constexpr: diagnostic improvements for invalid lvalue-to-rvalue conversions in
constant expressions.
llvm-svn: 147035
diff --git a/clang/test/CXX/expr/expr.const/p2-0x.cpp b/clang/test/CXX/expr/expr.const/p2-0x.cpp
index aa83fc7..157645f 100644
--- a/clang/test/CXX/expr/expr.const/p2-0x.cpp
+++ b/clang/test/CXX/expr/expr.const/p2-0x.cpp
@@ -146,26 +146,50 @@
//int n : []{ return 1; }();
};
-// FIXME:
// - an lvalue-to-rvalue conversion (4.1) unless it is applied to
-//
-// - a non-volatile glvalue of integral or enumeration type that refers to a
-// non-volatile const object with a preceding initialization, initialized with
-// a constant expression [Note: a string literal (2.14.5 [lex.string])
-// corresponds to an array of such objects. -end note], or
-//
-// - a non-volatile glvalue of literal type that refers to a non-volatile
-// object defined with constexpr, or that refers to a sub-object of such an
-// object, or
-//
-// - a non-volatile glvalue of literal type that refers to a non-volatile
-// temporary object whose lifetime has not ended, initialized with a constant
-// expression;
+namespace LValueToRValue {
+ // - a non-volatile glvalue of integral or enumeration type that refers to a
+ // non-volatile const object with a preceding initialization, initialized
+ // with a constant expression [Note: a string literal (2.14.5 [lex.string])
+ // corresponds to an array of such objects. -end note], or
+ volatile const int vi = 1; // expected-note {{here}}
+ const int ci = 1;
+ volatile const int &vrci = ci;
+ static_assert(vi, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type 'const volatile int'}}
+ static_assert(const_cast<int&>(vi), ""); // expected-error {{constant expression}} expected-note {{read of volatile object 'vi'}}
+ static_assert(vrci, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
+
+ // - a non-volatile glvalue of literal type that refers to a non-volatile
+ // object defined with constexpr, or that refers to a sub-object of such an
+ // object, or
+ struct S {
+ constexpr S(int=0) : i(1), v(1) {}
+ constexpr S(const S &s) : i(2), v(2) {}
+ int i;
+ volatile int v;
+ };
+ constexpr S s;
+ constexpr volatile S vs; // expected-note {{here}}
+ constexpr const volatile S &vrs = s;
+ static_assert(s.i, "");
+ static_assert(s.v, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
+ static_assert(vs.i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
+ static_assert(const_cast<int&>(vs.i), ""); // expected-error {{constant expression}} expected-note {{read of volatile object 'vs'}}
+ static_assert(vrs.i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
+
+ // - a non-volatile glvalue of literal type that refers to a non-volatile
+ // temporary object whose lifetime has not ended, initialized with a
+ // constant expression;
+ constexpr volatile S f() { return S(); }
+ static_assert(f().i, ""); // ok! there's no lvalue-to-rvalue conversion here!
+ static_assert(((volatile const S&&)(S)0).i, ""); // expected-error {{constant expression}} expected-note {{subexpression}}
+}
// FIXME:
//
-// DR1312: The proposed wording for this defect has issues, so we instead
-// prohibit casts from pointers to cv void (see core-20842 and core-20845).
+// DR1312: The proposed wording for this defect has issues, so we ignore this
+// bullet and instead prohibit casts from pointers to cv void (see core-20842
+// and core-20845).
//
// - an lvalue-to-rvalue conversion (4.1 [conv.lval]) that is applied to a
// glvalue of type cv1 T that refers to an object of type cv2 U, where T and U
@@ -175,14 +199,13 @@
// - an lvalue-to-rvalue conversion (4.1) that is applied to a glvalue that
// refers to a non-active member of a union or a subobject thereof;
-// FIXME:
// - an id-expression that refers to a variable or data member of reference type
// unless the reference has a preceding initialization, initialized with a
// constant expression;
namespace References {
const int a = 2;
int &b = *const_cast<int*>(&a);
- int c = 10;
+ int c = 10; // expected-note 2 {{here}}
int &d = c;
constexpr int e = 42;
int &f = const_cast<int&>(e);
@@ -195,8 +218,8 @@
struct S {
int A : a;
int B : b;
- int C : c; // expected-error {{constant expression}}
- int D : d; // expected-error {{constant expression}}
+ int C : c; // expected-error {{constant expression}} expected-note {{read of non-const variable 'c'}}
+ int D : d; // expected-error {{constant expression}} expected-note {{read of non-const variable 'c'}}
int D2 : &d - &c + 1;
int E : e / 2;
int F : f - 11;