Re: [PATCH] Handle OP_THIS in tracepoints

[Pedro Alves <pedro@codesourcery.com>]

On Thursday 24 December 2009 16:34:54, Pedro Alves wrote:
> This is busted, and was later fixed in our internal
> tree.  :-)  The selected frame, and the current language
> don't have anything to do with the context in which
> the tracepoint runs.  E.g.:
> 
> (gdb) trace 'Foo::Bar()'
> (gdb) actions 
> (gdb) collect foo_field
> 
> Here, the `this' for foo_field needs to be
> looked up in the context of Foo::Bar, not of whatever
> context/frame the user had selected when she issued
> the 'actions' command.

On Thursday 24 December 2009 18:08:01, Pedro Alves wrote:
> On Thursday 24 December 2009 17:57:39, Stan Shebs wrote:
> > it should be no  
> > problem to prepare the patch! :-)
> 
> Will do.

Here it is.

2009-12-24  Pedro Alves  <pedro@codesourcery.com>

	gdb/
	* ax-gdb.c (gen_expr) <OP_THIS>: Lookup `this' in the context of
	the tracepoint, not of the selected frame and language.

-- 
Pedro Alves

---
 gdb/ax-gdb.c |   21 +++++----------------
 1 file changed, 5 insertions(+), 16 deletions(-)

Index: src/gdb/ax-gdb.c
===================================================================
--- src.orig/gdb/ax-gdb.c	2009-12-24 17:08:57.000000000 +0000
+++ src/gdb/ax-gdb.c	2009-12-24 18:12:32.000000000 +0000
@@ -1762,30 +1762,19 @@ gen_expr (struct expression *exp, union 
 
     case OP_THIS:
       {
-	char *name;
-	struct frame_info *frame;
+	char *this_name;
 	struct symbol *func, *sym;
 	struct block *b;
 
-	name = current_language->la_name_of_this;
-	if (!name)
-	  error (_("no `this' in current language"));
-
-	frame = get_selected_frame (_("no frame selected"));
-
-	func = get_frame_function (frame);
-	if (!func)
-	  error (_("no `%s' in nameless context"), name);
-
+	func = block_linkage_function (block_for_pc (ax->scope));
+	this_name = language_def (SYMBOL_LANGUAGE (func))->la_name_of_this;
 	b = SYMBOL_BLOCK_VALUE (func);
-	if (dict_empty (BLOCK_DICT (b)))
-	  error (_("no args, no `%s' in block"), name);
 
 	/* Calling lookup_block_symbol is necessary to get the LOC_REGISTER
 	   symbol instead of the LOC_ARG one (if both exist).  */
-	sym = lookup_block_symbol (b, name, NULL, VAR_DOMAIN);
+	sym = lookup_block_symbol (b, this_name, NULL, VAR_DOMAIN);
 	if (!sym)
-	  error (_("no `%s' found"), name);
+	  error (_("no `%s' found"), this_name);
 

 	gen_var_ref (exp->gdbarch, ax, value, sym);
 	(*pc) += 2;