The crt0.o was handled in a subdir-by-subdir basis: it would be compiled
in one (e.g. libc/sys/$arch/), then copied up one level (libc/sys/), then
copied up another (libc/) before finally being copied & installed in the
top newlib dir. The libc/sys/ copy was cleaned up, and then the top dir
was changed to copy it directly out of the libc/sys/$arch/ dir. But the
libc/sys/ copy to libc/ was left behind. Clean that up now too.
These targets don't actually cross-compile -- they try to pull some
objects out of the host's /lib/libc.a, /lib/libm.a, and /lib/crt0.o
directly and merge them into newlib's own libraries. This is hard
to keep working and impossible to test. Considering the vintage of
such targets, and gcc dropping them many many years ago, drop them
from newlib too. This will make cleaning up the build a lot easier.
This was only ever used for i?86-pc-linux-gnu targets, but that's been
broken for years, and has since been dropped. So clean this up too.
This also deletes the funky objectlist logic since it only existed for
the libtool libraries. Since it was the only thing left in the small
Makefile.shared file, we can punt that too.
This was only used by the i?86-pc-linux-gnu target which we've removed,
and even though it's using a "sys/linux/" dir to make it sound like it
only depends on the Linux kernel, it's actually tied to glibc APIs built
on top of Linux. Since the code relies on internal glibc APIs and has
been broken for some time, punt it all. If someone wants to bring it
back, they can try and actually keep the Linux-vs-glibc APIs separate.
This logic was added to libc & libm to get it working again after some
reworks in the CPP handling, but now that that's settled, let's move
this to the common newlib configure logic. This will make it easier
to consolidate all the configure calls into the top-level newlib dir.
This does create a lot of noise in the generate scripts, but that's
because of the ordering of the calls, not because of correctness. We
will try to draw that back down in follow up commits as we modernize
the toolchain calls in here.
THe stdio subdir is actually required by the documentation. The
stdio/def is handled dynamically, but libc.texi always expects it
to be included, and fails if it isn't. So making it required when
building docs is safe.
The xdr subdir is handled dynamically, but it doesn't include any
docs, so the dynamic logic isn't (currently) adding any value. So
making it required when building docs is safe.
That leaves: iconv, stdio64, posix, and signal subdirs. The chapters
have a little disclaimer saying they are system-dependent, but even
then, imo having stable manuals regardless of the target is preferable,
and we can add more disclaimer language to these chapters if we want.
This doesn't touch the man page codepaths, just the info/pdf.
Restore the call to AC_NO_EXECUTABLES -- I naively assumed in commit
2e9aa5f56c ("newlib: update preprocessor
configure checks") that checking for a preprocessor would not involve
linking code. Unfortunately, autoconf will implicitly check that the
compiler "works" before allowing it to be used, and that involves a
link test, and that fails because newlib provides the C library which
is needed to pass a link test.
There is some code in NEWLIB_CONFIGURE specifically to help mitigate
these, but it's not kicking in here for some reason, so let's just add
the AC_NO_EXECUTABLES call back until we can unwind that custom logic.
Additionally, we have to call AC_PROG_CPP explicitly. This was being
invoked later on, but only in the use_libtool=yes codepath, and that
is almost never enabled.
The machine configure scripts are all effectively stub scripts that
pass the higher level options to its own makefile. There were only
three doing custom tests. The rest were all effectively the same as
the libc/ configure script.
So instead of recursively running configure in all of these subdirs,
generate their makefiles from the top-level configure. For the few
unique ones, deploy a pattern of including subdir logic via m4:
m4_include([machine/nds32/acinclude.m4])
Some of the generated machine makefiles have a bunch of extra stuff
added to them, but that's because they were inconsistent in their
configure libtool calls. The top-level has it, so it exports some
new vars to the ones that weren't already.
The sys configure scripts are almost all effectively stub scripts that
pass the higher level options to its own makefile. The phoenix & linux
ones are a bit more complicated with nested subdirs, so those have been
left alone for now. Plus, I don't really have a way of testing them.
There's no need to have a sys/ subdir just to copy the sys/$arch/crt0.o
up to sys/crt0.o, and then have libc/ copy sys/crt0.o up again. Just
have libc/ refer to sys/$arch/crt0.o directly and drop the intermediate
makefile entirely.
The sys/{configure,Makefile} files exist to fan out to the specific
sys/$arch/ subdir, and to possibly generate a crt0. We already have
all that same info in the libc/ dir itself, so by moving the recursive
configure and make calls into it, we can cut off some of this logic
entirely and save the overhead.
For arches that don't have a sys subdir, it means they can skip the
logic entirely.
The sys subdir itself is kept for the crt0 logic, for now. We'll try
and clean that up next.
The machine/{configure,Makefile} files exist only to fan out to the
specific machine/$arch/ subdir. We already have all that same info
in the libc/ dir itself, so by moving the recursive configure and
make calls into it, we can cut off this logic entirely and save the
overhead.
For arches that don't have a machine subdir, it means they can skip
the logic entirely. Although there's prob not too many of those.
This was added decades ago, but the commit message lacks any
explanation, and it was unused when it was merged. It's still
unused today. So punt it all.
Now that we require a recent version of autoconf, we can rely on this
macro working. This change was already made to libm, but these other
dirs were missed as I didn't notice it being duplicated in 3 places.
The AC_LIBTOOL_WIN32_DLL macro has been deprecated for a while and code
should call LT_INIT with win32-dll instead. Update the calls to match.
The generated code is noisy not because of substantial differences, but
because the order of some macros change (i.e. instead of calling AS and
then CC, CC is called first and then AS).
The newlib & libgloss dirs are already generated using autoconf-2.69.
To avoid merging new code and/or accidental regeneration using diff
versions, leverage config/override.m4 to pin to 2.69 exactly. This
matches what gcc/binutils/gdb are already doing.
The README file already says to use autoconf-2.69.
To accomplish this, it's just as simple as adding -I flags to the
top-level config/ dir when running aclocal. This is because the
override.m4 file overrides AC_INIT to first require the specific
autoconf version before calling the real AC_INIT.
Mike Frysinger