Add C++11 compiler support detection feature

This is currently copied from http://quickgit.kde.org/index.php?p=scratch%2Fdakon%2Fcmake-cxx11.git
but there is a chance that in future it will be merged into CMake proper.

cmake/Modules/CheckCXX11Features.cmake

@@ -0,0 +1,132 @@
+# - Check which parts of the C++11 standard the compiler supports
+#
+# When found it will set the following variables
+#
+#  CXX11_COMPILER_FLAGS         - the compiler flags needed to get C++11 features
+#
+#  HAS_CXX11_AUTO               - auto keyword
+#  HAS_CXX11_AUTO_RET_TYPE      - function declaration with deduced return types
+#  HAS_CXX11_CLASS_OVERRIDE     - override and final keywords for classes and methods
+#  HAS_CXX11_CONSTEXPR          - constexpr keyword
+#  HAS_CXX11_CSTDINT_H          - cstdint header
+#  HAS_CXX11_DECLTYPE           - decltype keyword
+#  HAS_CXX11_FUNC               - __func__ preprocessor constant
+#  HAS_CXX11_INITIALIZER_LIST   - initializer list
+#  HAS_CXX11_LAMBDA             - lambdas
+#  HAS_CXX11_LIB_REGEX          - regex library
+#  HAS_CXX11_LONG_LONG          - long long signed & unsigned types
+#  HAS_CXX11_NULLPTR            - nullptr
+#  HAS_CXX11_RVALUE_REFERENCES  - rvalue references
+#  HAS_CXX11_SIZEOF_MEMBER      - sizeof() non-static members
+#  HAS_CXX11_STATIC_ASSERT      - static_assert()
+#  HAS_CXX11_VARIADIC_TEMPLATES - variadic templates
+
+#=============================================================================
+# Copyright 2011,2012 Rolf Eike Beer <eike@sf-mail.de>
+# Copyright 2012 Andreas Weis
+#
+# Distributed under the OSI-approved BSD License (the "License");
+# see accompanying file Copyright.txt for details.
+#
+# This software is distributed WITHOUT ANY WARRANTY; without even the
+# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the License for more information.
+#=============================================================================
+# (To distribute this file outside of CMake, substitute the full
+#  License text for the above reference.)
+
+if (NOT CMAKE_CXX_COMPILER_LOADED)
+    message(FATAL_ERROR "CheckCXX11Features modules only works if language CXX is enabled")
+endif ()
+
+cmake_minimum_required(VERSION 2.8.3)
+
+#
+### Check for needed compiler flags
+#
+include(CheckCXXCompilerFlag)
+check_cxx_compiler_flag("-std=c++11" _HAS_CXX11_FLAG)
+if (NOT _HAS_CXX11_FLAG)
+    check_cxx_compiler_flag("-std=c++0x" _HAS_CXX0X_FLAG)
+endif ()
+
+if (_HAS_CXX11_FLAG)
+    set(CXX11_COMPILER_FLAGS "-std=c++11")
+elseif (_HAS_CXX0X_FLAG)
+    set(CXX11_COMPILER_FLAGS "-std=c++0x")
+endif ()
+
+function(cxx11_check_feature FEATURE_NAME RESULT_VAR)
+    if (NOT DEFINED ${RESULT_VAR})
+        set(_bindir "${CMAKE_CURRENT_BINARY_DIR}/cxx11_${FEATURE_NAME}")
+
+        set(_SRCFILE_BASE ${CMAKE_CURRENT_LIST_DIR}/CheckCXX11Features/cxx11-test-${FEATURE_NAME})
+        set(_LOG_NAME "\"${FEATURE_NAME}\"")
+        message(STATUS "Checking C++11 support for ${_LOG_NAME}")
+
+        set(_SRCFILE "${_SRCFILE_BASE}.cpp")
+        set(_SRCFILE_FAIL "${_SRCFILE_BASE}_fail.cpp")
+        set(_SRCFILE_FAIL_COMPILE "${_SRCFILE_BASE}_fail_compile.cpp")
+
+        if (CROSS_COMPILING)
+            try_compile(${RESULT_VAR} "${_bindir}" "${_SRCFILE}"
+                        COMPILE_DEFINITIONS "${CXX11_COMPILER_FLAGS}")
+            if (${RESULT_VAR} AND EXISTS ${_SRCFILE_FAIL})
+                try_compile(${RESULT_VAR} "${_bindir}_fail" "${_SRCFILE_FAIL}"
+                            COMPILE_DEFINITIONS "${CXX11_COMPILER_FLAGS}")
+            endif (${RESULT_VAR} AND EXISTS ${_SRCFILE_FAIL})
+        else (CROSS_COMPILING)
+            try_run(_RUN_RESULT_VAR _COMPILE_RESULT_VAR
+                    "${_bindir}" "${_SRCFILE}"
+                    COMPILE_DEFINITIONS "${CXX11_COMPILER_FLAGS}")
+            if (_COMPILE_RESULT_VAR AND NOT _RUN_RESULT_VAR)
+                set(${RESULT_VAR} TRUE)
+            else (_COMPILE_RESULT_VAR AND NOT _RUN_RESULT_VAR)
+                set(${RESULT_VAR} FALSE)
+            endif (_COMPILE_RESULT_VAR AND NOT _RUN_RESULT_VAR)
+            if (${RESULT_VAR} AND EXISTS ${_SRCFILE_FAIL})
+                try_run(_RUN_RESULT_VAR _COMPILE_RESULT_VAR
+                        "${_bindir}_fail" "${_SRCFILE_FAIL}"
+                         COMPILE_DEFINITIONS "${CXX11_COMPILER_FLAGS}")
+                if (_COMPILE_RESULT_VAR AND _RUN_RESULT_VAR)
+                    set(${RESULT_VAR} TRUE)
+                else (_COMPILE_RESULT_VAR AND _RUN_RESULT_VAR)
+                    set(${RESULT_VAR} FALSE)
+                endif (_COMPILE_RESULT_VAR AND _RUN_RESULT_VAR)
+            endif (${RESULT_VAR} AND EXISTS ${_SRCFILE_FAIL})
+        endif (CROSS_COMPILING)
+        if (${RESULT_VAR} AND EXISTS ${_SRCFILE_FAIL_COMPILE})
+            try_compile(_TMP_RESULT "${_bindir}_fail_compile" "${_SRCFILE_FAIL_COMPILE}"
+                        COMPILE_DEFINITIONS "${CXX11_COMPILER_FLAGS}")
+            if (_TMP_RESULT)
+                set(${RESULT_VAR} FALSE)
+            else (_TMP_RESULT)
+                set(${RESULT_VAR} TRUE)
+            endif (_TMP_RESULT)
+        endif (${RESULT_VAR} AND EXISTS ${_SRCFILE_FAIL_COMPILE})
+
+        if (${RESULT_VAR})
+            message(STATUS "Checking C++11 support for ${_LOG_NAME}: works")
+        else (${RESULT_VAR})
+            message(STATUS "Checking C++11 support for ${_LOG_NAME}: not supported")
+        endif (${RESULT_VAR})
+        set(${RESULT_VAR} ${${RESULT_VAR}} CACHE INTERNAL "C++11 support for ${_LOG_NAME}")
+    endif (NOT DEFINED ${RESULT_VAR})
+endfunction(cxx11_check_feature)
+
+cxx11_check_feature("__func__" HAS_CXX11_FUNC)
+cxx11_check_feature("auto" HAS_CXX11_AUTO)
+cxx11_check_feature("auto_ret_type" HAS_CXX11_AUTO_RET_TYPE)
+cxx11_check_feature("class_override_final" HAS_CXX11_CLASS_OVERRIDE)
+cxx11_check_feature("constexpr" HAS_CXX11_CONSTEXPR)
+cxx11_check_feature("cstdint" HAS_CXX11_CSTDINT_H)
+cxx11_check_feature("decltype" HAS_CXX11_DECLTYPE)
+cxx11_check_feature("initializer_list" HAS_CXX11_INITIALIZER_LIST)
+cxx11_check_feature("lambda" HAS_CXX11_LAMBDA)
+cxx11_check_feature("long_long" HAS_CXX11_LONG_LONG)
+cxx11_check_feature("nullptr" HAS_CXX11_NULLPTR)
+cxx11_check_feature("regex" HAS_CXX11_LIB_REGEX)
+cxx11_check_feature("rvalue-references" HAS_CXX11_RVALUE_REFERENCES)
+cxx11_check_feature("sizeof_member" HAS_CXX11_SIZEOF_MEMBER)
+cxx11_check_feature("static_assert" HAS_CXX11_STATIC_ASSERT)
+cxx11_check_feature("variadic_templates" HAS_CXX11_VARIADIC_TEMPLATES)

cmake/Modules/CheckCXX11Features/cxx11-test-__func__.cpp

@@ -0,0 +1,8 @@
+int main(void)
+{
+	if (!__func__)
+		return 1;
+	if (!(*__func__))
+		return 1;
+	return 0;
+}

cmake/Modules/CheckCXX11Features/cxx11-test-auto.cpp

@@ -0,0 +1,12 @@
+
+int main()
+{
+	auto i = 5;
+	auto f = 3.14159f;
+	auto d = 3.14159;
+	bool ret = (
+		(sizeof(f) < sizeof(d)) &&
+		(sizeof(i) == sizeof(int))
+	);
+	return ret ? 0 : 1;
+}

cmake/Modules/CheckCXX11Features/cxx11-test-auto_fail_compile.cpp

@@ -0,0 +1,7 @@
+int main(void)
+{
+	// must fail because there is no initializer
+	auto i;
+
+	return 0;
+}

cmake/Modules/CheckCXX11Features/cxx11-test-auto_ret_type.cpp

@@ -0,0 +1,8 @@
+auto foo(int i) -> int {
+	return i - 1;
+}
+
+int main()
+{
+	return foo(1);
+}

cmake/Modules/CheckCXX11Features/cxx11-test-class_override_final.cpp

@@ -0,0 +1,21 @@
+class base {
+public:
+    virtual int foo(int a)
+     { return 4 + a; }
+    int bar(int a) final
+     { return a - 2; }
+};
+
+class sub final : public base {
+public:
+    virtual int foo(int a) override
+     { return 8 + 2 * a; };
+};
+
+int main(void)
+{
+    base b;
+    sub s;
+
+    return (b.foo(2) * 2 == s.foo(2)) ? 0 : 1;
+}

cmake/Modules/CheckCXX11Features/cxx11-test-class_override_final_fail_compile.cpp

@@ -0,0 +1,25 @@
+class base {
+public:
+    virtual int foo(int a)
+     { return 4 + a; }
+    virtual int bar(int a) final
+     { return a - 2; }
+};
+
+class sub final : public base {
+public:
+    virtual int foo(int a) override
+     { return 8 + 2 * a; };
+    virtual int bar(int a)
+     { return a; }
+};
+
+class impossible : public sub { };
+
+int main(void)
+{
+    base b;
+    sub s;
+
+    return 1;
+}

cmake/Modules/CheckCXX11Features/cxx11-test-constexpr.cpp

@@ -0,0 +1,19 @@
+constexpr int square(int x)
+{
+	return x*x;
+}
+
+constexpr int the_answer()
+{
+	return 42;
+}
+
+int main()
+{
+	int test_arr[square(3)];
+	bool ret = (
+		(square(the_answer()) == 1764) &&
+		(sizeof(test_arr)/sizeof(test_arr[0]) == 9)
+	);
+	return ret ? 0 : 1;
+}

cmake/Modules/CheckCXX11Features/cxx11-test-cstdint.cpp

@@ -0,0 +1,11 @@
+#include <cstdint>
+
+int main()
+{
+	bool test =
+		(sizeof(int8_t) == 1) &&
+		(sizeof(int16_t) == 2) &&
+		(sizeof(int32_t) == 4) &&
+		(sizeof(int64_t) == 8);
+	return test ? 0 : 1;
+}

cmake/Modules/CheckCXX11Features/cxx11-test-decltype.cpp

@@ -0,0 +1,10 @@
+bool check_size(int i)
+{
+	return sizeof(int) == sizeof(decltype(i));
+}
+
+int main()
+{
+	bool ret = check_size(42);
+	return ret ? 0 : 1;
+}

cmake/Modules/CheckCXX11Features/cxx11-test-initializer_list.cpp

@@ -0,0 +1,27 @@
+#include <vector>
+
+class seq {
+public:
+    seq(std::initializer_list<int> list);
+
+    int length() const;
+private:
+    std::vector<int> m_v;
+};
+
+seq::seq(std::initializer_list<int> list)
+    : m_v(list)
+{
+}
+
+int seq::length() const
+{
+    return m_v.size();
+}
+
+int main(void)
+{
+    seq a = {18, 20, 2, 0, 4, 7};
+
+    return (a.length() == 6) ? 0 : 1;
+}

cmake/Modules/CheckCXX11Features/cxx11-test-lambda.cpp

@@ -0,0 +1,5 @@
+int main()
+{
+	int ret = 0;
+	return ([&ret]() -> int { return ret; })();
+}

cmake/Modules/CheckCXX11Features/cxx11-test-long_long.cpp

@@ -0,0 +1,7 @@
+int main(void)
+{
+	long long l;
+	unsigned long long ul;
+
+	return ((sizeof(l) >= 8) && (sizeof(ul) >= 8)) ? 0 : 1;
+}

cmake/Modules/CheckCXX11Features/cxx11-test-nullptr.cpp

@@ -0,0 +1,6 @@
+int main(void)
+{
+	void *v = nullptr;
+
+	return v ? 1 : 0;
+}

cmake/Modules/CheckCXX11Features/cxx11-test-nullptr_fail_compile.cpp

@@ -0,0 +1,6 @@
+int main(void)
+{
+	int i = nullptr;
+
+	return 1;
+}

cmake/Modules/CheckCXX11Features/cxx11-test-regex.cpp

@@ -0,0 +1,26 @@
+#include <algorithm>
+#include <regex>
+
+int parse_line(std::string const& line)
+{
+	std::string tmp;
+	if(std::regex_search(line, std::regex("(\\s)+(-)?(\\d)+//(-)?(\\d)+(\\s)+"))) {
+		tmp = std::regex_replace(line, std::regex("(-)?(\\d)+//(-)?(\\d)+"), std::string("V"));
+	} else if(std::regex_search(line, std::regex("(\\s)+(-)?(\\d)+/(-)?(\\d)+(\\s)+"))) {
+		tmp = std::regex_replace(line, std::regex("(-)?(\\d)+/(-)?(\\d)+"), std::string("V"));
+	} else if(std::regex_search(line, std::regex("(\\s)+(-)?(\\d)+/(-)?(\\d)+/(-)?(\\d)+(\\s)+"))) {
+		tmp = std::regex_replace(line, std::regex("(-)?(\\d)+/(-)?(\\d)+/(-)?(\\d)+"), std::string("V"));
+	} else {
+		tmp = std::regex_replace(line, std::regex("(-)?(\\d)+"), std::string("V"));
+	}
+	return static_cast<int>(std::count(tmp.begin(), tmp.end(), 'V'));
+}
+
+int main()
+{
+	bool test = (parse_line("f 7/7/7 -3/3/-3 2/-2/2") == 3) &&
+				(parse_line("f 7//7 3//-3 -2//2") == 3) &&
+				(parse_line("f 7/7 3/-3 -2/2") == 3) &&
+				(parse_line("f 7 3 -2") == 3);
+	return test ? 0 : 1;
+}

cmake/Modules/CheckCXX11Features/cxx11-test-rvalue-references.cpp

@@ -0,0 +1,57 @@
+#include <cassert>
+
+class rvmove {
+public:
+   void *ptr;
+   char *array;
+
+   rvmove()
+    : ptr(0),
+    array(new char[10])
+   {
+     ptr = this;
+   }
+
+   rvmove(rvmove &&other)
+    : ptr(other.ptr),
+    array(other.array)
+   {
+    other.array = 0;
+    other.ptr = 0;
+   }
+
+   ~rvmove()
+   {
+    assert(((ptr != 0) && (array != 0)) || ((ptr == 0) && (array == 0)));
+    delete[] array;
+   }
+
+   rvmove &operator=(rvmove &&other)
+   {
+     delete[] array;
+     ptr = other.ptr;
+     array = other.array;
+     other.array = 0;
+     other.ptr = 0;
+     return *this;
+   }
+
+   static rvmove create()
+   {
+     return rvmove();
+   }
+private:
+  rvmove(const rvmove &);
+  rvmove &operator=(const rvmove &);
+};
+
+int main()
+{
+  rvmove mine;
+  if (mine.ptr != &mine)
+    return 1;
+  mine = rvmove::create();
+  if (mine.ptr == &mine)
+    return 1;
+  return 0;
+}

cmake/Modules/CheckCXX11Features/cxx11-test-sizeof_member.cpp

@@ -0,0 +1,14 @@
+struct foo {
+	char bar;
+	int baz;
+};
+
+int main(void)
+{
+	bool ret = (
+		(sizeof(foo::bar) == 1) &&
+		(sizeof(foo::baz) >= sizeof(foo::bar)) &&
+		(sizeof(foo) >= sizeof(foo::bar) + sizeof(foo::baz))
+	);
+	return ret ? 0 : 1;
+}

cmake/Modules/CheckCXX11Features/cxx11-test-sizeof_member_fail.cpp

@@ -0,0 +1,9 @@
+struct foo {
+	int baz;
+	double bar;
+};
+
+int main(void)
+{
+	return (sizeof(foo::bar) == 4) ? 0 : 1;
+}

cmake/Modules/CheckCXX11Features/cxx11-test-static_assert.cpp

@@ -0,0 +1,5 @@
+int main(void)
+{
+	static_assert(0 < 1, "your ordering of integers is screwed");
+	return 0;
+}

cmake/Modules/CheckCXX11Features/cxx11-test-static_assert_fail_compile.cpp

@@ -0,0 +1,5 @@
+int main(void)
+{
+	static_assert(1 < 0, "your ordering of integers is screwed");
+	return 0;
+}

cmake/Modules/CheckCXX11Features/cxx11-test-variadic_templates.cpp

@@ -0,0 +1,23 @@
+int Accumulate()
+{
+	return 0;
+}
+
+template<typename T, typename... Ts>
+int Accumulate(T v, Ts... vs)
+{
+	return v + Accumulate(vs...);
+}
+
+template<int... Is>
+int CountElements()
+{
+	return sizeof...(Is);
+}
+
+int main()
+{
+	int acc = Accumulate(1, 2, 3, 4, -5);
+	int count = CountElements<1,2,3,4,5>();
+	return ((acc == 5) && (count == 5)) ? 0 : 1;
+}