gnu/packages/patches/flann-cmake-3.11.patch

   1 Fixes this issue:
   2  <https://github.com/mariusmuja/flann/issues/369>.
   3 Patch from Buildroot:
   4  <https://github.com/buildroot/buildroot/commit/45a39b3e2ba42b72d19bfcef30db1b8da9ead51a>.
   5
   6 From fa5ec96a94646492a3f908e12905b3e48a8e800b Mon Sep 17 00:00:00 2001
   7 From: Romain Naour <romain.naour@gmail.com>
   8 Date: Wed, 18 Apr 2018 20:24:13 +0200
   9 Subject: [PATCH] src/cpp: fix cmake >= 3.11 build
  10
  11 CMake < 3.11 doesn't support add_library() without any source file
  12 (i.e add_library(foo SHARED)). But flann CMake use a trick that use
  13 an empty string "" as source list (i.e add_library(foo SHARED "")).
  14 This look like a bug in CMake < 3.11.
  15
  16 With CMake >= 3.11, the new behaviour of add_library() break the
  17 existing flann CMake code.
  18
  19 From CMake Changelog [1]:
  20 "add_library() and add_executable() commands can now be called without
  21  any sources and will not complain as long as sources are added later
  22  via the target_sources() command."
  23
  24 Note: flann CMake code doesn't use target_sources() since no source file
  25 are provided intentionally since the flann shared library is created by
  26 linking with the flann_cpp_s static library with this line:
  27
  28 target_link_libraries(flann_cpp -Wl,-whole-archive flann_cpp_s -Wl,-no-whole-archive)
  29
  30 If you try to use "add_library(flann_cpp SHARED ${CPP_SOURCES})" (as it should
  31 be normally done), the link fail due to already defined symbol.
  32
  33 They are building the shared version using the static library "to speedup the
  34 build time" [3]
  35
  36 This issue is already reported upstream [2] with a proposed solution.
  37
  38 Upstream status: Pending
  39
  40 Fixes:
  41 http://autobuild.buildroot.net/results/b2f/b2febfaf8c44ce477b3e4a5b9b976fd25e8d7454
  42
  43 [1] https://cmake.org/cmake/help/v3.11/release/3.11.html
  44 [2] https://github.com/mariusmuja/flann/issues/369
  45 [3] https://github.com/mariusmuja/flann/commit/0fd62b43be2fbb0b8d791ee36290791224dc030c
  46
  47 Signed-off-by: Romain Naour <romain.naour@gmail.com>
  48 ---
  49  src/cpp/CMakeLists.txt | 4 ++--
  50  src/cpp/empty.cpp      | 1 +
  51  2 files changed, 3 insertions(+), 2 deletions(-)
  52  create mode 100644 src/cpp/empty.cpp
  53
  54 diff --git a/src/cpp/CMakeLists.txt b/src/cpp/CMakeLists.txt
  55 index b44a735..a816863 100644
  56 --- a/src/cpp/CMakeLists.txt
  57 +++ b/src/cpp/CMakeLists.txt
  58 @@ -29,7 +29,7 @@ if (BUILD_CUDA_LIB)
  59  endif()
  60
  61  if(CMAKE_SYSTEM_NAME STREQUAL "Linux" AND CMAKE_COMPILER_IS_GNUCC)
  62 -    add_library(flann_cpp SHARED "")
  63 +    add_library(flann_cpp SHARED "empty.cpp")
  64      set_target_properties(flann_cpp PROPERTIES LINKER_LANGUAGE CXX)
  65      target_link_libraries(flann_cpp -Wl,-whole-archive flann_cpp_s -Wl,-no-whole-archive)
  66
  67 @@ -85,7 +85,7 @@ if (BUILD_C_BINDINGS)
  68      set_property(TARGET flann_s PROPERTY COMPILE_DEFINITIONS FLANN_STATIC)
  69
  70      if(CMAKE_SYSTEM_NAME STREQUAL "Linux" AND CMAKE_COMPILER_IS_GNUCC)
  71 -        add_library(flann SHARED "")
  72 +        add_library(flann SHARED "empty.cpp")
  73          set_target_properties(flann PROPERTIES LINKER_LANGUAGE CXX)
  74          target_link_libraries(flann -Wl,-whole-archive flann_s -Wl,-no-whole-archive)
  75      else()
  76 diff --git a/src/cpp/empty.cpp b/src/cpp/empty.cpp
  77 new file mode 100644
  78 index 0000000..40a8c17
  79 --- /dev/null
  80 +++ b/src/cpp/empty.cpp
  81 @@ -0,0 +1 @@
  82 +/* empty */
  83 --
  84 2.14.3