better -ffast-math handling

issue #488

See also
http://public.kitware.com/pipermail/cmake/2015-April/060479.html

CMakeLists.txt

@@ -190,7 +190,7 @@ if(CMAKE_COMPILER_IS_GNUCC)
   # For all builds, make sure openjpeg is std99 compliant:
   # set(CMAKE_C_FLAGS "-Wall -std=c99 ${CMAKE_C_FLAGS}") # FIXME: this setting prevented us from setting a coverage build.
   # Do not use ffast-math for all build, it would produce incorrect results, only set for release:
-  set(CMAKE_C_FLAGS_RELEASE "-ffast-math ${CMAKE_C_FLAGS_RELEASE}")
+  SET(OPENJPEG_LIBRARY_COMPILE_OPTIONS ${OPENJPEG_LIBRARY_COMPILE_OPTIONS} "$<$<CONFIG:Release>:-ffast-math>")
 endif()
 
 #-----------------------------------------------------------------------------

src/lib/openjp2/CMakeLists.txt

@@ -85,6 +85,7 @@ if(UNIX)
   target_link_libraries(${OPENJPEG_LIBRARY_NAME} m)
 endif()
 set_target_properties(${OPENJPEG_LIBRARY_NAME} PROPERTIES ${OPENJPEG_LIBRARY_PROPERTIES})
+target_compile_options(${OPENJPEG_LIBRARY_NAME} PRIVATE ${OPENJPEG_LIBRARY_COMPILE_OPTIONS})
 
 # Install library
 install(TARGETS ${OPENJPEG_LIBRARY_NAME}

src/lib/openjp3d/CMakeLists.txt

@@ -27,6 +27,7 @@ if(UNIX)
   target_link_libraries(${OPENJP3D_LIBRARY_NAME} m)
 endif()
 set_target_properties(${OPENJP3D_LIBRARY_NAME} PROPERTIES ${OPENJPEG_LIBRARY_PROPERTIES})
+target_compile_options(${OPENJP3D_LIBRARY_NAME} PRIVATE ${OPENJPEG_LIBRARY_COMPILE_OPTIONS})
 
 # Install library
 install(TARGETS ${OPENJP3D_LIBRARY_NAME}

src/lib/openjpip/CMakeLists.txt

@@ -61,6 +61,7 @@ endif()
 add_library(openjpip ${OPENJPIP_SRCS} ${LOCAL_SRCS})
 set_target_properties(openjpip
   PROPERTIES ${OPENJPEG_LIBRARY_PROPERTIES})
+target_compile_options(openjpip PRIVATE ${OPENJPEG_LIBRARY_COMPILE_OPTIONS})
 target_link_libraries(openjpip ${OPENJPEG_LIBRARY_NAME})
 if(WIN32)
   # add Winsock on windows+mingw

src/lib/openjpwl/CMakeLists.txt

@@ -51,6 +51,7 @@ if(UNIX)
 endif()
 set_target_properties(openjpwl
   PROPERTIES ${OPENJPEG_LIBRARY_PROPERTIES})
+target_compile_options(openjpwl PRIVATE ${OPENJPEG_LIBRARY_COMPILE_OPTIONS})
 
 # Install library
 install(TARGETS openjpwl

src/lib/openmj2/CMakeLists.txt

@@ -46,6 +46,7 @@ if(UNIX)
   target_link_libraries(${OPENMJ2_LIBRARY_NAME} m)
 endif()
 set_target_properties(${OPENMJ2_LIBRARY_NAME} PROPERTIES ${OPENJPEG_LIBRARY_PROPERTIES})
+target_compile_options(${OPENJ2_LIBRARY_NAME} PRIVATE ${OPENJPEG_LIBRARY_COMPILE_OPTIONS})
 
 # Install library
 install(TARGETS ${OPENMJ2_LIBRARY_NAME}