https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126962
--- Comment #5 from David Binderman <dcb314 at hotmail dot com> ---
(In reply to David Binderman from comment #4)
> I tried it again on 20260821, only a day later, with a more recent
> gcc trunk and, much to my surprise, the problem didn't appear.
>
> Looks like cannot reproduce to me.
It seems to have returned.
The configure line is:
CFLAGS="-g1 -O3 -march=native -Wall -Wlogical-op" \
CXXFLAGS="-g1 -O3 -march=native -Wall -Wlogical-op" \
../trunk/configure --prefix=$HOME/gcc/results.$DATE.valgrind \
--disable-bootstrap \
--disable-doc \
--disable-fixincludes \
--disable-multilib \
--with-pkgversion=$HASH \
--enable-checking=valgrind \
--enable-languages=c,c++,fortran
Native is znver3. Command line is:
/home/dcb42/gcc/working/./gcc/xgcc -shared-libgcc
-B/home/dcb42/gcc/working/./gc
c -nostdinc++ -L/home/dcb42/gcc/working/x86_64-pc-linux-gnu/libstdc++-v3/src
-L/
home/dcb42/gcc/working/x86_64-pc-linux-gnu/libstdc++-v3/src/.libs
-L/home/dcb42/
gcc/working/x86_64-pc-linux-gnu/libstdc++-v3/libsupc++/.libs
-B/home/dcb42/gcc/r
esults.20261009.valgrind/x86_64-pc-linux-gnu/bin/
-B/home/dcb42/gcc/results.2026
1009.valgrind/x86_64-pc-linux-gnu/lib/ -isystem
/home/dcb42/gcc/results.20261009
.valgrind/x86_64-pc-linux-gnu/include -isystem
/home/dcb42/gcc/results.20261009.
valgrind/x86_64-pc-linux-gnu/sys-include -x c++-header -nostdinc++ -g -O2
-g1
-O3 -march=native -Wall -Wlogical-op -D_GNU_SOURCE
-I/home/dcb42/gcc/working/x
86_64-pc-linux-gnu/libstdc++-v3/include/x86_64-pc-linux-gnu
-I/home/dcb42/gcc/wo
rking/x86_64-pc-linux-gnu/libstdc++-v3/include
-I/home/dcb42/gcc/trunk/libstdc++
-v3/libsupc++ -O2 -g -std=gnu++0x
/home/dcb42/gcc/trunk/libstdc++-v3/include/pr
ecompiled/stdc++.h
and produces:
==2406178== Invalid read of size 32
==2406178== at 0x705436: unify_pack_expansion(tree_node*, tree_node*,
tree_node*, tree_node*, unification_kind_t, bool, bool) (pt.cc:26205)
==2406178== by 0x6ED3DF: unify(tree_node*, tree_node*, tree_node*,
tree_node*, int, bool) (pt.cc:26977)
==2406178== by 0x6EC210: unify(tree_node*, tree_node*, tree_node*,
tree_node*, int, bool) (pt.cc:27201)
==2406178== by 0x6ED382: unify(tree_node*, tree_node*, tree_node*,
tree_node*, int, bool) (pt.cc:26971)
==2406178== by 0x714E38: get_partial_spec_bindings(tree_node*, tree_node*,
tree_node*) (pt.cc:27861)
==2406178== by 0x717C7C: process_partial_specialization(tree_node*)
(pt.cc:5526)
==2406178== by 0x7198A8: push_template_decl (pt.cc:6076)
I will have a go at a reduction.
