Cleanup CMake build a bit

1. Add checks for Unix/Linux-specific header files (similar to
configure.ac)

2. Added a check for the `-std=c99` flag. It appears that some of this
code uses C99 and compiling without this flag produces quite a few
warnings.

Signed-off-by: Michael Steinert <mike.steinert@gmail.com>

2 files changed, 163 insertions, 0 deletions

diff --git a/cmake/CheckCCompilerFlag.cmake b/cmake/CheckCCompilerFlag.cmake
new file mode 100644
index 0000000..3fba297
--- /dev/null
+++ b/cmake/CheckCCompilerFlag.cmake
@@ -0,0 +1,62 @@
+# - Check whether the C compiler supports a given flag.
+# CHECK_C_COMPILER_FLAG(<flag> <var>)
+#  <flag> - the compiler flag
+#  <var>  - variable to store the result
+# This internally calls the check_c_source_compiles macro.
+# See help for CheckCSourceCompiles for a listing of variables
+# that can modify the build.
+
+#=============================================================================
+# Copyright 2006-2011 Kitware, Inc.
+# Copyright 2006 Alexander Neundorf <neundorf@kde.org>
+# Copyright 2011 Matthias Kretz <kretz@kde.org>
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# * Redistributions of source code must retain the above copyright
+#   notice, this list of conditions and the following disclaimer.
+#
+# * Redistributions in binary form must reproduce the above copyright
+#   notice, this list of conditions and the following disclaimer in the
+#   documentation and/or other materials provided with the distribution.
+#
+# * Neither the names of Kitware, Inc., the Insight Software Consortium,
+#   nor the names of their contributors may be used to endorse or promote
+#   products derived from this software without specific prior written
+#   permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#=============================================================================
+
+INCLUDE(CheckCSourceCompiles)
+
+MACRO (CHECK_C_COMPILER_FLAG _FLAG _RESULT)
+   SET(SAFE_CMAKE_REQUIRED_DEFINITIONS "${CMAKE_REQUIRED_DEFINITIONS}")
+   SET(CMAKE_REQUIRED_DEFINITIONS "${_FLAG}")
+   CHECK_C_SOURCE_COMPILES("int main(void) { return 0; }" ${_RESULT}
+     # Some compilers do not fail with a bad flag
+     FAIL_REGEX "command line option .* is valid for .* but not for C" # GNU
+     FAIL_REGEX "unrecognized .*option"                     # GNU
+     FAIL_REGEX "unknown .*option"                          # Clang
+     FAIL_REGEX "ignoring unknown option"                   # MSVC
+     FAIL_REGEX "warning D9002"                             # MSVC, any lang
+     FAIL_REGEX "option .*not supported"                    # Intel
+     FAIL_REGEX "[Uu]nknown option"                         # HP
+     FAIL_REGEX "[Ww]arning: [Oo]ption"                     # SunPro
+     FAIL_REGEX "command option .* is not recognized"       # XL
+     FAIL_REGEX "WARNING: unknown flag:"                    # Open64
+     )
+   SET (CMAKE_REQUIRED_DEFINITIONS "${SAFE_CMAKE_REQUIRED_DEFINITIONS}")
+ENDMACRO (CHECK_C_COMPILER_FLAG)
diff --git a/cmake/CheckIncludeFiles.cmake b/cmake/CheckIncludeFiles.cmake
new file mode 100644
index 0000000..0420951
--- /dev/null
+++ b/cmake/CheckIncludeFiles.cmake
@@ -0,0 +1,101 @@
+# - Check if the files can be included
+#
+# CHECK_INCLUDE_FILES(INCLUDE VARIABLE)
+#
+#  INCLUDE  - list of files to include
+#  VARIABLE - variable to return result
+#
+# The following variables may be set before calling this macro to
+# modify the way the check is run:
+#
+#  CMAKE_REQUIRED_FLAGS = string of compile command line flags
+#  CMAKE_REQUIRED_DEFINITIONS = list of macros to define (-DFOO=bar)
+#  CMAKE_REQUIRED_INCLUDES = list of include directories
+
+#=============================================================================
+# Copyright 2003-2012 Kitware, Inc.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# * Redistributions of source code must retain the above copyright
+#   notice, this list of conditions and the following disclaimer.
+#
+# * Redistributions in binary form must reproduce the above copyright
+#   notice, this list of conditions and the following disclaimer in the
+#   documentation and/or other materials provided with the distribution.
+#
+# * Neither the names of Kitware, Inc., the Insight Software Consortium,
+#   nor the names of their contributors may be used to endorse or promote
+#   products derived from this software without specific prior written
+#   permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#=============================================================================
+
+MACRO(CHECK_INCLUDE_FILES INCLUDE VARIABLE)
+  IF("${VARIABLE}" MATCHES "^${VARIABLE}$")
+    SET(CMAKE_CONFIGURABLE_FILE_CONTENT "/* */\n")
+    IF(CMAKE_REQUIRED_INCLUDES)
+      SET(CHECK_INCLUDE_FILES_INCLUDE_DIRS "-DINCLUDE_DIRECTORIES=${CMAKE_REQUIRED_INCLUDES}")
+    ELSE(CMAKE_REQUIRED_INCLUDES)
+      SET(CHECK_INCLUDE_FILES_INCLUDE_DIRS)
+    ENDIF(CMAKE_REQUIRED_INCLUDES)
+    SET(CHECK_INCLUDE_FILES_CONTENT "/* */\n")
+    SET(MACRO_CHECK_INCLUDE_FILES_FLAGS ${CMAKE_REQUIRED_FLAGS})
+    FOREACH(FILE ${INCLUDE})
+      SET(CMAKE_CONFIGURABLE_FILE_CONTENT
+        "${CMAKE_CONFIGURABLE_FILE_CONTENT}#include <${FILE}>\n")
+    ENDFOREACH(FILE)
+    SET(CMAKE_CONFIGURABLE_FILE_CONTENT
+      "${CMAKE_CONFIGURABLE_FILE_CONTENT}\n\nint main(){return 0;}\n")
+    CONFIGURE_FILE("${CMAKE_ROOT}/Modules/CMakeConfigurableFile.in"
+      "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckIncludeFiles.c" @ONLY IMMEDIATE)
+
+    SET(_INCLUDE ${INCLUDE}) # remove empty elements
+    IF("${_INCLUDE}" MATCHES "^([^;]+);.+;([^;]+)$")
+      LIST(LENGTH _INCLUDE _INCLUDE_LEN)
+      SET(_description "${_INCLUDE_LEN} include files ${CMAKE_MATCH_1}, ..., ${CMAKE_MATCH_2}")
+    ELSEIF("${_INCLUDE}" MATCHES "^([^;]+);([^;]+)$")
+      SET(_description "include files ${CMAKE_MATCH_1}, ${CMAKE_MATCH_2}")
+    ELSE()
+      SET(_description "include file ${_INCLUDE}")
+    ENDIF()
+
+    MESSAGE(STATUS "Looking for ${_description}")
+    TRY_COMPILE(${VARIABLE}
+      ${CMAKE_BINARY_DIR}
+      ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckIncludeFiles.c
+      COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
+      CMAKE_FLAGS
+      -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_INCLUDE_FILES_FLAGS}
+      "${CHECK_INCLUDE_FILES_INCLUDE_DIRS}"
+      OUTPUT_VARIABLE OUTPUT)
+    IF(${VARIABLE})
+      MESSAGE(STATUS "Looking for ${_description} - found")
+      SET(${VARIABLE} 1 CACHE INTERNAL "Have include ${INCLUDE}")
+      FILE(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
+        "Determining if files ${INCLUDE} "
+        "exist passed with the following output:\n"
+        "${OUTPUT}\n\n")
+    ELSE(${VARIABLE})
+      MESSAGE(STATUS "Looking for ${_description} - not found.")
+      SET(${VARIABLE} "" CACHE INTERNAL "Have includes ${INCLUDE}")
+      FILE(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
+        "Determining if files ${INCLUDE} "
+        "exist failed with the following output:\n"
+        "${OUTPUT}\nSource:\n${CMAKE_CONFIGURABLE_FILE_CONTENT}\n")
+    ENDIF(${VARIABLE})
+  ENDIF("${VARIABLE}" MATCHES "^${VARIABLE}$")
+ENDMACRO(CHECK_INCLUDE_FILES)