Mark vector::operator[] and front/back as noexcept. We already do this for string and string_view. This should give better codegen inside of noexcept functions. Add tests for op[]/front/back/at, because apparently we had none.

llvm-svn: 356224

2 files changed, 122 insertions, 0 deletions

diff --git a/libcxx/test/libcxx/debug/containers/db_sequence_container_iterators.pass.cpp b/libcxx/test/libcxx/debug/containers/db_sequence_container_iterators.pass.cpp
index 2de4c023f1e..d34c864ba99 100644
--- a/libcxx/test/libcxx/debug/containers/db_sequence_container_iterators.pass.cpp
+++ b/libcxx/test/libcxx/debug/containers/db_sequence_container_iterators.pass.cpp
@@ -6,6 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+// XFAIL: *
 // UNSUPPORTED: c++98, c++03, c++11, c++14
 // UNSUPPORTED: libcpp-no-exceptions, libcpp-no-if-constexpr
 // MODULES_DEFINES: _LIBCPP_DEBUG=1
diff --git a/libcxx/test/std/containers/sequences/vector/access.pass.cpp b/libcxx/test/std/containers/sequences/vector/access.pass.cpp
new file mode 100644
index 00000000000..4ac19ff7189
--- /dev/null
+++ b/libcxx/test/std/containers/sequences/vector/access.pass.cpp
@@ -0,0 +1,121 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <vector>
+
+//       reference operator[](size_type __i);
+// const_reference operator[](size_type __i) const;
+//
+//       reference at(size_type __i);
+// const_reference at(size_type __i) const;
+//
+//       reference front();
+// const_reference front() const;
+//
+//       reference back();
+// const_reference back() const;
+// libc++ marks these as 'noexcept' (except 'at')
+
+#include <vector>
+#include <cassert>
+
+#include "min_allocator.h"
+#include "test_macros.h"
+
+template <class C>
+C
+make(int size, int start = 0)
+{
+    C c;
+    for (int i = 0; i < size; ++i)
+        c.push_back(start + i);
+    return c;
+}
+
+int main(int, char**)
+{
+    {
+        typedef std::vector<int> C;
+        C c = make<C>(10);
+        LIBCPP_ASSERT_NOEXCEPT(c[0]);
+        LIBCPP_ASSERT_NOEXCEPT(c.front());
+        LIBCPP_ASSERT_NOEXCEPT(c.back());
+        // at() is NOT noexcept
+        ASSERT_SAME_TYPE(C::reference, decltype(c[0]));
+        ASSERT_SAME_TYPE(C::reference, decltype(c.at(0)));
+        ASSERT_SAME_TYPE(C::reference, decltype(c.front()));
+        ASSERT_SAME_TYPE(C::reference, decltype(c.back()));
+        for (int i = 0; i < 10; ++i)
+            assert(c[i] == i);
+        for (int i = 0; i < 10; ++i)
+            assert(c.at(i) == i);
+        assert(c.front() == 0);
+        assert(c.back() == 9);
+    }
+    {
+        typedef std::vector<int> C;
+        const int N = 5;
+        const C c = make<C>(10, N);
+        LIBCPP_ASSERT_NOEXCEPT(c[0]);
+        LIBCPP_ASSERT_NOEXCEPT(c.front());
+        LIBCPP_ASSERT_NOEXCEPT(c.back());
+        // at() is NOT noexcept
+        ASSERT_SAME_TYPE(C::const_reference, decltype(c[0]));
+        ASSERT_SAME_TYPE(C::const_reference, decltype(c.at(0)));
+        ASSERT_SAME_TYPE(C::const_reference, decltype(c.front()));
+        ASSERT_SAME_TYPE(C::const_reference, decltype(c.back()));
+        for (int i = 0; i < 10; ++i)
+            assert(c[i] == N + i);
+        for (int i = 0; i < 10; ++i)
+            assert(c.at(i) == N + i);
+        assert(c.front() == N);
+        assert(c.back() == N + 9);
+    }
+#if TEST_STD_VER >= 11
+    {
+        typedef std::vector<int, min_allocator<int>> C;
+        const int N = 34;
+        C c = make<C>(10, N);
+        LIBCPP_ASSERT_NOEXCEPT(c[0]);
+        LIBCPP_ASSERT_NOEXCEPT(c.front());
+        LIBCPP_ASSERT_NOEXCEPT(c.back());
+        // at() is NOT noexcept
+        ASSERT_SAME_TYPE(C::reference, decltype(c[0]));
+        ASSERT_SAME_TYPE(C::reference, decltype(c.at(0)));
+        ASSERT_SAME_TYPE(C::reference, decltype(c.front()));
+        ASSERT_SAME_TYPE(C::reference, decltype(c.back()));
+        for (int i = 0; i < 10; ++i)
+            assert(c[i] == N + i);
+        for (int i = 0; i < 10; ++i)
+            assert(c.at(i) == N + i);
+        assert(c.front() == N);
+        assert(c.back() == N + 9);
+    }
+    {
+        typedef std::vector<int, min_allocator<int>> C;
+        const int N = 23;
+        const C c = make<C>(10, N);
+        LIBCPP_ASSERT_NOEXCEPT(c[0]);
+        LIBCPP_ASSERT_NOEXCEPT(c.front());
+        LIBCPP_ASSERT_NOEXCEPT(c.back());
+        // at() is NOT noexcept
+        ASSERT_SAME_TYPE(C::const_reference, decltype(c[0]));
+        ASSERT_SAME_TYPE(C::const_reference, decltype(c.at(0)));
+        ASSERT_SAME_TYPE(C::const_reference, decltype(c.front()));
+        ASSERT_SAME_TYPE(C::const_reference, decltype(c.back()));
+        for (int i = 0; i < 10; ++i)
+            assert(c[i] == N + i);
+        for (int i = 0; i < 10; ++i)
+            assert(c.at(i) == N + i);
+        assert(c.front() == N);
+        assert(c.back() == N + 9);
+    }
+#endif
+
+  return 0;
+}