# Find the libunwind library
#
#  LIBUNWIND_FOUND       - True if libunwind was found.
#  LIBUNWIND_LIBRARIES   - The libraries needed to use libunwind
#  LIBUNWIND_INCLUDE_DIR - Location of unwind.h and libunwind.h

#  INPUT: LIBUNWIND_ROOT - path where include + lib of libunwind installation is located
 
FIND_PATH(LIBUNWIND_INCLUDE_DIR libunwind.h
          HINTS
          /usr/
          PATH_SUFFIXES include
          PATHS "${LIBUNWIND_ROOT}/include"
)
 
FIND_LIBRARY(LIBUNWIND_GENERIC_LIBRARY libunwind.a unwind
             HINTS
             /usr/
             PATH_SUFFIXES lib 
             PATHS "${LIBUNWIND_ROOT}/lib"
)

if (LIBUNWIND_INCLUDE_DIR) 
# nothing
if (LIBUNWIND_GENERIC_LIBRARY) 
  SET(LIBUNWIND_LIBRARIES ${LIBUNWIND_GENERIC_LIBRARY})

# For some reason, we have to link to two libunwind shared object files:
# one arch-specific and one not.
if (CMAKE_SYSTEM_PROCESSOR MATCHES "^arm")
    SET(LIBUNWIND_ARCH "arm")
elseif (CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64" OR CMAKE_SYSTEM_PROCESSOR STREQUAL "amd64")
    SET(LIBUNWIND_ARCH "x86_64")
elseif (CMAKE_SYSTEM_PROCESSOR MATCHES "^i.86$")
    SET(LIBUNWIND_ARCH "x86")
endif()

if (LIBUNWIND_ARCH)
    FIND_LIBRARY(LIBUNWIND_SPECIFIC_LIBRARY libunwind-${LIBUNWIND_ARCH}.a "unwind-${LIBUNWIND_ARCH}"
                 HINTS
                 /usr/
	         PATH_SUFFIXES lib
                 PATHS "${LIBUNWIND_ROOT}"
)
    if (NOT LIBUNWIND_SPECIFIC_LIBRARY)
        MESSAGE(FATAL_ERROR "failed to find unwind-${LIBUNWIND_ARCH}")
    endif ()
    SET(LIBUNWIND_LIBRARIES ${LIBUNWIND_LIBRARIES} ${LIBUNWIND_SPECIFIC_LIBRARY})
endif(LIBUNWIND_ARCH)

include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(libunwind DEFAULT_MSG LIBUNWIND_INCLUDE_DIR)

MARK_AS_ADVANCED(LIBUNWIND_LIBRARIES LIBUNWIND_INCLUDE_DIR)

else (LIBUNWIND_GENERIC_LIBRARY)
MESSAGE("-- Could NOT find Libunwind ")
endif (LIBUNWIND_GENERIC_LIBRARY)
else (LIBUNWIND_INCLUDE_DIR)
MESSAGE("-- Could NOT find libunwind.h")
endif (LIBUNWIND_INCLUDE_DIR)