[CMake] Problems with parallel builds

[Denis Scherbakov]

David,

Thank you for spending your time to resolve my problem.

Unfortunately you suggestion did not help.

Introduction of new custom targets in my case leads to the fact that
I have one custom target that depends on another custom target. I get:

gmake[3]: *** No rule to make target 'customTargetA', needed by 'customTargetB'.  Stop.

And in this case it is not even a parallel build.

Now I remember that I already tried this custom-target trick about
a year ago and it failed with "gmake" error I specified above.

So CMake is not parallel build ready.
BTW, "gmake -j4 targetA targetB" also fails. You need to "gmake -j4 targetA"
and then "gamake -j4 targetB" to get correct results.

Denis

--- On Thu, 11/18/10, David Cole <david.cole at kitware.com> wrote:

> From: David Cole <david.cole at kitware.com>
> Subject: Re: [CMake] Problems with parallel builds
> To: "Denis Scherbakov" <denis_scherbakov at yahoo.com>
> Cc: cmake at cmake.org
> Date: Thursday, November 18, 2010, 6:43 AM
> Try:
> ADD_CUSTOM_TARGET(MyHeaders ALL DEPENDS MyFile.hh)
> 
> Without the "ALL" your target is not included in the set of
> targets
> built by a "make" or a "make all" -- without your target
> included in
> "make" there is nothing for the subsequent targets to
> depend on.
> Perhaps we should add a warning to add_dependencies if
> expressing a
> dependency on something not in "all" by default....
> 
> 
> On Thu, Nov 18, 2010 at 9:33 AM, Denis Scherbakov
> <denis_scherbakov at yahoo.com>
> wrote:
> > Hi, David,
> >
> > I did as you suggested:
> >
> > ADD_CUSTOM_COMMAND(OUTPUT MyFile.hh ...)
> > ADD_CUTSOM_TARGET(MyHeaders DEPENDS MyFile.hh)
> >
> > ADD_LIBRARY(MYLIB ${MYLIB_SRCS})
> > ADD_DEPENDENCIES(MYLIB  MyHeaders)
> >
> > ADD_LIBRARY(MYLIBpic ${MYLIB_SRCS})
> > ADD_DEPENDENCIES(MYLIBpic  MyHeaders)
> >
> > Didn't work. Target "MyHeaders" is build two times
> when I do "gmake -j2"
> > I see two "Generating MyFile.hh" lines and MyFile.hh
> has duplicate lines.
> >
> > Denis
> >
> >> David Cole wrote:
> >>
> >> The easiest way to make this work is to have a
> separate
> >> custom target
> >> that depends on the output of the custom command,
> and then
> >> to have the
> >> two libraries depend on that custom target with
> >> add_dependencies...
> >>
> >
> >
> >
> >
>