On 2021-05-03 5:51 p.m., Alan Modra wrote: > I wasn't talking about running configure, I was talking about running > make. For example, you configure and make binutils as usual, then > after making a change to ld/ files, run make in the ld build dir. I > don't tend to do that myself but I do run "make check" sometimes in a > subdir expecting to get the same results in that subdir as if "make > check" was run from the top level.
Ah yeah, that works just fine. During my edit-build-cycle, I typically only "make" in gdb/, or whatever I'm working on at the moment. It saves some precious milliseconds! > But I should have just tried it myself rather than asking. CC, CPP > and others are inherited from the top level and appear with -std=gnu99 > in the subdir Makefiles. So it seems all the AC_PROG_CC in subdir > configure.ac can stay as they are. Yes, the top-level passes CC=... and others when it configures the subdirectories. The subdirectories remember how they were configures (in config.status), so that even if a "make" in the subdirectory ends up re-running configure (because configure changed), the CC value will be remembered. Simon