ahatanak updated this revision to Diff 92583.
ahatanak added a comment.
Rebase and ping.
https://reviews.llvm.org/D22391
Files:
include/clang/Basic/DiagnosticGroups.td
include/clang/Basic/DiagnosticSemaKinds.td
include/clang/Sema/Sema.h
lib/Sema/SemaChecking.cpp
lib/Sema/SemaDecl.cpp
lib/Sema/SemaExpr.cpp
test/Analysis/nullability-no-arc.mm
test/Analysis/nullability_nullonly.mm
test/Sema/conditional-expr.c
test/Sema/null_constant_to_nonnull.c
Index: test/Sema/null_constant_to_nonnull.c
===================================================================
--- /dev/null
+++ test/Sema/null_constant_to_nonnull.c
@@ -0,0 +1,7 @@
+// RUN: %clang_cc1 -fsyntax-only -Wnullable-to-nonnull-conversion %s -verify
+
+void null_const_to_nonnull(int c) {
+ int * _Nonnull p0 = 0; // expected-warning{{implicitly casting a null constant to non-nullable pointer type 'int * _Nonnull'}}
+ int * _Nonnull p1;
+ int * _Nonnull p2 = c ? p1 : 0; // expected-warning{{implicit conversion from nullable pointer 'int * _Nullable' to non-nullable pointer type 'int * _Nonnull'}}
+}
Index: test/Sema/conditional-expr.c
===================================================================
--- test/Sema/conditional-expr.c
+++ test/Sema/conditional-expr.c
@@ -17,7 +17,7 @@
dp = ip; // expected-warning {{incompatible pointer types assigning to 'double *' from 'int *'}}
dp = 0 ? (double *)0 : (void *)0;
vp = 0 ? (double *)0 : (void *)0;
- ip = 0 ? (double *)0 : (void *)0; // expected-warning {{incompatible pointer types assigning to 'int *' from 'double *'}}
+ ip = 0 ? (double *)0 : (void *)0; // expected-warning {{incompatible pointer types assigning to 'int *' from 'double * _Nullable'}}
const int *cip;
vp = (0 ? vp : cip); // expected-warning {{discards qualifiers}}
@@ -90,7 +90,7 @@
int f0(int a) {
// GCC considers this a warning.
- return a ? f1() : nil; // expected-warning {{pointer/integer type mismatch in conditional expression ('int' and 'void *')}} expected-warning {{incompatible pointer to integer conversion returning 'void *' from a function with result type 'int'}}
+ return a ? f1() : nil; // expected-warning {{pointer/integer type mismatch in conditional expression ('int' and 'void *')}} expected-warning {{incompatible pointer to integer conversion returning 'void * _Nullable' from a function with result type 'int'}}
}
int f2(int x) {
Index: test/Analysis/nullability_nullonly.mm
===================================================================
--- test/Analysis/nullability_nullonly.mm
+++ test/Analysis/nullability_nullonly.mm
@@ -100,7 +100,7 @@
}
void testObjCARCExplicitZeroInitialization() {
- TestObject * _Nonnull explicitlyZeroInitialized = nil; // expected-warning {{nil assigned to a pointer which is expected to have non-null value}}
+ TestObject * _Nonnull explicitlyZeroInitialized = nil; // expected-warning {{nil assigned to a pointer which is expected to have non-null value}} expected-warning{{implicitly casting a null constant to non-nullable pointer type 'TestObject * _Nonnull __strong'}}
}
// Under ARC, returned expressions of ObjC objects types are are implicitly
Index: test/Analysis/nullability-no-arc.mm
===================================================================
--- test/Analysis/nullability-no-arc.mm
+++ test/Analysis/nullability-no-arc.mm
@@ -43,7 +43,7 @@
}
void testObjCNonARCExplicitZeroInitialization() {
- TestObject * _Nonnull explicitlyZeroInitialized = nil; // expected-warning {{nil assigned to a pointer which is expected to have non-null value}}
+ TestObject * _Nonnull explicitlyZeroInitialized = nil; // expected-warning {{nil assigned to a pointer which is expected to have non-null value}} expected-warning {{implicitly casting a null constant to non-nullable pointer type 'TestObject * _Nonnull'}}
}
@interface ClassWithInitializers : NSObject
Index: lib/Sema/SemaExpr.cpp
===================================================================
--- lib/Sema/SemaExpr.cpp
+++ lib/Sema/SemaExpr.cpp
@@ -7105,20 +7105,26 @@
}
/// Compute the nullability of a conditional expression.
-static QualType computeConditionalNullability(QualType ResTy, bool IsBin,
- QualType LHSTy, QualType RHSTy,
- ASTContext &Ctx) {
+static QualType computeConditionalNullability(Sema &S, QualType ResTy,
+ bool IsBin, Expr *LHSExpr,
+ Expr *RHSExpr, ASTContext &Ctx) {
if (!ResTy->isAnyPointerType())
return ResTy;
- auto GetNullability = [&Ctx](QualType Ty) {
+ auto GetNullability = [&S, &Ctx](QualType Ty, Expr *E = nullptr) {
+ // If E evaluates to a null constant, return nullable.
+ if (E && S.checkNonNullExpr(E))
+ return NullabilityKind::Nullable;
+
Optional<NullabilityKind> Kind = Ty->getNullability(Ctx);
if (Kind)
return *Kind;
return NullabilityKind::Unspecified;
};
- auto LHSKind = GetNullability(LHSTy), RHSKind = GetNullability(RHSTy);
+ QualType LHSTy = LHSExpr->getType(), RHSTy = RHSExpr->getType();
+ auto LHSKind = GetNullability(LHSTy, LHSExpr);
+ auto RHSKind = GetNullability(RHSTy, RHSExpr);
NullabilityKind MergedKind;
// Compute nullability of a binary conditional expression.
@@ -7220,7 +7226,6 @@
LHSExpr = CondExpr = opaqueValue;
}
- QualType LHSTy = LHSExpr->getType(), RHSTy = RHSExpr->getType();
ExprValueKind VK = VK_RValue;
ExprObjectKind OK = OK_Ordinary;
ExprResult Cond = CondExpr, LHS = LHSExpr, RHS = RHSExpr;
@@ -7235,8 +7240,8 @@
CheckBoolLikeConversion(Cond.get(), QuestionLoc);
- result = computeConditionalNullability(result, commonExpr, LHSTy, RHSTy,
- Context);
+ result = computeConditionalNullability(*this, result, commonExpr, LHSExpr,
+ RHSExpr, Context);
if (!commonExpr)
return new (Context)
Index: lib/Sema/SemaDecl.cpp
===================================================================
--- lib/Sema/SemaDecl.cpp
+++ lib/Sema/SemaDecl.cpp
@@ -10151,6 +10151,8 @@
Init = Result.getAs<Expr>();
}
+ checkVarDeclInit(DclT, Init);
+
// Check for self-references within variable initializers.
// Variables declared within a function/method body (except for references)
// are handled by a dataflow analysis.
Index: lib/Sema/SemaChecking.cpp
===================================================================
--- lib/Sema/SemaChecking.cpp
+++ lib/Sema/SemaChecking.cpp
@@ -2353,7 +2353,7 @@
/// Checks if a the given expression evaluates to null.
///
/// \brief Returns true if the value evaluates to null.
-static bool CheckNonNullExpr(Sema &S, const Expr *Expr) {
+static bool CheckNonNullExpr(const Sema &S, const Expr *Expr) {
// If the expression has non-null type, it doesn't evaluate to null.
if (auto nullability
= Expr->IgnoreImplicit()->getType()->getNullability(S.Context)) {
@@ -2378,6 +2378,10 @@
!Result);
}
+bool Sema::checkNonNullExpr(const Expr *E) const {
+ return CheckNonNullExpr(*this, E);
+}
+
static void CheckNonNullArgument(Sema &S,
const Expr *ArgExpr,
SourceLocation CallSiteLoc) {
@@ -7864,6 +7868,11 @@
}
}
+void Sema::checkVarDeclInit(QualType DeclTy, Expr *Init) {
+ if (isNonNullType(Context, DeclTy) && CheckNonNullExpr(*this, Init))
+ Diag(Init->getLocStart(), diag::warn_null_constant_to_nonnull) << DeclTy;
+}
+
//===--- CHECK: Floating-Point comparisons (-Wfloat-equal) ---------------===//
/// Check for comparisons of floating point operands using != and ==.
Index: include/clang/Sema/Sema.h
===================================================================
--- include/clang/Sema/Sema.h
+++ include/clang/Sema/Sema.h
@@ -10065,6 +10065,8 @@
static bool GetFormatNSStringIdx(const FormatAttr *Format, unsigned &Idx);
+ bool checkNonNullExpr(const Expr *E) const;
+
private:
bool CheckFormatArguments(const FormatAttr *Format,
ArrayRef<const Expr *> Args,
@@ -10100,6 +10102,8 @@
const AttrVec *Attrs = nullptr,
const FunctionDecl *FD = nullptr);
+ void checkVarDeclInit(QualType DeclTy, Expr *Init);
+
void CheckFloatComparison(SourceLocation Loc, Expr* LHS, Expr* RHS);
void CheckImplicitConversions(Expr *E, SourceLocation CC = SourceLocation());
void CheckBoolLikeConversion(Expr *E, SourceLocation CC);
Index: include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- include/clang/Basic/DiagnosticSemaKinds.td
+++ include/clang/Basic/DiagnosticSemaKinds.td
@@ -8919,6 +8919,10 @@
"type %1">,
InGroup<NullableToNonNullConversion>, DefaultIgnore;
+def warn_null_constant_to_nonnull : Warning<
+ "implicitly casting a null constant to non-nullable pointer type %0">,
+ InGroup<NullConstantToNonnull>;
+
def err_nullability_cs_multilevel : Error<
"nullability keyword %0 cannot be applied to multi-level pointer type %1">;
def note_nullability_type_specifier : Note<
Index: include/clang/Basic/DiagnosticGroups.td
===================================================================
--- include/clang/Basic/DiagnosticGroups.td
+++ include/clang/Basic/DiagnosticGroups.td
@@ -290,6 +290,7 @@
def NullabilityDeclSpec : DiagGroup<"nullability-declspec">;
def NullabilityInferredOnNestedType : DiagGroup<"nullability-inferred-on-nested-type">;
def NullableToNonNullConversion : DiagGroup<"nullable-to-nonnull-conversion">;
+def NullConstantToNonnull : DiagGroup<"null-constant-to-nonnull">;
def NullabilityCompletenessOnArrays : DiagGroup<"nullability-completeness-on-arrays">;
def NullabilityCompleteness : DiagGroup<"nullability-completeness",
[NullabilityCompletenessOnArrays]>;
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