teak-llvm/clang/test/SemaCXX/warn-global-constructors.cpp
Jordan Rose d4503da40c Unnamed bitfields don't block constant evaluation of constexpr ctors
C++14 [dcl.constexpr]p4 states that in the body of a constexpr
constructor,

> every non-variant non-static data member and base class sub-object
  shall be initialized

However, [class.bit]p2 notes that

> Unnamed bit-fields are not members and cannot be initialized.

Therefore, we should make sure to filter them out of the check that
all fields are initialized.

Fixing this makes the constant evaluator a bit smarter, and
specifically allows constexpr constructors to avoid tripping
-Wglobal-constructors when the type contains unnamed bitfields.

Reviewed at https://reviews.llvm.org/D39035.

llvm-svn: 316408
2017-10-24 02:17:07 +00:00

148 lines
2.9 KiB
C++

// RUN: %clang_cc1 -std=c++11 -fsyntax-only -Wglobal-constructors %s -verify
int opaque_int();
namespace test0 {
// These should never require global constructors.
int a;
int b = 20;
float c = 5.0f;
// This global constructor is avoidable based on initialization order.
int d = b; // expected-warning {{global constructor}}
// These global constructors are unavoidable.
int e = opaque_int(); // expected-warning {{global constructor}}
int f = b; // expected-warning {{global constructor}}
}
namespace test1 {
struct A { int x; };
A a;
A b = A();
A c = { 10 };
A d = { opaque_int() }; // expected-warning {{global constructor}}
A e = A(A());
A f = A(a); // expected-warning {{global constructor}}
A g(a); // expected-warning {{global constructor}}
A h((A())); // elided
A i((A(A()))); // elided
}
namespace test2 {
struct A { A(); };
A a; // expected-warning {{global constructor}}
A b[10]; // expected-warning {{global constructor}}
A c[10][10]; // expected-warning {{global constructor}}
A &d = a;
A &e = b[5];
A &f = c[5][7];
}
namespace test3 {
struct A { ~A(); };
A a; // expected-warning {{global destructor}}
A b[10]; // expected-warning {{global destructor}}
A c[10][10]; // expected-warning {{global destructor}}
A &d = a;
A &e = b[5];
A &f = c[5][7];
}
namespace test4 {
char a[] = "hello";
char b[6] = "hello";
char c[][6] = { "hello" };
}
namespace test5 {
struct A { A(); };
void f1() {
static A a;
}
void f2() {
static A& a = *new A;
}
}
namespace test6 {
struct A { ~A(); };
void f1() {
static A a;
}
void f2() {
static A& a = *new A;
}
}
namespace pr8095 {
struct Foo {
int x;
Foo(int x1) : x(x1) {}
};
void foo() {
static Foo a(0);
}
struct Bar {
~Bar();
};
void bar() {
static Bar b;
}
}
namespace referencemember {
struct A { int &a; };
int a;
A b = { a };
}
namespace pr19253 {
struct A { ~A() = default; };
A a;
struct B { ~B(); };
struct C : B { ~C() = default; };
C c; // expected-warning {{global destructor}}
class D {
friend struct E;
~D() = default;
};
struct E : D {
D d;
~E() = default;
};
E e;
}
namespace pr20420 {
// No warning is expected. This used to crash.
void *array_storage[1];
const int &global_reference = *(int *)array_storage;
}
namespace bitfields {
struct HasUnnamedBitfield {
unsigned a;
unsigned : 20;
unsigned b;
constexpr HasUnnamedBitfield() : a(), b() {}
constexpr HasUnnamedBitfield(unsigned a, unsigned b) : a(a), b(b) {}
explicit HasUnnamedBitfield(unsigned a) {}
};
const HasUnnamedBitfield zeroConst{};
HasUnnamedBitfield zeroMutable{};
const HasUnnamedBitfield explicitConst{1, 2};
HasUnnamedBitfield explicitMutable{1, 2};
const HasUnnamedBitfield nonConstexprConst{1}; // expected-warning {{global constructor}}
HasUnnamedBitfield nonConstexprMutable{1}; // expected-warning {{global constructor}}
}