* utils.c (do_value_free): New function.

(make_cleanup_value_free): Likewise. * dwarf2loc.c (dwarf2_evaluate_loc_desc_full): Handle value freeing correctly. (dwarf2_loc_desc_needs_frame): Call make_cleanup_value_free_to_mark. * dwarf2expr.h (struct dwarf_expr_context) <mark>: Remove field. * dwarf2expr.c (free_dwarf_expr_context): Don't call value_free_to_mark. (new_dwarf_expr_context): Don't call value_mark. * dwarf2-frame.c (execute_stack_op): Call make_cleanup_value_free_to_mark. * defs.h (make_cleanup_value_free): Declare.
2011-05-13 15:44:49 +00:00
parent 3ac5406bdb
commit 72fc29ff12
7 changed files with 52 additions and 7 deletions
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,19 @@
+2011-05-13  Tom Tromey  <tromey@redhat.com>
+
+	* utils.c (do_value_free): New function.
+	(make_cleanup_value_free): Likewise.
+	* dwarf2loc.c (dwarf2_evaluate_loc_desc_full): Handle value
+	freeing correctly.
+	(dwarf2_loc_desc_needs_frame): Call
+	make_cleanup_value_free_to_mark.
+	* dwarf2expr.h (struct dwarf_expr_context) <mark>: Remove field.
+	* dwarf2expr.c (free_dwarf_expr_context): Don't call
+	value_free_to_mark.
+	(new_dwarf_expr_context): Don't call value_mark.
+	* dwarf2-frame.c (execute_stack_op): Call
+	make_cleanup_value_free_to_mark.
+	* defs.h (make_cleanup_value_free): Declare.
+
 2011-05-13  Thiago Jung Bauermann  <bauerman@br.ibm.com>

 	* mi/mi-main.c (mi_cmd_execute): Use cleanup from
--- a/gdb/defs.h
+++ b/gdb/defs.h
@@ -362,6 +362,7 @@ extern struct cleanup *
  make_cleanup_restore_ui_file (struct ui_file **variable);

 extern struct cleanup *make_cleanup_value_free_to_mark (struct value *);
+extern struct cleanup *make_cleanup_value_free (struct value *);

 extern struct cleanup *make_final_cleanup (make_cleanup_ftype *, void *);

--- a/gdb/dwarf2-frame.c
+++ b/gdb/dwarf2-frame.c
@@ -402,6 +402,7 @@ execute_stack_op (const gdb_byte *exp, ULONGEST len, int addr_size,

  ctx = new_dwarf_expr_context ();
  old_chain = make_cleanup_free_dwarf_expr_context (ctx);
+  make_cleanup_value_free_to_mark (value_mark ());

  ctx->gdbarch = get_frame_arch (this_frame);
  ctx->addr_size = addr_size;
--- a/gdb/dwarf2expr.c
+++ b/gdb/dwarf2expr.c
@@ -104,7 +104,6 @@ new_dwarf_expr_context (void)
  retval->num_pieces = 0;
  retval->pieces = 0;
  retval->max_recursion_depth = 0x100;
-  retval->mark = value_mark ();
  return retval;
 }

@@ -113,7 +112,6 @@ new_dwarf_expr_context (void)
 void
 free_dwarf_expr_context (struct dwarf_expr_context *ctx)
 {
-  value_free_to_mark (ctx->mark);
  xfree (ctx->stack);
  xfree (ctx->pieces);
  xfree (ctx);
--- a/gdb/dwarf2expr.h
+++ b/gdb/dwarf2expr.h
@@ -81,10 +81,6 @@ struct dwarf_expr_context
  /* Offset used to relocate DW_OP_addr argument.  */
  CORE_ADDR offset;

-  /* The evaluator is value-based, and frees values up to this point
-     when the expression context is destroyed.  */
-  struct value *mark;
-
  /* An opaque argument provided by the caller, which will be passed
     to all of the callback functions.  */
  void *baton;
--- a/gdb/dwarf2loc.c
+++ b/gdb/dwarf2loc.c
@@ -1086,7 +1086,7 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame,
  struct value *retval;
  struct dwarf_expr_baton baton;
  struct dwarf_expr_context *ctx;
-  struct cleanup *old_chain;
+  struct cleanup *old_chain, *value_chain;
  struct objfile *objfile = dwarf2_per_cu_objfile (per_cu);
  volatile struct gdb_exception ex;

@@ -1106,6 +1106,7 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame,

  ctx = new_dwarf_expr_context ();
  old_chain = make_cleanup_free_dwarf_expr_context (ctx);
+  value_chain = make_cleanup_value_free_to_mark (value_mark ());

  ctx->gdbarch = get_objfile_arch (objfile);
  ctx->addr_size = dwarf2_per_cu_addr_size (per_cu);
@@ -1128,6 +1129,7 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame,
    {
      if (ex.error == NOT_AVAILABLE_ERROR)
 	{
+	  do_cleanups (old_chain);
 	  retval = allocate_value (type);
 	  mark_value_bytes_unavailable (retval, 0, TYPE_LENGTH (type));
 	  return retval;
@@ -1150,6 +1152,9 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame,

      c = allocate_piece_closure (per_cu, ctx->num_pieces, ctx->pieces,
 				  ctx->addr_size);
+      /* We must clean up the value chain after creating the piece
+	 closure but before allocating the result.  */
+      do_cleanups (value_chain);
      retval = allocate_computed_value (type, &pieced_value_funcs, c);
      VALUE_FRAME_ID (retval) = frame_id;
      set_value_offset (retval, byte_offset);
@@ -1166,6 +1171,7 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame,

 	    if (byte_offset != 0)
 	      error (_("cannot use offset on synthetic pointer to register"));
+	    do_cleanups (value_chain);
 	    if (gdb_regnum != -1)
 	      retval = value_from_register (type, gdb_regnum, frame);
 	    else
@@ -1179,6 +1185,7 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame,
 	    CORE_ADDR address = dwarf_expr_fetch_address (ctx, 0);
 	    int in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 0);

+	    do_cleanups (value_chain);
 	    retval = allocate_value_lazy (type);
 	    VALUE_LVAL (retval) = lval_memory;
 	    if (in_stack_memory)
@@ -1201,6 +1208,13 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame,
 	    val_bytes += byte_offset;
 	    n -= byte_offset;

+	    /* Preserve VALUE because we are going to free values back
+	       to the mark, but we still need the value contents
+	       below.  */
+	    value_incref (value);
+	    do_cleanups (value_chain);
+	    make_cleanup_value_free (value);
+
 	    retval = allocate_value (type);
 	    contents = value_contents_raw (retval);
 	    if (n > TYPE_LENGTH (type))
@@ -1218,6 +1232,7 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame,
 	    if (byte_offset + TYPE_LENGTH (type) > n)
 	      invalid_synthetic_pointer ();

+	    do_cleanups (value_chain);
 	    retval = allocate_value (type);
 	    contents = value_contents_raw (retval);

@@ -1231,6 +1246,7 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame,
 	  break;

 	case DWARF_VALUE_OPTIMIZED_OUT:
+	  do_cleanups (value_chain);
 	  retval = allocate_value (type);
 	  VALUE_LVAL (retval) = not_lval;
 	  set_value_optimized_out (retval, 1);
@@ -1353,6 +1369,7 @@ dwarf2_loc_desc_needs_frame (const gdb_byte *data, unsigned short size,

  ctx = new_dwarf_expr_context ();
  old_chain = make_cleanup_free_dwarf_expr_context (ctx);
+  make_cleanup_value_free_to_mark (value_mark ());

  ctx->gdbarch = get_objfile_arch (objfile);
  ctx->addr_size = dwarf2_per_cu_addr_size (per_cu);
--- a/gdb/utils.c
+++ b/gdb/utils.c
@@ -448,6 +448,22 @@ make_cleanup_value_free_to_mark (struct value *mark)
  return make_my_cleanup (&cleanup_chain, do_value_free_to_mark, mark);
 }

+/* Helper for make_cleanup_value_free.  */
+
+static void
+do_value_free (void *value)
+{
+  value_free (value);
+}
+
+/* Free VALUE.  */
+
+struct cleanup *
+make_cleanup_value_free (struct value *value)
+{
+  return make_my_cleanup (&cleanup_chain, do_value_free, value);
+}
+
 struct cleanup *
 make_my_cleanup2 (struct cleanup **pmy_chain, make_cleanup_ftype *function,
 		  void *arg,  void (*free_arg) (void *))