mirror of
https://github.com/bminor/binutils-gdb.git
synced 2025-12-27 09:38:57 +00:00
dd787f5e65
This changes the DWARF reader to share partial symtabs (or indices if they are available) across objfiles. This has a few parts. * If multiple objfiles backed by the same BFD can share partial symtabs (see below), a single dwarf2_per_bfd is created. It is stored in the per-bfd `dwarf2_per_bfd_bfd_data_key` registry. Multiple dwarf2_per_objfile objects will point to the same instance. The lifetime of these dwarf2_per_bfd objects is naturally handled. When all the objfiles using the BFD are destroyed, the BFD's refount drops to 0, which triggers the removal of the corresponding dwarf2_per_bfd object from the registry and its destruction. * If multiple objfiles backed by the same BFD can't share partial symtabs (see below), one dwarf2_per_bfd object is created for each objfile. Each dwarf2_per_objfile will point to their own instance of dwarf2_per_bfd. These instances of dwarf2_per_bfd are kept in a per-objfile registry, meaning that when the objfile gets destroyed, the dwarf2_per_bfd instance gets destroyed as well. * objfile::partial_symtabs is changed to be a shared_ptr again. This lets us stash a second reference in dwarf2_per_bfd; if the DWARF data is being shared, we can simply copy this value to the new objfile. * Two dwarf2_per_objfile objects backed by the same BFD may share a dwarf2_per_bfd instance if: * No other symbol reader has found symbols, and * No BFD section rqeuires relocation YYYY-MM-DD Tom Tromey <tom@tromey.com> YYYY-MM-DD Simon Marchi <simon.marchi@efficios.com> * objfiles.h (struct objfile) <partial_symtabs>: Now a shared_ptr. * dwarf2/read.h (struct dwarf2_per_objfile) <partial_symtabs>: New member. * dwarf2/read.c (dwarf2_per_bfd_bfd_data_key, dwarf2_per_bfd_objfile_data_key>: New globals. (dwarf2_has_info): Use shared dwarf2_per_bfd if possible. (dwarf2_get_section_info): Use get_dwarf2_per_objfile. (dwarf2_initialize_objfile): Consider cases where per_bfd can be shared. (dwarf2_build_psymtabs): Set objfile::partial_symtabs and short-circuit when sharing. (dwarf2_build_psymtabs): Set dwarf2_per_objfile::partial_symtabs. (dwarf2_psymtab::expand_psymtab): Use free_cached_comp_units.