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-rw-r--r--include/clang/AST/Expr.h11
-rw-r--r--include/clang/Basic/DiagnosticGroups.td4
-rw-r--r--include/clang/Basic/DiagnosticSemaKinds.td3
-rw-r--r--lib/AST/Expr.cpp9
-rw-r--r--lib/Sema/SemaExpr.cpp5
-rw-r--r--lib/Sema/SemaOverload.cpp18
-rw-r--r--test/SemaCXX/constant-expression-cxx11.cpp8
-rw-r--r--test/SemaCXX/lambda-expressions.cpp6
-rw-r--r--test/SemaTemplate/explicit-instantiation.cpp4
-rw-r--r--test/SemaTemplate/instantiate-member-class.cpp7
10 files changed, 53 insertions, 22 deletions
diff --git a/include/clang/AST/Expr.h b/include/clang/AST/Expr.h
index 29e3649a27..89c003c8f6 100644
--- a/include/clang/AST/Expr.h
+++ b/include/clang/AST/Expr.h
@@ -541,8 +541,15 @@ public:
/// \brief Expression is not a Null pointer constant.
NPCK_NotNull = 0,
- /// \brief Expression is a Null pointer constant built from a zero integer.
- NPCK_ZeroInteger,
+ /// \brief Expression is a Null pointer constant built from a zero integer
+ /// expression that is not a simple, possibly parenthesized, zero literal.
+ /// C++ Core Issue 903 will classify these expressions as "not pointers"
+ /// once it is adopted.
+ /// http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903
+ NPCK_ZeroExpression,
+
+ /// \brief Expression is a Null pointer constant built from a literal zero.
+ NPCK_ZeroLiteral,
/// \brief Expression is a C++0X nullptr.
NPCK_CXX0X_nullptr,
diff --git a/include/clang/Basic/DiagnosticGroups.td b/include/clang/Basic/DiagnosticGroups.td
index 8811e6aa36..b95a90bd21 100644
--- a/include/clang/Basic/DiagnosticGroups.td
+++ b/include/clang/Basic/DiagnosticGroups.td
@@ -33,6 +33,7 @@ def StringConversion : DiagGroup<"string-conversion">;
def SignConversion : DiagGroup<"sign-conversion">;
def BoolConversion : DiagGroup<"bool-conversion">;
def IntConversion : DiagGroup<"int-conversion">;
+def NonLiteralNullConversion : DiagGroup<"non-literal-null-conversion">;
def NullConversion : DiagGroup<"null-conversion">;
def BuiltinRequiresHeader : DiagGroup<"builtin-requires-header">;
def CXXCompat: DiagGroup<"c++-compat">;
@@ -314,7 +315,8 @@ def Conversion : DiagGroup<"conversion",
StringConversion,
SignConversion,
BoolConversion,
- NullConversion,
+ NullConversion, // NULL->non-pointer
+ NonLiteralNullConversion, // (1-1)->pointer (etc)
IntConversion]>,
DiagCategory<"Value Conversion Issue">;
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 566a8f01fa..7b3cd0fb77 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1896,6 +1896,9 @@ def warn_impcast_different_enum_types : Warning<
def warn_impcast_bool_to_null_pointer : Warning<
"initialization of pointer of type %0 to null from a constant boolean "
"expression">, InGroup<BoolConversion>;
+def warn_non_literal_null_pointer : Warning<
+ "expression which evaluates to zero treated as a null pointer constant of "
+ "type %0">, InGroup<NonLiteralNullConversion>;
def warn_impcast_null_pointer_to_integer : Warning<
"implicit conversion of NULL constant to %0">,
InGroup<NullConversion>;
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index 9df850d6bd..d3aff2455c 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -2903,7 +2903,7 @@ Expr::isNullPointerConstant(ASTContext &Ctx,
llvm_unreachable("Unexpected value dependent expression!");
case NPC_ValueDependentIsNull:
if (isTypeDependent() || getType()->isIntegralType(Ctx))
- return NPCK_ZeroInteger;
+ return NPCK_ZeroExpression;
else
return NPCK_NotNull;
@@ -2977,7 +2977,12 @@ Expr::isNullPointerConstant(ASTContext &Ctx,
return NPCK_NotNull;
}
- return (EvaluateKnownConstInt(Ctx) == 0) ? NPCK_ZeroInteger : NPCK_NotNull;
+ if (EvaluateKnownConstInt(Ctx) != 0)
+ return NPCK_NotNull;
+
+ if (isa<IntegerLiteral>(this))
+ return NPCK_ZeroLiteral;
+ return NPCK_ZeroExpression;
}
/// \brief If this expression is an l-value for an Objective C
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index bfe72423e1..6a503ee2d9 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -4632,7 +4632,10 @@ bool Sema::DiagnoseConditionalForNull(Expr *LHSExpr, Expr *RHSExpr,
if (NullKind == Expr::NPCK_NotNull)
return false;
- if (NullKind == Expr::NPCK_ZeroInteger) {
+ if (NullKind == Expr::NPCK_ZeroExpression)
+ return false;
+
+ if (NullKind == Expr::NPCK_ZeroLiteral) {
// In this case, check to make sure that we got here from a "NULL"
// string in the source code.
NullExpr = NullExpr->IgnoreParenImpCasts();
diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index 7fac1c6ec4..a8744899d7 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -2562,13 +2562,17 @@ bool Sema::CheckPointerConversion(Expr *From, QualType ToType,
Kind = CK_BitCast;
- if (!IsCStyleOrFunctionalCast &&
- Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy) &&
- From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull))
- DiagRuntimeBehavior(From->getExprLoc(), From,
- PDiag(diag::warn_impcast_bool_to_null_pointer)
- << ToType << From->getSourceRange());
-
+ if (!IsCStyleOrFunctionalCast && !FromType->isAnyPointerType() &&
+ From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) ==
+ Expr::NPCK_ZeroExpression) {
+ if (Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy))
+ DiagRuntimeBehavior(From->getExprLoc(), From,
+ PDiag(diag::warn_impcast_bool_to_null_pointer)
+ << ToType << From->getSourceRange());
+ else if (!isUnevaluatedContext())
+ Diag(From->getExprLoc(), diag::warn_non_literal_null_pointer)
+ << ToType << From->getSourceRange();
+ }
if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) {
if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) {
QualType FromPointeeType = FromPtrType->getPointeeType(),
diff --git a/test/SemaCXX/constant-expression-cxx11.cpp b/test/SemaCXX/constant-expression-cxx11.cpp
index 0b7a6555e0..a3ead79a84 100644
--- a/test/SemaCXX/constant-expression-cxx11.cpp
+++ b/test/SemaCXX/constant-expression-cxx11.cpp
@@ -710,10 +710,16 @@ static_assert(&ok2 == pok2, "");
static_assert((Base2*)(Derived*)(Base*)pb1 == pok2, "");
static_assert((Derived*)(Base*)pb1 == (Derived*)pok2, "");
-constexpr Base *nullB = 42 - 6 * 7;
+constexpr Base *nullB = 42 - 6 * 7; // expected-warning {{expression which evaluates to zero treated as a null pointer constant of type 'Class::Base *const'}}
static_assert((Bottom*)nullB == 0, "");
static_assert((Derived*)nullB == 0, "");
static_assert((void*)(Bottom*)nullB == (void*)(Derived*)nullB, "");
+Base * nullB2 = '\0'; // expected-warning {{expression which evaluates to zero treated as a null pointer constant of type 'Class::Base *'}}
+Base * nullB3 = (0);
+// We suppress the warning in unevaluated contexts to workaround some gtest
+// behavior. Once this becomes an error this isn't a problem anymore.
+static_assert(nullB == (1 - 1), "");
+
namespace ConversionOperators {
diff --git a/test/SemaCXX/lambda-expressions.cpp b/test/SemaCXX/lambda-expressions.cpp
index 198f8cf1fe..0fd634502b 100644
--- a/test/SemaCXX/lambda-expressions.cpp
+++ b/test/SemaCXX/lambda-expressions.cpp
@@ -117,16 +117,16 @@ namespace NullPtr {
const int m = 0;
[=] {
- int &k = f(m); // a null pointer constant
+ int &k = f(m); // expected-warning{{expression which evaluates to zero treated as a null pointer constant of type 'int *'}}
} ();
[=] () -> bool {
- int &k = f(m); // a null pointer constant
+ int &k = f(m); // expected-warning{{expression which evaluates to zero treated as a null pointer constant of type 'int *'}}
return &m == 0;
} ();
[m] {
- int &k = f(m); // a null pointer constant
+ int &k = f(m); // expected-warning{{expression which evaluates to zero treated as a null pointer constant of type 'int *'}}
} ();
}
}
diff --git a/test/SemaTemplate/explicit-instantiation.cpp b/test/SemaTemplate/explicit-instantiation.cpp
index 13d76befe2..e3e77d0828 100644
--- a/test/SemaTemplate/explicit-instantiation.cpp
+++ b/test/SemaTemplate/explicit-instantiation.cpp
@@ -14,7 +14,7 @@ struct X0 {
T f0(T x) {
return x + 1; // expected-error{{invalid operands}}
}
- T* f0(T*, T*) { return T(); }
+ T* f0(T*, T*) { return T(); } // expected-warning{{expression which evaluates to zero treated as a null pointer constant of type 'int *'}}
template<typename U>
T f0(T, U) { return T(); }
@@ -32,7 +32,7 @@ struct NotDefaultConstructible { // expected-note{{candidate constructor (the im
template NotDefaultConstructible X0<NotDefaultConstructible>::value; // expected-note{{instantiation}}
template int X0<int>::f0(int);
-template int* X0<int>::f0(int*, int*);
+template int* X0<int>::f0(int*, int*); // expected-note{{in instantiation of member function 'X0<int>::f0' requested here}}
template int X0<int>::f0(int, float);
template int X0<int>::f0(int) const; // expected-error{{does not refer}}
diff --git a/test/SemaTemplate/instantiate-member-class.cpp b/test/SemaTemplate/instantiate-member-class.cpp
index bb6427670c..7b42a27d6b 100644
--- a/test/SemaTemplate/instantiate-member-class.cpp
+++ b/test/SemaTemplate/instantiate-member-class.cpp
@@ -124,19 +124,20 @@ namespace rdar10397846 {
{
struct B
{
- struct C { C() { int *ptr = I; } }; // expected-error{{cannot initialize a variable of type 'int *' with an rvalue of type 'int'}}
+ struct C { C() { int *ptr = I; } }; // expected-error{{cannot initialize a variable of type 'int *' with an rvalue of type 'int'}} \
+ expected-warning{{expression which evaluates to zero treated as a null pointer constant of type 'int *'}}
};
};
template<int N> void foo()
{
- class A<N>::B::C X; // expected-note{{in instantiation of member function}}
+ class A<N>::B::C X; // expected-note 2 {{in instantiation of member function}}
int A<N+1>::B::C::*member = 0;
}
void bar()
{
- foo<0>();
+ foo<0>(); // expected-note{{in instantiation of function template}}
foo<1>(); // expected-note{{in instantiation of function template}}
}
}
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2025-08-04 04:49:52 +0000