This patch promotes the PKGVERSION and BUGURL options to toolchain level so that
all toolchain components supporting them can benefit from them.
These options are passed to configure through --with-pkgversion and
--with-bugurl.
They are supported by binutils 2.18+, gcc 4.3+, eglibc 2.9+ and gdb 7.0+.
Signed-off-by: "Benoît THÉBAUDEAU" <benoit.thebaudeau@advansee.com>
This patch adds a blind option CC_GCC_HAS_PKGVERSION_BUGURL to test the support
of --with-pkgversion and --with-bugurl by GCC's configure.
Signed-off-by: "Benoît THÉBAUDEAU" <benoit.thebaudeau@advansee.com>
kconfig bools are disabled by default, so specifying 'default n' is useless and
noisy. This patch removes all occurrences of 'default n'.
Signed-off-by: "Benoît THÉBAUDEAU" <benoit.thebaudeau@advansee.com>
If check_for is able to find the required prog/inc/lib, allow it to
set an arbitrary variable to 'y'. This variable is then pushed down
to the kconfig definition.
For example:
has_or_abort prog=foobar kconfig=has_foobar
If foobar is available, it yields a kconfig variable defaulting to y:
config CONFIGURE_has_foobar
bool
default y
If foobar is missing, it yields a kconfig variable defaulting to n:
config CONFIGURE_has_foobar
bool
Thus it is possible to depends on that variabel to show/hide options:
config SOME_FEATURE
bool
prompt "Some feature"
depends on CONFIGURE_has_foobar
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Update help entries for thos variables that accept multiple
arguments with spaces (aka. array-capable variables).
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Make it explicit that a variable is an array bu the name of the variable.
It will be used later when .config gets munged to allow both multiple
arguments and arguments with spaces at the same time to be passed from the
configuration down to the build scripts.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Now that kconfig can include a file multiple times, link the glibc/eglibc
common stuff to two .in.2 files.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
The latest kconfig stuff is more stringent when it comes to validating
the dependency of the symbols. It is no longer possible to have a symbol
depend on itself (such as our construct for arch/cc/libc/... was doing).
Fix our generated-file infrastructure to avoid these situations when the
new kconfig stuff will be merged (in a following changeset).
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Since the gcc configuration changes, the way to select the
dependent companion libraries has changed. The addToolVersion
script was not updated to match, and a new gcc version was
added with this script.
Fix the gcc version; the script will be updated in a subsequent
changeset.
Reported-by: Xun Li <lxfind@gmail.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
It can be quite confusing for a new-comer to find strange
version numbers for gdb, so hide the Linaro versions by
default.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Move options around so it feels more organised.
Add comments to separate groups of related options.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Re-organise the sub-menu so that:
- the kernels list comes first,
- followed by kernels generic options
- followed by kernels specific options
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Re-organise the sub-menu so that:
- the archs list comes first,
- followed by archs generic options
- followed by archs specific options
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
In backend mode, setting the sysroot name is the
responsibility of the upper-layer build system.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Managing the shared version of the companion libraries
has become cumbersome.
Also, it will one day be possible to use the companion
libraries from the host distribution, and then we will
be able to easily use either shared or static libs.
As a side note, while working on the canadian-rework
series, it has become quite more complex to properly
handle shared companion libraries, as they need to be
built both for the build and gost systems. That's not
easy to handle. At all.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
gold can not build glibc/eglibc, force use of the BFD
linker during the toolchain build.
Reported-by: Bill Pringlemeir <bpringle@sympatico.ca>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
gold is not capable of building glibc/eglibc, so we have to
force using the BFD linker, ld.bfd.
Offer a blind option that affected components can select to
force use of the BFD linker during the build.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
gold is not capable of building glibc/eglibc. See this thread:
http://sourceware.org/ml/crossgcc/2011-04/msg00010.html
Reported-by: Bill Pringlemeir <bpringle@sympatico.ca>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
The gold linker does currently support only a limited set of architectures:
- x86 (32- and 64-bit)
- ARM
Hide the gold option for other architectures.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Add support for building SPARC targeted toolchain.
With this patch I have built a working sparc V8 (32 toolchain).
Testing shows that not all gcc versions works well:
4.4.1 OK (kernel builds and the final kernel can boot)
4.4.2 Not tested
4.4.3 Not tested
4.4.4 BAD (Kernel can build but fails during boot)
4.4.5 BAD (Kernel can build but fails during boot)
4.5.1 BAD (Build fails with a spill related ICE - http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35664)
4.5.2 OK (kernel builds and boots)
I have successfully been using the 4.5.2 version for a few months.
This patch does not add support for the LEON variant.
That may come later.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
[yann.morin.1998@anciens.enib.fr: for 32-bit, default CT_TARGET_ARCH is OK]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
PPL 0.11+ installs three libs: lippl, libppl_c and libpwl.
libppl_c has a dependency on libpwl (at least for watchdog stuff).
While gcc correctly links with libppl and libppl_c, it does not
pull libpwl in. In case of shared libs, this is not a problem, as
libppl_c has a NEEDED dependency on libpwl. But for static libs,
that does not work. Although libppl_c.la exists and has a correct
dependency on lipwl, somehow gcc misses it. So we have to force
pulling libpwl when needed.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
It can be quite confusing for a new-comer to find strange
version numbers for gcc, so hide the Linaro versions by
default.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Before gcc 4.6 was released, Linaro has a pre-release available.
Include that version in the config list.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
So far, we've had a version always select appropriate _or_later option,
which in turn would select all previous _or_later options.
Because the dependencies on companion libs were cumulative, that was
working OK. But the upcoming 4.6 will no longer depend on libelf, so
we can't keep the cumulative scheme we've been using so far.
Have each release family select the corresponding dependencies, instead
of relying on selecting previous _or_later.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Plugins are shared objects, and when building a toolchain statically,
the gcc build system breaks havok (although there is no hard technical
reasons it should not be possible)...
And consequently, do not enable plugin supoprt in binutils.
Reported-by: Thomas Spurden <thomas@ado.is-a-geek.net>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
In fact, it is only supported in a few legacy versions.
Keep LT available for all eglibc versions, although it might need
a similar safeguard...
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
By default, recent versions of glibc and eglibc will build some
functions that take format strings (eg. printf, syslog...) with
run-time checks against some format string attacks. This is
called a fortified build.
Unfortunately, this fails somehow while building the instrumented
version of syslog, with some kind of circular dependency...
Disable fortified builds by default, and hide the enabling option
behind EXPERIMENTAL for daring users...
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
I haven't noticed the usual experimental testers complain about eglibc
2.11 or 2.12 being unstable. So stop marking them as experimental.
Signed-off-by: Bryan Hundven <bryanhundven@gmail.com>
We make it an option, as not all combinations of architectures
vs. compiler vs. glibc/eglibc exhibit the issue. Mostly visible
on old glibc versions, it seems...
This is a missing part from the glibc/eglibc merger... :-/
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Enabling plugins in binutils is not enough, and gcc also
needs to be ./configured with --enable-plugins, although
this is not documented anywhere... :-/
Reported-by: karthik duraisami <kdconstant@hotmail.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Since the advent of make-3.82, some packages now break due to changes
in make-3.82, being stricter than 3.81 when interpreting the Makefiles.
This has bugged us a bit too much so far, and I believe fixing all
of them is a long road, while simply building make-3.81 is the easiest
route for now.
Of course, in the long term, packages will get fixed upstream, and we
should back-port the fixes to old versions, and get rid of building
make-3.81. In the meantime...
Reported several times on the mailing list.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
In certain circumstances, removing the destination/installation directory
is a bad idea. For example, when the build environment is already taking
care of sanitising the build tree, and pre-installs stuff in there, it is
a very bad idea to remove the destination directory.
This happens now in buildroot, as the crostool-NG backend now installs the
toolchain in the common host-tools directory, and pre-install there a few
host-utilities (eg. host-automake and host-gawk).
Provide a config knob to turn on/off the removal of the destination
directory, defaulting to 'y' (previous behavior), and forced to 'n' when
used as a backend.
Reported-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Use of the sysroot is highly recommended, and the non-sysroot case is
both obsolete and not widely tested.
Before the non-sysroot case can go away, deprecate it.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Depending on local policies, some users have expressed a need to
have the sysroot be named differently than the hard-coded name.
Add an option for that.
Default to 'sysroot' to match the existing literature.
While at it, replace 'sys-root' with 'sysroot' everywhere we
reference the sysroot.
Reported-by: Alexey Kuznetsov <Alexey.KUZNETSOV@youtransactor.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
This is an obsolete version which is no longer used by any sample (the only
user, the ia64 sample, has been removed).
It also makes the code path a bit complex, with twists just to accomodate
that version. Removing the version will make those twists go away, and
will ease commonalisation of glibc and eglibc in the future (hopefully!).
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
ia64 is broken in every gcc/glibc combinations I tested (except for the
existing sample that used very old versions).
Nobody complained on the list about not being able to build recent versions.
So the only way forward I can see is to remove the architecture altogether.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
When both gold and ld are installed, add a wrapper that calls
to either gold or ld.
In case the wrapper is installed, we also need to symlink ld.bfd
and ld.gold for the core_cc steps.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
When configured with support for threads, gold can link in
parallel, possibly cooperating with a make jobserver.
Add an option enabling threads.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
gold is a new, optimised, multi-threaded linker with support
for plugins.
Add support for gold starting with binutils 2.21. Although 2.20
also had gold, the configure flags have changed, and supporting
2.20 would be a mess in the code.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Add BINUTILS_2_21_or_later blind option. It will be used to add
conditional support for building 'gold' on versions that have it.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
In the previous patches to glibc and uclibc, we standardized on hidden
version names:
LIBC_<LIBC NAME>_V_<VERSION>
This patch updates EGLIBC to be the same for consistency to:
LIBC_EGLIBC_V_<VERSION>
Signed-off-by: Bryan Hundven <bryanhundven@gmail.com>
Hidden version names for uClibc conflicted:
LIBC_UCLIBC_V_0_9_30_2
LIBC_V_0_9_30_1
name them constantly as:
LIBC_UCLIBC_V_<version>
Also update the build script where we use snapshots by version or snapshots by date.
Signed-off-by: Bryan Hundven <bryanhundven@gmail.com>
- add 2.6.36.2.
- bump to 2.6.35.10, which is a new longterm.
- bump to 2.6.32.27 and 2.6.27.57, the two old longterms.
- update longterm descriptions.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Building non-threaded glibc has been unsupported for a long time, now:
http://sourceware.org/ml/libc-alpha/2005-08/msg00091.html
As eglibc is a spin-off of glibc: ditto.
So do not offer that possibility in the menuconfig.
Thanks to Thomas Petazzoni for spotting, and helping to solve, the issue!
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
If the global static option is set, then build the final gcc statically.
Signed-off-by: "Bryan Hundven" <bryanhundven@gmail.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
If the global static option is set, then build binutils statically.
Signed-off-by: "Bryan Hundven" <bryanhundven@gmail.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
If the global static option is set, then build host binutils statically.
Signed-off-by: "Bryan Hundven" <bryanhundven@gmail.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
If the global static toolchain option is selected, then do not
prompt the user whether to build shared companion libraries.
Signed-off-by: "Bryan Hundven" <bryanhundven@gmail.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Add a config option to statically build the host tools.
Impacted tools can use that option to decide wether to build
statically or shared.
For now, no tool uses it, but they'll be added one at a time
in the next commits.
Signed-off-by: "Bryan Hundven" <bryanhundven@gmail.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
This rules out 0.15.5 and previous versions, that did not
have this option, so remove them from the list. Anyway,
they were marked 'OBSOLETE', so it's not a big loss...
[Yann E. MORIN: remove obsolete versions]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
When the toolchain has no support for shared libraries, there is no
point in installing the cross-ldd helper.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Adds support to enable/disable IOs of floating point values
(float, double, and long double).
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
libssp is the run-time Stack-Smashing Protection library.
It can be usefull to have or miss, depends...
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
libgomp is the GNU implementation of the OpenMP API.
It can be usefull to have or miss, depends...
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
It makes sense to have all library-related config knobs in
the same place; and it makes sense to have all other misc
config knobs in the same other place.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Directly select-ing the required companion libraries means we can not
disable them. That's OK for now, as we systematically build them when
they are required.
But with distros coming up-to-speed, we will need to disable the build
later-on.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
To decide whether we need to backup the companion libraries,
do not rely on the !shared case. In the future other cases
may require not to save the companion libraries (eg. if using
the ones provided by the host distro).
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
While GMP and MPFR are required by gcc>=4.3 (to build the frontends),
and MPC is required by gcc>=4.5, the other libs are not. If they are
present then gcc will enable advanced features; if they are missing,
then gcc will (should) simply disable those features.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
This adds selection for one of the o32, n32 and n64 ABIs.
Later, we can easily use those boolean options, rather than
relying on a user-supplied string option.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Move the arch-specific options to the second-part of
the generated files, so they appear after the generic
options, but before the optimisations.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
'targets' is not really meaningfull.
'build' means what it means.
'.build' just hides it as well! :-)
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Remove those versions whose series does no longer appear on the
front page of kernel.org
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
The help entries for each of the companion libraries are now
wrong, and anyway are not displayed. Nuke, nuke, nuke...
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
As there's no longer any user of the companion libraries on the
target, nuke the build for the target.
Well, at least, there's libelf that's still needed by ltrace, so
we keep it.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Although the gdb ./configure advertises for GMP and MPFR, those libraries
are not used by gdb (the ./configure is used across different packages,
hence the check for GMP/MPFR). See:
http://sourceware.org/ml/crossgcc/2010-08/msg00168.html
The same applies to MPC.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
sstrip is causing more trouble and grief than tolerable.
It is broken at least on PPC. It does not build on non-ELF
systems (eg. mingw32, MacOS-X...). Plus, it is easy to
install.
Hide it behind OBSOLETE.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Parallel downloads can be a bit harsh on the servers,
and some will fail (eg. uclibc.org) in some cases.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
This version has been released a couple of month ago, but it never reached
crosstool-ng tree. This may be linked to the fact that the current 0.9.30.2,
once patched, has nothing much different from 0.9.30.3, released.
I'm not including any patch with this upgrade, on purpose.
Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>
To reduce filesizes of the toolchain and even improve build times
of projects to be build with this toolchain it is usefull to strip
the delivered toolchain executables. Since it is not likely that we
will debug the toolchain executables itself we do not need the
debug information inside the executables itself.
Signed-off-by: Remy Bohmer <linux@bohmer.net>
For some scenarii, libmudflap is not very usefull
or can break the build. Make in an optioon that
defaults to 'N' to be on the safe side.
For the core gcc-s, there is absolutely no need
to build libmidflap.
Idea from: Bernhard Pfund <bernhard@chapter7.ch>
It seems that using pre-generated locale data can be more problematic
than usefull in some circumstances.
Offer a config knob to enable/disable use of the pregen locale data.
Also, do not extract pregen locales data ourselves, it's broken.
I was unable to make the cross-ldd from uClibc to work, and
it is not possible to build it on non-POSIX system.
Besides, we have a generic script that is in the starting-blocks
to replace it, that will work for any C library, and also will
work on non-POSIX systems. Bonus!
uClibc >= 0.9.30 supports three verbosity levels, according to "make help":
V="" - Quiet build (default)
V=1 - Brief build (show defines, ld flags)
V=2 - Very verbose build
I think older versions of uClibc treat V=2 the same as V=1.
For current uClibc, only V=2 shows the full command lines.
Signed-off-by: Johannes Stezenbach <js@sig21.net>
Add several development libraries to the build of the mingw cross-compiler
to be used on target
Libraries:
PDCurses (port of the ncurses library)
GnuRX (the regex library)
DirectX
OpenGL
Signed-off-by: Bart vdr. Meulen <bartvdrmeulen@gmail.com>
[yann.morin.1998@anciens.enib.fr: don't show DX and RX versions if disabled]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Add the option to build a cross-compiler for kernel type 'mingw'.
The resulting cross-compiler can be used to build applications on a Linux host
that can be run on a Windows target.
Compiler is build using the mingwrt and w32-api packages aviable from the
MinGW project (http://sourceforge.net/projects/mingw).
The windows headers (w32-api package) are extracting with the kernel_headers
step The libraries and other headers from both packages are build and
installed in the various steps of libc
Signed-off-by: Bart vdr Meulen <bartvdrmeulen@gmail.com>
[yann.morin.1998@anciens.enib.fr: fix kernel headers comment, don't "return 0"]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Accept a local tarball name as the source of the Linux kernel headers,
rather than forcing the user to use either an upstream tarball, or a
local pre-installed headers tree.
Some components have configuration options that can depend on
generic options, so they should go below those.
uClibc for example:
- has its own options (wchar...)
- uses the generic options (threads...)
- if linuxthreads chosen, offers two impls
So we need to be able to split the components options in 2,
one part that is above the generic options, and one part that
ends up below the generic options.
This patch adds support for installing the gcc test suite. A helper
Makefile is provided for building and running the gcc tests.
The default configuration runs all gcc tests and requires automatic
ssh/scp login access to a networked target board. See README for
more details.
Note: Current feature is tested with the powerpc-unknown-linux-gnu
sample but it should work with others as well.
Signed-off-by: Martin Lund <mgl@doredevelopment.dk>
Insight seems to be very slow to follow up on mainstreram gdb.
Latest snapshots are more than 6 months old.
Moreover, I don't have time to maintain insight support in crosstool-NG;
and, because I don't use it, I am unable to find any breakage.
For uClibc, the name of the Blackfin architecture is 'bfin'. Actually,
the naming of the architecture is quite messy: for toolchain tuples
and uClibc, it's bfin, but for the kernel, it's blackfin. We've
arbitraly choosen to name it "blackfin" in Crosstool-NG.
Add Blackfin-related uClibc patch to fix a build failure related to
fork() being used in unistd/daemon.c.
Yann E. MORIN:
Apply the patch to the kernel/linux build script to use 'linux'
in the noMMU tuples. See:
http://sourceware.org/ml/crossgcc/2010-04/msg00010.html
When building a baremetal cross compiler I want to be able to select
the elf format and not be forced to build the elf2flt package.
Signed-off-by: Bart vdr. Meulen <bartvdrmeulen@gmail.com>
[Yann E. MORIN: tweak the commit message]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>
[Yann E. MORIN: mark it EXPERIMENTAL]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
If threads are disabled in libc, we don't want to enable them in the
final compiler. Doing so pass the configure stage, but fails latter on
a missing <pthread.h>.
Moreover, we don't want to build libgomp if threads are disabled; its
configure script would fails anyway.
Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>