Somehow "patch #0" of my series didn't go out. So, I'm sending it separately. Sorry about that. I don't know what happened, so I wouldn't be totally surprised if it made its way to the list some day :)
This patch series resurrects my automatic dependency tracking patch from eons ago. That patch was ultimately reverted due to a GNU make bug. This time around, thanks to git, I chose to make a patch series. This way, even if we stumble across the bug again (it is not clear it was ever fixed), we can determine which patch triggers it, and still possibly gain some benefit from the remaining patches. This series is not "complete" in the sense that there are automatic dependency tracking opportunities that it does not implement. In particular, these still remain to be converted: * The files in config/ * The Ada front end * The "build" objects Still, I think this series is a big improvement over the status quo. If you read patch #14, you'll see that it deletes a huge number of hand-maintained dependencies. The overall approach used here is the one that has been used by many projects for many years -- at least including all automake-based projects, libcpp, and gdb. It is reasonably robust. Dependencies are generated as a side effect of compilation. These dependencies are then written to ".Po" files in the build tree; they are included into the Makefile via the GNU make "include" feature. The only difficulty here is that generated files must be built before object files. In order to avoid hand-maintaining dependencies on generated files, we have an order-only dependency (another GNU make feature) to ensure that generated files are built before we build any host .o. This series fixes a few latent bugs in the current Makefiles. I tested this by bootstrapping it on x86-64 Fedora 18, and also PPC64 Fedora 18 (gcc110 -- nice machine). I also did a number of clean builds of the gcc directory at various -j levels (including -j129 -- thank you gcc110) to try to flush out any missing dependencies on generated files. This is essentially the same series as appears on the branch in gcc.git. It has just been rebased into a patch series form. Thank you again, git. Let me know what you think. Tom
