GCC 8.3 and ABI check

[Andreas Schneider]

On Tuesday, April 9, 2019 6:28:44 AM CEST Amitay Isaacs via samba-technical 
wrote:
> Hi,
> 
> With gcc 8.3.1 on fedora 29, ABI check keeps failing for various
> conditions.  Noticed this when I tried building ctdb for the latest
> master with developer build.

Hi Amitay,

> Issues:
> 
> 1. We might have to add "-g" to build if abi_check is enabled.
> (abi_check gets enabled for developer build).
> 
> 2. The missing debug information from shared library when optimize
> flags are used, seems like a bug in gcc.  Anyone has any other ideas
> on how to confirm that?    To work around this problem we might need
> to add "-g -O0" to CFLAGS if abi_check is enabled.

The ABI check only reliably works with CFLAGS="-Og -g" as it needs to contain 
DWARF debug info to get the symbol signatures.

> If you are on a different platform (different version of gcc), can you
> check if abi check works?
> 
> $ cd samba/lib/talloc
> $ ./configure --abi-check
> $ make
> $ CFLAGS="-O2" ./configure --abi-check
> $ make

I guess this is probably because the optimizer is less aggressive or not as 
advanced as on x86-64.


	Andreas

-- 
Andreas Schneider                      asn at samba.org
Samba Team                             www.samba.org
GPG-ID:     8DFF53E18F2ABC8D8F3C92237EE0FC4DCC014E3D