From 86a722b9114d09b4036118a2b09650468bd2cdd4 Mon Sep 17 00:00:00 2001
From: Kefu Chai <kchai@redhat.com>
Date: Wed, 20 Nov 2019 22:00:12 +0800
Subject: [PATCH] cmake: include ${fmt_INCLUDE_DIR} instead

we should not hardwire the include path to the fmt submodule,
there is chance that we are using libfmt installed in system.

in my case, crimson fails to link because the the ABI of libfmt
is not compatible with that of libfmt included as a submodule

: && ccache /usr/bin/g++-9 .... \
 -o bin/crimson-osd  -Wl,-rpath,::::::::::::::::::: lib/libcrimson-common.a lib/libcrimson-os.a lib/libcrimson.a \
  .... \
  /usr/lib/x86_64-linux-gnu/libfmt.a \
  ...

/usr/bin/ld: src/crimson/osd/CMakeFiles/crimson-osd.dir/main.cc.o: in function `void fmt::v5::basic_writer<fmt::v5::back_insert_range<fmt::v5::internal::basic_buffer<char> >
>::write_double<double>(double, fmt::v5::basic_format_specs<char
> const&)':
/var/ssd/ceph/build/../src/fmt/include/fmt/format.h:2822: undefined reference to `bool fmt::v5::internal::grisu2_format<double, 0>(double, fmt::v5::internal::basic_buffer<char>&, int, bool, int&)'
/usr/bin/ld: src/crimson/osd/CMakeFiles/crimson-osd.dir/main.cc.o: in function `void fmt::v5::basic_writer<fmt::v5::back_insert_range<fmt::v5::internal::basic_buffer<char> > >::write_double<long
double>(long double, fmt::v5::basic_format_
specs<char> const&)':
/var/ssd/ceph/build/../src/fmt/include/fmt/format.h:2822: undefined reference to `bool fmt::v5::internal::grisu2_format<double, 0>(double, fmt::v5::internal::basic_buffer<char>&, int, bool, int&)'
/usr/bin/ld: src/crimson/osd/CMakeFiles/crimson-osd.dir/osd.cc.o: in function `void fmt::v5::basic_writer<fmt::v5::output_range<std::back_insert_iterator<fmt::v5::internal::basic_buffer<char> >, char>
>::write_double<double>(double, fmt::
v5::basic_format_specs<char> const&)':
/var/ssd/ceph/build/../src/fmt/include/fmt/format.h:2822: undefined reference to `bool fmt::v5::internal::grisu2_format<double, 0>(double, fmt::v5::internal::basic_buffer<char>&, int, bool, int&)'
/usr/bin/ld: src/crimson/osd/CMakeFiles/crimson-osd.dir/osd.cc.o: in function `void fmt::v5::basic_writer<fmt::v5::output_range<std::back_insert_iterator<fmt::v5::internal::basic_buffer<char> >, char>
>::write_double<long double>(long dou
ble, fmt::v5::basic_format_specs<char> const&)':
/var/ssd/ceph/build/../src/fmt/include/fmt/format.h:2822: undefined reference to `bool fmt::v5::internal::grisu2_format<double, 0>(double, fmt::v5::internal::basic_buffer<char>&, int, bool, int&)'
collect2: error: ld returned 1 exit status

Signed-off-by: Kefu Chai <kchai@redhat.com>
---
 src/CMakeLists.txt | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 9ccada1f5389..9a6f48f6fd42 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -288,11 +288,13 @@ include_directories(SYSTEM "${CMAKE_SOURCE_DIR}/src/xxHash")
 include_directories(SYSTEM "${CMAKE_SOURCE_DIR}/src/rapidjson/include")
 
 find_package(fmt 5.2.1 QUIET)
-if(NOT fmt_FOUND)
+if(fmt_FOUND)
+  include_directories(SYSTEM "${fmt_INCLUDE_DIR}")
+else()
   message(STATUS "Could not find fmt, will build it")
   add_subdirectory(fmt)
+  include_directories(SYSTEM "${CMAKE_SOURCE_DIR}/src/fmt/include")
 endif()
-include_directories(SYSTEM "${CMAKE_SOURCE_DIR}/src/fmt/include")
 
 if(WITH_SEASTAR)
   find_package(c-ares 1.13.0 QUIET)
-- 
2.47.3