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, 14 insertions, 16 deletions

diff --git a/gdb/dwarf2-frame.c b/gdb/dwarf2-frame.c
index 11258ea026..48963de383 100644
--- a/gdb/dwarf2-frame.c
+++ b/gdb/dwarf2-frame.c
@@ -369,29 +369,27 @@ execute_stack_op (const gdb_byte *exp, ULONGEST len, int addr_size,
 		  CORE_ADDR offset, struct frame_info *this_frame,
 		  CORE_ADDR initial, int initial_in_stack_memory)
 {
-  struct dwarf_expr_context *ctx;
   CORE_ADDR result;
   struct cleanup *old_chain;
 
-  ctx = new_dwarf_expr_context ();
-  old_chain = make_cleanup_free_dwarf_expr_context (ctx);
-  make_cleanup_value_free_to_mark (value_mark ());
+  dwarf_expr_context ctx;
+  old_chain = make_cleanup_value_free_to_mark (value_mark ());
 
-  ctx->gdbarch = get_frame_arch (this_frame);
-  ctx->addr_size = addr_size;
-  ctx->ref_addr_size = -1;
-  ctx->offset = offset;
-  ctx->baton = this_frame;
-  ctx->funcs = &dwarf2_frame_ctx_funcs;
+  ctx.gdbarch = get_frame_arch (this_frame);
+  ctx.addr_size = addr_size;
+  ctx.ref_addr_size = -1;
+  ctx.offset = offset;
+  ctx.baton = this_frame;
+  ctx.funcs = &dwarf2_frame_ctx_funcs;
 
-  dwarf_expr_push_address (ctx, initial, initial_in_stack_memory);
-  dwarf_expr_eval (ctx, exp, len);
+  dwarf_expr_push_address (&ctx, initial, initial_in_stack_memory);
+  dwarf_expr_eval (&ctx, exp, len);
 
-  if (ctx->location == DWARF_VALUE_MEMORY)
-    result = dwarf_expr_fetch_address (ctx, 0);
-  else if (ctx->location == DWARF_VALUE_REGISTER)
+  if (ctx.location == DWARF_VALUE_MEMORY)
+    result = dwarf_expr_fetch_address (&ctx, 0);
+  else if (ctx.location == DWARF_VALUE_REGISTER)
     result = read_addr_from_reg (this_frame,
-				 value_as_long (dwarf_expr_fetch (ctx, 0)));
+				 value_as_long (dwarf_expr_fetch (&ctx, 0)));
   else
     {
       /* This is actually invalid DWARF, but if we ever do run across