Bug 31344 – [Qt] Fix a problem in the qmake project files that caused nmake to reparse idl files every time.

• Component: Tools / Tests
• Status: RESOLVED FIXED

[Jocelyn Turcotte]

The processing of an idl file could generate both a .cpp and a .h. The way it worked is that the .cpp would be dependent on the idl, but the .h was dependent on the .cpp using a rule that reparse all idl files of that type.
If the .idl timestamp changed, it would recreate both as intended, however if the timestamp of the cpp was a bit later than the one of its sibbling .h, 
the command would be rerun.

[Jocelyn Turcotte]

Created attachment 42947 [details]
Patch

This patch make the .h use the same dependency list and generation command as the .cpp generated by the same idl.

[Simon Hausmann]

Comment on attachment 42947 [details]
Patch

Hmm, I see the problem. But this will break parallel builds, where make will execute the same command in parallel to generate both files at the same time:

If Foo.idl is processed by $cmd to generate Foo.cpp and Foo.h at the same time, then with this patch and a parallel build $cmd is executed twice and both processes will race for generating the two files.

[Jocelyn Turcotte]

Fixed in r53187