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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]]
## Boehm GC
GCC includes an own variant of [[/Boehm_GC]] that is based on an upstream
version, but with own patches, etc. This is used for Java. (There are patches
(apparently not committed) that GCC itself can use it, too:
<http://gcc.gnu.org/wiki/Garbage_collection_tuning>.)
Patches to GCC's fork should be contributed back to upstream [[/Boehm_GC]].
[[tschwinge]] reviewed (but only briefly for large parts) the differences on
2010-12-08, based on the [[GCC Git mirror's
8e79e9d43f32c8852f068da91d655297d92ac0f4 (2010-11-29)
sources|source_repositories/GCC]] and Boehm GC's CVS HEAD sources from
2010-12-02, converted to [[Git, correspondingly
1c2455988a8f59a5f83b986b9156f03be395b3b6|source_repositories/boehm_gc]].
On 2010-11-17,
[[tschwinge]] reviewed the Debian GCC Boehm GC changes, compared them to the
upstream code, and put it into the local *hurd/boehm-gc/config_backport*
branch, planning to submit it to gcc-patches after testing with the GCC
testsuite.
* Check
* 02e191ba495b4ec87aeb961ff9afdb666287104a
* ce062771587f6637ce09f79c36e24de691032919
* a9cc177ef514d6eb39db72c82911fcea2cd70dba
* 7b8d306d18986cd98808c9ed5d3a696a186dc213
Looks generally OK.
* a3a3fd06ae58af9591a95c94245809b0359289ff
Looks OK.
* fe5ef4a01870545d0344e670cd528ad096ebab1d
OK.
# Configuration
<!--
git checkout reviewed
git log --reverse --pretty=fuller --stat=$COLUMNS,$COLUMNS -p -C --cc ..upstream/master
-i
/^commit |^---$|hurd|linux
-->
Last reviewed up to the [[Git mirror's 9aa4b6a8046270a9dbdf47827f1ea873217d7aa5
(2011-11-28) sources|source_repositories/gcc]].
<http://gcc.gnu.org/install/configure.html> has documentation for the
`configure` switches.
* Configure fragments that have `*linux*` cases might/should often contain
those for us (and GNU/k*BSD) as well.
* `configure.ac`
* `libgomp/configure.tgt`
* `libstdc++-v3/configure.host`
`abi_baseline_pair` etc. setting.
* `libstdc++-v3/config/os/gnu-linux/*`
Is used for all GNU systems, as per `libstdc++-v3/configure.host`.
Should rename to `gnu` to reflect this?
* `gcc/acinclude.m4`:`gcc_GAS_FLAGS`: always pass `--32` to assembler for
x86 Linux. (Why?)
* `hurd/usr`
`NATIVE_SYSTEM_HEADER_DIR`, `638454a19c1c08f01c10517bc72a114250fc4f33`,
[[!message-id "mcrzkhcbftp.fsf@coign.corp.google.com"]].
Debian.
* Eventually: get rid of this special-casing. [[!message-id
"gckk1s$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__
* [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)
# Build
Here's a log of a GCC build run; this is from our [[Git repository's
74a56c71c55f667824eb2ef1d62d408e9c000d5e (2011-10-23)
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 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 2.9 GiB, and needs roughly 2.75 h on kepler.SCHWINGE and
13.25 h on coulomb.SCHWINGE.
## Analysis
$ diff -wu <(ssh kepler.SCHWINGE 'cd tmp/source/gcc/ && cat hurd/master.build/log_build* | sed -e "s%\(/media/data\)\?${PWD}%[...]%g"' | sed -f open_issues/gcc/log_build-linux.sed) <(ssh coulomb.SCHWINGE 'cd tmp/gcc/ && cat hurd/master.build/log_build* | sed -e "s%\(/media/erich\)\?${PWD}%[...]%g"' | sed -f open_issues/gcc/log_build-hurd.sed) > open_issues/gcc/log_build.diff
[[log_build.diff]].
* [[`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`
* `-ftls-model=initial-exec -march=i486 -mtune=i686`
* Missing `EOWNERDEAD`, `ENOTRECOVERABLE`. What're they used for?
* `RLIMIT_VMEM`. Usage kosher?
* `basic_file.cc`
+basic_file.cc: In member function 'std::streamsize std::__basic_file<char>::showmanyc()':
+basic_file.cc:347:33: warning: enumeral and non-enumeral type in conditional expression [enabled by default]
* `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 ../.././gcc/gthr-default.h:1:0,
+ from [...]/hurd/master/libobjc/../gcc/gthr.h:160,
+ from [...]/hurd/master/libobjc/thr.c:45:
+[...]/hurd/master/libobjc/../gcc/gthr-posix.h: In function '__gthread_objc_thread_set_priority':
+[...]/hurd/master/libobjc/../gcc/gthr-posix.h:389:41: 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]
* `gnu/java/net/natPlainSocketImpl.cc`
libtool: compile: [...]/hurd/master.build/./gcc/xgcc [...] -c gnu/java/net/natPlainSocketImpl.cc [...]
+gnu/java/net/natPlainSocketImpl.cc: In member function 'virtual jint gnu::java::net::PlainSocketImpl::available()':
+gnu/java/net/natPlainSocketImpl.cc:515:27: warning: enumeral and non-enumeral type in conditional expression [enabled by default]
* `gnu/java/nio/channels/natFileChannelImpl.cc`
libtool: compile: [...]/hurd/master.build/./gcc/xgcc [...] -c gnu/java/nio/channels/natFileChannelImpl.cc [...]
+gnu/java/nio/channels/natFileChannelImpl.cc: In member function 'jint gnu::java::nio::channels::FileChannelImpl::available()':
+gnu/java/nio/channels/natFileChannelImpl.cc:388:20: warning: enumeral and non-enumeral type in conditional expression [enabled by default]
* `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`
# Install
$ make install 2>&1 | tee log_install
[...]
This takes up around 630 MiB, and needs roughly 4 min on kepler.SCHWINGE and 35
min on coulomb.SCHWINGE.
## Analysis
$ diff -wu <(ssh kepler.SCHWINGE 'cd tmp/source/gcc/ && cat hurd/master.build/log_install | sed -e "s%\(/media/data\)\?${PWD}%[...]%g"' | sed -f open_issues/gcc/log_install-linux.sed) <(ssh coulomb.SCHWINGE 'cd tmp/gcc/ && cat hurd/master.build/log_install | sed -e "s%\(/media/erich\)\?${PWD}%[...]%g"' | sed -f open_issues/gcc/log_install-hurd.sed) > open_issues/gcc/log_install.diff
[[log_install.diff]].
* `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)
# 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 check 2>&1 | tee log_check
[...]
This needs roughly TODO min on kepler.SCHWINGE and TODO min on
coulomb.SCHWINGE.
$ ssh kepler.SCHWINGE 'cd tmp/source/gcc/ && sed < hurd/master.build/gcc/TODO -e "s%\(/media/data\)\?${PWD}%[...]%g"' > open_issues/gcc/sum_linux
$ ssh coulomb.SCHWINGE 'cd tmp/gcc/ && sed < hurd/master.build/gcc/TODO -e "s%\(/media/erich\)\?${PWD}%[...]%g"' > open_issues/gcc/sum_hurd
Comparing the results files, [[sum_linux]] to [[sum_hurd]]:
$ diff -u -F ^Running open_issues/gcc/sum_linux open_issues/gcc/sum_hurd > open_issues/gcc/sum.diff
[[open_issues/gcc/sum.diff]].
## Analysis
TODO.
# Specific Languages
* [[GNAT]]
* [[gccgo]]