Remove use of _alloca

... to express their dependency on this library and retrieve any
configuration information such as the include directory, binary
to link to (if any), transitive dependencies, necessary compiler
options or the required c++ standards level.

.travis.yml

@@ -1,4 +1,4 @@
-# Copyright 2016, 2017, 2018 Peter Dimov
+# Copyright 2016-2019 Peter Dimov
 # Distributed under the Boost Software License, Version 1.0.
 # (See accompanying file LICENSE_1_0.txt or copy at http://boost.org/LICENSE_1_0.txt)
 
@@ -6,8 +6,6 @@ language: cpp
 
 sudo: false
 
-python: "2.7"
-
 branches:
   only:
     - master
@@ -109,7 +107,7 @@ matrix:
 
     - os: linux
       compiler: g++-8
-      env: TOOLSET=gcc COMPILER=g++-8 CXXSTD=03,11,14,17
+      env: TOOLSET=gcc COMPILER=g++-8 CXXSTD=03,11,14,17,2a
       addons:
         apt:
           packages:
@@ -320,6 +318,17 @@ matrix:
             - ubuntu-toolchain-r-test
             - llvm-toolchain-trusty-6.0
 
+    - os: linux
+      compiler: clang++-7
+      env: TOOLSET=clang COMPILER=clang++-7 CXXSTD=03,11,14,17,2a
+      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
@@ -352,13 +361,20 @@ matrix:
       compiler: clang++
       env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z
 
+    - os: linux
+      compiler: g++
+      env: CMAKE_SUBDIR_TEST=1
+      script:
+      - cd libs/system/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
   - cd ..
   - git clone -b $BOOST_BRANCH --depth 1 https://github.com/boostorg/boost.git boost-root
   - cd boost-root
-  - git submodule update --init tools/build
-  - git submodule update --init libs/config
   - git submodule update --init tools/boostdep
   - cp -r $TRAVIS_BUILD_DIR/* libs/system
   - python tools/boostdep/depinst/depinst.py system

CMakeLists.txt

@@ -0,0 +1,20 @@
+# Copyright 2018 Mike Dev
+# 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
+
+# Partial (add_subdirectory only) and experimental CMake support
+# Subject to change; please do not rely on the contents of this file yet
+
+cmake_minimum_required(VERSION 3.5)
+project(BoostSystem LANGUAGES CXX)
+
+add_library(boost_system INTERFACE)
+add_library(Boost::system ALIAS boost_system)
+
+target_include_directories(boost_system INTERFACE include)
+
+target_link_libraries(boost_system
+    INTERFACE
+        Boost::config
+        Boost::winapi
+)

appveyor.yml

@@ -46,10 +46,8 @@ install:
   - cd ..
   - git clone -b %BOOST_BRANCH% --depth 1 https://github.com/boostorg/boost.git boost-root
   - cd boost-root
-  - git submodule update --init tools/build
-  - git submodule update --init libs/config
   - git submodule update --init tools/boostdep
-  - xcopy /s /e /q %APPVEYOR_BUILD_FOLDER% libs\system
+  - xcopy /s /e /q %APPVEYOR_BUILD_FOLDER% libs\system\
   - python tools/boostdep/depinst/depinst.py system
   - cmd /c bootstrap
   - b2 -d0 headers

include/boost/system/detail/system_category_win32.hpp

@@ -81,37 +81,54 @@ inline char const * system_category_message_win32( int ev, char * buffer, std::s
         return buffer;
     }
 
-#if defined(__GNUC__)
-# define BOOST_SYSTEM_ALLOCA __builtin_alloca
-#else
-# define BOOST_SYSTEM_ALLOCA _alloca
+    boost::winapi::UINT_ const code_page = message_cp_win32();
+
+    int r = 0;
+
+#if !defined(BOOST_NO_ANSI_APIS)
+
+    if( code_page == boost::winapi::CP_ACP_ )
+    {
+        using namespace boost::winapi;
+
+        DWORD_ retval = boost::winapi::FormatMessageA(
+            FORMAT_MESSAGE_FROM_SYSTEM_ | FORMAT_MESSAGE_IGNORE_INSERTS_,
+            NULL,
+            ev,
+            MAKELANGID_( LANG_NEUTRAL_, SUBLANG_DEFAULT_ ), // Default language
+            buffer,
+            static_cast<DWORD_>( len ),
+            NULL
+        );
+
+        r = static_cast<int>( retval );
+    }
+    else
+
 #endif
 
-    wchar_t * wbuffer = static_cast<wchar_t*>( BOOST_SYSTEM_ALLOCA( len * sizeof( wchar_t ) ) );
-
-#undef BOOST_SYSTEM_ALLOCA
-
-    using namespace boost::winapi;
-
-    DWORD_ retval = boost::winapi::FormatMessageW(
-        FORMAT_MESSAGE_FROM_SYSTEM_ | FORMAT_MESSAGE_IGNORE_INSERTS_,
-        NULL,
-        ev,
-        MAKELANGID_( LANG_NEUTRAL_, SUBLANG_DEFAULT_ ), // Default language
-        wbuffer,
-        static_cast<DWORD_>( len ),
-        NULL
-    );
-
-    if( retval == 0 )
     {
-        return unknown_message_win32( ev, buffer, len );
+        using namespace boost::winapi;
+
+        wchar_t * lpMsgBuf = 0;
+
+        DWORD_ retval = boost::winapi::FormatMessageW(
+            FORMAT_MESSAGE_ALLOCATE_BUFFER_ | FORMAT_MESSAGE_FROM_SYSTEM_ | FORMAT_MESSAGE_IGNORE_INSERTS_,
+            NULL,
+            ev,
+            MAKELANGID_( LANG_NEUTRAL_, SUBLANG_DEFAULT_ ), // Default language
+            (LPWSTR_) &lpMsgBuf,
+            0,
+            NULL
+        );
+
+        if( retval != 0 )
+        {
+            r = boost::winapi::WideCharToMultiByte( code_page, 0, lpMsgBuf, -1, buffer, static_cast<int>( len ), NULL, NULL );
+            boost::winapi::LocalFree( lpMsgBuf );
+        }
     }
 
-    UINT_ const code_page = message_cp_win32();
-
-    int r = boost::winapi::WideCharToMultiByte( code_page, 0, wbuffer, -1, buffer, static_cast<int>( len ), NULL, NULL );
-
     if( r == 0 )
     {
         return unknown_message_win32( ev, buffer, len );

test/Jamfile.v2

@@ -108,6 +108,10 @@ system-run initialization_test.cpp ;
 
 run header_only_test.cpp : : : -<library>/boost/system//boost_system ;
 run header_only_test.cpp : : : -<library>/boost/system//boost_system <define>BOOST_NO_ANSI_APIS : header_only_test_no_ansi ;
+run header_only_test.cpp : : : -<library>/boost/system//boost_system <define>BOOST_SYSTEM_USE_UTF8 : header_only_test_utf8 ;
+
+run error_code_test.cpp : : : -<library>/boost/system//boost_system <define>BOOST_ERROR_CODE_HEADER_ONLY <define>BOOST_NO_ANSI_APIS : error_code_test_no_ansi ;
+run error_code_test.cpp : : : -<library>/boost/system//boost_system <define>BOOST_ERROR_CODE_HEADER_ONLY <define>BOOST_SYSTEM_USE_UTF8 : error_code_test_utf8 ;
 
 run config_test.cpp : : : <test-info>always_show_run_output ;
 

test/cmake_subdir_test/CMakeLists.txt

@@ -0,0 +1,22 @@
+# 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/system)
+add_subdirectory(../../../assert boostorg/assert)
+add_subdirectory(../../../config boostorg/config)
+add_subdirectory(../../../core boostorg/core)
+add_subdirectory(../../../predef boostorg/predef)
+add_subdirectory(../../../winapi boostorg/winapi)
+
+add_executable(quick ../quick.cpp)
+target_link_libraries(quick Boost::system Boost::core)
+
+enable_testing()
+add_test(quick quick)
+
+add_custom_target(check COMMAND ${CMAKE_CTEST_COMMAND} --output-on-failure -C $<CONFIG>)