[petsc-users] Makefile options to leave .o files?

[Jed Brown]

On Thu, Sep 16, 2010 at 20:26, Keita Teranishi <keita at cray.com> wrote:
> I have observed that the default option of the makefile at the main
> directory deletes libpetsc.a file before compiling the source code files.
>   Is there any options that keep libpetsc.a, and only compile those modified
> after libpetsc.a?

You can run make from subdirectories, but PETSc's normal recursive
make system does not do proper dependency analysis.  If you are using
petsc-dev, there are two options.

config/builder.py leaves the .o files behind, but will require
rebuilding everything each time you switch PETSC_ARCH (this is an
implementation issue that could be fixed).

If you have CMake (>=2.6.2) installed, you can run make from the build
directory (as in make -j5 -C $PETSC_DIR/$PETSC_ARCH, the environment
variables are irrelevant for this option).  This will only rebuild
what is necessary, and the .o files are separate for each PETSC_ARCH.

Jed