[cmake-developers] [PATCH] Qt4Macros generate resources with same file name

[Clinton Stimpson]

How does qmake handle this conflict of resource names?

The QT4_MAKE_OUTPUT_FILE() part looks fine to me.

However, have you considered an alternative to 
string(RANDOM LENGTH 16 outfilename)
which is to allow the caller to pass in the "-name ..." option.

qt4_add_resources(app_source_res res_a.qrc OPTIONS -name res_a)
qt4_add_resources(app_source_res res_b.qrc OPTIONS -name res_b)

If the caller needs truly random names, the caller could still do a 
string(RANDOM ...).

Clint

On Tuesday, November 24, 2015 11:01:27 AM Joseph Shen wrote:
> Dear CMake developers:
> 
> Please view attached small patch that try to fix Qt4Macros generate
> resources with same file name error.
> 
> Right now, in the CMake main branch, using cmake with Qt4 library
> add resources project can be done like this:
> 
>      qt4_add_resources(app_source_res res_a.qrc)
>      qt4_add_resources(app_source_res res_b.qrc)
> 
> and above two line added two resource file, but if we try to add resource
> file with same name, a very subtle error will happen: only one file will
> be compile the as resources, and the other was totally ignored.
> 
> In some big projects, using the same file name as resource file name
> can be very common, especially when we using multi cmake files try
> to make the whole project into small ones, in each cmake files someone
> maybe just using the same resources file name like res.qrc which is
> located in the sub module resources folder.
> 
>        qt4_add_resources(app_source_res res.qrc)
> 
> so, if they try to do this, and in the last add ${app_source_res} to the
> dependency list using:
> 
>       add_executable(project_name ${app_source_res} ...)
> 
> but in reality they just add one resources file, but CMake do not report
> any error or warning.
> 
> From the source of Qt4Macros we can see:
> 
> line 211:   get_filename_component(outfilename ${it} NAME_WE)
> line 244:   ARGS ${rcc_options} -name ${outfilename} -o ${outfile} ${infile}
> 
> 
> became we just using NAME_WE as the output file, if two files with same
> file name, one will overwrite the other, and this is the reason why the
> error
> will happen.
> 
> To fix this, I view the whole Qt4Macros source file, find a function
> QT4_MAKE_OUTPUT_FILE already exist to do something just what we
> need. so I work out a patch add two line code and remove two, and it works
> good to me, and I think this might fix the problem.
> 
> Please view this patch, thanks :)