gdb/dwarf: use all_units_range in dwarf2_base_index_functions::expand_all_symtabs
Commit 292041562289 ("gdb/dwarf: use ranged for loop in some spots")
broke some tests notably gdb.base/maint.exp with the fission board.
$ ./gdb -nx -q --data-directory=data-directory testsuite/outputs/gdb.base/maint/maint -ex start -ex "maint expand-sym" -batch
...
Temporary breakpoint 1, main (argc=1, argv=0x7fffffffdc48, envp=0x7fffffffdc58) at /home/smarchi/src/binutils-gdb/gdb/testsuite/gdb.base/break.c:43
43 if (argc == 12345) { /* an unlikely value < 2^16, in case uninited */ /* set breakpoint 6 here */
/usr/include/c++/14.2.1/debug/safe_iterator.h:392:
In function:
gnu_debug::_Safe_iterator<_Iterator, _Sequence, _Category>&
gnu_debug::_Safe_iterator<_Iterator, _Sequence, _Category>::operator++()
[with _Iterator = gnu_cxx::
normal_iterator<std::unique_ptr<dwarf2_per_cu, dwarf2_per_cu_deleter>*,
std::vector<std::unique_ptr<dwarf2_per_cu, dwarf2_per_cu_deleter>,
std::allocator<std::unique_ptr<dwarf2_per_cu, dwarf2_per_cu_deleter> > >
>; _Sequence = std::debug::vector<std::unique_ptr<dwarf2_per_cu,
dwarf2_per_cu_deleter> >; _Category = std::forward_iterator_tag]
Error: attempt to increment a singular iterator.
Note that this is caught because I build with -D_GLIBCXX_DEBUG=1.
Otherwise, it might crash more randomly, or just not crash at all (but
still be buggy).
While iterating on the all_units vector, some type units get added
there:
#0 add_type_unit (per_bfd=0x51b000044b80, section=0x50e0000c2280, sect_off=0, length=74, sig=4367013491293299229) at /home/smarchi/src/binutils-gdb/gdb/dwarf2/read.c:2576
#1 0x00005555618a3a40 in lookup_dwo_signatured_type (cu=0x51700009b580, sig=4367013491293299229) at /home/smarchi/src/binutils-gdb/gdb/dwarf2/read.c:2664
#2 0x00005555618ee176 in queue_and_load_dwo_tu (dwo_unit=0x521000120e00, cu=0x51700009b580) at /home/smarchi/src/binutils-gdb/gdb/dwarf2/read.c:8329
#3 0x00005555618eeafe in queue_and_load_all_dwo_tus (cu=0x51700009b580) at /home/smarchi/src/binutils-gdb/gdb/dwarf2/read.c:8366
#4 0x00005555618966a6 in dw2_do_instantiate_symtab (per_cu=0x50f0000043c0, per_objfile=0x516000065a80, skip_partial=true) at /home/smarchi/src/binutils-gdb/gdb/dwarf2/read.c:1695
#5 0x00005555618968d4 in dw2_instantiate_symtab (per_cu=0x50f0000043c0, per_objfile=0x516000065a80, skip_partial=true) at /home/smarchi/src/binutils-gdb/gdb/dwarf2/read.c:1719
#6 0x000055556189ac3f in dwarf2_base_index_functions::expand_all_symtabs (this=0x502000024390, objfile=0x516000065780) at /home/smarchi/src/binutils-gdb/gdb/dwarf2/read.c:1977
This invalidates the iterator in
dwarf2_base_index_functions::expand_all_symtabs, which is caught by the
libstdc++ debug mode.
I'm not entirely sure that it is correct to append type units from dwo
files to the all_units vector like this. The
dwarf2_find_containing_comp_unit function expects a precise ordering of
the elements of the all_units vector, to be able to do a binary search.
Appending a type unit at the end at this point certainly doesn't respect
that ordering.
For now I'd just like to undo the regression. Do that by using
all_units_range in the ranged for loop. I will keep in mind to
investigate whether this insertion of type units in all_units after the
fact really makes sense or not.
Change-Id: Iec131e59281cf2dbd12d3f3d163b59018fdc54da
1 file changed
