Fwd: Re: Fwd: Re: [PATCH] libkdeinit symbol pruning

[Karl Vogel]

David Faure wrote:

> ----------  Forwarded Message  ----------
> 
> Subject: Re: Fwd: Re: [PATCH] libkdeinit symbol pruning
> Date: Tuesday 20 July 2004 21:30
> From: Stephan Kulow <coolo at kde.org>
> To: David Faure <faure at kde.org>
> 
> That am_edit patch is broken, the unsermake patch should work :)
> 
> Greetings, Stephan
> 
> -------------------------------------------------------

Great! But I'm wondering what the problem with the am_edit patch was then?!


Anyway.. more goodies.. I just finished testing the GCC visibility patch on QT 
(gcc 3.4):

* Normal build

$ objdump -CT libqt-mt.so.3.3.2|egrep "g +DF .text"|wc -l
14019

libqt-mt.so.3.3.2: 41138 relocations, 10177 relative (24%), 9322 PLT entries


* build with visibility patch

$ objdump -CT libqt-mt.so.3.3.2|egrep "g +DF .text"|wc -l
11851

libqt-mt.so.3.3.2:40993 relocations, 14275 relative (34%), 7573 PLT entries


The binary was 980Kb smaller (but both were already extremely large since it 
was a debug build).



Non-debug stripped builds give:

$ ls -l libqt-mt.so.3.3.2
-rwxrwxr-x  1 kvo kvo 8225336 Jul 21 01:46 libqt-mt.so.3.3.2
$ ls -l libqt-mt.so.3.3.2
-rwxrwxr-x  1 kvo kvo 8655704 Jul 21 02:00 libqt-mt.so.3.3.2

430Kb saving.

libqt-mt.so.3.3.2: 40966 relocations, 14267 relative (34%), 6291 PLT entries
libqt-mt.so.3.3.2: 41114 relocations, 10174 relative (24%), 8069 PLT entries

1778 PLT entries less.


There was only 1 minor problem.. KDE was using a symbol from QT that wasn't 
exported (qt_try_modal in src/kernel/qapplication_x11.cpp). So I added a 
Q_EXPORT in front of it.

For the rest, all I did was add the -fvisibility=hidden to QMAKE_CXXFLAGS and 
edited qglobal.h to set Q_EXPORT to __attribute__((visibility ("default")))



So looks like promoting the use of KDE_EXPORT is a worthwhile cause.. together 
with an autoconf check for the -fvisibility gcc option.