Merge pull request #12036 from kjbracey-arm/callback_fiddle

Callback extension and optimisation

TESTS/mbed_functional/callback/main.cpp

@@ -18,9 +18,27 @@
 #include "greentea-client/test_env.h"
 #include "unity.h"
 #include "utest.h"
+#include <mstd_functional>
 
 using namespace utest::v1;
 
+template <typename T>
+using func0_type = T();
+
+template <typename T>
+using func1_type = T(T);
+
+template <typename T>
+using func2_type = T(T, T);
+
+template <typename T>
+using func3_type = T(T, T, T);
+
+template <typename T>
+using func4_type = T(T, T, T, T);
+
+template <typename T>
+using func5_type = T(T, T, T, T, T);
 
 // static functions
 template <typename T>
@@ -523,13 +541,17 @@ void test_dispatch0()
     Verifier<T>::verify0(&const_volatile_void_func0<T>, (const volatile Thing<T> *)&thing);
     Verifier<T>::verify0(callback(static_func0<T>));
 
-    Callback<T()> cb(static_func0);
+    Callback<T()> cb(static_func0<T>);
     Verifier<T>::verify0(cb);
-    cb = static_func0;
+    TEST_ASSERT_TRUE(cb);
+    func0_type<T> *p = nullptr;
+    cb = p;
+    TEST_ASSERT_FALSE(cb);
+    cb = static_func0<T>;
     Verifier<T>::verify0(cb);
     cb = {&bound_func0<T>, &thing};
     Verifier<T>::verify0(&cb, &Callback<T()>::call);
-    Verifier<T>::verify0(&Callback<T()>::thunk, (void *)&cb);
+    Verifier<T>::verify0(&Callback<T()>::thunk, &cb);
 }
 
 template <typename T>
@@ -554,9 +576,13 @@ void test_dispatch1()
     Verifier<T>::verify1(&const_volatile_void_func1<T>, (const volatile Thing<T> *)&thing);
     Verifier<T>::verify1(callback(static_func1<T>));
 
-    Callback<T(T)> cb(static_func1);
+    Callback<T(T)> cb(static_func1<T>);
     Verifier<T>::verify1(cb);
-    cb = static_func1;
+    TEST_ASSERT_TRUE(cb);
+    func1_type<T> *p = nullptr;
+    cb = p;
+    TEST_ASSERT_FALSE(cb);
+    cb = static_func1<T>;
     Verifier<T>::verify1(cb);
     cb = {&bound_func1<T>, &thing};
     Verifier<T>::verify1(&cb, &Callback<T(T)>::call);
@@ -585,9 +611,13 @@ void test_dispatch2()
     Verifier<T>::verify2(&const_volatile_void_func2<T>, (const volatile Thing<T> *)&thing);
     Verifier<T>::verify2(callback(static_func2<T>));
 
-    Callback<T(T, T)> cb(static_func2);
+    Callback<T(T, T)> cb(static_func2<T>);
     Verifier<T>::verify2(cb);
-    cb = static_func2;
+    TEST_ASSERT_TRUE(cb);
+    func2_type<T> *p = nullptr;
+    cb = p;
+    TEST_ASSERT_FALSE(cb);
+    cb = static_func2<T>;
     Verifier<T>::verify2(cb);
     cb = {&bound_func2<T>, &thing};
     Verifier<T>::verify2(&cb, &Callback<T(T, T)>::call);
@@ -616,9 +646,13 @@ void test_dispatch3()
     Verifier<T>::verify3(&const_volatile_void_func3<T>, (const volatile Thing<T> *)&thing);
     Verifier<T>::verify3(callback(static_func3<T>));
 
-    Callback<T(T, T, T)> cb(static_func3);
+    Callback<T(T, T, T)> cb(static_func3<T>);
     Verifier<T>::verify3(cb);
-    cb = static_func3;
+    TEST_ASSERT_TRUE(cb);
+    func3_type<T> *p = nullptr;
+    cb = p;
+    TEST_ASSERT_FALSE(cb);
+    cb = static_func3<T>;
     Verifier<T>::verify3(cb);
     cb = {&bound_func3<T>, &thing};
     Verifier<T>::verify3(&cb, &Callback<T(T, T, T)>::call);
@@ -647,9 +681,13 @@ void test_dispatch4()
     Verifier<T>::verify4(&const_volatile_void_func4<T>, (const volatile Thing<T> *)&thing);
     Verifier<T>::verify4(callback(static_func4<T>));
 
-    Callback<T(T, T, T, T)> cb(static_func4);
+    Callback<T(T, T, T, T)> cb(static_func4<T>);
     Verifier<T>::verify4(cb);
-    cb = static_func4;
+    TEST_ASSERT_TRUE(cb);
+    func4_type<T> *p = nullptr;
+    cb = p;
+    TEST_ASSERT_FALSE(cb);
+    cb = static_func4<T>;
     Verifier<T>::verify4(cb);
     cb = {&bound_func4<T>, &thing};
     Verifier<T>::verify4(&cb, &Callback<T(T, T, T, T)>::call);
@@ -678,15 +716,159 @@ void test_dispatch5()
     Verifier<T>::verify5(&const_volatile_void_func5<T>, (const volatile Thing<T> *)&thing);
     Verifier<T>::verify5(callback(static_func5<T>));
 
-    Callback<T(T, T, T, T, T)> cb(static_func5);
+    Callback<T(T, T, T, T, T)> cb(static_func5<T>);
     Verifier<T>::verify5(cb);
-    cb = static_func5;
+    TEST_ASSERT_TRUE(cb);
+    func5_type<T> *p = nullptr;
+    cb = p;
+    TEST_ASSERT_FALSE(cb);
+    cb = static_func5<T>;
     Verifier<T>::verify5(cb);
     cb = {&bound_func5<T>, &thing};
     Verifier<T>::verify5(&cb, &Callback<T(T, T, T, T, T)>::call);
+#if 0
     Verifier<T>::verify5(&Callback<T(T, T, T, T, T)>::thunk, (void *)&cb);
+#endif
 }
 
+#include <mstd_functional>
+
+struct TrivialFunctionObject {
+    TrivialFunctionObject(int n) : val(n)
+    {
+    }
+
+    int operator()(int x) const
+    {
+        return x + val;
+    }
+private:
+    int val;
+};
+
+/* Exact count of copy, construction and destruction may vary depending on
+ * copy elision by compiler, but the derived live count can be relied upon.
+ */
+static int construct_count;
+static int destruct_count;
+static int copy_count;
+
+static int live_count()
+{
+    return construct_count - destruct_count;
+}
+
+struct FunctionObject {
+    FunctionObject(int n) : val(n)
+    {
+        construct_count++;
+    }
+
+    FunctionObject(const FunctionObject &other) : val(other.val)
+    {
+        construct_count++;
+        copy_count++;
+    }
+
+    ~FunctionObject()
+    {
+        destruct_count++;
+        destroyed = true;
+    }
+
+    int operator()(int x) const
+    {
+        return destroyed ? -1000 : x + val;
+    }
+private:
+    const int val;
+    bool destroyed = false;
+};
+
+void test_trivial()
+{
+    TrivialFunctionObject fn(1);
+    TEST_ASSERT_EQUAL(2, fn(1));
+    Callback<int(int)> cb(fn);
+    TEST_ASSERT_TRUE(cb);
+    TEST_ASSERT_EQUAL(2, cb(1));
+    fn = 5;
+    TEST_ASSERT_EQUAL(6, fn(1));
+    TEST_ASSERT_EQUAL(2, cb(1));
+    cb = std::ref(fn);
+    fn = 10;
+    TEST_ASSERT_EQUAL(11, fn(1));
+    TEST_ASSERT_EQUAL(11, cb(1));
+    cb = TrivialFunctionObject(3);
+    TEST_ASSERT_EQUAL(7, cb(4));
+    cb = nullptr;
+    TEST_ASSERT_FALSE(cb);
+    cb = TrivialFunctionObject(7);
+    Callback<int(int)> cb2(cb);
+    TEST_ASSERT_EQUAL(8, cb(1));
+    TEST_ASSERT_EQUAL(9, cb2(2));
+    cb2 = cb;
+    TEST_ASSERT_EQUAL(6, cb2(-1));
+    cb = cb;
+    TEST_ASSERT_EQUAL(8, cb(1));
+    cb = std::negate<int>();
+    TEST_ASSERT_EQUAL(-4, cb(4));
+    cb = [](int x) {
+        return x - 7;
+    };
+    TEST_ASSERT_EQUAL(1, cb(8));
+    cb = cb2 = nullptr;
+    TEST_ASSERT_FALSE(cb);
+}
+
+#if MBED_CONF_PLATFORM_CALLBACK_NONTRIVIAL
+void test_nontrivial()
+{
+    {
+        FunctionObject fn(1);
+        TEST_ASSERT_EQUAL(1, construct_count);
+        TEST_ASSERT_EQUAL(0, destruct_count);
+        TEST_ASSERT_EQUAL(2, fn(1));
+        Callback<int(int)> cb(fn);
+        TEST_ASSERT_TRUE(cb);
+        TEST_ASSERT_EQUAL(2, live_count());
+        TEST_ASSERT_EQUAL(2, cb(1));
+        cb = std::ref(fn);
+        TEST_ASSERT_EQUAL(1, live_count());
+        TEST_ASSERT_EQUAL(5, cb(4));
+        cb = FunctionObject(3);
+        TEST_ASSERT_EQUAL(2, live_count());
+        TEST_ASSERT_EQUAL(7, cb(4));
+        cb = nullptr;
+        TEST_ASSERT_FALSE(cb);
+        TEST_ASSERT_EQUAL(1, live_count());
+        cb = FunctionObject(7);
+        TEST_ASSERT_EQUAL(2, live_count());
+        int old_copy_count = copy_count;
+        Callback<int(int)> cb2(cb);
+        TEST_ASSERT_EQUAL(old_copy_count + 1, copy_count);
+        TEST_ASSERT_EQUAL(3, live_count());
+        TEST_ASSERT_EQUAL(8, cb(1));
+        TEST_ASSERT_EQUAL(9, cb2(2));
+        old_copy_count = copy_count;
+        cb2 = cb;
+        TEST_ASSERT_EQUAL(old_copy_count + 1, copy_count);
+        TEST_ASSERT_EQUAL(3, live_count());
+        TEST_ASSERT_EQUAL(6, cb2(-1));
+        int old_construct_count = construct_count;
+        old_copy_count = copy_count;
+        cb = cb;
+        TEST_ASSERT_EQUAL(3, live_count());
+        TEST_ASSERT_EQUAL(old_construct_count, construct_count);
+        TEST_ASSERT_EQUAL(old_copy_count, copy_count);
+        cb = cb2 = nullptr;
+        TEST_ASSERT_FALSE(cb);
+        TEST_ASSERT_EQUAL(1, live_count());
+    }
+    TEST_ASSERT_EQUAL(0, live_count());
+}
+#endif
+
 
 // Test setup
 utest::v1::status_t test_setup(const size_t number_of_cases)
@@ -702,7 +884,10 @@ Case cases[] = {
     Case("Testing callbacks with 2 uint64s", test_dispatch2<uint64_t>),
     Case("Testing callbacks with 3 uint64s", test_dispatch3<uint64_t>),
     Case("Testing callbacks with 4 uint64s", test_dispatch4<uint64_t>),
+// IAR currently crashes at link time with this test - skip it as it's well beyond anything needed by real code
+#ifndef __ICCARM__
     Case("Testing callbacks with 5 uint64s", test_dispatch5<uint64_t>),
+#endif
 #elif DO_SMALL_TEST
     Case("Testing callbacks with 0 uchars", test_dispatch0<unsigned char>),
     Case("Testing callbacks with 1 uchars", test_dispatch1<unsigned char>),
@@ -717,6 +902,10 @@ Case cases[] = {
     Case("Testing callbacks with 3 ints", test_dispatch3<int>),
     Case("Testing callbacks with 4 ints", test_dispatch4<int>),
     Case("Testing callbacks with 5 ints", test_dispatch5<int>),
+    Case("Testing trivial function object", test_trivial),
+#if MBED_CONF_PLATFORM_CALLBACK_NONTRIVIAL
+    Case("Testing non-trivial function object", test_nontrivial),
+#endif
 #endif
 };
 

TESTS/mbed_platform/Transaction/main.cpp

@@ -58,7 +58,11 @@ void test_Transaction_init()
     TEST_ASSERT_EQUAL(rx_buffer_size,   test_transaction.get_transaction()->rx_length);
     TEST_ASSERT_EQUAL(event_id,         test_transaction.get_transaction()->event);
     TEST_ASSERT_EQUAL(word_width,       test_transaction.get_transaction()->width);
-    TEST_ASSERT_EQUAL(callback,         test_transaction.get_transaction()->callback);
+#if MBED_CONF_PLATFORM_CALLBACK_COMPARABLE
+    TEST_ASSERT_TRUE(callback == test_transaction.get_transaction()->callback);
+#else
+    TEST_ASSERT_FALSE(nullptr == test_transaction.get_transaction()->callback)
+#endif
 }
 
 /** Test Transaction class - creation without initialisation

TESTS/network/emac/emac_util.h

@@ -102,8 +102,6 @@ char emac_if_get_trace_level();
 
 void emac_if_trace_to_ascii_hex_dump(const char *prefix, int len, char *data);
 
-void emac_if_link_state_change_cb(void *data, bool up);
-
 unsigned char *emac_if_get_own_addr(void);
 
 int emac_if_get_mtu_size();

UNITTESTS/features/netsocket/NetworkInterface/unittest.cmake

@@ -3,6 +3,8 @@
 # UNIT TESTS
 ####################
 
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DMBED_CONF_PLATFORM_CALLBACK_COMPARABLE")
+
 # Source files
 set(unittest-sources
   ../features/netsocket/SocketAddress.cpp

UNITTESTS/target_h/platform/cxxsupport/mstd_new

@@ -0,0 +1,56 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2019 ARM Limited
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef MSTD_NEW_
+#define MSTD_NEW_
+
+/* <mstd_new>
+ *
+ * - includes toolchain's <new>
+ * - For all toolchains, C++17 backports:
+ *   - mstd::launder
+ */
+
+#include <new>
+#if __cpp_lib_launder < 201606
+#include <type_traits>
+#endif
+
+namespace mstd
+{
+using std::nothrow_t;
+using std::nothrow;
+using std::new_handler;
+using std::set_new_handler;
+
+#if __cpp_lib_launder >= 201606
+using std::launder;
+#else
+template <typename T>
+constexpr T *launder(T *p) noexcept
+{
+    static_assert(!std::is_function<T>::value && !std::is_void<T>::value, "Can only launder complete object types");
+#if defined __clang__ || __GNUC__ >= 9
+    return __builtin_launder(p);
+#else
+    return p;
+#endif
+}
+#endif
+
+} // namespace mstd
+
+#endif // MSTD_NEW_

UNITTESTS/target_h/platform/cxxsupport/mstd_type_traits

@@ -300,20 +300,6 @@ struct remove_cvref : type_identity<std::remove_cv_t<std::remove_reference_t<T>>
 template <typename T>
 using remove_cvref_t = typename remove_cvref<T>::type;
 
-/* C++20 unwrap_reference */
-template <typename T>
-struct unwrap_reference : type_identity<T> { };
-template <typename T>
-struct unwrap_reference<std::reference_wrapper<T>> : type_identity<T &> { };
-template <typename T>
-using unwrap_reference_t = typename unwrap_reference<T>::type;
-
-/* C++20 unwrap_ref_decay */
-template <typename T>
-struct unwrap_ref_decay : unwrap_reference<std::decay_t<T>> { };
-template <typename T>
-using unwrap_ref_decay_t = typename unwrap_ref_decay<T>::type;
-
 }
 
 #if __cpp_lib_invoke < 201411

features/netsocket/NetworkInterface.cpp

@@ -141,6 +141,7 @@ void NetworkInterface::add_event_listener(mbed::Callback<void(nsapi_event_t, int
     attach(mbed::callback(&call_all_event_listeners, this));
 }
 
+#if MBED_CONF_PLATFORM_CALLBACK_COMPARABLE
 void NetworkInterface::remove_event_listener(mbed::Callback<void(nsapi_event_t, intptr_t)> status_cb)
 {
     iface_eventlist_t *event_list = get_interface_event_list_head();
@@ -152,6 +153,7 @@ void NetworkInterface::remove_event_listener(mbed::Callback<void(nsapi_event_t,
         }
     }
 }
+#endif
 
 NetworkInterface::~NetworkInterface()
 {

features/netsocket/NetworkInterface.h

@@ -352,6 +352,7 @@ public:
      */
     void add_event_listener(mbed::Callback<void(nsapi_event_t, intptr_t)> status_cb);
 
+#if MBED_CONF_PLATFORM_CALLBACK_COMPARABLE
     /** Remove event listener from interface.
      *
      * Remove previously added callback from the handler list.
@@ -359,6 +360,7 @@ public:
      *  @param status_cb The callback to unregister.
      */
     void remove_event_listener(mbed::Callback<void(nsapi_event_t, intptr_t)> status_cb);
+#endif
 
     /** Get the connection status.
      *

platform/mbed_lib.json

@@ -123,6 +123,14 @@
             "help": "The maximum CThunk objects used at the same time. This must be greater than 0 and less 256",
             "value": 8
         },
+        "callback-nontrivial": {
+            "help": "Enables support for non-trivial callable objects in Callback. Can be disabled to save ROM if no-one is using non-trivial types. Changing this value may cause incompatibility with pre-built binaries.",
+            "value": true
+        },
+        "callback-comparable": {
+            "help": "Enables support for comparing two Callbacks. See notes on operator== for limitations. Can be disabled to save ROM if not required.",
+            "value": true
+        },
         "crash-capture-enabled": {
             "help": "Enables crash context capture when the system enters a fatal error/crash.",
             "value": false

platform/mbed_retarget.h

@@ -34,11 +34,8 @@
  */
 #ifndef __error_t_defined
 #define __error_t_defined 1
-#include <errno.h>
-#undef __error_t_defined
-#else
-#include <errno.h>
 #endif
+#include <errno.h>
 
 #if defined __has_include
 #  if __has_include (<sys/stat.h>)

platform/mbed_toolchain.h

@@ -19,6 +19,10 @@
 
 #include "platform/mbed_preprocessor.h"
 
+/* Workaround to prevent GCC library defining error_t, which can collide */
+#ifndef __error_t_defined
+#define __error_t_defined 1
+#endif
 
 // Warning for unsupported compilers
 #if !defined(__GNUC__)   /* GCC        */ \