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[[!tag open_issue_gcc]]
Here's what's to be done for maintaining GCC.
Apart from the target-specific configuration machinery, there shouldn't be any
major differences within GCC between the GNU/Hurd and GNU/Linux ports, for
example. Especially all the compiler magic is all the same.
[[!toc levels=2]]
# [[General information|/gcc]]
# [[Sources|source_repositories/gcc]]
# Configuration
<!--
git checkout reviewed
git log --reverse --pretty=fuller --stat=$COLUMNS,$COLUMNS -p -C --cc ..upstream/trunk
-i
/^commit |^---$|hurd|linux|nptl|glibc
-->
Last reviewed up to the [[Git mirror's dfed30bca14de84e0446cc02f5a27407dbfdc3e1
(2012-06-11) sources|source_repositories/gcc]].
<http://gcc.gnu.org/install/configure.html> has documentation for the
`configure` switches.
* Configure fragments that have `*linux*` cases might/should often contain
those for us (and GNU/k*BSD) as well.
* `configure.ac`
* `libgomp/configure.tgt`
* `libstdc++-v3/configure.host`
`abi_baseline_pair` etc. setting.
* `libstdc++-v3/config/os/gnu-linux/*`
Is used for all GNU systems, as per `libstdc++-v3/configure.host`.
Should rename to `gnu-user` to reflect this?
* `gcc/acinclude.m4`:`gcc_GAS_FLAGS`: always pass `--32` to assembler for
x86 Linux. (Why?)
* `hurd/usr`
`NATIVE_SYSTEM_HEADER_DIR`, `638454a19c1c08f01c10517bc72a114250fc4f33`,
[[!message-id "mcrzkhcbftp.fsf@coign.corp.google.com"]].
Debian.
* Eventually: get rid of this special-casing. [[!message-id
"gckk1s$e0b$1@ger.gmane.org"]].
* [[`libmudflap`|libmudflap]].
* Might [`-fsplit-stack`](http://nickclifton.livejournal.com/6889.html) be
worthwhile w.r.t. our [[multithreaded|multithreading]] libraries?
* Also see `libgcc/config/i386/morestack.S`: comments w.r.t
`TARGET_THREAD_SPLIT_STACK_OFFSET`; likely needs porting.
As per `libgcc/config/i386/t-stack-i386`, the former file is only used for
`-fsplit-stack` support -- which is currently enabled for us in
`libgcc/config.host`, but not usable via GCC proper.
* `gcc/config/gnu-user.h` defines `*SPLIT_STACK*` macros -- which aren't
valid for us (yet), I think.
* `--enable-languages=[...]`
* GNAT is not yet ported / bootstrapped?
* The Google Go's libgo (introduced in
e440a3286bc89368b8d3a8fd6accd47191790bf2 (2010-12-03)) needs
OS configuration / support.
* `--enable-frame-pointer`
`gcc/configure.ac`: `enable_frame_pointer=no`
* `--with-dwarf2`?
* `--enable-werror`
* `--enable-checking`
* `--enable-linker-build-id`
* `--enable-gnu-unique-object`
* `--enable-lto`, `--enable-gold`
[[binutils_gold]]
* `--enable-indirect-function`
[[IFUNC]]
* <http://gcc.gnu.org/ml/gcc/2007-11/msg00289.html>,
<http://gcc.gnu.org/ml/gcc-patches/2010-12/msg00672.html>
* `gcc/config/t-linux` should be named `gcc/config/t-gnu-user` or
similar. Likewise for `gcc/config/i386/t-linux`.
* Debian's GCC package has Hurd-specific patches. Some have been forwarded
upstream (and have been ignored). [[Thomas_Schwinge|tschwinge]] is working
on getting them integrated.
* [\[meta-bug\] bootstrap bugs for
\*-gnu\*](http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21824)
* [build system: gcc\_cv\_libc\_provides\_ssp and
NATIVE\_SYSTEM\_HEADER\_DIR](http://gcc.gnu.org/ml/gcc/2008-10/msg00130.html)
* [-fstack-protector shouldn't use TLS in freestanding
mode](http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29838)
* Check before/after Joseph changes. (Should be fine.)
* 34618b3190c110b8926cc2b1db4b4eac95451995
What's this used for? (Check ML.) Ask to include i686-pc-gnu (once it is
buildable out of the box)? See also
73905b5de0d9a086f22ded7638bb1c0ae1b91326.
* Various testsuite bits should include `*-*-gnu*`, too.
* [low] [[toolchain/cross-gnu]] toolchain bootstrap vs. `fenv.h` in libgcc's
libbid:
[...]/xgcc [...] -DIN_LIBGCC2 -fbuilding-libgcc [...] -Dinhibit_libc [...] -o bid_decimal_globals.o [...] -c [...]/libgcc/config/libbid/bid_decimal_globals.c
[...]/libgcc/config/libbid/bid_decimal_globals.c:47:18: fatal error: fenv.h: No such file or directory
compilation terminated.
make[1]: *** [bid_decimal_globals.o] Error 1
make[1]: Leaving directory `/media/boole-data/thomas/tmp/gnu-0/src/gcc.obj/i686-pc-gnu/libgcc'
make: *** [all-target-libgcc] Error 2
See threads at [[!message-id
"AANLkTinY1Cd4_qO_9euYJN8zev4hdr7_ANpjNG+yGRMn@mail.gmail.com"]],
[[!message-id "20110328225532.GE5293@synopsys.com"]], [[!message-id
"4D52D522.1040804@gmail.com"]]. Can simply configure the first GCC with
`--disable-decimal-float`.
Alternatively, can we use `#ifndef inhibit_libc` for this (these?) file(s)?
See `generic-nonstrack.c`, for example. The latter (and also
`generic-morestack-thread.c`) also has a nice explanation of `inhibit_libc`
which could be centralized at one place, for example definition of
`inhibit_libc`.
* [low] [[toolchain/cross-gnu]]
The directory that should contain system headers does not exist:
/media/boole-data/thomas/tmp/gnu-0/sys_root/usr/include
make[2]: *** [stmp-fixinc] Error 1
make[2]: Leaving directory `/media/boole-data/thomas/tmp/gnu-0/src/gcc.obj/gcc'
make[1]: *** [all-gcc] Error 2
make[1]: Leaving directory `/media/boole-data/thomas/tmp/gnu-0/src/gcc.obj'
`mkdir` the directory for now, but what is really going on? GCC has *use
`/usr/include` patch*, but glibc still installs into `/include/`?
* `__GLIBC__`
IRC, freenode, #hurd, 2012-01-05:
<civodul> on GNU/kFreeBSD, it's GCC that defines __GLIBC__, funny
<youpi> ??
<youpi> not from features.h ?
<civodul> in gcc/config/kfreebsd-gnu.h
<civodul> :-)
<pinotree> correct, it's enabled in gcc's config
<pinotree> i discovered that after banging my head on the wall trying
to find out why some stuff wasn't compiling even after kfreebsd
porting patches adding preprocessors checks for __GLIBC__
IRC, freenode, #hurd, 2012-05-25:
<gnu_srs> Hi, looks like __GLIBC__ is not defined by default for GNU?
<gnu_srs> touch foo.h; cpp -dM foo.h|grep LIBC: empty
<braunr> gnu_srs: well, this only tells your the compiler defaults
<tschwinge> gnu_srs: See the email I just sent.
[[!message-id "87396od3ej.fsf@schwinge.name"]]
<braunr> __GLIBC__ would probably be introduced by a glibc header
<gnu_srs> tschwinge: I saw your email. I wonder if features.h is
included in the kFreeBSD build of webkit.
<gnu_srs> It is defined in their build, but not in the Hurd build.
<pinotree> gcc on kfreebsd unconditionally defines __GLIBC__
<pinotree> (a bit stupid choice imho, but hardly something that could
be changed now...)
<braunr> :/
<braunr> personally i don't consider this only "a bit" stupid, as
kfreebsd is one of the various efforts pushing towards portability
<braunr> and using such hacks actually hinders portability ...
<pinotree> yeah don't tell me, i can remember at least half dozen of
occasions when a code wouldn't have been compiling at all on other
glibc platforms otherwise
<pinotree> sure, i have nothing against kfreebsd's efforts, but making
gcc define something which is proper of the libc used is stupid
<braunr> it is
<pinotree> i spotted changes like:
<pinotree> -#ifdef __linux
<pinotree> +#if defined(__linux__) || defined(__GLIBC__)
<pinotree> and wondered why they wouldn't work at all for us... and
then realized there were no #include in that file before that
preprocessor check
<tschwinge> This is even in upstream GCC gcc/config/kfreebsd-gnu.h:
<tschwinge> #define GNU_USER_TARGET_OS_CPP_BUILTINS() \
<tschwinge> do \
<tschwinge> { \
<tschwinge> builtin_define ("__FreeBSD_kernel__"); \
<tschwinge> builtin_define ("__GLIBC__"); \
<tschwinge> builtin_define_std ("unix"); \
<tschwinge> builtin_assert ("system=unix"); \
<tschwinge> builtin_assert ("system=posix"); \
<tschwinge> } \
<tschwinge> while (0)
<tschwinge> I might raise this upstream at some point.
<pinotree> tschwinge: i could guess the change was proposed by the
kfreebsd people, so asking them before at d-bsd@d.o would be a start
<tschwinge> pinotree: Ack.
<pinotree> especially that they would need to fix stuff afterwards
<pinotree> imho we could propose them the change, and if they agree put
that as local patch to debian's gcc4.6/.7 after wheezy, so there is
plenty of time for them to fix stuff
<pinotree> what should be done first is, however, find out why that
define has been added to gcc
* [low] Does `-mcpu=native` etc. work? (For example,
2ae1f0cc764e998bfc684d662aba0497e8723e52.)
* transactional memory, 4c0315d05fa0f707875686abc4f91f7a979a7c7b
* `config/mmap.m4`
* In `libitm/config/`, is the generic stuff (`tls.h`, etc.) enough for
us?
* f29a2041f32773464e226a83f41762c2e9cf658e
(e53a96c2136f7cdff4699475fea41afeed9dece3)
Testresults same as for GNU/Linux.
* [high] 3efc00f6f17778172d3fa7ac737fa1473b3b4d5a, `Check __GLIBC__ when
using __SIGRTMIN`. GCC PR52390. Fixed by
8d2259c83f94c082ad8a00b5d00bb639ce24efce.
* 15ac1e637ad0cb92bf7629205c617ea847a4b810 `Build 64-bit libffi multilib for
i?86-linux`.
* `libstdc++`: uses `_GLIBCXX_HAVE_TLS`, but where is this defined? Supposed
to come from `config/tls.m4:GCC_CHECK_TLS`?
* `libgcc/gthr-posix.h:__gthread_active_p` -- is this suitable for us? This
is used in libgcc for ObjC wrapper stuff and similar in libstdc++.
C.f. [[!message-id "x57jobtqx89w.fsf@frobland.mtv.corp.google.com"]],
[[!message-id "x57jd359fkx3.fsf@frobland.mtv.corp.google.com"]] as well as
[[!debbug 629866]]/[[!message-id
"20110609002620.GA16719@const.famille.thibault.fr"]].
# Build
Here's a log of a GCC build run; this is from our [[Git repository's
2e2db3f92b534460c68c2f9ae64455884424beb6 (2012-06-15; 2012-06-06)
sources|source_repositories/gcc]], run on kepler.SCHWINGE and coulomb.SCHWINGE.
$ export LC_ALL=C
$ (cd ../master/ && contrib/gcc_update --touch)
$ ../master/configure --prefix="$PWD".install SHELL=/bin/dash CC=gcc-4.6 CXX=g++-4.6 --enable-build-with-cxx --enable-languages=all,ada 2>&1 | tee log_build
[...]
$ make 2>&1 | tee log_build_
[...]
Different hosts may default to different shells and compiler versions; thus
harmonized.
This takes up around 3.1 GiB, and needs roughly 3.0 h on kepler.SCHWINGE and
12.75 h on coulomb.SCHWINGE.
<!--
$ (make && touch .go-install) 2>&1 | tee log_build_ && test -f .go-install && (make install && touch .go-check) 2>&1 | tee log_install && test -f .go-check && make -k RUNTESTFLAGS=-v check 2>&1 | tee log_check
-->
## Analysis
$ toolchain/logs/process gcc build
* [[`checking if gcc static flag -static
works... no`|glibc_madvise_vs_static_linking]]
Addressed in Debian glibc.
* DFP
Addressed in *hurd/decimal_floating_point* branch.
+configure: WARNING: decimal float is not supported for this target, ignored
... and later on:
-checking for decimal floating point... bid
+checking for decimal floating point... configure: WARNING: decimal float is not supported for this target, ignored
+dpd
... and later on:
-checking whether decimal floating point is supported... yes
+checking whether decimal floating point is supported... no
+configure: WARNING: decimal float is not supported for this target, ignored
* `libstdc++-v3/acinclude.m4`: ISO/IEC TR 24733
-checking for ISO/IEC TR 24733 ... yes
+checking for ISO/IEC TR 24733 ... no
* `--enable-decimal-float`, `--enable-fixed-point`, `--with-long-double-128`
`configure: WARNING: decimal float is not supported for this target,
ignored`
* `libgcc/configure.ac` [might
need](http://gcc.gnu.org/ml/gcc-patches/2008-10/msg00315.html) to be
aligned for us to the `*linux*` cases. As well as at the end of
`libgcc/config.host`. Check.
checking whether decimal floating point is supported... no
checking whether fixed-point is supported... no
* `host-linux.c` vs. `host-default.c`
* *fixincludes* stuff
* malloc?
-cat ../../hurd/gcc/config/i386/pmm_malloc.h > mm_malloc.h
+cat ../../hurd/gcc/config/i386/gmm_malloc.h > mm_malloc.h
Comes from `gcc/config.gcc`: `i386/t-pmm_malloc` vs. `i386/t-gmm_malloc`
for `i[34567]86-*-linux*` vs. `i[34567]86-*-*`.
* *libgomp*
* `libgomp/config/linux/`, `libgomp/config/linux/x86`
`sed`ed away.
* `-ftls-model=initial-exec -march=i486 -mtune=i686`
`sed`ed away.
* Missing `EOWNERDEAD`, `ENOTRECOVERABLE`. What're they used for?
* `RLIMIT_VMEM`. Usage kosher?
* `libtool: link: ar rc .libs/libstdc++.a [...]`
Just different order of object files, or another problem? TODO
* `libobjc/encoding.c`:
libtool: compile: [...]/hurd/master.build/./gcc/xgcc [...] [...]/hurd/master/libobjc/encoding.c -c [...]
+[...]/hurd/master/libobjc/encoding.c:128:1: warning: '_darwin_rs6000_special_round_type_align' defined but not used [-Wunused-function]
* `libobjc/thr.c`: `gcc/gthr-posix.h`
libtool: compile: [...]/hurd/master.build/./gcc/xgcc [...] [...]/hurd/master/libobjc/thr.c -c [...]
+In file included from [...]/hurd/master/libobjc/../libgcc/gthr.h:142:0,
+ from [...]/hurd/master/libobjc/thr.c:45:
+../libgcc/gthr-default.h: In function '__gthread_objc_thread_set_priority':
+../libgcc/gthr-default.h:388:41: warning: unused parameter 'priority' [-Wunused-parameter]
* `/proc/self/*`
-checking for /proc/self/exe... yes
-checking for /proc/self/maps... yes
+checking for /proc/self/exe... no
+checking for /proc/self/maps... no
* GCJ: `java-signal.h`, `java-signal-aux.h`
-config.status: linking ../../../hurd/libjava/include/i386-signal.h to include/java-signal.h
-config.status: linking ../../../hurd/libjava/include/i386-signal.h to include/java-signal-aux.h
+config.status: linking ../../../hurd/libjava/include/default-signal.h to include/java-signal.h
+config.status: linking ../../../hurd/libjava/include/default-signal.h to include/java-signal-aux.h
* GCJ: `jni_md.h`
-checking jni_md.h support... yes
+checking jni_md.h support... configure: WARNING: no
* *default library search path*
-checking for the default library search path... /lib /usr/lib /lib/i386-linux-gnu /usr/lib/i386-linux-gnu /lib/i486-linux-gnu /usr/lib/i486-linux-gnu /usr/local/lib /lib64 /usr/lib64
+checking for the default library search path... /lib /usr/lib
* `./classpath/[...]/*.properties`
Just different order of files, or another problem?
* `libjava/gnu/gcj/util/natGCInfo.cc`
libtool: compile: [...]/hurd/master.build/./gcc/xgcc [...] -c ../../../master/libjava/gnu/gcj/util/natGCInfo.cc [...]
+../../../master/libjava/gnu/gcj/util/natGCInfo.cc:440:1: warning: unused parameter 'name' [-Wunused-parameter]
+../../../master/libjava/gnu/gcj/util/natGCInfo.cc:446:1: warning: unused parameter 'name' [-Wunused-parameter]
+../../../master/libjava/gnu/gcj/util/natGCInfo.cc:452:1: warning: unused parameter 'name' [-Wunused-parameter]
* `libgcj.la`
Just different order of object files, or another problem?
Is there a pattern that GNU/Hurd hands out the files alphabetically sorted
where it wouldn't need to ([[!taglink open_issue_hurd]])?
* `libjvm.la`, `.libs/libjvm.so`, `libgij.la`, `.libs/libgij.so.12.0.0`
`-Wl,-Bsymbolic` vs. `-Wl,-Bsymbolic-functions`
* `jar`
make[2]: Entering directory `[...]/hurd/master.build/[ARCH]/libjava'
-: make ; exec make "AR_FLAGS=rc" [...] "RANLIB=ranlib" "DESTDIR=" "JAR=[...]/hurd/master.build/[ARCH]/libjava/scripts/jar" DO=all multi-do
+: make ; exec make "AR_FLAGS=rc" [...] "RANLIB=ranlib" "DESTDIR=" "JAR=jar" DO=all multi-do
Probably because kepler.SCHWINGE has an OpenJDK `/usr/bin/jar`, and
coulomb.SCHWINGE a GCJ one.
There are other instances of this in the following.
* *default library search path*
-checking for the default library search path... /lib /usr/lib /lib/[MULTIARCH] /usr/lib/[MULTIARCH] /lib/i486-linux-gnu /usr/lib/i486-linux-gnu /usr/local/lib /lib64 /usr/lib64
+checking for the default library search path... /lib /usr/lib
Should be aligned by Samuel's binutils patch.
* `value-unwind.h`
-DEFINES='' HEADERS='../../../master/libgcc/config/i386/value-unwind.h' \
+DEFINES='' HEADERS='' \
../../../master/libgcc/mkheader.sh > tmp-libgcc_tm.h
Comes from `gcc/config.gcc`: for `i[34567]86-*-linux*`
vs. `i[34567]86-*-*`, but apparently is important only for *x86_64* anyway.
* `soft-fp` prototypes
../../../master/libgcc/soft-fp/eqtf2.c:34:9: warning: no previous prototype for '__eqtf2' [-Wmissing-prototypes]
+../../../master/libgcc/soft-fp/eqtf2.c:50:1: warning: no previous prototype for '__netf2' [-Wmissing-prototypes]
../../../master/libgcc/soft-fp/getf2.c:34:9: warning: no previous prototype for '__getf2' [-Wmissing-prototypes]
+../../../master/libgcc/soft-fp/getf2.c:50:1: warning: no previous prototype for '__gttf2' [-Wmissing-prototypes]
../../../master/libgcc/soft-fp/letf2.c:34:9: warning: no previous prototype for '__letf2' [-Wmissing-prototypes]
+../../../master/libgcc/soft-fp/letf2.c:50:1: warning: no previous prototype for '__lttf2' [-Wmissing-prototypes]
* `libatomic` on GNU/Linux compiles several more files than on GNU/Hurd. Is
that correct? Probably futex support.
# Install
$ make install 2>&1 | tee log_install
[...]
This takes up around 850 MiB, and needs roughly 4 min on kepler.SCHWINGE and 45
min on coulomb.SCHWINGE.
## Analysis
$ toolchain/logs/process gcc install
* `libtool: finish`: `ldconfig` is not run for the Hurd.
[[libtool]].
* `libjvm.la`, `.libs/libjvm.so`, `libgij.la`, `.libs/libgij.so.12.0.0`
`-Wl,-Bsymbolic` vs. `-Wl,-Bsymbolic-functions` (as above)
* `jar`: as above.
# Testsuite
<http://gcc.gnu.org/install/test.html>
Testing on GNU/Hurd is blocked on
[[fork_mach_port_mod_refs_ekern_urefs_owerflow]].
TODO. Can use parallel testing, see [[!message-id
"20110331070322.GI11563@sunsite.ms.mff.cuni.cz"]].
$ make -k RUNTESTFLAGS=-v check 2>&1 | tee log_check
[...]
This needs roughly 6.5 h on kepler.SCHWINGE and 50.25 h on coulomb.SCHWINGE.
## Analysis
$ toolchain/logs/process gcc test
TODO.
# Specific Languages
* [[GNAT]]
* [[gccgo]]