diff options
Diffstat (limited to 'clang/test/SemaCXX/constant-expression-cxx11.cpp')
| -rw-r--r-- | clang/test/SemaCXX/constant-expression-cxx11.cpp | 45 |
1 files changed, 42 insertions, 3 deletions
diff --git a/clang/test/SemaCXX/constant-expression-cxx11.cpp b/clang/test/SemaCXX/constant-expression-cxx11.cpp index f7bd01c59c9..3a460c93af0 100644 --- a/clang/test/SemaCXX/constant-expression-cxx11.cpp +++ b/clang/test/SemaCXX/constant-expression-cxx11.cpp @@ -339,6 +339,30 @@ static_assert(!same(4, 4), ""); static_assert(same(n, n), ""); static_assert(sameTemporary(9), ""); +struct A { int &&r; }; +struct B { A &&a1; A &&a2; }; + +constexpr B b1 { { 1 }, { 2 } }; // expected-note {{temporary created here}} +static_assert(&b1.a1 != &b1.a2, ""); +static_assert(&b1.a1.r != &b1.a2.r, ""); // expected-error {{constant expression}} expected-note {{outside the expression that created the temporary}} + +constexpr B &&b2 { { 3 }, { 4 } }; // expected-note {{temporary created here}} +static_assert(&b1 != &b2, ""); +static_assert(&b1.a1 != &b2.a1, ""); // expected-error {{constant expression}} expected-note {{outside the expression that created the temporary}} + +constexpr thread_local B b3 { { 1 }, { 2 } }; // expected-error {{constant expression}} expected-note {{reference to temporary}} expected-note {{here}} +void foo() { + constexpr static B b1 { { 1 }, { 2 } }; // ok + constexpr thread_local B b2 { { 1 }, { 2 } }; // expected-error {{constant expression}} expected-note {{reference to temporary}} expected-note {{here}} + constexpr B b3 { { 1 }, { 2 } }; // expected-error {{constant expression}} expected-note {{reference to temporary}} expected-note {{here}} +} + +constexpr B &&b4 = ((1, 2), 3, 4, B { {10}, {{20}} }); // expected-warning 4{{unused}} +static_assert(&b4 != &b2, ""); + +// Proposed DR: copy-elision doesn't trigger lifetime extension. +constexpr B b5 = B{ {0}, {0} }; // expected-error {{constant expression}} expected-note {{reference to temporary}} expected-note {{here}} + } constexpr int strcmp_ce(const char *p, const char *q) { @@ -572,7 +596,7 @@ struct E { constexpr E() : p(&p) {} void *p; }; -constexpr const E &e1 = E(); // expected-error {{constant expression}} expected-note {{reference to temporary is not a constant expression}} expected-note {{temporary created here}} +constexpr const E &e1 = E(); // This is a constant expression if we elide the copy constructor call, and // is not a constant expression if we don't! But we do, so it is. constexpr E e2 = E(); @@ -1282,8 +1306,23 @@ struct Wrap { constexpr const Wrap &g(const Wrap &w) { return w; } constexpr int k2 = g({0}).value; // ok -constexpr const int &i = 0; // expected-error {{constant expression}} expected-note {{temporary}} expected-note 2{{here}} -constexpr const int j = i; // expected-error {{constant expression}} expected-note {{initializer of 'i' is not a constant expression}} +// The temporary here has static storage duration, so we can bind a constexpr +// reference to it. +constexpr const int &i = 1; +constexpr const int j = i; +static_assert(j == 1, ""); + +// The temporary here is not const, so it can't be read outside the expression +// in which it was created (per the C++14 rules, which we use to avoid a C++11 +// defect). +constexpr int &&k = 1; // expected-note {{temporary created here}} +constexpr const int l = k; // expected-error {{constant expression}} expected-note {{read of temporary}} + +void f() { + // The temporary here has automatic storage duration, so we can't bind a + // constexpr reference to it. + constexpr const int &i = 1; // expected-error {{constant expression}} expected-note 2{{temporary}} +} } |
