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-rw-r--r--clang/include/clang/Sema/Sema.h5
-rw-r--r--clang/lib/Sema/Sema.cpp27
-rw-r--r--clang/lib/Sema/SemaExprCXX.cpp7
-rw-r--r--clang/test/Sema/nullability.c3
-rw-r--r--clang/test/SemaCXX/nullability.cpp32
5 files changed, 61 insertions, 13 deletions
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index abdab029676..a158e50f548 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -3511,6 +3511,11 @@ public:
void DiagnoseSelfMove(const Expr *LHSExpr, const Expr *RHSExpr,
SourceLocation OpLoc);
+ /// \brief Warn if we're implicitly casting from a _Nullable pointer type to a
+ /// _Nonnull one.
+ void diagnoseNullableToNonnullConversion(QualType DstType, QualType SrcType,
+ SourceLocation Loc);
+
ParsingDeclState PushParsingDeclaration(sema::DelayedDiagnosticPool &pool) {
return DelayedDiagnostics.push(pool);
}
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index b87fb52f4d2..39b8cc9f0c6 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -349,6 +349,20 @@ void Sema::PrintStats() const {
AnalysisWarnings.PrintStats();
}
+void Sema::diagnoseNullableToNonnullConversion(QualType DstType,
+ QualType SrcType,
+ SourceLocation Loc) {
+ Optional<NullabilityKind> ExprNullability = SrcType->getNullability(Context);
+ if (!ExprNullability || *ExprNullability != NullabilityKind::Nullable)
+ return;
+
+ Optional<NullabilityKind> TypeNullability = DstType->getNullability(Context);
+ if (!TypeNullability || *TypeNullability != NullabilityKind::NonNull)
+ return;
+
+ Diag(Loc, diag::warn_nullability_lost) << SrcType << DstType;
+}
+
/// ImpCastExprToType - If Expr is not of type 'Type', insert an implicit cast.
/// If there is already an implicit cast, merge into the existing one.
/// The result is of the given category.
@@ -372,18 +386,7 @@ ExprResult Sema::ImpCastExprToType(Expr *E, QualType Ty,
assert((VK == VK_RValue || !E->isRValue()) && "can't cast rvalue to lvalue");
#endif
- // Check whether we're implicitly casting from a nullable type to a nonnull
- // type.
- if (auto exprNullability = E->getType()->getNullability(Context)) {
- if (*exprNullability == NullabilityKind::Nullable) {
- if (auto typeNullability = Ty->getNullability(Context)) {
- if (*typeNullability == NullabilityKind::NonNull) {
- Diag(E->getLocStart(), diag::warn_nullability_lost)
- << E->getType() << Ty;
- }
- }
- }
- }
+ diagnoseNullableToNonnullConversion(Ty, E->getType(), E->getLocStart());
QualType ExprTy = Context.getCanonicalType(E->getType());
QualType TypeTy = Context.getCanonicalType(Ty);
diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index b6c5d792b6d..e5df6c1bf33 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -3118,6 +3118,7 @@ Sema::PerformImplicitConversion(Expr *From, QualType ToType,
ToType = ToAtomic->getValueType();
}
+ QualType InitialFromType = FromType;
// Perform the first implicit conversion.
switch (SCS.First) {
case ICK_Identity:
@@ -3488,6 +3489,12 @@ Sema::PerformImplicitConversion(Expr *From, QualType ToType,
VK_RValue, nullptr, CCK).get();
}
+ // If this conversion sequence succeeded and involved implicitly converting a
+ // _Nullable type to a _Nonnull one, complain.
+ if (CCK == CCK_ImplicitConversion)
+ diagnoseNullableToNonnullConversion(ToType, InitialFromType,
+ From->getLocStart());
+
return From;
}
diff --git a/clang/test/Sema/nullability.c b/clang/test/Sema/nullability.c
index 8a621d3b5f8..bbe5cb4143a 100644
--- a/clang/test/Sema/nullability.c
+++ b/clang/test/Sema/nullability.c
@@ -112,4 +112,7 @@ _Nonnull int *returns_int_ptr(int x) {
void nullable_to_nonnull(_Nullable int *ptr) {
int *a = ptr; // okay
_Nonnull int *b = ptr; // expected-warning{{implicit conversion from nullable pointer 'int * _Nullable' to non-nullable pointer type 'int * _Nonnull'}}
+ b = ptr; // expected-warning{{implicit conversion from nullable pointer 'int * _Nullable' to non-nullable pointer type 'int * _Nonnull'}}
+
+ accepts_nonnull_1(ptr); // expected-warning{{implicit conversion from nullable pointer 'int * _Nullable' to non-nullable pointer type 'int * _Nonnull'}}
}
diff --git a/clang/test/SemaCXX/nullability.cpp b/clang/test/SemaCXX/nullability.cpp
index edce6b057bd..c73c01a0a86 100644
--- a/clang/test/SemaCXX/nullability.cpp
+++ b/clang/test/SemaCXX/nullability.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -std=c++11 -fsyntax-only -Wno-nullability-declspec %s -verify
+// RUN: %clang_cc1 -std=c++11 -fsyntax-only -Wno-nullability-declspec %s -verify -Wnullable-to-nonnull-conversion
#if __has_feature(nullability)
#else
@@ -67,3 +67,33 @@ void test_accepts_nonnull_null_pointer_literal_template() {
}
template void test_accepts_nonnull_null_pointer_literal_template<&accepts_nonnull_4>(); // expected-note{{instantiation of function template specialization}}
+
+void TakeNonnull(void *_Nonnull);
+// Check different forms of assignment to a nonull type from a nullable one.
+void AssignAndInitNonNull() {
+ void *_Nullable nullable;
+ void *_Nonnull p(nullable); // expected-warning{{implicit conversion from nullable pointer 'void * _Nullable' to non-nullable pointer type 'void * _Nonnull'}}
+ void *_Nonnull p2{nullable}; // expected-warning{{implicit conversion from nullable pointer 'void * _Nullable' to non-nullable pointer type 'void * _Nonnull'}}
+ void *_Nonnull p3 = {nullable}; // expected-warning{{implicit conversion from nullable pointer 'void * _Nullable' to non-nullable pointer type 'void * _Nonnull'}}
+ void *_Nonnull p4 = nullable; // expected-warning{{implicit conversion from nullable pointer 'void * _Nullable' to non-nullable pointer type 'void * _Nonnull'}}
+ void *_Nonnull nonnull;
+ nonnull = nullable; // expected-warning{{implicit conversion from nullable pointer 'void * _Nullable' to non-nullable pointer type 'void * _Nonnull'}}
+ nonnull = {nullable}; // expected-warning{{implicit conversion from nullable pointer 'void * _Nullable' to non-nullable pointer type 'void * _Nonnull'}}
+
+ TakeNonnull(nullable); //expected-warning{{implicit conversion from nullable pointer 'void * _Nullable' to non-nullable pointer type 'void * _Nonnull}}
+ TakeNonnull(nonnull); // OK
+}
+
+void *_Nullable ReturnNullable();
+
+void AssignAndInitNonNullFromFn() {
+ void *_Nonnull p(ReturnNullable()); // expected-warning{{implicit conversion from nullable pointer 'void * _Nullable' to non-nullable pointer type 'void * _Nonnull'}}
+ void *_Nonnull p2{ReturnNullable()}; // expected-warning{{implicit conversion from nullable pointer 'void * _Nullable' to non-nullable pointer type 'void * _Nonnull'}}
+ void *_Nonnull p3 = {ReturnNullable()}; // expected-warning{{implicit conversion from nullable pointer 'void * _Nullable' to non-nullable pointer type 'void * _Nonnull'}}
+ void *_Nonnull p4 = ReturnNullable(); // expected-warning{{implicit conversion from nullable pointer 'void * _Nullable' to non-nullable pointer type 'void * _Nonnull'}}
+ void *_Nonnull nonnull;
+ nonnull = ReturnNullable(); // expected-warning{{implicit conversion from nullable pointer 'void * _Nullable' to non-nullable pointer type 'void * _Nonnull'}}
+ nonnull = {ReturnNullable()}; // expected-warning{{implicit conversion from nullable pointer 'void * _Nullable' to non-nullable pointer type 'void * _Nonnull'}}
+
+ TakeNonnull(ReturnNullable()); //expected-warning{{implicit conversion from nullable pointer 'void * _Nullable' to non-nullable pointer type 'void * _Nonnull}}
+}
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