This was disabled as part of the migration away from the cygnus option
as that implied no-dependencies.
We currently have 1-to-1 updates enabled -- if you touch a .c file,
the corresponding .o file will be rebuilt. But if you touch a header
file, none of the files using that get rebuilt.
Integrate the old libm/test/ subdir into the main build. It hasn't
been used in a long time causing the code to rot a bit. I've fixed
some of those, but it still fails for many ports, so it's disabled
by default. People who want to take a closer look can run:
$ make libm/test/test
To help prevent people from missing running this script, integrate it
into the build via maintainer mode.
Also fix the inverted exit status to make this work correctly -- for
some reason, it exited 1 when it worked, and 0 when it failed.
Replace all of the individual autotool steps with a single autoreconf.
This simplifies the documentation greatly, and in the current system,
only takes ~10 seconds to regenerate everything.
Update the developer documentation to cover all the major components
of the current build system. Hopefully this is a fairly complete road
map to everything. I tried to include everything that I wish I knew
when I started hacking on this :P.
Convert all the libc/ subdir makes into the top-level Makefile. This
allows us to build all of libc 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 libc.a. The
machine override logic is maintained though by way of Makefile include
ordering, and source file accumulation in libc_a_SOURCES.
There's a few dummy.c files that are no longer necessary since we aren't
doing the lib.a accumulating, so punt them.
The winsup code has been pulling the internal newlib ssp library out,
but that doesn't exist anymore, so change that to pull the objects.
Rather than define per-object rules in the Makefile, have small files
that define & include the right content. This simplifies the build
rules, and makes understanding the source a little easier (imo) as it
makes all the subdirs behave the same: you have 1 source file and it
produces 1 object. It's also about the same amount of boiler plate,
without having to define custom build rules that can fall out of sync.
We also realign the free & pvalloc definitions: common code puts these
in malloc.o & valloc.o respectively, not in free.o & pvalloc.o objects.
This will also be important as we merge the libc.a build into the top
dir since it relies on a single flat list of objects for overrides.
The mallopt symbol is defined in tiny-malloc.c, not mallocr.c, but
the Makefile in here tries to compile it out of the latter. This
leads to mallopt never being defined.
The build also creates mallinfo.o & mallopt.o & mallstats.o objects
to override common ones, but the common dir doesn't use these names.
Instead, it places these all in mstats.o.
So move the build define logic to a dedicated file and compile it
directly to make things a bit simpler while fixing the missing func
and aligning objects with the cmomon code.
Rather than define per-object rules in the Makefile, have small files
that define & include the right content. This simplifies the build
rules, and makes understanding the source a little easier (imo) as it
makes all the subdirs behave the same: you have 1 source file and it
produces 1 object. It's also about the same amount of boiler plate,
without having to define custom build rules that can fall out of sync.
This will also be important as we merge the libc.a build into the top
dir since it relies on a single flat list of objects for overrides.
Also take the opportunity to clean up the unnecessary header deps in
here. Automake provides dependency generation for free now.
Some awk implementations such as old versions of mawk do not support the
length() function. Use the return value of the POSIX split() function instead.
This file is a little confusing: it provides all of the mallocr logic,
but is compiled multiple times to produce a unique symbol each time.
For example, building mallocr.c with -DDEFINE_FREER produces freer.o
that only defines _free_r(). This is fine for most symbols, but it's
a little confusing when defining mallocr itself -- we produce a file
with the same symbol name, but we still need -DDEFINE_MALLOCR. In
order to move the logic from the build rules to source files, using
mallocr.c both as a multiplexer and for defining a single symbol is a
bit tricky. It's possible (if we add a lot of redundant preprocessor
checks to mallocr.c, or we add complicated build flags just for this
one files), but it's easier if we simply rename this to a dedicated
file. So let's do that.
We do this as a dedicated commit because the next one will create a
new mallocr.c file and git's automatic diff algorithms can handle
trivial renames, but it can't handle renames+creates in the same
commit.
Simplify the build system logic a bit by moving the mallocr.c ->
nano-mallocr.c redirection from the Makefile to the source files.
This allows for consistent object name usage regardless of the
configuration options used in case a machine dir wants to define
its own override.
Since we already set up _LIBC to indicate source files are building
for newlib, we don't need this malloc-specific symbol. Convert it
over to simplify the build a bit.
The current targ-include setup runs `cp` every header file it installs,
in serial. This can be a little noticeable on systems, so cleanup the
logic to rely on cp's ability to copy multiple files to a directory in
a single call.
We still need a check for empty directories with no headers (i.e. the
glob doesn't match anything), so add a helper variable to contain that
logic to reduce the boiler plate a little.
Rather than define per-object rules in the Makefile, have small files
that define & include the right content. This simplifies the build
rules, and makes understanding the source a little easier (imo) as it
makes all the subdirs behave the same: you have 1 source file and it
produces 1 object. It's also about the same amount of boiler plate,
without having to define custom build rules that can fall out of sync.
Some of these rules were already unnecessary as they were compiling a
single source file into the same named object w/out custom flags, and
Automake handles that for us completely.
This will also be important as we merge the libc.a build into the top
dir since it relies on a single flat list of objects for overrides.
Also take the opportunity to clean up the unnecessary header deps in
here. Automake provides dependency generation for free now.
Since POSIX cp requires copying a file to a directory without having
to specify the name explicitly, rely on that to avoid calling basename
on every source file.
We can also drop the stub `true` call if the -f test failed. The use
of `if` already takes care of that in POSIX shell.
This kills off the last configure script under libc/ and folds it
into the top newlib configure script. The a lot of the logic was
already in the top configure script, so move what's left into a
libc/acinclude.m4 file.
I split libg.a out into a sep target from libc.a for the main dir in
commit f2b053f49e ("newlib: separate out
libg from libc"), but missed the multilib dirs. That leads to an
uncommon parallel build failure:
- libc.a rule runs & finishes
- $(BUILD_MULTISUBDIR)/libc.a rule runs
-> failure due to libg.a not yet existing
- libg.a rule runs & finishes
Split the multilib libg rule out from libc too so it can depend on the
main libg directly and avoid this race.
Remove dependency on __sdidinit member of struct _reent to check
object initialization. Like __sdidinit, the __cleanup member of
struct _reent is initialized in the __sinit() function. Checking
initialization against __cleanup serves the same purpose and will
reduce overhead in the __sfp() function in a follow up patch.
The crt0.o was handled in a subdir-by-subdir basis: it would be compiled
in one (e.g. libc/sys/$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 headers aren't installed, so use "" includes instead of <> so
we don't search system header paths. This matches the style used
elsewhere in the tree for these local headers, and makes it work
w/out explicit -I flags (as needed with non-recursive make).
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.
Make this a separate target from libc so that we can migrate libc over
to automake more easily. Having it integrated into the libc target is
difficult to handle when using automake rules which expect a one-to-one
mapping between names & inputs.
When migrating the manual to the top-level, the include order was
sorted by name of the subdir. But this changed the chapter order
of the manual in the process. Change the sorting back to match
existing chapters and update the comments to explain.
Using xxx_LIBADD, xxx_DEPENDENCIES, and EXTRA_xxx_SOURCES is one way of
conditionally including files into a target. But it's meant more for the
cases where the variables added to LIBADD & DEPENDENCIES are constructed
via substitution (e.g. AC_SUBST) or other dynamic methods. With Automake
conditionals, then the much simpler form is to conditionally append to
the xxx_SOURCES variable and let Automake sort everything out.
Commit 8fa73a9f84 changed how fenv.c is
compiled wrt mips16 targets used the wrong variable to add fenv.o to
libm.a. Fix that thinko so it's included in the build again.
The top-level newlib dir already takes care of recursing into the
sys/xxx/include/ subdirs and installing any headers found, so the
rtems subdir doesn't need to do this itself.
Replace the custom build rules (which require copying & pasting from the
current Makefile) with small stub files. This allows us to drop the rules
entirely and let Automake provide everything.
These subdirs don't actually use anything from libm. The common dir
in particular only has 4 header files, and none are included here.
The xstormy16 code has a comment mentioning why this hack is here, but
it refers to code that was removed when its configure script was merged
up a level.
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 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.
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 phoenix/ dir itself, so by moving the recursive configure and
make calls into it, we can cut off this logic entirely and save the
overhead.
These were never added to the tree, and as we transition from autoconf
to automake, it really wants the latter subdirs to always exist. These
don't, so delete the logic.
The original cut for small arguments at |x|<2**-70 (copied from the
double version) produces that when computing nadj we get a subnormal
number for t*x and thus, the division of pi/subnormal will be INF and
the logarithm of it too, which is wrong as a result for lgammaf in this
range.
The proposed new limit seems to be safe and has been tested to
produce accurate results.
(Courtesy of Andreas Jung, ESA)
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.
Correct the overflow limit in the variable o_threshold to be consistent
with the FLT_UWORD_LOG_MAX variable used by the internal implementation
of the expf algorithm itself.
The u_threshold variable has also been modified to be written in the
same format.
Note that this fix improves the situation but does not completely
correct the inconsistencies regarding the overflow and underflow limits
between the expf wrapper (wf_exp.c) and the expf algorithm itself
(ef_exp.c).
Currently these limits are different for the
_FLT_LARGEST_EXPONENT_IS_NORMAL and _FLT_NO_DENORMALS cases as well as
for the case where __OBSOLETE_MATH is not defined (only for the
underflow limit in this case).
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.
Mike Frysinger
Sebastian Huber
Jeff Johnston
Matt Joyce
Andoni Arregi