1# - Check if _FILE_OFFSET_BITS macro needed for large files
2# CHECK_FILE_OFFSET_BITS ()
3#
4# The following variables may be set before calling this macro to
5# modify the way the check is run:
6#
7#  CMAKE_REQUIRED_FLAGS = string of compile command line flags
8#  CMAKE_REQUIRED_DEFINITIONS = list of macros to define (-DFOO=bar)
9#  CMAKE_REQUIRED_INCLUDES = list of include directories
10# Copyright (c) 2009, Michihiro NAKAJIMA
11#
12# Redistribution and use is allowed according to the terms of the BSD license.
13# For details see the accompanying COPYING-CMAKE-SCRIPTS file.
14
15#INCLUDE(CheckCSourceCompiles)
16
17GET_FILENAME_COMPONENT(_selfdir_CheckFileOffsetBits
18	 "${CMAKE_CURRENT_LIST_FILE}" PATH)
19
20MACRO (CHECK_FILE_OFFSET_BITS)
21  IF(NOT DEFINED _FILE_OFFSET_BITS)
22    MESSAGE(STATUS "Cheking _FILE_OFFSET_BITS for large files")
23    TRY_COMPILE(__WITHOUT_FILE_OFFSET_BITS_64
24      ${CMAKE_CURRENT_BINARY_DIR}
25      ${_selfdir_CheckFileOffsetBits}/CheckFileOffsetBits.c
26      COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS})
27    IF(NOT __WITHOUT_FILE_OFFSET_BITS_64)
28      TRY_COMPILE(__WITH_FILE_OFFSET_BITS_64
29        ${CMAKE_CURRENT_BINARY_DIR}
30        ${_selfdir_CheckFileOffsetBits}/CheckFileOffsetBits.c
31        COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS} -D_FILE_OFFSET_BITS=64)
32    ENDIF(NOT __WITHOUT_FILE_OFFSET_BITS_64)
33
34    IF(NOT __WITHOUT_FILE_OFFSET_BITS_64 AND __WITH_FILE_OFFSET_BITS_64)
35      SET(_FILE_OFFSET_BITS 64 CACHE INTERNAL "_FILE_OFFSET_BITS macro needed for large files")
36      MESSAGE(STATUS "Cheking _FILE_OFFSET_BITS for large files - needed")
37    ELSE(NOT __WITHOUT_FILE_OFFSET_BITS_64 AND __WITH_FILE_OFFSET_BITS_64)
38      SET(_FILE_OFFSET_BITS "" CACHE INTERNAL "_FILE_OFFSET_BITS macro needed for large files")
39      MESSAGE(STATUS "Cheking _FILE_OFFSET_BITS for large files - not needed")
40    ENDIF(NOT __WITHOUT_FILE_OFFSET_BITS_64 AND __WITH_FILE_OFFSET_BITS_64)
41  ENDIF(NOT DEFINED _FILE_OFFSET_BITS)
42
43ENDMACRO (CHECK_FILE_OFFSET_BITS)
44