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// RUN: %clang_cc1 -fsyntax-only -Wself-assign-field -DDUMMY -verify %s
// RUN: %clang_cc1 -fsyntax-only -Wself-assign-field -DV0 -verify %s
// RUN: %clang_cc1 -fsyntax-only -Wself-assign-field -DV1 -verify %s
// RUN: %clang_cc1 -fsyntax-only -Wself-assign-field -DV2 -verify %s
// RUN: %clang_cc1 -fsyntax-only -Wself-assign-field -DV3 -verify %s
// RUN: %clang_cc1 -fsyntax-only -Wself-assign-field -DV4 -verify %s
#ifdef DUMMY
struct S {};
#else
struct S {
#if defined(V0)
S() = default;
#elif defined(V1)
S &operator=(const S &) = default;
#elif defined(V2)
S &operator=(S &) = default;
#elif defined(V3)
S &operator=(const S &);
#elif defined(V4)
S &operator=(S &);
#else
#error Define something!
#endif
S &operator*=(const S &);
S &operator/=(const S &);
S &operator%=(const S &);
S &operator+=(const S &);
S &operator-=(const S &);
S &operator<<=(const S &);
S &operator>>=(const S &);
S &operator&=(const S &);
S &operator|=(const S &);
S &operator^=(const S &);
S &operator=(const volatile S &) volatile;
};
#endif
struct C {
S a;
S b;
void f() {
a = a; // expected-warning {{assigning field to itself}}
b = b; // expected-warning {{assigning field to itself}}
a = b;
this->a = a; // expected-warning {{assigning field to itself}}
this->b = b; // expected-warning {{assigning field to itself}}
a = this->a; // expected-warning {{assigning field to itself}}
b = this->b; // expected-warning {{assigning field to itself}}
this->a = this->a; // expected-warning {{assigning field to itself}}
this->b = this->b; // expected-warning {{assigning field to itself}}
a = b;
a = this->b;
this->a = b;
this->a = this->b;
#ifndef DUMMY
a *= a;
a /= a; // expected-warning {{assigning field to itself}}
a %= a; // expected-warning {{assigning field to itself}}
a += a;
a -= a; // expected-warning {{assigning field to itself}}
a <<= a;
a >>= a;
a &= a; // expected-warning {{assigning field to itself}}
a |= a; // expected-warning {{assigning field to itself}}
a ^= a; // expected-warning {{assigning field to itself}}
#endif
}
void false_positives() {
#define OP =
#define LHS a
#define RHS a
// These shouldn't warn due to the use of the preprocessor.
a OP a;
LHS = a;
a = RHS;
LHS OP RHS;
#undef OP
#undef LHS
#undef RHS
// Ways to silence the warning.
a = *&a;
a = (S &)a;
a = static_cast<decltype(a) &>(a);
}
#ifndef DUMMY
volatile S vol_a;
void vol_test() {
// Volatile stores aren't side-effect free.
vol_a = vol_a;
volatile S &vol_a_ref = vol_a;
vol_a_ref = vol_a_ref;
}
#endif
};
// Do not diagnose self-assigment in an unevaluated context
struct SNoExcept {
SNoExcept() = default;
SNoExcept &operator=(const SNoExcept &) noexcept;
};
struct false_positives_unevaluated_ctx_class {
SNoExcept a;
void false_positives_unevaluated_ctx(SNoExcept a) noexcept(noexcept(a = a)) {
decltype(a = a) b = a;
static_assert(noexcept(a = a), "");
static_assert(sizeof(a = a), "");
}
};
template <typename T>
struct TemplateClass {
T var;
void f() {
var = var; // expected-warning {{assigning field to itself}}
}
};
void instantiate() {
{
TemplateClass<int> c;
c.f();
}
{
TemplateClass<S> c;
c.f();
}
}
// It may make sense not to warn on the rest of the tests.
// It may be a valid use-case to self-assign to tell the compiler that
// it is ok to vectorize the store.
void f0(C *s, C *t) {
s->a = s->a;
t->a = s->a;
}
void f1(C &s, C &t) {
s.a = s.a;
t.a = s.a;
}
struct T {
C *s;
};
void f2(T *t, T *t2) {
t->s->a = t->s->a;
t2->s->a = t->s->a;
}
void f3(T &t, T &t2) {
t.s->a = t.s->a;
t2.s->a = t.s->a;
}
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