# This file can be included after at least one language is enabled, but before all of them are.
# It sets up all of the CMake options that affect compiler flags.

# Set up options which affect compiler flags.
#------------------------------------------------------------------------------------------

#Dragonegg option
set(DRAGONEGG "" CACHE PATH "Path to the the Dragonegg gcc to LLVM bridge. Set to empty string to disable.  If specified, it will be applied to any GCC compilers in use (gcc, g++, and gfortran).")

 # Check dragonegg
if(DRAGONEGG)
	if(NOT EXISTS ${DRAGONEGG})
		message(FATAL_ERROR "Dragonegg enabled, but the Dragonegg path ${DRAGONEGG} does not point to a file.")    
    endif()
endif()

#shared vs static option
option(STATIC "If true, build static libraries and freestanding (except for data files) executables. Otherwise, compile common code into shared libraries and link them to programs. \
The runtime path is set properly now, so unless you move the installation AND don't source amber.sh you won't have to mess with LD_LIBRARY PATH" FALSE)

if(STATIC)
	set(SHARED FALSE)
else()
	set(SHARED TRUE)
endif()	


option(LARGE_FILE_SUPPORT "Build C code with large file support.  Always on when building for a 64 bit target." TRUE)

# FFT support 
option(USE_FFT "Whether to use the Fastest Fourier Transform in the West library and build RISM and the PBSA FFT solver." TRUE)

#set default library type appropriately
set(BUILD_SHARED_LIBS ${SHARED})

# NOTE: The correct way to handle optimization is to use generator expressions based on the current configuration.
# However, sometimes I need to use set_property(SOURCE PROPERTY COMPILE_FLAGS) to set compile flags for individual source files.
# This property didn't support generator expressions until CMake 3.8. Grrrrr.
# So, we use CMAKE_<LANG>_FLAGS_DEBUG for per-config debugging flags, but use a separate optimization switch.
option(OPTIMIZE "Whether to build code with compiler flags for optimization." TRUE)

option(UNUSED_WARNINGS "Enable warnings about unused variables.  Really clutters up the build output." FALSE)
option(UNINITIALIZED_WARNINGS "Enable warnings about uninitialized variables.  Kind of clutters up the build output, but these need to be fixed." TRUE)

option(DOUBLE_PRECISION "Build Amber's Fortran programs with double precision math." TRUE)


#let's try to enforce a reasonable standard here
set(CMAKE_C_STANDARD 99)
set(CMAKE_CXX_STANDARD 11)

# I can't think of any better place to put this...

#------------------------------------------------------------------------------
#  Now that we have our compiler, detect target architecture.
#  This is kind of a hack, but it works.
#  See TargetArch.cmake (from https://github.com/axr/solar-cmake) for details.  
#------------------------------------------------------------------------------
target_architecture(TARGET_ARCH)

if("${TARGET_ARCH}" STREQUAL unknown OR "${TARGET_ARCH}" STREQUAL "")
	message(FATAL_ERROR "Could not detect target architecture from compiler.  Does the compiler work?")
endif()   


#initialize SSE based on TARGET_ARCH
list_contains(SSE_SUPPORTED ${TARGET_ARCH} x86_64 ia64 i386)
set(SSE ${SSE_SUPPORTED} CACHE BOOL "Optimize for the SSE family of vectorizations.")
set(SSE_TYPES "" CACHE STRING "CPU types for which auto-dispatch code will be produced (Intel compilers version 11 and higher). Known valid
	options are SSE2, SSE3, SSSE3, SSE4.1 and SSE4.2. Multiple options (comma separated) are permitted.")

# Figure out no-undefined flag
if(${CMAKE_SYSTEM_NAME} STREQUAL Darwin)
	set(NO_UNDEFINED_FLAG "-Wl,-undefined,error")
elseif((${CMAKE_SYSTEM_NAME} STREQUAL Linux) OR MINGW)
	set(NO_UNDEFINED_FLAG "-Wl,--no-undefined")
else()
	set(NO_UNDEFINED_FLAG "")
endif()


#-------------------------------------------------------------------------------
# Set up a couple of convenience variables to make checking the target OS less verbose
#-------------------------------------------------------------------------------
test(TARGET_OSX "${CMAKE_SYSTEM_NAME}" STREQUAL Darwin)
test(TARGET_WINDOWS "${CMAKE_SYSTEM_NAME}" STREQUAL Windows)
test(TARGET_LINUX "${CMAKE_SYSTEM_NAME}" STREQUAL Linux OR "${CMAKE_SYSTEM_NAME}" STREQUAL Android) # Android is close enough to Linux for our purposes

test(HOST_OSX "${CMAKE_HOST_SYSTEM_NAME}" STREQUAL Darwin)
test(HOST_WINDOWS "${CMAKE_HOST_SYSTEM_NAME}" STREQUAL Windows)
test(HOST_LINUX "${CMAKE_HOST_SYSTEM_NAME}" STREQUAL Linux OR "${CMAKE_HOST_SYSTEM_NAME}" STREQUAL Android)

# --------------------------------------------------------------------
# Determine if we are mixing different vendors' compilers
# --------------------------------------------------------------------
set(MIXING_COMPILERS TRUE)
if(("${CMAKE_C_COMPILER_ID}" STREQUAL "" OR "${CMAKE_CXX_COMPILER_ID}" STREQUAL "") OR "${CMAKE_C_COMPILER_ID}" STREQUAL "${CMAKE_CXX_COMPILER_ID}")
	if(("${CMAKE_CXX_COMPILER_ID}" STREQUAL "" OR "${CMAKE_Fortran_COMPILER_ID}" STREQUAL "") OR "${CMAKE_CXX_COMPILER_ID}" STREQUAL "${CMAKE_Fortran_COMPILER_ID}")
		set(MIXING_COMPILERS FALSE)
	endif()
endif()

# --------------------------------------------------------------------
# Find all enabled languages
# --------------------------------------------------------------------
get_property(ALL_ENABLED_LANGUAGES GLOBAL PROPERTY ENABLED_LANGUAGES)

set(ENABLED_LANGUAGES "")
# filter out ancillary languages (RC, NONE, etc.)
foreach(LANG ${ALL_ENABLED_LANGUAGES})
	if("${LANG}" STREQUAL "C" OR "${LANG}" STREQUAL "CXX" OR "${LANG}" STREQUAL "Fortran")
		list(APPEND ENABLED_LANGUAGES ${LANG})
	endif()
endforeach()

# --------------------------------------------------------------------
# Minor bug fixes
# --------------------------------------------------------------------

# on MinGW there's a weird compatibility issue where FindBoost expects CMake to set a variable that it doesn't actually set
# so we have to help it out a bit

if(CMAKE_SIZEOF_VOID_P EQUAL 8)
	set(CMAKE_CXX_COMPILER_ARCHITECTURE_ID x64)
else()
	set(CMAKE_CXX_COMPILER_ARCHITECTURE_ID X86)
endif()

# For some reason, CMake isn't able to detect the implicit link dirs from PGI and doesn't see libraries in architecture dirs on Linux.
# This is ultimately a best-effort guess but should work for the common case. 
if("${CMAKE_C_COMPILER_ID}" STREQUAL "PGI" AND HOST_LINUX AND "${TARGET_ARCH}" STREQUAL "x86_64")

	list(APPEND CMAKE_INCLUDE_PATH /usr/include/x86_64-linux-gnu)
	list(APPEND CMAKE_LIBRARY_PATH /usr/lib/x86_64-linux-gnu)

endif()