Remove sym_fns::sym_read_psymbols

Partial symbols are read via the sym_fns::sym_read_psymbols function
pointer.  In order to separate the partial symbols from the objfile,
this must instead be done via a virtual method on
quick_symbol_functions.  This patch implements this change.

gdb/ChangeLog
2021-03-20  Tom Tromey  <tom@tromey.com>

	* xcoffread.c (xcoff_sym_fns): Update.
	* symfile.h (struct sym_fns) <sym_read_psymbols>: Remove.
	* symfile-debug.c (objfile::has_partial_symbols): Use
	can_lazily_read_symbols.
	(debug_sym_read_psymbols): Remove.
	(debug_sym_fns, install_symfile_debug_logging): Update.
	* quick-symbol.h (struct quick_symbol_functions)
	<can_lazily_read_symbols, read_partial_symbols>: New methods.
	* psymtab.c (require_partial_symbols): Use new 'qf' methods.
	* mipsread.c (ecoff_sym_fns): Update.
	* machoread.c (macho_sym_fns): Update.
	* elfread.c (struct lazy_dwarf_reader): New.
	(elf_symfile_read): Update.
	(read_psyms): Now a method of lazy_dwarf_reader.
	(elf_sym_fns): Update.
	(elf_sym_fns_lazy_psyms): Remove.
	* dbxread.c (aout_sym_fns): Update.
	* coffread.c (coff_sym_fns): Update.

1 files changed, 14 insertions, 0 deletions

diff --git a/gdb/quick-symbol.h b/gdb/quick-symbol.h
index 315a97a..dd2b896 100644
--- a/gdb/quick-symbol.h
+++ b/gdb/quick-symbol.h
@@ -237,6 +237,20 @@ struct quick_symbol_functions
   {
     /* Do nothing.  */
   }
+
+  /* Return true if this class can lazily read the symbols.  This may
+     only return true if there are in fact symbols to be read, because
+     this is used in the implementation of 'has_partial_symbols'.  */
+  virtual bool can_lazily_read_symbols ()
+  {
+    return false;
+  }
+
+  /* Read the partial symbols for OBJFILE.  This will only ever be
+     called if can_lazily_read_symbols returns true.  */
+  virtual void read_partial_symbols (struct objfile *objfile)
+  {
+  }
 };
 
 typedef std::unique_ptr<quick_symbol_functions> quick_symbol_functions_up;