Initial conversion of dwarf_expr_ctx

This is the first step in the conversion of dwarf_expr_ctx to a C++
class.  This conversion is done in steps to make the patches, and the
reviews, a bit simpler.  This patch changes dwarf_expr_ctx to be
stack-allocated and removes the associated cleanup.

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

	* dwarf2loc.c (dwarf2_evaluate_loc_desc_full): Stack-allocate
	dwarf_expr_context.  Remove cleanups.
	(dwarf2_locexpr_baton_eval)
	(dwarf2_loc_desc_get_symbol_read_needs):  Likewise.
	* dwarf2expr.h (dwarf_expr_context, ~dwarf_expr_context): Add
	constructors and destructors.
	(new_dwarf_expr_context, free_dwarf_expr_context)
	(make_cleanup_free_dwarf_expr_context): Don't declare.
	* dwarf2-frame.c (execute_stack_op): Stack-allocate
	dwarf_expr_context.  Remove cleanups.
	(dwarf_expr_context): Rename from new_dwarf_expr_context.  Turn
	into constructor.
	(free_dwarf_expr_context, free_dwarf_expr_context_cleanup):
	Remove.
	(~dwarf_expr_context): Rename from
	make_cleanup_free_dwarf_expr_context.  Turn into destructor.

1 files changed, 21 insertions, 34 deletions

diff --git a/gdb/dwarf2expr.c b/gdb/dwarf2expr.c
index 90e4e25..e8487a6 100644
--- a/gdb/dwarf2expr.c
+++ b/gdb/dwarf2expr.c
@@ -91,45 +91,32 @@ dwarf_expr_address_type (struct dwarf_expr_context *ctx)
 
 /* Create a new context for the expression evaluator.  */
 
-struct dwarf_expr_context *
-new_dwarf_expr_context (void)
+dwarf_expr_context::dwarf_expr_context ()
+: stack (NULL),
+  stack_len (0),
+  stack_allocated (10),
+  gdbarch (NULL),
+  addr_size (0),
+  ref_addr_size (0),
+  offset (0),
+  recursion_depth (0),
+  max_recursion_depth (0x100),
+  location (DWARF_VALUE_MEMORY),
+  len (0),
+  data (NULL),
+  initialized (0),
+  num_pieces (0),
+  pieces (NULL)
 {
-  struct dwarf_expr_context *retval;
-
-  retval = XCNEW (struct dwarf_expr_context);
-  retval->stack_len = 0;
-  retval->stack_allocated = 10;
-  retval->stack = XNEWVEC (struct dwarf_stack_value, retval->stack_allocated);
-  retval->num_pieces = 0;
-  retval->pieces = 0;
-  retval->max_recursion_depth = 0x100;
-  return retval;
+  this->stack = XNEWVEC (struct dwarf_stack_value, this->stack_allocated);
 }
 
-/* Release the memory allocated to CTX.  */
+/* Clean up a dwarf_expr_context.  */
 
-void
-free_dwarf_expr_context (struct dwarf_expr_context *ctx)
-{
-  xfree (ctx->stack);
-  xfree (ctx->pieces);
-  xfree (ctx);
-}
-
-/* Helper for make_cleanup_free_dwarf_expr_context.  */
-
-static void
-free_dwarf_expr_context_cleanup (void *arg)
-{
-  free_dwarf_expr_context ((struct dwarf_expr_context *) arg);
-}
-
-/* Return a cleanup that calls free_dwarf_expr_context.  */
-
-struct cleanup *
-make_cleanup_free_dwarf_expr_context (struct dwarf_expr_context *ctx)
+dwarf_expr_context::~dwarf_expr_context ()
 {
-  return make_cleanup (free_dwarf_expr_context_cleanup, ctx);
+  xfree (this->stack);
+  xfree (this->pieces);
 }
 
 /* Expand the memory allocated to CTX's stack to contain at least