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authorJulian Andres Klode <jak@debian.org>2016-08-20 03:22:24 +0200
committerJulian Andres Klode <jak@debian.org>2016-08-23 17:46:41 +0200
commit3fbd67460e1c4c38a79d00f09bf3113a39abbeca (patch)
tree1994b25c9bdd97659f4bee681207069d049c9887 /CMake/FindLFS.cmake
parent0919f1df552ddf022ce4508cbf40e04eae5ef896 (diff)
CMake: Add Large File Support
This module should cover all sorts of large file supports, as long as they either support the getconf LFS_CFLAGS command; or the _FILE_OFFSET_BITS=64 or _LARGE_FILES macros. Closes: #834767
Diffstat (limited to 'CMake/FindLFS.cmake')
-rw-r--r--CMake/FindLFS.cmake148
1 files changed, 148 insertions, 0 deletions
diff --git a/CMake/FindLFS.cmake b/CMake/FindLFS.cmake
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+++ b/CMake/FindLFS.cmake
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+# CMake support for large files
+#
+# Copyright (C) 2016 Julian Andres Klode <jak@debian.org>.
+#
+# Permission is hereby granted, free of charge, to any person
+# obtaining a copy of this software and associated documentation files
+# (the "Software"), to deal in the Software without restriction,
+# including without limitation the rights to use, copy, modify, merge,
+# publish, distribute, sublicense, and/or sell copies of the Software,
+# and to permit persons to whom the Software is furnished to do so,
+# subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+#
+# This defines the following variables
+#
+# LFS_DEFINITIONS - List of definitions to pass to add_definitions()
+# LFS_COMPILE_OPTIONS - List of definitions to pass to add_compile_options()
+# LFS_LIBRARIES - List of libraries and linker flags
+# LFS_FOUND - If there is Large files support
+#
+
+include(CheckCXXSourceCompiles)
+include(FindPackageHandleStandardArgs)
+
+# Test program to check for LFS. Requires that off_t has at least 8 byte large
+set(_lfs_test_source
+ "
+ #include <sys/types.h>
+ typedef char my_static_assert[sizeof(off_t) >= 8 ? 1 : -1];
+ int main(void) { return 0; }
+ "
+)
+
+# Check if the given options are needed
+#
+# This appends to the variables _lfs_cppflags, _lfs_cflags, and _lfs_ldflags,
+# it also sets LFS_FOUND to 1 if it works.
+function(_lfs_check_compiler_option var options definitions libraries)
+ set(CMAKE_REQUIRED_QUIET 1)
+ set(CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS} ${options})
+ set(CMAKE_REQUIRED_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS} ${definitions})
+ set(CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_DEFINITIONS} ${libraries})
+
+ message(STATUS "Looking for LFS support using ${options} ${definitions} ${libraries}")
+ check_cxx_source_compiles("${_lfs_test_source}" ${var})
+
+ if(${var})
+ message(STATUS "Looking for LFS support using ${options} ${definitions} ${libraries} - found")
+ set(_lfs_cppflags ${_lfs_cppflags} ${definitions} PARENT_SCOPE)
+ set(_lfs_cflags ${_lfs_cflags} ${options} PARENT_SCOPE)
+ set(_lfs_ldflags ${_lfs_ldflags} ${libraries} PARENT_SCOPE)
+ set(LFS_FOUND TRUE PARENT_SCOPE)
+ else()
+ message(STATUS "Looking for LFS support using ${options} ${definitions} ${libraries} - not found")
+ endif()
+endfunction()
+
+# Check for the availability of LFS.
+# The cases handled are:
+#
+# * Native LFS
+# * Output of getconf LFS_CFLAGS; getconf LFS_LIBS; getconf LFS_LDFLAGS
+# * Preprocessor flag -D_FILE_OFFSET_BITS=64
+# * Preprocessor flag -D_LARGE_FILES
+#
+function(_lfs_check)
+ set(_lfs_cflags)
+ set(_lfs_cppflags)
+ set(_lfs_ldflags)
+ set(_lfs_libs)
+ set(CMAKE_REQUIRED_QUIET 1)
+ message(STATUS "Looking for native LFS support")
+ check_cxx_source_compiles("${_lfs_test_source}" lfs_native)
+ if (lfs_native)
+ message(STATUS "Looking for native LFS support - found")
+ set(LFS_FOUND TRUE)
+ else()
+ message(STATUS "Looking for native LFS support - not found")
+ endif()
+
+ if (NOT LFS_FOUND)
+ # Check using getconf. If getconf fails, don't worry, the check in
+ # _lfs_check_compiler_option will fail as well.
+ execute_process(COMMAND getconf LFS_CFLAGS
+ OUTPUT_VARIABLE _lfs_cflags_raw
+ OUTPUT_STRIP_TRAILING_WHITESPACE
+ ERROR_QUIET)
+ execute_process(COMMAND getconf LFS_LIBS
+ OUTPUT_VARIABLE _lfs_libs_tmp
+ OUTPUT_STRIP_TRAILING_WHITESPACE
+ ERROR_QUIET)
+ execute_process(COMMAND getconf LFS_LDFLAGS
+ OUTPUT_VARIABLE _lfs_ldflags_tmp
+ OUTPUT_STRIP_TRAILING_WHITESPACE
+ ERROR_QUIET)
+
+ separate_arguments(_lfs_cflags_raw)
+ separate_arguments(_lfs_ldflags_tmp)
+ separate_arguments(_lfs_libs_tmp)
+
+ # Move -D flags to the place they are supposed to be
+ foreach(flag ${_lfs_cflags_raw})
+ if (flag MATCHES "-D.*")
+ list(APPEND _lfs_cppflags_tmp ${flag})
+ else()
+ list(APPEND _lfs_cflags_tmp ${flag})
+ endif()
+ endforeach()
+
+ # Check if the flags we received (if any) produce working LFS support
+ _lfs_check_compiler_option(lfs_getconf_works
+ "${_lfs_cflags_tmp}"
+ "${_lfs_cppflags_tmp}"
+ "${_lfs_libs_tmp};${_lfs_ldflags_tmp}")
+ endif()
+
+ if(NOT LFS_FOUND) # IRIX stuff
+ _lfs_check_compiler_option(lfs_need_n32 "-n32" "" "")
+ endif()
+ if(NOT LFS_FOUND) # Linux and friends
+ _lfs_check_compiler_option(lfs_need_file_offset_bits "" "-D_FILE_OFFSET_BITS=64" "")
+ endif()
+ if(NOT LFS_FOUND) # AIX
+ _lfs_check_compiler_option(lfs_need_large_files "" "-D_LARGE_FILES=1" "")
+ endif()
+
+ set(LFS_DEFINITIONS ${_lfs_cppflags} CACHE STRING "Extra definitions for large file support")
+ set(LFS_COMPILE_OPTIONS ${_lfs_cflags} CACHE STRING "Extra definitions for large file support")
+ set(LFS_LIBRARIES ${_lfs_libs} ${_lfs_ldflags} CACHE STRING "Extra definitions for large file support")
+ set(LFS_FOUND ${LFS_FOUND} CACHE INTERNAL "Found LFS")
+endfunction()
+
+if (NOT LFS_FOUND)
+ _lfs_check()
+endif()
+
+find_package_handle_standard_args(LFS "Could not find LFS. Set LFS_DEFINITIONS, LFS_COMPILE_OPTIONS, LFS_LIBRARIES." LFS_FOUND)