Re: [dpdk-dev] meson: wrong dependency in cross compilation on ARM

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 1/18/2021 12:05 PM, Ferruh Yigit wrote:
> On 1/18/2021 11:58 AM, Ferruh Yigit wrote:
>> On 1/18/2021 10:51 AM, Bruce Richardson wrote:
>>> On Fri, Jan 15, 2021 at 06:40:56PM +0000, Ferruh Yigit wrote:
>>>> On 12/21/2020 2:04 PM, Bruce Richardson wrote:
>>>>> On Mon, Dec 21, 2020 at 12:19:17PM +0000, Hemant Agrawal wrote:
>>>>>> Hi,
>>>>>>                   I am trying to cross compile DPDK for arm64 on a ubuntu 
>>>>>> machine, which has a zlib pre-installed for native env.
>>>>>>
>>>>>> I am encountering following build error in net_bnx2x as it has dependency 
>>>>>> on zlib.  It is trying to link with x86 arch based zlib.
>>>>>>
>>>>>> Cross compiling zlib and setting the PKG_CONFIG_PATH solve the issue. But, 
>>>>>> Is their an easy way to disable these dependencies?
>>>>>>
>>>>> Can you try with setting PKG_CONFIG_LIBDIR rather than PKG_CONFIG_PATH?
>>>>> PKG_CONFIG_PATH simply extends the search locations, which means that
>>>>> host-paths will still be searched, while PKG_CONFIG_LIBDIR replaces the
>>>>> default path, eliminating the host-based search paths.
>>>>>
>>>>
>>>> The 'PKG_CONFIG_LIBDIR' seems not taken into account by meson, Akhil
>>>> reported a 32bit build error when zlib is missing, I can reproduce the same.
>>>>
>>>> I have only 64bit version of the library:
>>>>
>>>> $ pkg-config --path zlib
>>>> /usr/lib64/pkgconfig/zlib.pc
>>>>
>>>> $ PKG_CONFIG_LIBDIR=/usr/lib/pkgconfig/ pkg-config --path zlib
>>>> <no output>
>>>> $ echo $?
>>>> 1
>>>>
>>>> When I run the meson as following:
>>>> "PKG_CONFIG_LIBDIR=/usr/lib/pkgconfig/ meson --werror -Dc_args=-m32
>>>> -Dc_link_args=-m32 -Dexamples=all build32"
>>>>
>>>> It still detects the zlib:
>>>> Run-time dependency zlib found: YES 1.2.11
>>>>
>>>
>>> I've just tried this on my system and it works as expected: the 32-bit lib
>>> is not found and a build succeeds. Omitting the PKG_CONFIG_LIBDIR and it is
>>> found, but linking fails due to "file in wrong format" errors, again as
>>> expected.
>>>
>>> In your case, I suspect it might be meson falling back to cmake in the
>>> detection logic. If you have cmake installed on your system, can you
>>> perhaps temporarily remove it, and retry the 32-bit build? If that is the
>>> cause, we can modify the dependency call to add "method: 'pkg-config'" to
>>> it, to force pkg-config searches only.
>>>
>>
>> Yes I have cmake, I will try without it.
>>
>> Meanwhile I have Fedora, and it seems it is using different version of the 
>> pkg-config (pkgconf), not sure if this can be a problem.
>>
> 
> I confirm removing the 'cmake' solved the issue, now I am getting:
> "Run-time dependency zlib found: NO (tried pkgconfig and cmake)"
> 
> And zlib dependent modules not enabled, so build runs successfully.

Following is fixing the problem [1], but isn't this a generic problem when 64bit 
version of a library installed but 32bit version of it is missing and 'cmake' 
exists?

Should all library discovery reduced to the 'pkg-config' only?



[1]
diff --git a/app/test/meson.build b/app/test/meson.build
index 94fd39fecb82..bdbc61947637 100644
--- a/app/test/meson.build
+++ b/app/test/meson.build
@@ -406,7 +406,7 @@ cflags += ['-DALLOW_INTERNAL_API']

  test_dep_objs = []
  if dpdk_conf.has('RTE_LIB_COMPRESSDEV')
-       compress_test_dep = dependency('zlib', required: false)
+       compress_test_dep = dependency('zlib', required: false, method: 
'pkg-config')
         if compress_test_dep.found()
                 test_dep_objs += compress_test_dep
                 test_sources += 'test_compressdev.c'
diff --git a/drivers/compress/zlib/meson.build b/drivers/compress/zlib/meson.build
index b19a6d2b161f..82cf0dddd649 100644
--- a/drivers/compress/zlib/meson.build
+++ b/drivers/compress/zlib/meson.build
@@ -1,7 +1,7 @@
  # SPDX-License-Identifier: BSD-3-Clause
  # Copyright(c) 2018 Cavium Networks

-dep = dependency('zlib', required: false)
+dep = dependency('zlib', required: false, method: 'pkg-config')
  if not dep.found()
         build = false
         reason = 'missing dependency, "zlib"'
diff --git a/drivers/net/bnx2x/meson.build b/drivers/net/bnx2x/meson.build
index 8837ef424760..e260b75926ec 100644
--- a/drivers/net/bnx2x/meson.build
+++ b/drivers/net/bnx2x/meson.build
@@ -7,7 +7,7 @@ if is_windows
         subdir_done()
  endif

-dep = dependency('zlib', required: false)
+dep = dependency('zlib', required: false, method: 'pkg-config')
  build = dep.found()
  reason = 'missing dependency, "zlib"'
  ext_deps += dep