On Wed, Sep 22 2021, Junio C Hamano wrote: > Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> writes: > >> The "COMPUTE_HEADER_DEPENDENCIES" feature added in [1] was extended to >> use auto-detection in [2]. Then when -Wpedantic support was added to >> DEVOPTS in [3] we started passing -Wpedantic in combination with >> -Werror to the compiler here. >> >> This broke the auto-detection, but since we'd quieted it in [4] we >> didn't find out. > > Are the references correct? I am not seeing "quiet"ing in [4]. The > redirection 2>&1 to cram error messages also to $(dep_check), hence > making it impossible to match '0', was done in [2]. Yes it's incorrect, I meant [2]. I had this right in my head, just got the references wrong somehow,thanks. > We did make the pedantic mode the default and pass both -pedantic > and -Wpedantic after [4]. Before we had only -pedantic. *nod* >> It was emitting all of this on STDERR under GCC: >> >> /dev/null:1: error: ISO C forbids an empty translation unit >> [-Werror=pedantic] >> cc1: note: unrecognized command-line option >> ‘-Wno-pedantic-ms-format’ may have been intended to silence >> earlier diagnostics >> cc1: all warnings being treated as errors >> >> Let's fix that bug by maintaining a NON_DEVELOPER_CFLAGS, it's like >> ALL_CFLAGS but without anything we add in config.mak.dev, and >> furthermore stop redirecting STDERR to /dev/null, this means that >> someone whose compiler doesn't support this will see this output, but >> also this new message: >> >> Non-zero 1 exit with COMPUTE_HEADER_DEPENDENCIES=auto, set it to "yes" or "no" to quiet auto-detect > > > Hmmmmmph. > > I recentaly saw many .depend directories (not necessarily empty) > left after "make distclean". After building on one branch, I often > check out a different branch then run distclean on the new branch, > so leftover build artifacts are not necessarily a bug in our > Makefile, but the bug you found may explain it? Yes, I'll update the commit message, the problem is that we'll empty the dep_dirs list if we're not *currently* making them, that's a logic error in a few places in the Makefile, i.e. conflating currently building X with wanting to clean X. [Will respond to the rest with a re-roll and/or in other replies in-thread]
