Introduce minimal_symbol_reader

This patch introduced minimal_symbol_reader, a RAII-based class which
replaces the current make_cleanup_discard_minimal_symbols.

2016-10-21  Tom Tromey  <tom@tromey.com>

	* xcoffread.c (xcoff_initial_scan): Use
	minimal_symbol_reader.
	* mipsread.c (mipscoff_symfile_read): Use
	minimal_symbol_reader.
	* minsyms.h (minimal_symbol_reader): New class.
	(init_minimal_symbol_collection)
	(make_cleanup_discard_minimal_symbols, install_minimal_symbols):
	Don't declare.
	* minsyms.c (minimal_symbol_reader): Renamed from
	init_minimal_symbol_collection, turned into constructor.
	(~minimal_symbol_reader): Renamed from
	do_discard_minimal_symbols_cleanup, turned into destructor.
	(make_cleanup_discard_minimal_symbols): Remove.
	(minimal_symbol_reader::install): Rename form
	install_minimal_symbols.
	* mdebugread.c (elfmdebug_build_psymtabs): Use
	minimal_symbol_reader.
	* machoread.c (macho_symfile_read): Use
	minimal_symbol_reader.
	* elfread.c (elf_read_minimal_symbols): Use
	minimal_symbol_reader.
	* dbxread.c (dbx_symfile_read): Use minimal_symbol_reader.
	* coffread.c (coff_symfile_read): Use
	minimal_symbol_reader.

1 files changed, 24 insertions, 19 deletions

diff --git a/gdb/minsyms.h b/gdb/minsyms.h
index 8857f1a..d75bd41 100644
--- a/gdb/minsyms.h
+++ b/gdb/minsyms.h
@@ -53,21 +53,33 @@ struct bound_minimal_symbol
    as opaque and use functions provided by minsyms.c to inspect them.
 */
 
-/* Prepare to start collecting minimal symbols.  This should be called
-   by a symbol reader to initialize the minimal symbol module.
-   Currently, minimal symbol table creation is not reentrant; it
-   relies on global (static) variables in minsyms.c.  */
+/* An RAII-based object that is used to record minimal symbols while
+   they are being read.  */
+class minimal_symbol_reader
+{
+ public:
+
+  /* Prepare to start collecting minimal symbols.  This should be called
+     by a symbol reader to initialize the minimal symbol module.
+     Currently, minimal symbol table creation is not reentrant; it
+     relies on global (static) variables in minsyms.c.  */
+
+  explicit minimal_symbol_reader ();
+
+  ~minimal_symbol_reader ();
 
-void init_minimal_symbol_collection (void);
+  /* Install the minimal symbols that have been collected into the
+     given objfile.  */
 
-/* Return a cleanup which is used to clean up the global state left
-   over by minimal symbol creation.  After calling
-   init_minimal_symbol_collection, a symbol reader should call this
-   function.  Then, after all minimal symbols have been read,
-   regardless of whether they are installed or not, the cleanup
-   returned by this function should be run.  */
+  void install (struct objfile *);
 
-struct cleanup *make_cleanup_discard_minimal_symbols (void);
+ private:
+
+  /* No need for these.  They are intentionally not defined anywhere.  */
+  minimal_symbol_reader &operator=
+    (const minimal_symbol_reader &);
+  minimal_symbol_reader (const minimal_symbol_reader &);
+};
 
 /* Record a new minimal symbol.  This is the "full" entry point;
    simpler convenience entry points are also provided below.
@@ -122,13 +134,6 @@ struct minimal_symbol *prim_record_minimal_symbol_and_info
      int section,
      struct objfile *);
 
-/* Install the minimal symbols that have been collected into the given
-   objfile.  After this is called, the cleanup returned by
-   make_cleanup_discard_minimal_symbols should be run in order to
-   clean up global state.  */
-
-void install_minimal_symbols (struct objfile *);
-
 /* Create the terminating entry of OBJFILE's minimal symbol table.
    If OBJFILE->msymbols is zero, allocate a single entry from
    OBJFILE->objfile_obstack; otherwise, just initialize