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.
When we had configure scripts in subdirs, the newlib_basedir value
was computed relative to that, and it'd be the same when used in the
Makefile in the same dir. With many subdir configure scripts removed,
the top-level configure & Makefile can't use the same relative path.
So switch the subdir Makefiles over to abs_newlib_basedir when they
use -I to find source headers.
Do this for all subdirs, even ones with configure scripts and where
newlib_basedir works. This makes the code consistent, and avoids
surprises if the configure script is ever removed in the future as
part of merging to the higher level.
Some of the subdirs were using -I$(newlib_basedir)/../newlib/ for
some reason. Collapse those too since newlib_basedir points to the
newlib source tree already.
The machine configure scripts are all effectively stub scripts that
pass the higher level options to its own makefile. The only one doing
any custom tests was nds32. The rest were all effectively the same as
the libm/ configure script.
So instead of recursively running configure in all of these subdirs,
generate their makefiles from the top-level configure. For nds32,
deploy a pattern of including subdir logic via m4:
m4_include([machine/nds32/acinclude.m4])
Even its set of checks are very small -- it does 2 preprocessor tests
and sets up 2 makefile conditionals.
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.
Since automake already sets per-library CCASFLAGS to $(AM_CCASFLAGS)
by default, there's no need to explicitly set it here.
Many of these dirs don't have .S files in the first place, so the rule
doesn't even do anything. That can easily be seen when Makefile.in has
no changes as a result.
For the dirs with .S files, the custom rules are the same as the pattern
.S.o rules, so this is a nice cleanup.
The only dir that was adding extra flags (newlib/libc/machine/mn10300/)
to the per-library setting can have it moved to the global AM_CCASFLAGS
since the subdir only has one target. Although the setting just adds
extra debugging flags, so maybe it should be deleted in general.
There are a few dirs that we leave the redundant setting in place. This
is to workaround an automake limitation in subdirs that support building
with & w/out libtool:
https://www.gnu.org/software/automake/manual/html_node/Objects-created-both-with-libtool-and-without.html
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.
Since automake deprecated the INCLUDES name in favor of AM_CPPFLAGS,
change all existing users over. The generated code is the same since
the two variables have been used in the same exact places by design.
There are other cleanups to be done, but lets focus on just renaming
here so we can upgrade to a newer automake version w/out triggering
new warnings.
The code accessing the floating point control/status register, namely
#define __cfc1(__fcsr) __asm __volatile("cfc1 %0, $31" : "=r" (__fcsr)
does not compile with mips16. This changed the makefile to pass -mno-mips16 to avoid the following
compiler error:
mips-mti-elf fails with "Error: unrecognized opcode `cfc1 $3,$31'"
