Add as_lval argument to expression evaluator

There are cases where the result of the expression evaluation is
expected to be in a form of a value and not location description.

One place that has this requirement is dwarf_entry_parameter_to_value
function, but more are expected in the future. Until now, this
requirement was fulfilled by extending the evaluated expression with
a DW_OP_stack_value operation at the end.

New implementation, introduces a new evaluation argument instead.

	* dwarf2/expr.c (dwarf_expr_context::fetch_result): Add as_lval
	argument.
	(dwarf_expr_context::eval_exp): Add as_lval argument.
	* dwarf2/expr.h (struct dwarf_expr_context): Add as_lval
	argument to fetch_result and eval_exp methods.
	* dwarf2/frame.c (execute_stack_op): Add as_lval argument.
	* dwarf2/loc.c (dwarf_entry_parameter_to_value): Remove
	DWARF expression extension.
	(dwarf2_evaluate_loc_desc_full): Add as_lval argument support.
	(dwarf2_evaluate_loc_desc): Add as_lval argument support.
	(dwarf2_locexpr_baton_eval): Add as_lval argument support.

1 files changed, 1 insertions, 1 deletions

diff --git a/gdb/dwarf2/frame.c b/gdb/dwarf2/frame.c
index ae26a8868d1..f3d38771708 100644
--- a/gdb/dwarf2/frame.c
+++ b/gdb/dwarf2/frame.c
@@ -233,7 +233,7 @@ execute_stack_op (const gdb_byte *exp, ULONGEST len, int addr_size,
   scoped_value_mark free_values;
 
   ctx.push_address (initial, initial_in_stack_memory);
-  value *result_val = ctx.evaluate (exp, len, nullptr, this_frame);
+  value *result_val = ctx.evaluate (exp, len, true, nullptr, this_frame);
 
   if (VALUE_LVAL (result_val) == lval_memory)
     return value_address (result_val);