[Bug bootstrap/66038] [5 regression] (stage 2) build/genmatch issue (gcc/hash-table.h|c) with --disable-checking [ introduced by r218976 ]

[kumba at gentoo dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66038

--- Comment #32 from Joshua Kinard <kumba at gentoo dot org> ---
(In reply to Richard Biener from comment #30)
> Any status update?  Does bootstrap work on trunk (with --disable-checking)?

Okay, here's updates from the MIPS angle on a few configurations:

MIPS-IV, Big-endian, N32, glibc (mips64-unknown-linux-gnu):
Still fails with either --disable-checking or --enable-checking=release.  Same
problem as before:

build/genmatch --gimple
/usr/obj/portage/sys-devel/gcc-5.3.0/work/gcc-5.3.0/gcc/match.pd \
    > tmp-gimple-match.c
/bin/bash: line 1: 16563 Segmentation fault      build/genmatch --gimple
/usr/obj/portage/sys-devel/gcc-5.3.0/work/gcc-5.3.0/gcc/match.pd >
tmp-gimple-match.c
Makefile:2325: recipe for target 's-match' failed
make[3]: *** [s-match] Error 139
make[3]: *** Waiting for unfinished jobs....

Can't test O32/glibc at present due to accidentally mangling my old O32 rootfs.
 Might get something up and working again at some point, but I *highly* suspect
the problem only exists in N32 (unknown about N64).  See below for why.

---

MIPS-IV, Big-endian, O32, uclibc (mips-unknown-linux-uclibc):
--disable-checking appears to produce an ICE in an O32/uclibc rootfs.  I assume
you'll want a fresh bug opened on this:
/usr/obj/portage/sys-devel/gcc-5.3.0/work/gcc-5.3.0/gcc/../libcpp/include  \
        -o build/genoutput.o
/usr/obj/portage/sys-devel/gcc-5.3.0/work/gcc-5.3.0/gcc/genoutput.c
/usr/obj/portage/sys-devel/gcc-5.3.0/work/gcc-5.3.0/gcc/genautomata.c: In
function 'void form_regexp(regexp_t)':
/usr/obj/portage/sys-devel/gcc-5.3.0/work/gcc-5.3.0/gcc/genautomata.c:6867:1:
internal compiler error: in maybe_record_trace_start, at dwarf2cfi.c:2318
 }
 ^
Please submit a full bug report,
with preprocessed source if appropriate.
See <https://bugs.gentoo.org/> for instructions.
Makefile:2451: recipe for target 'build/genautomata.o' failed
make[3]: *** [build/genautomata.o] Error 1
make[3]: *** Waiting for unfinished jobs....

I'll have to re-create the above scenario to do so, as I'm running a few
different experiments w/ uclibc at the moment, so I need to make sure it really
is --disable-checking causing the problem there and I'll run the bug through
our (Gentoo's) toolchain team first before opening a PR here.

---

Now, same O32/uclibc rootfs, --enable-checking=release, gcc-5.3.0 works fine
(so far).  This is why I suspect the N32 case is broken only.  I don't know how
good N32 support in uclibc is, so I can't test that configuration to verify.

So to tackle the N32 issue, are there any additional tricks you want me to try
to get, say, a static copy of genmatch built w/ debugging symbols and then step
through it in GDB to see what may be triggering the segfault?  I didn't try
removing the 'gcc_checking_assert', as suggested in earlier comments.

N32 does affect the reported size of several datatypes, so that may be the
source of the issue on MIPS.