables explicit suppression with a cast to nonnull.
+ Nullability ValueExprTypeLevelNullability = Nullability::Unspecified;
+ const Expr *ValueExpr = matchValueExprForBind(S);
+ if (ValueExpr) {
+ ValueExprTypeLevelNullability =
+ getNullabilityAnnotation(lookThroughImplicitCasts(ValueExpr)->getType());
+ }
+
+ bool NullAssignedToNonNull = (LocNullability == Nullability::Nonnull &&
+ RhsNullness == NullConstraint::IsNull);
if (Filter.CheckNullPassedToNonnull &&
- RhsNullness == NullConstraint::IsNull &&
+ NullAssignedToNonNull &&
ValNullability != Nullability::Nonnull &&
- LocNullability == Nullability::Nonnull &&
+ ValueExprTypeLevelNullability != Nullability::Nonnull &&
!isARCNilInitializedLocal(C, S)) {
static CheckerProgramPointTag Tag(this, "NullPassedToNonnull");
ExplodedNode *N = C.generateErrorNode(State, &Tag);
if (!N)
return;
- const Stmt *ValueExpr = matchValueExprForBind(S);
- if (!ValueExpr)
- ValueExpr = S;
+
+ const Stmt *ValueStmt = S;
+ if (ValueExpr)
+ ValueStmt = ValueExpr;
reportBugIfInvariantHolds("Null is assigned to a pointer which is "
"expected to have non-null value",
ErrorKind::NilAssignedToNonnull, N, nullptr, C,
- ValueExpr);
+ ValueStmt);
return;
}
+
+ // If null was returned from a non-null function, mark the nullability
+ // invariant as violated even if the diagnostic was suppressed.
+ if (NullAssignedToNonNull) {
+ State = State->set<InvariantViolated>(true);
+ C.addTransition(State);
+ return;
+ }
+
// Intentionally missing case: '0' is bound to a reference. It is handled by
// the DereferenceChecker.
Modified: cfe/trunk/test/Analysis/nullability.mm
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/nullability.mm?rev=266219&r1=266218&r2=266219&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/nullability.mm (original)
+++ cfe/trunk/test/Analysis/nullability.mm Wed Apr 13 12:59:24 2016
@@ -174,6 +174,47 @@ void testIndirectCastNilToNonnullAndPass
takesNonnull(p); // expected-warning {{Null passed to a callee that
requires a non-null 1st parameter}}
}
+void testDirectCastNilToNonnullAndAssignToLocalInInitializer() {
+ Dummy * _Nonnull nonnullLocalWithAssignmentInInitializer = (Dummy *
_Nonnull)0; // no-warning
+ (void)nonnullLocalWithAssignmentInInitializer;
+
+ // Since we've already had an invariant violation along this path,
+ // we shouldn't warn here.
+ nonnullLocalWithAssignmentInInitializer = 0;
+ (void)nonnullLocalWithAssignmentInInitializer;
+
+}
+
+void testDirectCastNilToNonnullAndAssignToLocal(Dummy * _Nonnull p) {
+ Dummy * _Nonnull nonnullLocalWithAssignment = p;
+ nonnullLocalWithAssignment = (Dummy * _Nonnull)0; // no-warning
+ (void)nonnullLocalWithAssignment;
+
+ // Since we've already had an invariant violation along this path,
+ // we shouldn't warn here.
+ nonnullLocalWithAssignment = 0;
+ (void)nonnullLocalWithAssignment;
+}
+
+void testDirectCastNilToNonnullAndAssignToParam(Dummy * _Nonnull p) {
+ p = (Dummy * _Nonnull)0; // no-warning
+}
+
+@interface ClassWithNonnullIvar : NSObject {
+ Dummy *_nonnullIvar;
+}
+@end
+
+@implementation ClassWithNonnullIvar
+-(void)testDirectCastNilToNonnullAndAssignToIvar {
+ _nonnullIvar = (Dummy * _Nonnull)0; // no-warning;
+
+ // Since we've already had an invariant violation along this path,
+ // we shouldn't warn here.
+ _nonnullIvar = 0;
+}
+@end
+
void testIndirectNilPassToNonnull() {
Dummy *p = 0;
takesNonnull(p); // expected-warning {{Null passed to a callee that
requires a non-null 1st parameter}}
@@ -479,9 +520,7 @@ void callMethodInSystemHeader() {
}
-(id _Nonnull)methodWithNilledOutInternal {
- // The cast below should (but does not yet) suppress the warning on the
- // assignment.
- _nilledOutInternal = (id _Nonnull)nil; // expected-warning {{Null is
assigned to a pointer which is expected to have non-null value}}
+ _nilledOutInternal = (id _Nonnull)nil;
return nil; // no-warning
}
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