ceph/cmake/modules/Findfmt.cmake
Kefu Chai 8df0e40b46 cmake: require 4.0.0 <= libfmt-dev < 5.0.0
FMT_VERSION is now living in fmt/core.h in libfmt >= 5.0, so we cannot
parse fmt/format.h for libfmt's version anymore. also we don't need
Findfmt.cmake now. because libfmt-dev 4.0 and up is required by seastar,
also it's libfmt-dev 3.x's cmake module which fails to offer fmt::fmt
target. in other words, it's safe to drop libfmt 3.x support. but 5.0.0
is not compatible with seastar, we will have failures like:

In file included from
/home/smithfarm/src/ceph/smithfarm/ceph/src/seastar/include/seastar/core/aligned_buffer.hh:25:0,
                 from
/home/smithfarm/src/ceph/smithfarm/ceph/src/seastar/include/seastar/core/reactor.hh:26,
                 from
/home/smithfarm/src/ceph/smithfarm/ceph/src/seastar/include/seastar/core/alien.hh:35,
                 from
/home/smithfarm/src/ceph/smithfarm/ceph/src/seastar/src/core/alien.cc:23:
/home/smithfarm/src/ceph/smithfarm/ceph/src/seastar/include/seastar/core/print.hh:
In function 'seastar::sstring seastar::format(const char*, A&& ...)':
/home/smithfarm/src/ceph/smithfarm/ceph/src/seastar/include/seastar/core/print.hh:135:10:
error: 'MemoryWriter' is not a member of 'fmt'
     fmt::MemoryWriter out;
          ^~~~~~~~~~~~
/home/smithfarm/src/ceph/smithfarm/ceph/src/seastar/include/seastar/core/print.hh:136:5:
error: 'out' was not declared in this scope
     out.write(fmt, std::forward<A>(a)...);
     ^~~

so, we should build libfmt even if we have libfmt-dev 5.x

Signed-off-by: Kefu Chai <kchai@redhat.com>
2018-08-02 22:14:03 +08:00

44 lines
1.4 KiB
CMake

find_path(fmt_INCLUDE_DIR NAMES fmt/format.h)
if(fmt_INCLUDE_DIR)
set(_fmt_version_file "${fmt_INCLUDE_DIR}/fmt/format.h")
if(NOT EXISTS "${_fmt_version_file}")
set(_fmt_version_file "${fmt_INCLUDE_DIR}/fmt/core.h")
endif()
if(EXISTS "${_fmt_version_file}")
# parse "#define FMT_VERSION 40100" to 4.1.0
file(STRINGS "${fmt_INCLUDE_DIR}/fmt/format.h" fmt_VERSION_LINE
REGEX "^#define[ \t]+FMT_VERSION[ \t]+[0-9]+$")
string(REGEX REPLACE "^#define[ \t]+FMT_VERSION[ \t]+([0-9]+)$"
"\\1" fmt_VERSION "${fmt_VERSION_LINE}")
foreach(ver "fmt_VERSION_PATCH" "fmt_VERSION_MINOR" "fmt_VERSION_MAJOR")
math(EXPR ${ver} "${fmt_VERSION} % 100")
math(EXPR fmt_VERSION "(${fmt_VERSION} - ${${ver}}) / 100")
endforeach()
set(fmt_VERSION
"${fmt_VERSION_MAJOR}.${fmt_VERSION_MINOR}.${fmt_VERSION_PATCH}")
endif()
endif()
find_library(fmt_LIBRARY NAMES fmt)
include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(fmt
REQUIRED_VARS fmt_INCLUDE_DIR fmt_LIBRARY
VERSION_VAR fmt_VERSION)
mark_as_advanced(
fmt_INCLUDE_DIR
fmt_LIBRARY
fmt_VERSION_MAJOR
fmt_VERSION_MINOR
fmt_VERSION_PATCH
fmt_VERSION_STRING)
if(fmt_FOUND AND NOT (TARGET fmt::fmt))
add_library(fmt::fmt UNKNOWN IMPORTED)
set_target_properties(fmt::fmt PROPERTIES
INTERFACE_INCLUDE_DIRECTORIES "${fmt_INCLUDE_DIR}"
IMPORTED_LINK_INTERFACE_LANGUAGES "CXX"
IMPORTED_LOCATION "${fmt_LIBRARY}")
endif()