Internally we noticed that some tests would fail like so on Windows:
warning: Section .debug_aranges in [...] has duplicate debug_info_offset 0x0, ignoring .debug_aranges.
Debugging showed that, in fact, a second CU was being created at this
offset. We tracked this down to the fact that, while the ELF reader
is careful to re-use the per-BFD data, other readers are not, and
could re-read the DWARF data multiple times.
However, since the change to allow an objfile to have multiple "quick
symbol" implementations, there's no reason for this approach -- it's
safe and easy for all symbol readers to reuse the per-BFD data when
reading DWARF.
This patch implements this idea, simplifying dwarf2_build_psymtabs and
making it private, and then switching to dwarf2_initialize_objfile as
the sole way to start the DWARF reader.
Note that, while I think the call to dwarf2_build_frame_info in
machoread.c is also obsolete, I haven't attempted to remove it here.
This commit brings all the changes made by running gdb/copyright.py
as per GDB's Start of New Year Procedure.
For the avoidance of doubt, all changes in this commits were
performed by the script.
Now that the quick functions are separate from the object file format,
there's no need to have elfread.c push a new entry on the objfile 'qf'
list. Instead, this detail can be pushed into the DWARF reader. That
is what this patch implements.
I wasn't sure whether lazy reading still makes sense or not. It's
still only used by ELF, and only in certain situations (like vfork, I
think). It may not be carrying its weight, so we may want to consider
removing this in the future.
Also, I'm unclear on why the various indices are only used for ELF.
This seems sub-optimal. However, I haven't tried to address that
here.
gdb/ChangeLog
2021-03-28 Tom Tromey <tom@tromey.com>
* elfread.c (can_lazily_read_symbols): Move to dwarf2/read.c.
(elf_symfile_read): Simplify.
* dwarf2/read.c (struct lazy_dwarf_reader): Move from elfread.c.
(make_lazy_dwarf_reader): New function.
(make_dwarf_gdb_index, make_dwarf_debug_names): Now static.
(dwarf2_initialize_objfile): Return void. Remove index_kind
parameter. Push on 'qf' list.
* dwarf2/public.h (dwarf2_initialize_objfile): Change return
type. Remove 'index_kind' parameter.
(make_dwarf_gdb_index, make_dwarf_debug_names): Don't declare.
This changes quick_symbol_functions to be a base class with pure
virtual methods, rather than a struct holding function pointers.
Then, objfile is changed to hold a unique_ptr to an instance of this
class.
struct psymbol_functions is put into psympriv.h, and not psymtab.c,
because that is convenient later in the series.
gdb/ChangeLog
2021-03-20 Tom Tromey <tom@tromey.com>
* psympriv.h (struct psymbol_functions): New.
* symfile.c (syms_from_objfile_1, reread_symbols): Update.
* symfile-debug.c (objfile::find_compunit_symtab_by_address)
(objfile::lookup_global_symbol_language): Update.
* quick-symbol.h (struct quick_symbol_functions): Convert function
pointers to methods. Add virtual destructor.
(quick_symbol_functions_up): New typedef.
* psymtab.h (psym_functions, dwarf2_gdb_index_functions)
(dwarf2_debug_names_functions): Don't declare.
(make_psymbol_functions): Declare.
* psymtab.c (psymbol_functions::map_symtabs_matching_filename)
(psymbol_functions::find_pc_sect_compunit_symtab)
(psymbol_functions::lookup_symbol)
(psymbol_functions::lookup_global_symbol_language)
(psymbol_functions::find_last_source_symtab)
(psymbol_functions::forget_cached_source_info)
(psymbol_functions::print_stats, psymbol_functions::dump)
(psymbol_functions::expand_symtabs_for_function)
(psymbol_functions::expand_all_symtabs)
(psymbol_functions::expand_symtabs_with_fullname)
(psymbol_functions::map_symbol_filenames)
(psymbol_functions::map_matching_symbols)
(psymbol_functions::expand_symtabs_matching)
(psymbol_functions::has_symbols)
(psymbol_functions::find_compunit_symtab_by_address): Rename.
(psym_functions): Remove.
(make_psymbol_functions): New function.
* objfiles.h (struct objfile) <qf>: Change type.
* elfread.c (elf_symfile_read): Update.
* dwarf2/read.c (struct dwarf2_base_index_functions)
(struct dwarf2_gdb_index, struct dwarf2_debug_names_index): New.
(make_dwarf_gdb_index, make_dwarf_debug_names): New functions.
(dwarf2_base_index_functions::find_last_source_symtab)
(dwarf2_base_index_functions::forget_cached_source_info)
(dwarf2_base_index_functions::map_symtabs_matching_filename)
(dwarf2_gdb_index::lookup_symbol)
(dwarf2_base_index_functions::print_stats)
(dwarf2_gdb_index::dump)
(dwarf2_gdb_index::expand_symtabs_for_function)
(dwarf2_base_index_functions::expand_all_symtabs)
(dwarf2_base_index_functions::expand_symtabs_with_fullname):
Rename.
(dwarf2_gdb_index::map_matching_symbols): New method.
(dwarf2_gdb_index::expand_symtabs_matching): New method.
(dwarf2_base_index_functions::find_pc_sect_compunit_symtab)
(dwarf2_base_index_functions::map_symbol_filenames)
(dwarf2_base_index_functions::has_symbols): Rename.
(dwarf2_gdb_index_functions): Remove.
(dwarf2_debug_names_index::lookup_symbol)
(dwarf2_debug_names_index::dump)
(dwarf2_debug_names_index::expand_symtabs_for_function)
(dwarf2_debug_names_index::map_matching_symbols)
(dwarf2_debug_names_index::expand_symtabs_matching): Rename.
(dwarf2_debug_names_functions): Remove.
* dwarf2/public.h (make_dwarf_gdb_index, make_dwarf_debug_names):
Declare.
This moves some more DWARF code out of symfile.h and into a new
header, dwarf2/public.h. This header is intended to describe the
public API of the DWARF reader.
gdb/ChangeLog
2021-03-20 Tom Tromey <tom@tromey.com>
* coffread.c: Include dwarf2/public.h.
* dwarf2/frame.c: Include dwarf2/public.h.
* dwarf2/index-write.h: Include dwarf2/public.h, not symfile.h.
* dwarf2/public.h: New file.
* dwarf2/read.c: Include dwarf2/public.h.
* elfread.c: Include dwarf2/public.h.
* machoread.c: Include dwarf2/public.h.
* symfile.h (dwarf2_has_info, enum dw_index_kind)
(dwarf2_initialize_objfile, dwarf2_build_psymtabs)
(dwarf2_build_frame_info): Move to dwarf2/public.h.
* xcoffread.c: Include dwarf2/public.h.
