Merge pull request #32 from gmbeard/multi-target-windows-api

Multi target windows api

CMakeLists.txt

@@ -15,6 +15,7 @@ else()
 endif()
 
 project(mio VERSION 1.0.0 LANGUAGES C CXX)
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/cmake")
 include (CTest)
 include (CMakeDependentOption)
 
@@ -40,22 +41,41 @@ CMAKE_DEPENDENT_OPTION(mio.tests
 # transitively to linking targets. In our case, this amounts to an include
 # directory and project header files.
 #
-add_library(mio INTERFACE)
+add_library(mio_base INTERFACE)
-add_library(mio::mio ALIAS mio)
 
 #
 # mio requires C++ 11 support, at a minimum. Setting the `cxx_std_11` compile
 # features ensures that the corresponding C++ standard flag is populated in
 # targets linking to mio
 #
-target_compile_features(mio INTERFACE cxx_std_11)
+target_compile_features(mio_base INTERFACE cxx_std_11)
+
+# 
+# On Windows, so as to be a "good citizen", mio offers two different 
+# targets that control the imported surface area of the Windows API. The 
+# default `mio` target sets the necessary flags for a minimal Win API 
+# (`WIN32_LEAN_AND_MEAN`, etc.), while the `mio_full_winapi` target sets 
+# none of these flags so will not disable any of the modules.
+# 
+if(WIN32)
+    include(WinApiLevels)
+else()
+    # On non-Windows systems, the `mio` and `mio_base` targets are 
+    # effectively identical.
+    add_library(mio INTERFACE)
+    target_link_libraries(mio
+        INTERFACE mio_base
+    )
+endif()
+
+add_library(mio::mio ALIAS mio)
 
 #
 # The include directory for mio can be expected to vary between build
 # and installaion. Here we use a CMake generator expression to dispatch
 # on how the configuration under which this library is being consumed.
 #
-target_include_directories(mio INTERFACE
+target_include_directories(mio_base INTERFACE
   $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/include>
   $<INSTALL_INTERFACE:include>)
 
@@ -84,7 +104,7 @@ install(DIRECTORY include/
 # generate a CMake configuration file for consumption by CMake's `find_package`
 # intrinsic
 #
-install(TARGETS mio EXPORT mioConfig)
+install(TARGETS mio_base mio EXPORT mioConfig)
 install(EXPORT mioConfig
   FILE mioConfig.cmake
   NAMESPACE mio::

README.md

@@ -285,6 +285,8 @@ find_package( mio REQUIRED )
 target_link_libraries( MyTarget PUBLIC mio::mio )
 ```
 
+**WINDOWS USERS**: The `mio::mio` target `#define`s `WIN32_LEAN_AND_MEAN` and `NOMINMAX`. The former ensures the imported surface area of the Win API is minimal, and the latter disables Windows' `min` and `max` macros so they don't intefere with `std::min` and `std::max`. Because *mio* is a header only library, these defintions will leak into downstream CMake builds. If their presence is causing problems with your build then you can use the alternative `mio::mio_full_winapi` target, which adds none of these defintions.
+
 If mio was installed to a non-conventional location, it may be necessary for downstream projects to specify the mio installation root directory via either
 
 + the `CMAKE_PREFIX_PATH` configuration option,

cmake/WinApiLevels.cmake

@@ -0,0 +1,14 @@
+add_library(mio_full_winapi INTERFACE)
+target_link_libraries(mio_full_winapi
+    INTERFACE mio_base
+)
+add_library(mio::mio_full_winapi ALIAS mio_full_winapi)
+
+add_library(mio INTERFACE)
+target_link_libraries(mio
+    INTERFACE mio_full_winapi
+)
+target_compile_definitions(mio
+    INTERFACE WIN32_LEAN_AND_MEAN NOMINMAX
+)
+install(TARGETS mio_full_winapi EXPORT mioConfig)

include/mio/CMakeLists.txt

@@ -3,7 +3,7 @@
 # doing so populates these files in the source listing when CMake is used
 # to generate XCode and Visual Studios projects
 #
-target_sources(mio INTERFACE
+target_sources(mio_base INTERFACE
   $<BUILD_INTERFACE:
     ${CMAKE_CURRENT_LIST_DIR}/mmap.hpp
     ${CMAKE_CURRENT_LIST_DIR}/page.hpp

include/mio/detail/CMakeLists.txt

@@ -3,7 +3,7 @@
 # detail files in the source listing for CMake-generated IDE projects
 #
 if(NOT subproject)
-  target_sources(mio INTERFACE
+  target_sources(mio_base INTERFACE
     $<BUILD_INTERFACE:
       ${CMAKE_CURRENT_LIST_DIR}/mmap.ipp
       ${CMAKE_CURRENT_LIST_DIR}/string_util.hpp>)

include/mio/page.hpp

@@ -22,9 +22,6 @@
 #define MIO_PAGE_HEADER
 
 #ifdef _WIN32
-# ifndef WIN32_LEAN_AND_MEAN
-#  define WIN32_LEAN_AND_MEAN
-# endif // WIN32_LEAN_AND_MEAN
 # include <windows.h>
 #else
 # include <unistd.h>

test/CMakeLists.txt

@@ -7,4 +7,9 @@ if(WIN32)
     target_link_libraries(mio.unicode.test PRIVATE mio::mio)
     target_compile_definitions(mio.unicode.test PRIVATE UNICODE)
     add_test(NAME mio.unicode.test COMMAND mio.test)
+
+    add_executable(mio.fullwinapi.test test.cpp)
+    target_link_libraries(mio.fullwinapi.test 
+        PRIVATE mio::mio_full_winapi)
+    add_test(NAME mio.fullwinapi.test COMMAND mio.test)
 endif()