Let's build small Qt libraries! (Step 2: Optimize build-settings)

Peppy · wrote on 17 May 2011, 18:14

But they were designed about 20 years before, and probably they will change...

But back to the topic, I don't remember what it was...

I think: http://wiki.wxwidgets.org/Reducing_Executable_Size (--strip-all)

Hedge · wrote on 17 May 2011, 18:22

Thanks for clarifying that CFLAGS-thing. I'm currently writing my BA so I've got time to try some configurations (and also the MSVC-compiler).

I'll post the details here.

However I've a problem atm ...size-wise.
My application, although build in release-mode asks for the debug-DLLs as well (QtGui4d.dll etc.) when I try to execute it on another PC. Any ideas what would could've gone wrong?
The executables size is much smaller than in debug-mode (400kb vs. 2.4MB).

Peppy · wrote on 17 May 2011, 18:25

Yes, executable is much more smaller than DLLs (who knows why?)...

Why that happens? Good question... Please make new thread, it's new question, and it'll going to off topic...

Hedge · wrote on 17 May 2011, 18:31

There's already a thread "here":here http://developer.qt.nokia.com/forums/viewthread/6033/ regarding that question but no one had a good idea yet.
I threw it in b/c it didn't seem to be too off-topic (it's influencing the application-size in a very bad way).

Peppy · wrote on 17 May 2011, 18:39

Yes, but this topic is named as "Minimizing sizes of DLLs" not as "Issue with DLLs" ;) That's just detial, but that I've learnt on other board as moderator (just my habit :-D)

Yes, it's quite strange...

deni-herdiman · wrote on 17 May 2011, 20:15

[quote author="Hedge" date="1305656526"]
However I've a problem atm ...size-wise.
My application, although build in release-mode asks for the debug-DLLs as well (QtGui4d.dll etc.) when I try to execute it on another PC. Any ideas what would could've gone wrong?
The executables size is much smaller than in debug-mode (400kb vs. 2.4MB).
[/quote]
if you're using UPX....
try delete pagefile.sys of your compiler's pc, than run your apps than something going haven...
sadly crash in previous trial... :(

Hedge · wrote on 17 May 2011, 20:16

The problem was another dll build in debug-mode. Peppy found the solution in the thread mentioned above.

Hedge · wrote on 18 May 2011, 10:45

I've got some results to show off.

I can't run configure with the Microsoft-compiler ("Your text to link here...":http://developer.qt.nokia.com/forums/viewthread/6060/).

For now I built Qt with the following configure-options:

@Configure -L -release -platform win32-g++ -opensource -no-exceptions -no-stl -no-opengl -no-openvg -no-libjpeg -no-libtiff -no-dsp -no-vcproj -no-webkit -no-scripttools -no-native-gestures -qconfig ali@

I checked off as much stuff as possible in my custom config-file but especially didn't know which GUI-components I could remove (I use the qml-desktop-components).

The result is a lower size of around 1MB (6,51MB compared to 7,55MB before)

@default size | self-compiled(gcc) | UPX -9 | Name

  2,43MB        |      2,04MB        |    0,80MB    | QTCore4.dll
  2,92MB        |      2,23MB        |    0,67MB    | QTDeclarative4.dll
  9,39MB        |      7,75MB        |    3,19MB    | QtGui4.dll
  1,15MB        |      0,77MB        |    0,28MB    | QTNetwork4.dll
  2,07MB        |      1,74MB        |    0,55MB    | QTScript4.dll
  0,20MB        |      0,20MB        |    0,08MB    | QTSql4.dll
  3,82MB        |      3,82MB        |    0,94MB    | QTXmlPatterns4.dll (wasn't compiled)

 21,98MB              18,55MB             6,51MB@

These were the old results:

@Uncompressed size | UPX -9 size | Name

  2,43MB          |    0,91MB    | QTCore4.dll
  2,92MB          |    0,86MB    | QTDeclarative4.dll
  9,39MB          |    3,69MB    | QtGui4.dll
  1,15MB          |    0,40MB    | QTNetwork4.dll
  2,07MB          |    0,65MB    | QTScript4.dll
  0,20MB          |    0,10MB    | QTSql4.dll
  3,82MB          |    0,94MB    | QTXmlPatterns4.dll

 21,98MB              7,55MB@

Peppy · wrote on 18 May 2011, 11:13

From 22MB to 6,5MB is quite good ;-) ... Do you have any start-up "speed" test? Is it slower/faster ?

Hedge · wrote on 18 May 2011, 11:14

No, my application doesn't work standalone right now in release-mode because of the problem mentioned in another thread.

Hedge · wrote on 18 May 2011, 14:50

Now I've compiled using MSVC2010 and excluding just a bit stuff (-no-stl, -no-exceptions etc).

These are the new results:

The result is a lower size of around 0,71 MB compared to the GCC-built libraries.

I'm trying to compile with exceptions now so I can get XMLPatterns built.

@default size | self-compiled(MSVC)| UPX -9 | Name

  2,43MB        |      1,85MB        |    0,82MB    | QTCore4.dll
  2,92MB        |      1,71MB        |    0,58MB    | QTDeclarative4.dll
  9,39MB        |      6,57MB        |    3,02MB    | QtGui4.dll
  1,15MB        |      0,59MB        |    0,24MB    | QTNetwork4.dll
  2,07MB        |      1,05MB        |    0,37MB    | QTScript4.dll
  0,20MB        |      0,13MB        |    0,07MB    | QTSql4.dll
  3,82MB        |      2,52MB        |    0,60MB    | QTXmlPatterns4.dll

 21,98MB              14,32MB             5,70MB@

These were the old results:

@Uncompressed size | UPX -9 size | Name

  2,43MB          |    0,91MB    | QTCore4.dll
  2,92MB          |    0,86MB    | QTDeclarative4.dll
  9,39MB          |    3,69MB    | QtGui4.dll
  1,15MB          |    0,40MB    | QTNetwork4.dll
  2,07MB          |    0,65MB    | QTScript4.dll
  0,20MB          |    0,10MB    | QTSql4.dll
  3,82MB          |    0,94MB    | QTXmlPatterns4.dll

 21,98MB              7,55MB@

SteveKing · wrote on 18 May 2011, 15:11

Hi,

I'm using Qt on WinCE 5, and using qconfig to rip out all of the QWidgets that I don't use, and compiling for optimize for size rather than speed I've managed to get QtGui down to between 5 and 6MB depending on the platform.

I've also remove QtSql and QtSvg support from QtDeclarative (as I don't use them) and that means another couple of hundred K that's saved. These changes are very minor code changes to the library.

Steve

andre · wrote on 18 May 2011, 15:39

Actually, I think some (groups of) widgets can be left out, by using the right #defines. In qabstractitemview.h, line 56, for instance, there is a conditional compilation like this:
@
#ifndef QT_NO_ITEMVIEWS
@

Another example is for XML (xmlstream.h, line 47):
@
#ifndef QT_NO_XMLSTREAM
@

I think that many Qt features can be compiled out this way, thus reducing the size of the Qt libraries.

Hedge · wrote on 18 May 2011, 15:48

@SteveKing, could you upload your qconfig somewhere? The example-ones distributed with Qt don't work at all and I couldn't get my own to compile past QtDeclarative.

I'm also intersted in the changes you made to leave out QtSql and QtSvg in QtDeclarative.

@Andre: That's the purpose of qconfig.
It adds define QT_NO_WHATEVER statements, but I found it difficulty to find a fully compiling configuration.

SteveKing · wrote on 19 May 2011, 09:50

@Hedge. Our "company website":http://www.domino-printing.com/Global/en/QuickStepQTFiles/QuickStepQTFiles.aspx has all of the Qt files we're using on it. The things you'll be interested in are:

4.7.2 Changed Files: This zip has the source I modified in Qt Declarative to remove the Sql support and the configuration files. It also includes a change to the Pixmap cache class to allow us to define the cache size.

4.7.2 Configuration Batch Files: This has the mkspecs for our WinCE platforms and also the configure batch files we use. Some of the configure options I've used don't do anything (-nomake), but I threw everything at it and haven't tidied them up yet!

The qconfig-QML.h is the minimum config for our WinCE application. _QML-http-html _and _QML-IC _are variations on this adding in some extra features as required. _QML-PC _is the minimum config I managed for a PC build, although even with this I hit problems building the active Qt components. I tried to fix this by modifying .pro files etc, but got nowhere and everything I use has been built by then so I stopped. The main reason the _qconfig-QML _didn't work with the PC build was because of all the tools that build with it, again I didn't investigate how to disable these.

If you find any of this useful and need to ask any more questions feel free to mail me.

Steve

Hedge · wrote on 19 May 2011, 09:55

Thanks for putting them up.
I'll try them as soon as I find the time to.

EDIT: I couldn't compile them. I think I'm out for now as Volker is right. It's eating plenty of time.