Add more xcode configurations to Travis

Travis CI shows linking errors on Linux and OS X when __cxa_uncaught_exceptions
is used to implement uncaught_exceptions. There's probably some library missing,
which should be linked in implicitly by the compiler, or the library indeed
does not export the symbol. In any case, __cxa_get_globals-based implementation
should provide the same effect.

.travis.yml

@@ -210,6 +210,17 @@ matrix:
             - ubuntu-toolchain-r-test
             - llvm-toolchain-trusty-6.0
 
+    - os: linux
+      compiler: clang++-7
+      env: TOOLSET=clang COMPILER=clang++-7 CXXSTD=03,11,14,17
+      addons:
+        apt:
+          packages:
+            - clang-7
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-trusty-7
+
     - os: linux
       compiler: clang++-6.0
       env: UBSAN=1 TOOLSET=clang COMPILER=clang++-6.0 CXXSTD=03,11,14,1z UBSAN_OPTIONS=print_stacktrace=1
@@ -229,6 +240,7 @@ matrix:
         apt:
           packages:
             - libc++-dev
+            - libc++abi-dev
 
     - os: linux
       compiler: clang++-libc++
@@ -237,23 +249,52 @@ matrix:
         apt:
           packages:
             - libc++-dev
+            - libc++abi-dev
 
     - os: osx
       compiler: clang++
       env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z
+      osx_image: xcode7.3
+
+    - os: osx
+      compiler: clang++
+      env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z
+      osx_image: xcode8.3
+
+    - os: osx
+      compiler: clang++
+      env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z
+      osx_image: xcode9.4
+
+    - os: osx
+      compiler: clang++
+      env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z
+      osx_image: xcode10.1
+
+    - os: linux
+      compiler: g++
+      env: CMAKE_SUBDIR_TEST=1
+      script:
+      - cd libs/core/test/cmake_subdir_test && mkdir __build__ && cd __build__
+      - cmake ..
+      - cmake --build .
+      - cmake --build . --target check
 
 install:
-  - BOOST_BRANCH=develop && [ "$TRAVIS_BRANCH" == "master" ] && BOOST_BRANCH=master || true
+  - BOOST_BRANCH=develop
+  - if [ "$TRAVIS_BRANCH" = "master" ]; then BOOST_BRANCH=master; fi
   - cd ..
   - git clone -b $BOOST_BRANCH https://github.com/boostorg/boost.git boost-root
   - cd boost-root
+  - git submodule init libs/headers
   - git submodule init libs/assert
   - git submodule init libs/config
   - git submodule init libs/predef
   - git submodule init libs/static_assert
   - git submodule init libs/type_traits
   - git submodule init tools/build
-  - git submodule update
+  - git submodule init tools/boost_install
+  - git submodule update --jobs 4
   - cp -r $TRAVIS_BUILD_DIR/* libs/core
   - ./bootstrap.sh
   - ./b2 headers
@@ -261,7 +302,8 @@ install:
 script:
   - |-
     echo "using $TOOLSET : : $COMPILER ;" > ~/user-config.jam
-  - ./b2 -j 3 libs/core/test toolset=$TOOLSET cxxstd=$CXXSTD variant=debug,release ${UBSAN:+cxxflags=-fsanitize=undefined cxxflags=-fno-sanitize-recover=undefined linkflags=-fsanitize=undefined define=UBSAN=1 debug-symbols=on} ${LINKFLAGS:+linkflags=$LINKFLAGS}
+  - BUILD_JOBS=`(nproc || sysctl -n hw.ncpu) 2> /dev/null`
+  - ./b2 -j $BUILD_JOBS libs/core/test toolset=$TOOLSET cxxstd=$CXXSTD variant=debug,release ${UBSAN:+cxxflags=-fsanitize=undefined cxxflags=-fno-sanitize-recover=undefined linkflags=-fsanitize=undefined define=UBSAN=1 debug-symbols=on} ${LINKFLAGS:+linkflags=$LINKFLAGS}
 
 notifications:
   email:

README.md

@@ -1,7 +1,7 @@
 Boost.Core
 ==========
 
-Boost.Core, part of collection of the [Boost C++ Libraries](http://github.com/boostorg), is a collection of core utilities used by other Boost libraries.
+Boost.Core, part of collection of the [Boost C++ Libraries](https://github.com/boostorg), is a collection of core utilities used by other Boost libraries.
 The criteria for inclusion is that the utility component be:
 
 * simple,
@@ -23,10 +23,10 @@ Master   | [![Build Status](https://travis-ci.org/boostorg/core.svg?branch=maste
 
 ### More information
 
-* [Documentation](http://boost.org/libs/core)
+* [Documentation](https://boost.org/libs/core)
 * [Report bugs](https://svn.boost.org/trac/boost/newticket?component=core;version=Boost%20Release%20Branch). Be sure to mention Boost version, platform and compiler you're using. A small compilable code sample to reproduce the problem is always good as well.
-* Submit your patches as pull requests against **develop** branch. Note that by submitting patches you agree to license your modifications under the [Boost Software License, Version 1.0](http://www.boost.org/LICENSE_1_0.txt).
+* Submit your patches as pull requests against **develop** branch. Note that by submitting patches you agree to license your modifications under the [Boost Software License, Version 1.0](https://www.boost.org/LICENSE_1_0.txt).
 
 ### License
 
-Distributed under the [Boost Software License, Version 1.0](http://boost.org/LICENSE_1_0.txt).
+Distributed under the [Boost Software License, Version 1.0](https://boost.org/LICENSE_1_0.txt).

appveyor.yml

@@ -55,13 +55,15 @@ install:
   - cd ..
   - git clone -b %BOOST_BRANCH% https://github.com/boostorg/boost.git boost-root
   - cd boost-root
+  - git submodule init libs/headers
   - git submodule init libs/assert
   - git submodule init libs/config
   - git submodule init libs/predef
   - git submodule init libs/static_assert
   - git submodule init libs/type_traits
   - git submodule init tools/build
-  - git submodule update
+  - git submodule init tools/boost_install
+  - git submodule update --jobs 4
   - xcopy /s /e /q %APPVEYOR_BUILD_FOLDER% libs\core
   - cmd /c bootstrap
   - b2 headers
@@ -71,4 +73,4 @@ build: off
 test_script:
   - PATH=%ADDPATH%%PATH%
   - if not "%CXXSTD%" == "" set CXXSTD=cxxstd=%CXXSTD%
-  - b2 -j 3 libs/core/test toolset=%TOOLSET% %CXXSTD%
+  - b2 -j %NUMBER_OF_PROCESSORS% libs/core/test toolset=%TOOLSET% %CXXSTD%

doc/core.qbk

@@ -57,3 +57,4 @@ criteria for inclusion is that the utility component be:
 [include scoped_enum.qbk]
 [include swap.qbk]
 [include typeinfo.qbk]
+[include uncaught_exceptions.qbk]

doc/uncaught_exceptions.qbk

@@ -0,0 +1,52 @@
+[/
+ / Copyright (c) 2018 Andrey Semashev
+ /
+ / Distributed under the Boost Software License, Version 1.0. (See accompanying
+ / file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+ /]
+
+[section:uncaught_exceptions uncaught_exceptions]
+
+[simplesect Authors]
+
+* Andrey Semashev
+
+[endsimplesect]
+
+[section Header <boost/core/uncaught_exceptions.hpp>]
+
+The header `<boost/core/uncaught_exceptions.hpp>` defines the `boost::core::uncaught_exceptions` function,
+which is a more portable implementation of the same named function introduced in C++17. The function
+returns the number of the currently pending exceptions. When that function returns a value greater than 0,
+throwing an exception from a destructor can terminate the program.
+
+Unfortunately, the function cannot be implemented on every pre-C++17 compiler, although the most commonly
+used compilers are supported. When the compiler does not provide the necessary functionality,
+`boost::core::uncaught_exceptions` returns a non-zero value if at least one exception is pending (i.e. not
+necessarily the number of pending exceptions), and `BOOST_CORE_UNCAUGHT_EXCEPTIONS_EMULATED` macro
+is defined.
+
+[section Example]
+``
+class my_class
+{
+private:
+    const unsigned int m_exception_count;
+
+public:
+    my_class() : m_exception_count(boost::core::uncaught_exceptions())
+    {
+    }
+
+    ~my_class() noexcept(false)
+    {
+        if (m_exception_count == boost::core::uncaught_exceptions())
+            do_something_potentially_throwing();
+    }
+};
+``
+[endsect]
+
+[endsect]
+
+[endsect]

include/boost/core/swap.hpp

@@ -21,13 +21,19 @@
 // avoid ambiguity when swapping objects of a Boost type that does
 // not have its own boost::swap overload.
 
+#include <boost/core/enable_if.hpp>
+#include <boost/config.hpp>
 #include <utility> //for std::swap (C++11)
 #include <algorithm> //for std::swap (C++98)
 #include <cstddef> //for std::size_t
-#include <boost/config.hpp>
 
 namespace boost_swap_impl
 {
+  // we can't use type_traits here
+
+  template<class T> struct is_const { enum _vt { value = 0 }; };
+  template<class T> struct is_const<T const> { enum _vt { value = 1 }; };
+
   template<class T>
   BOOST_GPU_ENABLED
   void swap_impl(T& left, T& right)
@@ -51,7 +57,8 @@ namespace boost
 {
   template<class T1, class T2>
   BOOST_GPU_ENABLED
-  void swap(T1& left, T2& right)
+  typename enable_if_c< !boost_swap_impl::is_const<T1>::value && !boost_swap_impl::is_const<T2>::value >::type
+  swap(T1& left, T2& right)
   {
     ::boost_swap_impl::swap_impl(left, right);
   }

include/boost/core/uncaught_exceptions.hpp

@@ -0,0 +1,131 @@
+/*
+ *             Copyright Andrey Semashev 2018.
+ * Distributed under the Boost Software License, Version 1.0.
+ *    (See accompanying file LICENSE_1_0.txt or copy at
+ *          https://www.boost.org/LICENSE_1_0.txt)
+ */
+/*!
+ * \file   uncaught_exceptions.hpp
+ * \author Andrey Semashev
+ * \date   2018-11-10
+ *
+ * \brief  This header provides an `uncaught_exception` function implementation, which was introduced in C++17.
+ *
+ * The code in this file is based on the implementation by Evgeny Panasyuk:
+ *
+ * https://github.com/panaseleus/stack_unwinding/blob/master/boost/exception/uncaught_exception_count.hpp
+ */
+
+#ifndef BOOST_CORE_UNCAUGHT_EXCEPTIONS_HPP_INCLUDED_
+#define BOOST_CORE_UNCAUGHT_EXCEPTIONS_HPP_INCLUDED_
+
+#include <exception>
+#include <boost/config.hpp>
+
+#if defined(BOOST_HAS_PRAGMA_ONCE)
+#pragma once
+#endif
+
+// Visual Studio 14 supports N4152 std::uncaught_exceptions()
+#if (defined(__cpp_lib_uncaught_exceptions) && __cpp_lib_uncaught_exceptions >= 201411) || \
+    (defined(_MSC_VER) && _MSC_VER >= 1900)
+#define BOOST_CORE_HAS_UNCAUGHT_EXCEPTIONS
+#endif
+
+#if !defined(BOOST_CORE_HAS_UNCAUGHT_EXCEPTIONS)
+
+// cxxabi.h availability macro
+#if defined(__has_include) && (!defined(BOOST_GCC) || (__GNUC__ >= 5))
+#   if __has_include(<cxxabi.h>)
+#       define BOOST_CORE_HAS_CXXABI_H
+#   endif
+#elif defined(__GLIBCXX__) || defined(__GLIBCPP__)
+#   define BOOST_CORE_HAS_CXXABI_H
+#endif
+
+#if defined(BOOST_CORE_HAS_CXXABI_H)
+// MinGW GCC 4.4 seem to not work the same way the newer GCC versions do. As a result, __cxa_get_globals based implementation will always return 0.
+// Just disable it for now and fall back to std::uncaught_exception().
+#if !(defined(__MINGW32__) && (defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__) < 405))
+#include <cxxabi.h>
+#include <cstring>
+#define BOOST_CORE_HAS_CXA_GET_GLOBALS
+// At least on MinGW and Linux, only GCC since 4.7 declares __cxa_get_globals() in cxxabi.h. Older versions of GCC do not expose this function but it's there.
+// On OpenBSD, it seems, the declaration is also missing.
+// Note that at least on FreeBSD 11, cxxabi.h declares __cxa_get_globals with a different exception specification, so we can't declare the function unconditionally.
+// On Linux with clang and libc++ and on OS X, there is a version of cxxabi.h from libc++abi that doesn't declare __cxa_get_globals, but provides __cxa_uncaught_exceptions.
+// The function only appeared in version _LIBCPPABI_VERSION >= 1002 of the library. Unfortunately, there are linking errors about undefined reference to __cxa_uncaught_exceptions
+// on Ubuntu Trusty and OS X, so we avoid using it and forward-declare __cxa_get_globals instead.
+#if !defined(__FreeBSD__) && \
+    ( \
+        (defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__) < 407) || \
+        defined(__OpenBSD__) || \
+        defined(_LIBCPPABI_VERSION) \
+    )
+namespace __cxxabiv1 {
+struct __cxa_eh_globals;
+#if defined(__OpenBSD__)
+extern "C" __cxa_eh_globals* __cxa_get_globals();
+#else
+extern "C" __cxa_eh_globals* __cxa_get_globals() BOOST_NOEXCEPT_OR_NOTHROW __attribute__((__const__));
+#endif
+} // namespace __cxxabiv1
+#endif
+#endif // !(defined(__MINGW32__) && (defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__) < 405))
+#endif // defined(BOOST_CORE_HAS_CXXABI_H)
+
+#if defined(_MSC_VER) && _MSC_VER >= 1400
+#include <cstring>
+#define BOOST_CORE_HAS_GETPTD
+namespace boost {
+namespace core {
+namespace detail {
+extern "C" void* _getptd();
+} // namespace detail
+} // namespace core
+} // namespace boost
+#endif // defined(_MSC_VER) && _MSC_VER >= 1400
+
+#endif // !defined(BOOST_CORE_HAS_UNCAUGHT_EXCEPTIONS)
+
+#if !defined(BOOST_CORE_HAS_UNCAUGHT_EXCEPTIONS) && !defined(BOOST_CORE_HAS_CXA_GET_GLOBALS) && !defined(BOOST_CORE_HAS_GETPTD)
+//! This macro is defined when `uncaught_exceptions` is not guaranteed to return values greater than 1 if multiple exceptions are pending
+#define BOOST_CORE_UNCAUGHT_EXCEPTIONS_EMULATED
+#endif
+
+namespace boost {
+
+namespace core {
+
+//! Returns the number of currently pending exceptions
+inline unsigned int uncaught_exceptions() BOOST_NOEXCEPT
+{
+#if defined(BOOST_CORE_HAS_UNCAUGHT_EXCEPTIONS)
+    // C++17 implementation
+    return static_cast< unsigned int >(std::uncaught_exceptions());
+#elif defined(BOOST_CORE_HAS_CXA_GET_GLOBALS)
+    // Tested on {clang 3.2,GCC 3.5.6,GCC 4.1.2,GCC 4.4.6,GCC 4.4.7}x{x32,x64}
+    unsigned int count;
+    std::memcpy(&count, reinterpret_cast< const unsigned char* >(::abi::__cxa_get_globals()) + sizeof(void*), sizeof(count)); // __cxa_eh_globals::uncaughtExceptions, x32 offset - 0x4, x64 - 0x8
+    return count;
+#elif defined(BOOST_CORE_HAS_GETPTD)
+    // MSVC specific. Tested on {MSVC2005SP1,MSVC2008SP1,MSVC2010SP1,MSVC2012}x{x32,x64}.
+    unsigned int count;
+    std::memcpy(&count, static_cast< const unsigned char* >(boost::core::detail::_getptd()) + (sizeof(void*) == 8u ? 0x100 : 0x90), sizeof(count)); // _tiddata::_ProcessingThrow, x32 offset - 0x90, x64 - 0x100
+    return count;
+#else
+    // Portable C++03 implementation. Does not allow to detect multiple nested exceptions.
+    return static_cast< unsigned int >(std::uncaught_exception());
+#endif
+}
+
+} // namespace core
+
+} // namespace boost
+
+#undef BOOST_CORE_HAS_CXXABI_H
+#undef BOOST_CORE_HAS_CXA_GET_GLOBALS
+#undef BOOST_CORE_HAS_UNCAUGHT_EXCEPTIONS
+#undef BOOST_CORE_HAS_GETPTD
+
+#endif // BOOST_CORE_UNCAUGHT_EXCEPTIONS_HPP_INCLUDED_

test/Jamfile.v2

@@ -138,5 +138,8 @@ run test_lib_typeid.cpp lib_typeid : : : <link>static : test_lib_typeid_static ;
 run test_lib_typeid.cpp lib_typeid : : : <link>shared <rtti>off : test_lib_typeid_shared_no_rtti ;
 run test_lib_typeid.cpp lib_typeid : : : <link>static <rtti>off  : test_lib_typeid_static_no_rtti ;
 
+run uncaught_exceptions.cpp : : : <exception-handling>on ;
+run uncaught_exceptions_np.cpp : : : <exception-handling>on ;
+
 use-project /boost/core/swap : ./swap ;
 build-project ./swap ;

test/cmake_subdir_test/CMakeLists.txt

@@ -0,0 +1,19 @@
+# Copyright 2018, 2019 Peter Dimov
+# Distributed under the Boost Software License, Version 1.0.
+# See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt
+
+cmake_minimum_required(VERSION 3.5)
+
+project(cmake_subdir_test LANGUAGES CXX)
+
+add_subdirectory(../.. boostorg/core)
+add_subdirectory(../../../assert boostorg/assert)
+add_subdirectory(../../../config boostorg/config)
+
+add_executable(quick ../quick.cpp)
+target_link_libraries(quick Boost::core)
+
+enable_testing()
+add_test(quick quick)
+
+add_custom_target(check COMMAND ${CMAKE_CTEST_COMMAND} --output-on-failure -C $<CONFIG>)

test/swap/Jamfile.v2

@@ -16,6 +16,9 @@ local compile_tests =
     mixed_headers_2.cpp
     ;
 
+local compile_fail_tests =
+    const_wrapper_fail.cpp ;
+
 local run_tests =
     primitive.cpp
     specialized_in_boost.cpp
@@ -49,6 +52,12 @@ rule test_all
         all_rules += [ compile $(file) : : "swap-$(test_name)" ] ;
     }
 
+    for file in $(compile_fail_tests)
+    {
+        local test_name = [ MATCH "([^.]*).cpp$" : $(file) ] ;
+        all_rules += [ compile-fail $(file) : : "swap-$(test_name)" ] ;
+    }
+
     for file in $(run_tests)
     {
         local test_name = [ MATCH "([^.]*).cpp$" : $(file) ] ;

test/swap/const_wrapper_fail.cpp

@@ -0,0 +1,28 @@
+// Copyright 2018 Andrzej Krzemieński
+// Copyright 2018 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+
+#include <boost/core/swap.hpp>
+
+namespace boost
+{
+  
+template<class T> struct Wrapper
+{
+    T value;
+};
+
+template<class T> inline void swap( Wrapper<T> & w, Wrapper<T> & v )
+{
+    boost::swap( w, v );
+}
+  
+} // namespace boost
+ 
+int main()
+{
+    boost::Wrapper<int> const w = { 2 };
+    boost::Wrapper<int> const v = { 3 };
+
+    swap( w, v );
+}

test/uncaught_exceptions.cpp

@@ -0,0 +1,55 @@
+/*
+ *             Copyright Andrey Semashev 2018.
+ * Distributed under the Boost Software License, Version 1.0.
+ *    (See accompanying file LICENSE_1_0.txt or copy at
+ *          https://www.boost.org/LICENSE_1_0.txt)
+ */
+/*!
+ * \file   uncaught_exceptions.cpp
+ * \author Andrey Semashev
+ * \date   2018-11-10
+ *
+ * \brief  This file contains tests for the uncaught_exceptions function.
+ *
+ * This file only contains the very basic checks of functionality that can be portably achieved
+ * through C++03 std::uncaught_exception.
+ */
+
+#include <boost/core/uncaught_exceptions.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+struct my_exception {};
+
+class exception_watcher
+{
+    unsigned int& m_count;
+
+public:
+    explicit exception_watcher(unsigned int& count) : m_count(count) {}
+    ~exception_watcher() { m_count = boost::core::uncaught_exceptions(); }
+};
+
+// Tests for uncaught_exceptions when used in a destructor while an exception propagates
+void test_in_destructor()
+{
+    const unsigned int root_count = boost::core::uncaught_exceptions();
+
+    unsigned int level1_count = root_count;
+    try
+    {
+        exception_watcher watcher(level1_count);
+        throw my_exception();
+    }
+    catch (...)
+    {
+    }
+
+    BOOST_TEST_NE(root_count, level1_count);
+}
+
+int main()
+{
+    test_in_destructor();
+
+    return boost::report_errors();
+}

test/uncaught_exceptions_np.cpp

@@ -0,0 +1,90 @@
+/*
+ *             Copyright Andrey Semashev 2018.
+ * Distributed under the Boost Software License, Version 1.0.
+ *    (See accompanying file LICENSE_1_0.txt or copy at
+ *          https://www.boost.org/LICENSE_1_0.txt)
+ */
+/*!
+ * \file   uncaught_exceptions_np.cpp
+ * \author Andrey Semashev
+ * \date   2018-11-10
+ *
+ * \brief  This file contains tests for the uncaught_exceptions function.
+ *
+ * This file contains checks that are compiler specific and not quite portable or require C++17.
+ */
+
+#include <boost/core/uncaught_exceptions.hpp>
+
+#if !defined(BOOST_CORE_UNCAUGHT_EXCEPTIONS_EMULATED)
+
+#include <boost/core/lightweight_test.hpp>
+
+struct my_exception1 {};
+struct my_exception2 {};
+
+class exception_watcher2
+{
+    unsigned int& m_count;
+
+public:
+    explicit exception_watcher2(unsigned int& count) : m_count(count) {}
+    ~exception_watcher2() { m_count = boost::core::uncaught_exceptions(); }
+};
+
+class exception_watcher1
+{
+    unsigned int& m_count1;
+    unsigned int& m_count2;
+
+public:
+    exception_watcher1(unsigned int& count1, unsigned int& count2) : m_count1(count1), m_count2(count2) {}
+    ~exception_watcher1()
+    {
+        m_count1 = boost::core::uncaught_exceptions();
+        try
+        {
+            exception_watcher2 watcher2(m_count2);
+            throw my_exception2();
+        }
+        catch (...)
+        {
+        }
+    }
+};
+
+// Tests for uncaught_exceptions when used in nested destructors while an exception propagates
+void test_in_nested_destructors()
+{
+    const unsigned int root_count = boost::core::uncaught_exceptions();
+
+    unsigned int level1_count = root_count, level2_count = root_count;
+    try
+    {
+        exception_watcher1 watcher1(level1_count, level2_count);
+        throw my_exception1();
+    }
+    catch (...)
+    {
+    }
+
+    BOOST_TEST_NE(root_count, level1_count);
+    BOOST_TEST_NE(root_count, level2_count);
+    BOOST_TEST_NE(level1_count, level2_count);
+}
+
+int main()
+{
+    test_in_nested_destructors();
+
+    return boost::report_errors();
+}
+
+#else
+
+int main()
+{
+    return 0;
+}
+
+#endif