[QBS] Usage qbs for editing Qt sources

[Christian Kandeler]

On 07/06/2015 09:51 AM, Christian Kandeler wrote:
> On 07/04/2015 03:28 PM, Smirnov Vladimir wrote:
>> I just tried some strange things which I want to share with others.
>> 1. I downloaded latest (5.5) Qt Sources, including all Addons.
>> 2. I created qbs file:
>> CppApplication
>> {
>> Depends { name: "Qt"; submodules: ['core', 'gui', 'widgets', 'network'] }
>> name: 'qt-source'
>> files: ['**/*.c','**/*.cc','**/*.cpp', '**/*.h']
>> }
>> and placed in qt Src root.
>
> Note that this is a bit dubious, as these files do not really belong to
> the same product.
>
>> 3. Opened It in QtCreator 3.4.2.
>> Project consumed 3.5 Gb RAM and after some minutes displayed all
>> contents. "Parsing C++ files" takes dozens of minutes.

I tested this on the command line. It took two seconds. So almost all of 
the time is spent in Qt Creator there.

>> I counted files in projects list, around 70 000 source files (Flat view
>> and then counting approx.).
>> 4. Viewing and editing  - no lags.
>> 5. Now i try to build "qmakeglobals.cpp" from qtbase/qmake lib.
>> 6.
>>
>> 19:37:20: Running steps for project qt-src...
>>
>> compiling qmakeglobals.cpp
>>
>> 20:54:25: Elapsed time: 1:17:05.
>
> Hm, this is a bit suprising. Not sure where that time is spent.

Ah, probably because all the rules are being executed. I think if you 
try this again (with any file), it will be much faster.


Christian