The new DWARF cooked indexer interacts poorly with the DWARF index
cache. In particular, the cache will require gdb to wait for the
cooked index to be finalized. As this happens in the foreground, it
means that users with this setting enabled will see a slowdown.
This patch changes gdb to write the cache entry a worker thread. (As
usual, in the absence of threads, this work is simply done immediately
in the main thread.)
Some care is taken to ensure that this can't crash, and that gdb will
not exit before the task is complete.
To avoid use-after-free problems, the DWARF per-BFD object explicitly
waits for the index cache task to complete.
To avoid gdb exiting early, an exit observer is used to wait for all
such pending tasks.
In normal use, neither of these waits will be very visible. For users
using "-batch" to pre-generate the index, though, it would be.
However I don't think there is much to be done about this, as it was
the status quo ante.
This commit is the result of running the gdb/copyright.py script,
which automated the update of the copyright year range for all
source files managed by the GDB project to be updated to include
year 2023.
My patches yesterday to unify the DWARF index base classes had a bug
-- namely, I did the wholesale dynamic_cast-to-static_cast too hastily
and introduced a crash. This can be seen by trying to add an index to
a file that has an index, or by running a test like gdb-index-cxx.exp
using the cc-with-debug-names.exp target board.
This patch fixes the crash by introducing a new virtual method and
removing some of the static casts.
Some generic code in the DWARF reader has a special case for older
versions of .gdb_index. This patch adds an ad hoc version check
method so that these spots can work without specific knowledge of
which index is in use.
This introduces dwarf_scanner_base, a base class for all the index
readers in the DWARF code. Then, it changes both mapped_index_base
and cooked_index_vector to derive from this new base class.
This changes the mapped index classes to create the
quick_symbol_functions objects. This is a step toward having a more
abstract interface to mapped indices.
