gdb: New API for tracking innermost block

This commit is preparation for a later change, at this point there
should be no user visible change.

We currently maintain a global innermost_block which tracks the most
inner block encountered when parsing an expression.

This commit wraps the innermost_block into a new class, and switches all
direct accesses to the variable to use the class API.

gdb/ChangeLog:

	* ada-exp.y (write_var_from_sym): Switch to innermost_block API.
	* ada-lang.c (resolve_subexp): Likewise.
	* breakpoint.c (set_breakpoint_condition) Likewise.
	(watch_command_1) Likewise.
	* c-exp.y (variable): Likewise.
	* d-exp.y (PrimaryExpression): Likewise.
	* f-exp.y (variable): Likewise.
	* go-exp.y (variable): Likewise.
	* m2-exp.y (variable): Likewise.
	* objfiles.c (objfile::~objfile): Likewise.
	* p-exp.y (variable): Likewise.
	* parse.c (innermost_block): Change type.
	* parser-defs.h (class innermost_block_tracker): New.
	(innermost_block): Change to innermost_block_tracker.
	* printcmd.c (display_command): Switch to innermost_block API.
	(do_one_display): Likewise.
	* rust-exp.y (do_one_display): Likewise.
	* symfile.c (clear_symtab_users): Likewise.
	* varobj.c (varobj_create): Switch to innermost_block API, replace
	use of innermost_block with block stored on varobj object.

1 files changed, 1 insertions, 1 deletions

diff --git a/gdb/symfile.c b/gdb/symfile.c
index f7f75b0..ab6ec1c 100644
--- a/gdb/symfile.c
+++ b/gdb/symfile.c
@@ -2900,7 +2900,7 @@ clear_symtab_users (symfile_add_flags add_flags)
      FIXME: It's not clear which of these are supposed to persist
      between expressions and which ought to be reset each time.  */
   expression_context_block = NULL;
-  innermost_block = NULL;
+  innermost_block.reset ();
 
   /* Varobj may refer to old symbols, perform a cleanup.  */
   varobj_invalidate ();