* [Buildroot] [PATCH] package/flann: fix build with cmake >= 3.11
@ 2018-04-18 19:19 Romain Naour
2018-04-19 20:54 ` Thomas Petazzoni
0 siblings, 1 reply; 3+ messages in thread
From: Romain Naour @ 2018-04-18 19:19 UTC (permalink / raw)
To: buildroot
CMake 3.11 changed the behaviour of add_library() that break the existing
flann CMake code.
From [1]:
"add_library() and add_executable() commands can now be called without
any sources and will not complain as long as sources are added later
via the target_sources() command."
This issue is already reported upstream [2] with a proposed solution.
Fixes:
http://autobuild.buildroot.net/results/b2f/b2febfaf8c44ce477b3e4a5b9b976fd25e8d7454
[1] https://cmake.org/cmake/help/v3.11/release/3.11.html
[2] https://github.com/mariusmuja/flann/issues/369
Signed-off-by: Romain Naour <romain.naour@gmail.com>
Cc: Davide Viti <zinosat@tiscali.it>
Cc: Bernd Kuhls <bernd.kuhls@t-online.de>
---
.../flann/0001-src-cpp-fix-cmake-3.11-build.patch | 48 ++++++++++++++++++++++
1 file changed, 48 insertions(+)
create mode 100644 package/flann/0001-src-cpp-fix-cmake-3.11-build.patch
diff --git a/package/flann/0001-src-cpp-fix-cmake-3.11-build.patch b/package/flann/0001-src-cpp-fix-cmake-3.11-build.patch
new file mode 100644
index 0000000000..5542c3cfc8
--- /dev/null
+++ b/package/flann/0001-src-cpp-fix-cmake-3.11-build.patch
@@ -0,0 +1,48 @@
+From fa5ec96a94646492a3f908e12905b3e48a8e800b Mon Sep 17 00:00:00 2001
+From: Romain Naour <romain.naour@gmail.com>
+Date: Wed, 18 Apr 2018 20:24:13 +0200
+Subject: [PATCH] src/cpp: fix cmake >= 3.11 build
+
+Upstream status: Pending
+
+https://github.com/mariusmuja/flann/issues/369
+
+Signed-off-by: Romain Naour <romain.naour@gmail.com>
+---
+ src/cpp/CMakeLists.txt | 4 ++--
+ src/cpp/empty.cpp | 1 +
+ 2 files changed, 3 insertions(+), 2 deletions(-)
+ create mode 100644 src/cpp/empty.cpp
+
+diff --git a/src/cpp/CMakeLists.txt b/src/cpp/CMakeLists.txt
+index b44a735..a816863 100644
+--- a/src/cpp/CMakeLists.txt
++++ b/src/cpp/CMakeLists.txt
+@@ -29,7 +29,7 @@ if (BUILD_CUDA_LIB)
+ endif()
+
+ if(CMAKE_SYSTEM_NAME STREQUAL "Linux" AND CMAKE_COMPILER_IS_GNUCC)
+- add_library(flann_cpp SHARED "")
++ add_library(flann_cpp SHARED "empty.cpp")
+ set_target_properties(flann_cpp PROPERTIES LINKER_LANGUAGE CXX)
+ target_link_libraries(flann_cpp -Wl,-whole-archive flann_cpp_s -Wl,-no-whole-archive)
+
+@@ -85,7 +85,7 @@ if (BUILD_C_BINDINGS)
+ set_property(TARGET flann_s PROPERTY COMPILE_DEFINITIONS FLANN_STATIC)
+
+ if(CMAKE_SYSTEM_NAME STREQUAL "Linux" AND CMAKE_COMPILER_IS_GNUCC)
+- add_library(flann SHARED "")
++ add_library(flann SHARED "empty.cpp")
+ set_target_properties(flann PROPERTIES LINKER_LANGUAGE CXX)
+ target_link_libraries(flann -Wl,-whole-archive flann_s -Wl,-no-whole-archive)
+ else()
+diff --git a/src/cpp/empty.cpp b/src/cpp/empty.cpp
+new file mode 100644
+index 0000000..40a8c17
+--- /dev/null
++++ b/src/cpp/empty.cpp
+@@ -0,0 +1 @@
++/* empty */
+--
+2.14.3
+
--
2.14.3
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [Buildroot] [PATCH] package/flann: fix build with cmake >= 3.11
2018-04-18 19:19 [Buildroot] [PATCH] package/flann: fix build with cmake >= 3.11 Romain Naour
@ 2018-04-19 20:54 ` Thomas Petazzoni
2018-04-20 20:13 ` Romain Naour
0 siblings, 1 reply; 3+ messages in thread
From: Thomas Petazzoni @ 2018-04-19 20:54 UTC (permalink / raw)
To: buildroot
Hello Romain,
On Wed, 18 Apr 2018 21:19:12 +0200, Romain Naour wrote:
> From [1]:
> "add_library() and add_executable() commands can now be called without
> any sources and will not complain as long as sources are added later
> via the target_sources() command."
I must be misunderstanding something then. The code currently is:
add_library(flann_cpp SHARED "")
So it has no source code, and this works fine with CMake < 3.11. And
you're saying that it's only in CMake >= 3.11 that having no source
code is valid.
And you fix that by adding a dummy source code file. I'm totally
confused here.
Also, why do they build a library with nothing inside ? Does it make
sense ?
Thanks,
Thomas
--
Thomas Petazzoni, CTO, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Buildroot] [PATCH] package/flann: fix build with cmake >= 3.11
2018-04-19 20:54 ` Thomas Petazzoni
@ 2018-04-20 20:13 ` Romain Naour
0 siblings, 0 replies; 3+ messages in thread
From: Romain Naour @ 2018-04-20 20:13 UTC (permalink / raw)
To: buildroot
Hi Thomas,
Le 19/04/2018 ? 22:54, Thomas Petazzoni a ?crit?:
> Hello Romain,
>
> On Wed, 18 Apr 2018 21:19:12 +0200, Romain Naour wrote:
>
>> From [1]:
>> "add_library() and add_executable() commands can now be called without
>> any sources and will not complain as long as sources are added later
>> via the target_sources() command."
>
> I must be misunderstanding something then. The code currently is:
>
> add_library(flann_cpp SHARED "")
>
> So it has no source code, and this works fine with CMake < 3.11. And
> you're saying that it's only in CMake >= 3.11 that having no source
> code is valid.
Well, it seems a bug in CMake < 3.11.
>
> And you fix that by adding a dummy source code file. I'm totally
> confused here.
So do I. I don't understand how it can work with older CMake.
> Also, why do they build a library with nothing inside ? Does it make
> sense ?
The library is created by linking with the flann_cpp_s static library with this
line:
target_link_libraries(flann_cpp -Wl,-whole-archive flann_cpp_s
-Wl,-no-whole-archive)
If you try to use "add_library(flann_cpp SHARED ${CPP_SOURCES})" (as it should
be normally done), the link fail due to already defined symbol.
They are building the shared version using the static library "to speedup the
build time":
https://github.com/mariusmuja/flann/commit/0fd62b43be2fbb0b8d791ee36290791224dc030c
Alpinelinux removed/commented retentively this part of the CMake code:
https://github.com/alpinelinux/aports/commit/fe5137a340af202cefe6b67601af0133b6b660bd
Best regards,
Romain
>
> Thanks,
>
> Thomas
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2018-04-18 19:19 [Buildroot] [PATCH] package/flann: fix build with cmake >= 3.11 Romain Naour
2018-04-19 20:54 ` Thomas Petazzoni
2018-04-20 20:13 ` Romain Naour
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