[Lldb-commits] [lldb] r210035 - Fix most of the remaining Windows build warnings.

[Zachary Turner]

Yes, this was for building with MSVC, which does not support those linker
options.  I guess either the patch you sent out earlier, or explicitly
excluding those compilers which don't support this flag works.


On Tue, Jun 17, 2014 at 1:11 PM, Todd Fiala <tfiala at google.com> wrote:

> Zachary - were you trying to build on Windows without a gcc-compatible
> compiler, and getting linker errors/warnings in that case?
>
> If so, a correct check might really be the final patch I sent out earlier:
>
> diff --git a/CMakeLists.txt b/CMakeLists.txt
> index bad83e8..4cfa1d9 100644
> --- a/CMakeLists.txt
> +++ b/CMakeLists.txt
> @@ -218,7 +218,8 @@ macro(add_lldb_library name)
>    endif ()
>
>    if(LLDB_USED_LIBS)
> -    if (LLVM_COMPILER_IS_GCC_COMPATIBLE)
> +    # The Darwin linker doesn't understand --start-group/--end-group.
> +    if (LLVM_COMPILER_IS_GCC_COMPATIBLE AND NOT "${CMAKE_SYSTEM_NAME}"
> MATCHES "Darwin")
>
>
>
> On Tue, Jun 17, 2014 at 1:02 PM, Todd Fiala <tfiala at google.com> wrote:
>
>> This latest patch works on Ubuntu12.04/gcc4.8.2 and MacOSX10.9.3/clang.
>>  But thinking more about it, the predicate as a whole (changing based on
>> compiler rather than Linker) is just incorrect.  So the platform checks
>> there before, which isn't a bad proxy for the system linker requirements,
>> is a better check than the compiler test.
>>
>> Zachary - what were you originally intending to address with the change?
>>  Which platform(s) were affected by the patch?  We can possibly handle that
>> via another mechanism.  In hindsight I'm not a big fan of testing the
>> compiler since it isn't enough to get this right on all platofmrs
>>
>> -Todd
>>
>>
>> On Tue, Jun 17, 2014 at 12:43 PM, Todd Fiala <tfiala at google.com> wrote:
>>
>>> Keying off that link executable variable won't work.  Here's what it's
>>> set to on MacOSX:
>>>
>>> CMAKE_CXX_LINK_EXECUTABLE=<CMAKE_CXX_COMPILER>  <FLAGS>
>>> <CMAKE_CXX_LINK_FLAGS> <LINK_FLAGS> <OBJECTS>  -o <TARGET> <LINK_LIBRARIES>
>>>
>>> Ok - so maybe what we need is this patch (which I'm testing over here
>>> now):
>>> diff --git a/CMakeLists.txt b/CMakeLists.txt
>>> index bad83e8..4cfa1d9 100644
>>> --- a/CMakeLists.txt
>>> +++ b/CMakeLists.txt
>>> @@ -218,7 +218,8 @@ macro(add_lldb_library name)
>>>    endif ()
>>>
>>>    if(LLDB_USED_LIBS)
>>> -    if (LLVM_COMPILER_IS_GCC_COMPATIBLE)
>>> +    # The Darwin linker doesn't understand --start-group/--end-group.
>>> +    if (LLVM_COMPILER_IS_GCC_COMPATIBLE AND NOT "${CMAKE_SYSTEM_NAME}"
>>> MATCHES "Darwin")
>>>        target_link_libraries(${name} ${cmake_2_8_12_PUBLIC}
>>>                              -Wl,--start-group ${LLDB_USED_LIBS}
>>> -Wl,--end-group)
>>>      else()
>>>
>>>
>>>
>>> On Tue, Jun 17, 2014 at 12:31 PM, Todd Fiala <tfiala at google.com> wrote:
>>>
>>>> It looks like we might be able to test ${CMAKE_CXX_LINK_EXECUTABLE} to
>>>> exclude those that don't need --start-group/--end-group linker flags.
>>>>
>>>> However, this is getting pretty far past the original contributor
>>>> patch.  I'm more inclined to roll it back at this point until the whole
>>>> thing gets more testing.
>>>>
>>>>
>>>> On Tue, Jun 17, 2014 at 12:25 PM, Todd Fiala <tfiala at google.com> wrote:
>>>>
>>>>> Ok - so given it's a linker related flags issue, what is the correct
>>>>> cmake way to test out the linker being used?
>>>>>
>>>>>
>>>>> On Tue, Jun 17, 2014 at 11:49 AM, Ed Maste <emaste at freebsd.org> wrote:
>>>>>
>>>>>> On 17 June 2014 14:33, Todd Fiala <tfiala at google.com> wrote:
>>>>>> >
>>>>>> > Hey Ed - can you test this out on FreeBSD?  This is a patch that
>>>>>> fixes cmake on MacOSX.  I verified it works on MacOSX and Linux with
>>>>>> cmake/ninja.
>>>>>> >
>>>>>> > The original code looks like it was opting in for the
>>>>>> --start-group/--end-group linker options on FreeBSD, which this patch would
>>>>>> change but might be a no-op on your end.
>>>>>>
>>>>>> It's odd that this is a compiler-dependent test, I'd expect it to be a
>>>>>> linker issue.  In any case, we definitely needed --start-group and
>>>>>> --end-group in the past.  If this test works with Linux though it will
>>>>>> probably work with FreeBSD too.  I'll test it.
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Todd Fiala | Software Engineer |  tfiala at google.com |  650-943-3180
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Todd Fiala | Software Engineer |  tfiala at google.com |  650-943-3180
>>>>
>>>
>>>
>>>
>>> --
>>> Todd Fiala | Software Engineer |  tfiala at google.com |  650-943-3180
>>>
>>
>>
>>
>> --
>> Todd Fiala | Software Engineer |  tfiala at google.com |  650-943-3180
>>
>
>
>
> --
> Todd Fiala | Software Engineer |  tfiala at google.com |  650-943-3180
>
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