Convert all the libm/ subdir makes into the top-level Makefile. This
allows us to build all of libm from the top Makefile without using any
recursive make calls. This is faster and avoids the funky lib.a logic
where we unpack subdir archives to repack into a single libm.a. The
machine override logic is maintained though by way of Makefile include
ordering, and source file accumulation in libm_a_SOURCES.
One thing to note is that this will require GNU Make because of:
libm_a_CFLAGS = ... $(libm_a_CFLAGS_$(subst /,_,$(@D)))
This was the only way I could find to supporting per-dir compiler
settings, and I couldn't find a POSIX compatible way of transforming
the variable content. I don't think this is a big deal as other
Makefiles in the tree are using GNU Make-specific syntax, but I call
this out as it's the only one so far in the new automake code that
I've been writing.
Automake doesn't provide precise control over the output object names
(by design). This is fine by default as we get consistent names in all
the subdirs: libm_a-<source>.o. But this relies on using the same set
of compiler flags for all objects. We currently compile libm/common/
with different optimizations than the rest.
If we want to compile objects differently, we can create an intermediate
archive with the subset of objects with unique flags, and then add those
objects to the main archive. But Automake will use a different prefix
for the objects, and thus we can't rely on ordering to override.
But if we leverage $@, we can turn Automake's CFLAGS into a multiplex
on a per-dir (and even per-file if we wanted) basis. Unfortunately,
since $@ contains /, Automake complains it's an invalid name. While
GNU Make supports this, it's a POSIX extension, so Automake flags it.
Using $(subst) avoids the Automake warning to get a POSIX compliant
name, albeit with a GNU Make extension.
This is used in a bunch of places, but nowhere is it ever set, and
nowhere can I find any documentation, nor can I find any other project
using it. So delete the flags to simplify.
These look like they were just copied & pasted from common/Makefile.am.
The funcs in this dir are all stubs that don't actually call any math
or builtin functions, and a simple compile shows they produce identical
object code. So delete to simplify the build rules.
This kills off the last configure script under libm/ and folds it
into the top newlib configure script. The vast majority of logic
was already in the top configure script, so move the little that
is left into a libm/acinclude.m4 file.
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.
Now that we use AC_NO_EXECUTABLES, and we require a recent version of
autoconf, we don't need to define our own copies of these macros. So
switch to the standard AC_PROG_CC.
This allows building the libc & libm pages in parallel, and drops
the duplication in the subdirs with the chew/chapter settings.
The unused rules in Makefile.shared are left in place to minimize
noise in the change.
When using the top-level configure script but subdir Makefiles, the
newlib_basedir value gets a bit out of sync: it's relative to where
configure lives, not where the Makefile lives. Move the abs setting
from the top-level configure script into acinclude.m4 so we can rely
on it being available everywhere. Although this commit doesn't use
it anywhere, just lays the groundwork.
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.
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 libm/ 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.
This matches what the other GNU toolchain projects have done already.
The generated diff in practice isn't terribly large. This will allow
more use of subdir local.mk includes due to fixes & improvements that
came after the 1.11 release series.
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 'cygnus' option was removed from automake 1.13 in 2012, so the
presence of this option prevents that or a later version of automake
being used.
A check-list of the effects of '--cygnus' from the automake 1.12
documentation, and steps taken (where possible) to preserve those
effects (See also this thread [1] for discussion on that):
[1] https://lists.gnu.org/archive/html/bug-automake/2012-03/msg00048.html
1. The foreign strictness is implied.
Already present in AM_INIT_AUTOMAKE in newlib/acinclude.m4
2. The options no-installinfo, no-dependencies and no-dist are implied.
Already present in AM_INIT_AUTOMAKE in newlib/acinclude.m4
Future work: Remove no-dependencies and any explicit header dependencies,
and use automatic dependency tracking instead. Are there explicit rules
which are now redundant to removing no-installinfo and no-dist?
3. The macro AM_MAINTAINER_MODE is required.
Already present in newlib/acinclude.m4
Note that maintainer-mode is still disabled by default.
4. Info files are always created in the build directory, and not in the
source directory.
This appears to be an error in the automake documentation describing
'--cygnus' [2]. newlib's info files are generated in the source
directory, and no special steps are needed to keep doing that.
[2] https://lists.gnu.org/archive/html/bug-automake/2012-04/msg00028.html
5. texinfo.tex is not required if a Texinfo source file is specified.
(The assumption is that the file will be supplied, but in a place that
automake cannot find.)
This effect is overriden by an explicit setting of the TEXINFO_TEX
variable (the directory part of which is fed into texi2X via the
TEXINPUTS environment variable).
6. Certain tools will be searched for in the build tree as well as in the
user's PATH. These tools are runtest, expect, makeinfo and texi2dvi.
For obscure automake reasons, this effect of '--cygnus' is not active
for makeinfo in newlib's configury.
However, there appears to be top-level configury which selects in-tree
runtest, expect and makeinfo, if present. So, if that works as it
appears, this effect is preserved. If not, this may cause problem if
anyone is building those tools in-tree.
This effect is not preserved for texi2dvi. This may cause problems if
anyone is building texinfo in-tree.
If needed, explicit checks for those tools looking in places relative to
$(top_srcdir)/../ as well as in PATH could be added.
7. The check target doesn't depend on all.
This effect is not preseved. The check target now depends on the all
target.
This concern seems somewhat academic given the current state of the
testsuite.
Also note that this doesn't touch libgloss.
So far the build mechanism in newlib only allowed to either define
machine-specific headers, or headers shared between all machines.
In some cases, architectures are sufficiently alike to share header
files between them, but not with other architectures. A good example
is ix86 vs. x86_64, which share certain traits with each other, but
not with other architectures.
Introduce a new configure variable called "shared_machine_dir". This
dir can then be used for headers shared between architectures.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
The default implementation of the fenv.h methods return
-EOPNOTSUP. Some of these have implementations appropriate
for soft-float.
The intention of the new fenv.h is that it be portable
and that architectures provide their own implementation
of sys/fenv.h.
Mike Frysinger
Jon Turney
David Macek
Corinna Vinschen
Jeff Johnston
Joel Sherrill