Merge topic 'Threads-CXX'

fff9434d FindThreads: officially announce it works with only C++ enabled
66db914a FindThreads: fix printing a pointer value in test code
0b38424c FindThreads: make the call to try_run() work also if only C++ is enabled
9924a212 FindThreads: replace CheckIncludeFiles by CheckIncludeFile
a27bc0cc Check(Function|Library|Symbol)Exists: make it work if only C++ is enabled
7279f293 FindThreads: add simple testcase

Help/release/dev/Threads-CXX.rst

@@ -0,0 +1,6 @@
+Threads-CXX
+------------
+
+* The :module:`CheckFunctionExists`, :module:`CheckLibraryExists`,
+  :module:`CheckSymbolExists`, and :module:`FindThreads` modules learned to
+  work in environments where only CXX is enabled.

Modules/CheckForPthreads.c

@@ -31,7 +31,7 @@ void* runner(void* args)
   int cc;
   for ( cc = 0; cc < 10; cc ++ )
     {
-    printf("%d CC: %d\n", (int)args, cc);
+    printf("%p CC: %d\n", args, cc);
     }
   res ++;
   return 0;

Modules/CheckFunctionExists.c

@@ -1,5 +1,8 @@
 #ifdef CHECK_FUNCTION_EXISTS
 
+#ifdef __cplusplus
+extern "C"
+#endif
 char CHECK_FUNCTION_EXISTS();
 #ifdef __CLASSIC_C__
 int main(){

Modules/CheckFunctionExists.cmake

@@ -57,14 +57,26 @@ macro(CHECK_FUNCTION_EXISTS FUNCTION VARIABLE)
     else()
       set(CHECK_FUNCTION_EXISTS_ADD_INCLUDES)
     endif()
+
+    if(CMAKE_C_COMPILER_LOADED)
+      set(_cfe_source ${CMAKE_ROOT}/Modules/CheckFunctionExists.c)
+    elseif(CMAKE_CXX_COMPILER_LOADED)
+      set(_cfe_source ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CheckFunctionExists/CheckFunctionExists.cxx)
+      configure_file(${CMAKE_ROOT}/Modules/CheckFunctionExists.c "${_cfe_source}" COPYONLY)
+    else()
+      message(FATAL_ERROR "CHECK_FUNCTION_EXISTS needs either C or CXX language enabled")
+    endif()
+
     try_compile(${VARIABLE}
       ${CMAKE_BINARY_DIR}
-      ${CMAKE_ROOT}/Modules/CheckFunctionExists.c
+      ${_cfe_source}
       COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
       ${CHECK_FUNCTION_EXISTS_ADD_LIBRARIES}
       CMAKE_FLAGS -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_FUNCTION_DEFINITIONS}
       "${CHECK_FUNCTION_EXISTS_ADD_INCLUDES}"
       OUTPUT_VARIABLE OUTPUT)
+    unset(_cfe_source)
+
     if(${VARIABLE})
       set(${VARIABLE} 1 CACHE INTERNAL "Have function ${FUNCTION}")
       if(NOT CMAKE_REQUIRED_QUIET)

Modules/CheckLibraryExists.cmake

@@ -53,15 +53,26 @@ macro(CHECK_LIBRARY_EXISTS LIBRARY FUNCTION LOCATION VARIABLE)
       set(CHECK_LIBRARY_EXISTS_LIBRARIES
         ${CHECK_LIBRARY_EXISTS_LIBRARIES} ${CMAKE_REQUIRED_LIBRARIES})
     endif()
+
+    if(CMAKE_C_COMPILER_LOADED)
+      set(_cle_source ${CMAKE_ROOT}/Modules/CheckFunctionExists.c)
+    elseif(CMAKE_CXX_COMPILER_LOADED)
+      set(_cle_source ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CheckLibraryExists/CheckFunctionExists.cxx)
+      configure_file(${CMAKE_ROOT}/Modules/CheckFunctionExists.c "${_cle_source}" COPYONLY)
+    else()
+      message(FATAL_ERROR "CHECK_FUNCTION_EXISTS needs either C or CXX language enabled")
+    endif()
+
     try_compile(${VARIABLE}
       ${CMAKE_BINARY_DIR}
-      ${CMAKE_ROOT}/Modules/CheckFunctionExists.c
+      ${_cle_source}
       COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
       LINK_LIBRARIES ${CHECK_LIBRARY_EXISTS_LIBRARIES}
       CMAKE_FLAGS
       -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_LIBRARY_EXISTS_DEFINITION}
       -DLINK_DIRECTORIES:STRING=${LOCATION}
       OUTPUT_VARIABLE OUTPUT)
+    unset(_cle_source)
 
     if(${VARIABLE})
       if(NOT CMAKE_REQUIRED_QUIET)

Modules/CheckSymbolExists.cmake

@@ -44,10 +44,14 @@
 # (To distribute this file outside of CMake, substitute the full
 #  License text for the above reference.)
 
-
-
 macro(CHECK_SYMBOL_EXISTS SYMBOL FILES VARIABLE)
-  _CHECK_SYMBOL_EXISTS("${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckSymbolExists.c" "${SYMBOL}" "${FILES}" "${VARIABLE}" )
+  if(CMAKE_C_COMPILER_LOADED)
+    _CHECK_SYMBOL_EXISTS("${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckSymbolExists.c" "${SYMBOL}" "${FILES}" "${VARIABLE}" )
+  elseif(CMAKE_CXX_COMPILER_LOADED)
+    _CHECK_SYMBOL_EXISTS("${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckSymbolExists.cxx" "${SYMBOL}" "${FILES}" "${VARIABLE}" )
+  else()
+    message(FATAL_ERROR "CHECK_SYMBOL_EXISTS needs either C or CXX language enabled")
+  endif()
 endmacro()
 
 macro(_CHECK_SYMBOL_EXISTS SOURCEFILE SYMBOL FILES VARIABLE)

Modules/FindThreads.cmake

@@ -39,7 +39,7 @@
 
 #=============================================================================
 # Copyright 2002-2009 Kitware, Inc.
-# Copyright 2011-2014 Rolf Eike Beer <eike@sf-mail.de>
+# Copyright 2011-2015 Rolf Eike Beer <eike@sf-mail.de>
 #
 # Distributed under the OSI-approved BSD License (the "License");
 # see accompanying file Copyright.txt for details.
@@ -51,15 +51,23 @@
 # (To distribute this file outside of CMake, substitute the full
 #  License text for the above reference.)
 
-include (CheckIncludeFiles)
 include (CheckLibraryExists)
 include (CheckSymbolExists)
 set(Threads_FOUND FALSE)
 set(CMAKE_REQUIRED_QUIET_SAVE ${CMAKE_REQUIRED_QUIET})
 set(CMAKE_REQUIRED_QUIET ${Threads_FIND_QUIETLY})
 
+if(CMAKE_C_COMPILER_LOADED)
+  include (CheckIncludeFile)
+elseif(CMAKE_CXX_COMPILER_LOADED)
+  include (CheckIncludeFileCXX)
+else()
+  message(FATAL_ERROR "FindThreads only works if either C or CXX language is enabled")
+endif()
+
 # Do we have sproc?
 if(CMAKE_SYSTEM_NAME MATCHES IRIX AND NOT CMAKE_THREAD_PREFER_PTHREAD)
+  include (CheckIncludeFiles)
   CHECK_INCLUDE_FILES("sys/types.h;sys/prctl.h"  CMAKE_HAVE_SPROC_H)
 endif()
 
@@ -83,11 +91,18 @@ macro(_check_pthreads_flag)
     # If we did not found -lpthread, -lpthread, or -lthread, look for -pthread
     if(NOT DEFINED THREADS_HAVE_PTHREAD_ARG)
       message(STATUS "Check if compiler accepts -pthread")
+      if(CMAKE_C_COMPILER_LOADED)
+        set(_threads_src ${CMAKE_CURRENT_LIST_DIR}/CheckForPthreads.c)
+      elseif(CMAKE_CXX_COMPILER_LOADED)
+        set(_threads_src ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/FindThreads/CheckForPthreads.cxx)
+        configure_file(${CMAKE_CURRENT_LIST_DIR}/CheckForPthreads.c "${_threads_src}" COPYONLY)
+      endif()
       try_run(THREADS_PTHREAD_ARG THREADS_HAVE_PTHREAD_ARG
         ${CMAKE_BINARY_DIR}
-        ${CMAKE_CURRENT_LIST_DIR}/CheckForPthreads.c
+        ${_threads_src}
         CMAKE_FLAGS -DLINK_LIBRARIES:STRING=-pthread
         COMPILE_OUTPUT_VARIABLE OUTPUT)
+      unset(_threads_src)
 
       if(THREADS_HAVE_PTHREAD_ARG)
         if(THREADS_PTHREAD_ARG STREQUAL "2")
@@ -120,7 +135,11 @@ if(CMAKE_HAVE_SPROC_H AND NOT CMAKE_THREAD_PREFER_PTHREAD)
   set(CMAKE_USE_SPROC_INIT 1)
 else()
   # Do we have pthreads?
-  CHECK_INCLUDE_FILES("pthread.h" CMAKE_HAVE_PTHREAD_H)
+  if(CMAKE_C_COMPILER_LOADED)
+    CHECK_INCLUDE_FILE("pthread.h" CMAKE_HAVE_PTHREAD_H)
+  else()
+    CHECK_INCLUDE_FILE_CXX("pthread.h" CMAKE_HAVE_PTHREAD_H)
+  endif()
   if(CMAKE_HAVE_PTHREAD_H)
 
     #

Tests/CMakeLists.txt

@@ -1365,6 +1365,8 @@ ${CMake_BINARY_DIR}/bin/cmake -DDIR=dev -P ${CMake_SOURCE_DIR}/Utilities/Release
     add_subdirectory(FindOpenSSL)
   endif()
 
+  add_subdirectory(FindThreads)
+
   # Matlab module
   if(CMake_TEST_FindMatlab)
     ADD_TEST_MACRO(FindMatlab.basic_checks      ${CMAKE_CTEST_COMMAND} -C $<CONFIGURATION>)

Tests/FindThreads/C-only/CMakeLists.txt

@@ -0,0 +1,10 @@
+cmake_minimum_required(VERSION 3.3 FATAL_ERROR)
+project(FindThreads_C-only C)
+
+set(CMAKE_THREAD_PREFER_PTHREAD On)
+find_package(Threads REQUIRED)
+
+if (NOT WIN32)
+  add_executable(thr ${CMAKE_CURRENT_SOURCE_DIR}/../../../Modules/CheckForPthreads.c)
+  target_link_libraries(thr Threads::Threads)
+endif ()

Tests/FindThreads/CMakeLists.txt

@@ -0,0 +1,11 @@
+foreach (_lang IN ITEMS C CXX)
+  add_test(NAME FindThreads.${_lang}-only COMMAND ${CMAKE_CTEST_COMMAND}
+    --build-and-test
+    "${CMake_SOURCE_DIR}/Tests/FindThreads/${_lang}-only"
+    "${CMake_BINARY_DIR}/Tests/FindThreads/${_lang}-only"
+    ${build_generator_args}
+    --build-project FindThreads_${_lang}-only
+    --build-options ${build_options}
+    --test-command ${CMAKE_CTEST_COMMAND} -V
+    )
+endforeach ()

Tests/FindThreads/CXX-only/CMakeLists.txt

@@ -0,0 +1,13 @@
+cmake_minimum_required(VERSION 3.3 FATAL_ERROR)
+project(FindThreads_CXX-only CXX)
+
+set(CMAKE_THREAD_PREFER_PTHREAD On)
+find_package(Threads REQUIRED)
+
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/../../../Modules/CheckForPthreads.c
+               ${CMAKE_CURRENT_BINARY_DIR}/CheckForPthreads.cxx)
+
+if (NOT WIN32)
+  add_executable(thr ${CMAKE_CURRENT_BINARY_DIR}/CheckForPthreads.cxx)
+  target_link_libraries(thr Threads::Threads)
+endif ()