Re: [dpdk-dev] [PATCH] build: fix experimental library versioning

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

On 2/21/2020 3:24 PM, David Marchand wrote:
> On Thu, Feb 20, 2020 at 8:55 PM Ferruh Yigit <ferruh.yigit@intel.com> wrote:
>>
>> The problem occurred when workaround that makes soname two digits
>> applied. With this change for the ABI version "20.0.1" the experimental
>> library version become ".so.2001".
>> After workaround removed in ABI version 21.0, the experimental library
>> version will become ".so.210".
>> "2001" is bigger value than "201" although it is a previous version of
>> the library version, this can break the version comparisons.
>>
>> To fix this, introducing a temporary sub level versioning for the
>> experimental libraries, so that minor version comparison will continue
>> to work.
>>
>> After change experimental libraries will follow below versioning:
>>
>> DPDK version  ABI version  soname       library name
>> ------------  -----------  ------       ------------
>> DPDK 19.11     20.0        .so.0.200    .so.0.200
>> DPDK 20.02     20.0.1      .so.0.200.1  .so.0.200.1
>> DPDK 20.05     20.0.2      .so.0.200.2  .so.0.200.2
>> DPDK 20.11     21.0        .so.0.210    .so.0.210
>> DPDK 21.02     21.1        .so.0.211    .so.0.211
>>
>> Note: After workaround removed in DPDK 20.11 and soname switch back to
>> single digit this patch won't work and needs to be updated.
>>
>> Fixes: f26c2b39b271 ("build: fix soname info for 19.11 compatibility")
>>
>> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
> 
> The soname change breaks existing applications like testpmd (linked to
> various experimental libraries).
> I have the full details if needed in a pastebin (v19.11, master, patch_applied).
> 
> $ LD_LIBRARY_PATH=$HOME/builds/x86_64-native-linux-gcc+shared+kmods/install/lib
> $HOME/abi/v19.11/x86_64-native-linux-gcc+shared+kmods/bin/testpmd
> /home/dmarchan/abi/v19.11/x86_64-native-linux-gcc+shared+kmods/bin/testpmd:
> error while loading shared libraries: librte_flow_classify.so.0.200:
> cannot open shared object file: No such file or directory
> 
> 
> libabigail reports this change as an error, so if it is intended, we
> need to bypass the check for those libraries.

soname change was intended, we don't provide any ABI compatibility in the
experimental libraries, keeping same soname may mislead as if we do.

The impact of it is, any application linked against experimental library will
need to recompile in new release.

Can we add exception to the the libabigail for experimental libraries?

> 
> Functions changes summary: 0 Removed, 0 Changed (2 filtered out), 0
> Added functions
> Variables changes summary: 0 Removed, 0 Changed, 0 Added variable
> ELF SONAME changed
> Functions changes summary: 0 Removed, 0 Changed (7 filtered out), 0
> Added functions
> Variables changes summary: 0 Removed, 0 Changed, 0 Added variable
> SONAME changed from 'librte_flow_classify.so.0.200' to
> 'librte_flow_classify.so.0.200.1'
> Error: ABI issue reported for 'abidiff --suppr
> /home/dmarchan/dpdk/devtools/libabigail.abignore --no-added-syms
> --headers-dir1 /home/dmarchan/abi/v19.11/x86_64-native-linux-gcc+shared+kmods/include
> --headers-dir2 /home/dmarchan/builds/x86_64-native-linux-gcc+shared+kmods/install/include
> /home/dmarchan/abi/v19.11/x86_64-native-linux-gcc+shared+kmods/dump/librte_flow_classify.dump
> /home/dmarchan/builds/x86_64-native-linux-gcc+shared+kmods/install/dump/librte_flow_classify.dump'
> 
> 
>