[CMake] Generating include files

[Urs Thuermann]

Michael Ellery <mellery451 at gmail.com> writes:

> if your source can be generated by simple substitution of variable
> values (like a template file), then configure_file() will do the
> trick. If the process to create the file is more complex, then
> add_custom_command() with an appropriate OUTPUT specification is
> probably what you want, something like:

Yes, the awk example was a simplification.  The table to be generated
is much larger using a somewhat more complex specification.  I don't
want to calculate at run-time in foo.c, but at compile-time so that it
can go into a static const int array.

> add_custom_command(OUTPUT tab.c  COMMAND "awk -f mktab > tab.c")

I have tried dozens of combinations with add_custom_command(),
include_directories(), and ${CMAKE_BINARY_DIR}.  Also the way you
show.  But the only way I found to have tab.c actually generated was
to put tab.c into the add_executable() specification, but then it
generates a tab.o which is linked into the executable.  But I want to
have the tab[] static, i.e. included into a C file, not linked in.

> You will need to make sure that some other target explicitly depends
> on tab.c (or whatever you name the output) to cause this custom rule
> to be executed.

Is there a way to specify that foo.o depends on tab.c?  For some
reason cmake's scan does not seem to find this.

urs