[lttng-dev] [lttng-ust GIT PULL] Doc: add a CMake example

[Philippe Proulx]

On Fri, Jun 17, 2016 at 11:13 AM, Sebastien Boisvert
<sboisvert at gydle.com> wrote:
>
>
> On 06/17/2016 11:00 AM, Philippe Proulx wrote:
>> On Fri, Jun 17, 2016 at 10:52 AM, Sebastien Boisvert
>> <sboisvert at gydle.com> wrote:
>>> Hi Phil,
>>>
>>> On 06/17/2016 10:25 AM, Philippe Proulx wrote:
>>>> On Fri, Jun 17, 2016 at 12:09 AM, Sebastien Boisvert
>>>> <sboisvert at gydle.com> wrote:
>>>>> Hi Mathieu,
>>>>>
>>>>> Please pull 7 commits for a new example in the documentation:
>>>>
>>>> Isn't the "standard" way to use CMake this, in terms of directories:
>>>>
>>>>     mkdir build
>>>>     cd build
>>>>     cmake ..
>>>>     make
>>>>
>>>> ?
>>>
>>> I can rename the directory from cmake-multiple-shared-libraries.build to build.
>>>
>>> I don't know if it is standard to create the build directory inside the source tree.
>>> I always do out-of-tree builds, but I don't know if it is incoherent with the standard way.
>>>
>>> Either way, I will make the changes you think are required.
>>
>> It's just something that I see often in simple examples, so it might be
>> a good idea to conform to this.
>
> I'll make the change.
>
>>
>>>
>>>>
>>>> Also, just a note: CMake 3.6 will have a FindLTTngUST [1] module which defines
>>>> an `LTTng::UST` imported target. This should be more robust than just:
>>>>
>>>
>>> I will add a check to detect CMake >= 3.6 and use find_package(LTTngUST) in that case.
>>
>> CMake 3.6 is not released yet, and when it does, few people will have
>> access to it
>> in the beginning I guess. You could include the whole module in the
>> example directory
>> (in a `CMake/modules` directory, for example), and still require CMake
>> 2.8.11. Eventually
>> when CMake 3.6 is available on all major distributions then we can switch to a
>> requirement of CMake 3.6 and use the built-in module. What do you think?
>
> I vote in favor of your solution that ships with the FindLTTngUST.cmake file and cake >= 2.8.11.
>
> Would CMake/modules be at the root of lttng-ust/ or in lttng-ust/doc/examples ?
>
> If this solution is chosen, I suppose that the -ldl will be taken care of by FindLTTngUST.

1. Use this CMakeLists.txt:

    cmake_minimum_required(VERSION 2.8.11)
    project(ALIGNER)
    list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")

    include_directories(.)

    include (FindLTTngUST REQUIRED)

    add_library(tracepoint-provider SHARED tracepoint-provider.cpp)
    target_link_libraries(tracepoint-provider LTTng::UST)

    add_library(aligner-lib SHARED aligner-lib.cpp)
    target_link_libraries(aligner-lib tracepoint-provider)

    add_library(tester-lib SHARED tester-lib.cpp)
    target_link_libraries(tester-lib tracepoint-provider)

    link_libraries(aligner-lib)

    add_executable(aligner aligner.cpp)

    add_executable(tester tester.cpp)
    target_link_libraries(tester tester-lib)

2. In the "cmake" directory, relative to this CMakeLists.txt file, put
   FindLTTngUST.cmake, but you need to replace the
   FindPackageHandleStandardArgs include line because we're not in
   CMake's source tree, so this is your file: <https://www.pastery.net/fvanfh/>.

Works for me:

    -- Found LTTngUST: /usr/local/lib/liblttng-ust.so;dl (found version "2.8.0")

Phil

>
>>
>>>
>>>>     target_link_libraries(tracepoint-provider dl lttng-ust)
>>>>
>>>> About this line, by the way, you should at least use `${CMAKE_DL_LIBS}` instead
>>>> of `dl`.
>>>>
>>>
>>> I will do this.
>>
>> Note however that the LTTng::UST imported target is linked with
>> `${CMAKE_DL_LIBS}` already.
>>
>> Phil
>>
>>>
>>>
>>> Thanks
>>>
>>>
>>>
>>>> Phil
>>>>
>>>>>
>>>>>
>>>>> The following changes since commit 01f0e40ce5b0c30c7c0706b63532049b311c83cf
>>>>> are available in the git repository at
>>>>>
>>>>> https://github.com/sebhtml/lttng-ust.git
>>>>> tags/cmake-multiple-shared-libraries.2016-06-17
>>>>>
>>>>>
>>>>> Sebastien Boisvert (7):
>>>>>       Doc: add CMake example
>>>>>       Doc: clean up cmake example
>>>>>       Doc: add a trace.sh script in the cmake example
>>>>>       Doc: clean up cmake file
>>>>>       Doc: fix English issue
>>>>>       Doc: rename cmake example
>>>>>       Doc: ship cmake example with 'make distcheck'
>>>>>
>>>>>
>>>>>
>>>>>  doc/examples/Makefile.am                                             | 15
>>>>> +++++++++++++
>>>>>  doc/examples/cmake-multiple-shared-libraries/CMakeLists.txt          | 20
>>>>> +++++++++++++++++
>>>>>  doc/examples/cmake-multiple-shared-libraries/README.md               | 52
>>>>> +++++++++++++++++++++++++++++++++++++++++++++
>>>>>  doc/examples/cmake-multiple-shared-libraries/aligner-lib.cpp         | 16
>>>>> ++++++++++++++
>>>>>  doc/examples/cmake-multiple-shared-libraries/aligner-lib.h           |  7
>>>>> ++++++
>>>>>  doc/examples/cmake-multiple-shared-libraries/aligner.cpp             | 10
>>>>> +++++++++
>>>>>  doc/examples/cmake-multiple-shared-libraries/tester-lib.cpp          | 16
>>>>> ++++++++++++++
>>>>>  doc/examples/cmake-multiple-shared-libraries/tester-lib.h            |  7
>>>>> ++++++
>>>>>  doc/examples/cmake-multiple-shared-libraries/tester.cpp              | 15
>>>>> +++++++++++++
>>>>>  doc/examples/cmake-multiple-shared-libraries/trace.sh                |  9
>>>>> ++++++++
>>>>>  doc/examples/cmake-multiple-shared-libraries/tracepoint-provider.cpp |  6
>>>>> ++++++
>>>>>  doc/examples/cmake-multiple-shared-libraries/tracepoint-provider.h   | 27
>>>>> +++++++++++++++++++++++
>>>>>  12 files changed, 200 insertions(+)
>>>>> _______________________________________________
>>>>> lttng-dev mailing list
>>>>> lttng-dev at lists.lttng.org
>>>>> https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev