Try to require C++14.
Now that we've dropped MSVC 2015, I believe we can rely on C++14 (which
is now seven years old). This switches the build to require C++14. I've
gone ahead and switched code in both public headers and within the
library, but if the public headers are a problem, we can revert those
separately.
C++14 doesn't get us quite as much as C++17, but see if we can get to
C++14 first. Still, std::enable_if_t and the less restricted constexpr
are nice wins.
Update-Note: C++14 is now required to build BoringSSL. If the build
breaks, make sure your compiler is C++14-capable and is not passing
-std=c++11. If this is causing problems for your project, let us know.
Change-Id: If03a88e3f8a11980180781f95b806e7f3c3cb6c3
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/52246
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
diff --git a/BUILDING.md b/BUILDING.md
index e9a2b0c..d3446f3 100644
--- a/BUILDING.md
+++ b/BUILDING.md
@@ -30,7 +30,7 @@
by CMake, it may be configured explicitly by setting
`CMAKE_ASM_NASM_COMPILER`.
- * C and C++ compilers with C++11 support are required. On Windows, MSVC from
+ * C and C++ compilers with C++14 support are required. On Windows, MSVC from
Visual Studio 2017 or later with Platform SDK 8.1 or later are supported,
but newer versions are recommended. Recent versions of GCC (6.1+) and Clang
should work on non-Windows platforms, and maybe on Windows too.
diff --git a/CMakeLists.txt b/CMakeLists.txt
index df2d630..dad27f8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -163,7 +163,7 @@
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${C_CXX_FLAGS} -Wmissing-declarations")
if(NOT MSVC)
- set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
+ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++14")
if(APPLE)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -stdlib=libc++")
endif()
diff --git a/crypto/test/abi_test.h b/crypto/test/abi_test.h
index ffe4479..1ba82b1 100644
--- a/crypto/test/abi_test.h
+++ b/crypto/test/abi_test.h
@@ -380,9 +380,9 @@
// CheckImpl implementation. It must be specialized for void returns because we
// call |func| directly.
template <typename R, typename... Args>
-inline typename std::enable_if<!std::is_void<R>::value, crypto_word_t>::type
-CheckImpl(Result *out, bool /* unwind */, R (*func)(Args...),
- typename DeductionGuard<Args>::Type... args) {
+inline std::enable_if_t<!std::is_void<R>::value, crypto_word_t> CheckImpl(
+ Result *out, bool /* unwind */, R (*func)(Args...),
+ typename DeductionGuard<Args>::Type... args) {
*out = Result();
return func(args...);
}
diff --git a/include/openssl/span.h b/include/openssl/span.h
index 38e9a96..67a1a5c 100644
--- a/include/openssl/span.h
+++ b/include/openssl/span.h
@@ -99,12 +99,11 @@
// Heuristically test whether C is a container type that can be converted into
// a Span by checking for data() and size() member functions.
//
- // TODO(davidben): Require C++14 support and switch to std::enable_if_t.
- // Perhaps even C++17 now?
+ // TODO(davidben): Require C++17 support for std::is_convertible_v, etc.
template <typename C>
- using EnableIfContainer = typename std::enable_if<
+ using EnableIfContainer = std::enable_if_t<
std::is_convertible<decltype(std::declval<C>().data()), T *>::value &&
- std::is_integral<decltype(std::declval<C>().size())>::value>::type;
+ std::is_integral<decltype(std::declval<C>().size())>::value>;
public:
constexpr Span() : Span(nullptr, 0) {}
@@ -113,14 +112,12 @@
template <size_t N>
constexpr Span(T (&array)[N]) : Span(array, N) {}
- template <
- typename C, typename = EnableIfContainer<C>,
- typename = typename std::enable_if<std::is_const<T>::value, C>::type>
+ template <typename C, typename = EnableIfContainer<C>,
+ typename = std::enable_if_t<std::is_const<T>::value, C>>
Span(const C &container) : data_(container.data()), size_(container.size()) {}
- template <
- typename C, typename = EnableIfContainer<C>,
- typename = typename std::enable_if<!std::is_const<T>::value, C>::type>
+ template <typename C, typename = EnableIfContainer<C>,
+ typename = std::enable_if_t<!std::is_const<T>::value, C>>
explicit Span(C &container)
: data_(container.data()), size_(container.size()) {}
diff --git a/include/openssl/stack.h b/include/openssl/stack.h
index 04e942c..df54713 100644
--- a/include/openssl/stack.h
+++ b/include/openssl/stack.h
@@ -443,16 +443,14 @@
// Stacks defined with |DEFINE_CONST_STACK_OF| are freed with |sk_free|.
template <typename Stack>
-struct DeleterImpl<
- Stack, typename std::enable_if<StackTraits<Stack>::kIsConst>::type> {
+struct DeleterImpl<Stack, std::enable_if_t<StackTraits<Stack>::kIsConst>> {
static void Free(Stack *sk) { sk_free(reinterpret_cast<_STACK *>(sk)); }
};
// Stacks defined with |DEFINE_STACK_OF| are freed with |sk_pop_free| and the
// corresponding type's deleter.
template <typename Stack>
-struct DeleterImpl<
- Stack, typename std::enable_if<!StackTraits<Stack>::kIsConst>::type> {
+struct DeleterImpl<Stack, std::enable_if_t<!StackTraits<Stack>::kIsConst>> {
static void Free(Stack *sk) {
// sk_FOO_pop_free is defined by macros and bound by name, so we cannot
// access it from C++ here.
@@ -502,18 +500,17 @@
};
template <typename Stack>
-using StackIterator = typename std::enable_if<StackTraits<Stack>::kIsStack,
- StackIteratorImpl<Stack>>::type;
+using StackIterator =
+ std::enable_if_t<StackTraits<Stack>::kIsStack, StackIteratorImpl<Stack>>;
} // namespace internal
// PushToStack pushes |elem| to |sk|. It returns true on success and false on
// allocation failure.
template <typename Stack>
-inline
- typename std::enable_if<!internal::StackTraits<Stack>::kIsConst, bool>::type
- PushToStack(Stack *sk,
- UniquePtr<typename internal::StackTraits<Stack>::Type> elem) {
+inline std::enable_if_t<!internal::StackTraits<Stack>::kIsConst, bool>
+PushToStack(Stack *sk,
+ UniquePtr<typename internal::StackTraits<Stack>::Type> elem) {
if (!sk_push(reinterpret_cast<_STACK *>(sk), elem.get())) {
return false;
}
diff --git a/ssl/internal.h b/ssl/internal.h
index 0087e7f..110b221 100644
--- a/ssl/internal.h
+++ b/ssl/internal.h
@@ -216,7 +216,7 @@
// may be C structs which require a |BORINGSSL_MAKE_DELETER| registration.
namespace internal {
template <typename T>
-struct DeleterImpl<T, typename std::enable_if<T::kAllowUniquePtr>::type> {
+struct DeleterImpl<T, std::enable_if_t<T::kAllowUniquePtr>> {
static void Free(T *t) { Delete(t); }
};
} // namespace internal
diff --git a/ssl/ssl_cipher.cc b/ssl/ssl_cipher.cc
index 60b3e2c..628dddc 100644
--- a/ssl/ssl_cipher.cc
+++ b/ssl/ssl_cipher.cc
@@ -1327,34 +1327,33 @@
using namespace bssl;
-static constexpr int ssl_cipher_id_cmp_inner(const SSL_CIPHER *a,
- const SSL_CIPHER *b) {
- // C++11's constexpr functions must have a body consisting of just a
- // return-statement.
- return (a->id > b->id) ? 1 : ((a->id < b->id) ? -1 : 0);
+static constexpr int ssl_cipher_id_cmp(const SSL_CIPHER *a,
+ const SSL_CIPHER *b) {
+ if (a->id > b->id) {
+ return 1;
+ }
+ if (a->id < b->id) {
+ return -1;
+ }
+ return 0;
}
-static int ssl_cipher_id_cmp(const void *in_a, const void *in_b) {
- return ssl_cipher_id_cmp_inner(reinterpret_cast<const SSL_CIPHER *>(in_a),
- reinterpret_cast<const SSL_CIPHER *>(in_b));
+static int ssl_cipher_id_cmp_void(const void *in_a, const void *in_b) {
+ return ssl_cipher_id_cmp(reinterpret_cast<const SSL_CIPHER *>(in_a),
+ reinterpret_cast<const SSL_CIPHER *>(in_b));
}
-template <typename T, size_t N>
-static constexpr size_t countof(T const (&)[N]) {
- return N;
+template <size_t N>
+static constexpr bool ssl_ciphers_sorted(const SSL_CIPHER (&ciphers)[N]) {
+ for (size_t i = 1; i < N; i++) {
+ if (ssl_cipher_id_cmp(&ciphers[i - 1], &ciphers[i]) >= 0) {
+ return false;
+ }
+ }
+ return true;
}
-template <typename T, size_t I>
-static constexpr int check_order(const T (&arr)[I], size_t N) {
- // C++11's constexpr functions must have a body consisting of just a
- // return-statement.
- return N > 1 ? ((ssl_cipher_id_cmp_inner(&arr[N - 2], &arr[N - 1]) < 0)
- ? check_order(arr, N - 1)
- : 0)
- : 1;
-}
-
-static_assert(check_order(kCiphers, countof(kCiphers)) == 1,
+static_assert(ssl_ciphers_sorted(kCiphers),
"Ciphers are not sorted, bsearch won't work");
const SSL_CIPHER *SSL_get_cipher_by_value(uint16_t value) {
@@ -1363,7 +1362,7 @@
c.id = 0x03000000L | value;
return reinterpret_cast<const SSL_CIPHER *>(bsearch(
&c, kCiphers, OPENSSL_ARRAY_SIZE(kCiphers), sizeof(SSL_CIPHER),
- ssl_cipher_id_cmp));
+ ssl_cipher_id_cmp_void));
}
uint32_t SSL_CIPHER_get_id(const SSL_CIPHER *cipher) { return cipher->id; }
diff --git a/util/BUILD.toplevel b/util/BUILD.toplevel
index cfa695a..1ec2bdf 100644
--- a/util/BUILD.toplevel
+++ b/util/BUILD.toplevel
@@ -137,9 +137,9 @@
"//conditions:default": [],
})
-# For C++ targets only (not C), compile with C++11 support.
+# For C++ targets only (not C), compile with C++14 support.
posix_copts_cxx = [
- "-std=c++11",
+ "-std=c++14",
"-Wmissing-declarations",
]
diff --git a/util/generate_build_files.py b/util/generate_build_files.py
index 3263d9b..186fb59 100644
--- a/util/generate_build_files.py
+++ b/util/generate_build_files.py
@@ -437,7 +437,7 @@
endif()
if(CMAKE_COMPILER_IS_GNUCXX OR CLANG)
- set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -fvisibility=hidden -fno-common -fno-exceptions -fno-rtti")
+ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++14 -fvisibility=hidden -fno-common -fno-exceptions -fno-rtti")
if(APPLE)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -stdlib=libc++")
endif()
