Re: PIE static library builds

["Mattias Rönnblom" <hofors@lysator.liu.se>]

On 2023-03-14 17:29, Bruce Richardson wrote:
> On Tue, Mar 14, 2023 at 05:22:02PM +0100, Mattias Rönnblom wrote:
>> Hi.
>>
>> Is the "b_staticpic" meson build option supposed to work with DPDK?
>>
>> Setting it to "false" (default is "true") causes link failures on Ubuntu
>> 22.04, with GCC 9 and 11, on v23.03rc1 and v22.11:
>>
>> /usr/bin/ld: lib/librte_eal.a.p/eal_common_eal_common_errno.c.o: relocation
>> R_X86_64_TPOFF32 against `per_lcore_retval.1' can not be used when making a
>> shared object; recompile with -fPIC
>> /usr/bin/ld: failed to set dynamic section sizes: bad value
>> collect2: error: ld returned 1 exit status
>>
>> Does something per-lcore/TLS-related require PIC builds, even for static
>> libraries?
>>
> I don't think that is the issue. The "issue" is that DPDK always does both
> static and shared builds from the same object files, so without -fPIC the
> shared library parts of the build fails. To support not using staticpic,
> we'd have to disable building the .so's in those cases, or each C file
> built twice.
> 

With "default_library" set to "static", shouldn't the shared objects be 
skipped? I can see now, they are not.

 From what I recall, PIC adds a significant overhead compared to PIE, 
especially with default symbol visibility (e.g., no -fhidden).