Constify some parameters in the varobj code

To make it clear that some functions should not modify the variable
object, this patch adds the const qualifier where it makes sense to some
struct varobj * parameters. Most getters should take a const pointer to
guarantee they don't modify the object.

Unfortunately, I couldn't add it to some callbacks (such as name_of_child).
In the C implementation, they call c_describe_child, which calls
varobj_get_path_expr. varobj_get_path_expr needs to modify the object in
order to cache the computed value. It therefore can't take a const
pointer, and it affects the whole call chain. I suppose that's where you
would use a "mutable" in C++.

I did that to make sure there was no other cases like the one fixed in
the previous patch. I don't think it can hurt.

gdb/ChangeLog:

	* ada-varobj.c (ada_number_of_children): Constify struct varobj *
	parameter.
	(ada_name_of_variable): Same.
	(ada_path_expr_of_child): Same.
	(ada_value_of_variable): Same.
	(ada_value_is_changeable_p): Same.
	(ada_value_has_mutated): Same.
	* c-varobj.c (varobj_is_anonymous_child): Same.
	(c_is_path_expr_parent): Same.
	(c_number_of_children): Same.
	(c_name_of_variable): Same.
	(c_path_expr_of_child): Same.
	(get_type): Same.
	(c_value_of_variable): Same.
	(cplus_number_of_children): Same.
	(cplus_name_of_variable): Same.
	(cplus_path_expr_of_child): Same.
	(cplus_value_of_variable): Same.
	* jv-varobj.c (java_number_of_children): Same.
	(java_name_of_variable): Same.
	(java_path_expr_of_child): Same.
	(java_value_of_variable): Same.
	* varobj.c (number_of_children): Same.
	(name_of_variable): Same.
	(is_root_p): Same.
	(varobj_ensure_python_env): Same.
	(varobj_get_objname): Same.
	(varobj_get_expression): Same.
	(varobj_get_display_format): Same.
	(varobj_get_display_hint): Same.
	(varobj_has_more): Same.
	(varobj_get_thread_id): Same.
	(varobj_get_frozen): Same.
	(dynamic_varobj_has_child_method): Same.
	(varobj_get_gdb_type): Same.
	(is_path_expr_parent): Same.
	(varobj_default_is_path_expr_parent): Same.
	(varobj_get_language): Same.
	(varobj_get_attributes): Same.
	(varobj_is_dynamic_p): Same.
	(varobj_get_child_range): Same.
	(varobj_value_has_mutated): Same.
	(varobj_get_value_type): Same.
	(number_of_children): Same.
	(name_of_variable): Same.
	(check_scope): Same.
	(varobj_editable_p): Same.
	(varobj_value_is_changeable_p): Same.
	(varobj_floating_p): Same.
	(varobj_default_value_is_changeable_p): Same.
	* varobj.h (struct lang_varobj_ops): Consitfy some struct varobj *
	parameters.
	(varobj_get_objname): Constify struct varobj * parameter.
	(varobj_get_expression): Same.
	(varobj_get_thread_id): Same.
	(varobj_get_frozen): Same.
	(varobj_get_child_range): Same.
	(varobj_get_display_hint): Same.
	(varobj_get_gdb_type): Same.
	(varobj_get_language): Same.
	(varobj_get_attributes): Same.
	(varobj_editable_p): Same.
	(varobj_floating_p): Same.
	(varobj_has_more): Same.
	(varobj_is_dynamic_p): Same.
	(varobj_ensure_python_env): Same.
	(varobj_default_value_is_changeable_p): Same.
	(varobj_value_is_changeable_p): Same.
	(varobj_get_value_type): Same.
	(varobj_is_anonymous_child): Same.
	(varobj_value_get_print_value): Same.
	(varobj_default_is_path_expr_parent): Same.

1 files changed, 30 insertions, 30 deletions

diff --git a/gdb/varobj.c b/gdb/varobj.c
index 28d388e..0daef91 100644
--- a/gdb/varobj.c
+++ b/gdb/varobj.c
@@ -193,9 +193,9 @@ static int install_new_value (struct varobj *var, struct value *value,
 
 /* Language-specific routines.  */
 
-static int number_of_children (struct varobj *);
+static int number_of_children (const struct varobj *);
 
-static char *name_of_variable (struct varobj *);
+static char *name_of_variable (const struct varobj *);
 
 static char *name_of_child (struct varobj *, int);
 
@@ -206,7 +206,7 @@ static struct value *value_of_child (struct varobj *parent, int index);
 static char *my_value_of_variable (struct varobj *var,
 				   enum varobj_display_formats format);
 
-static int is_root_p (struct varobj *var);
+static int is_root_p (const struct varobj *var);
 
 static struct varobj *varobj_add_child (struct varobj *var,
 					struct varobj_item *item);
@@ -230,7 +230,7 @@ static struct vlist **varobj_table;
 
 /* API Implementation */
 static int
-is_root_p (struct varobj *var)
+is_root_p (const struct varobj *var)
 {
   return (var->root->rootvar == var);
 }
@@ -239,7 +239,7 @@ is_root_p (struct varobj *var)
 /* Helper function to install a Python environment suitable for
    use during operations on VAR.  */
 struct cleanup *
-varobj_ensure_python_env (struct varobj *var)
+varobj_ensure_python_env (const struct varobj *var)
 {
   return ensure_python_env (var->root->exp->gdbarch,
 			    var->root->exp->language_defn);
@@ -487,7 +487,7 @@ varobj_get_handle (char *objname)
 /* Given the handle, return the name of the object.  */
 
 char *
-varobj_get_objname (struct varobj *var)
+varobj_get_objname (const struct varobj *var)
 {
   return var->obj_name;
 }
@@ -496,7 +496,7 @@ varobj_get_objname (struct varobj *var)
    result must be freed by the caller.  */
 
 char *
-varobj_get_expression (struct varobj *var)
+varobj_get_expression (const struct varobj *var)
 {
   return name_of_variable (var);
 }
@@ -600,13 +600,13 @@ varobj_set_display_format (struct varobj *var,
 }
 
 enum varobj_display_formats
-varobj_get_display_format (struct varobj *var)
+varobj_get_display_format (const struct varobj *var)
 {
   return var->format;
 }
 
 char *
-varobj_get_display_hint (struct varobj *var)
+varobj_get_display_hint (const struct varobj *var)
 {
   char *result = NULL;
 
@@ -630,7 +630,7 @@ varobj_get_display_hint (struct varobj *var)
 /* Return true if the varobj has items after TO, false otherwise.  */
 
 int
-varobj_has_more (struct varobj *var, int to)
+varobj_has_more (const struct varobj *var, int to)
 {
   if (VEC_length (varobj_p, var->children) > to)
     return 1;
@@ -643,7 +643,7 @@ varobj_has_more (struct varobj *var, int to)
    inside that thread, returns GDB id of the thread -- which
    is always positive.  Otherwise, returns -1.  */
 int
-varobj_get_thread_id (struct varobj *var)
+varobj_get_thread_id (const struct varobj *var)
 {
   if (var->root->valid_block && var->root->thread_id > 0)
     return var->root->thread_id;
@@ -665,7 +665,7 @@ varobj_set_frozen (struct varobj *var, int frozen)
 }
 
 int
-varobj_get_frozen (struct varobj *var)
+varobj_get_frozen (const struct varobj *var)
 {
   return var->frozen;
 }
@@ -741,7 +741,7 @@ install_dynamic_child (struct varobj *var,
 #if HAVE_PYTHON
 
 static int
-dynamic_varobj_has_child_method (struct varobj *var)
+dynamic_varobj_has_child_method (const struct varobj *var)
 {
   struct cleanup *back_to;
   PyObject *printer = var->dynamic->pretty_printer;
@@ -991,7 +991,7 @@ varobj_get_type (struct varobj *var)
 /* Obtain the type of an object variable.  */
 
 struct type *
-varobj_get_gdb_type (struct varobj *var)
+varobj_get_gdb_type (const struct varobj *var)
 {
   return var->type;
 }
@@ -1000,7 +1000,7 @@ varobj_get_gdb_type (struct varobj *var)
    a valid path expression?  */
 
 static int
-is_path_expr_parent (struct varobj *var)
+is_path_expr_parent (const struct varobj *var)
 {
   gdb_assert (var->root->lang_ops->is_path_expr_parent != NULL);
   return var->root->lang_ops->is_path_expr_parent (var);
@@ -1011,7 +1011,7 @@ is_path_expr_parent (struct varobj *var)
    parent.  */
 
 int
-varobj_default_is_path_expr_parent (struct varobj *var)
+varobj_default_is_path_expr_parent (const struct varobj *var)
 {
   return 1;
 }
@@ -1048,13 +1048,13 @@ varobj_get_path_expr (struct varobj *var)
 }
 
 const struct language_defn *
-varobj_get_language (struct varobj *var)
+varobj_get_language (const struct varobj *var)
 {
   return var->root->exp->language_defn;
 }
 
 int
-varobj_get_attributes (struct varobj *var)
+varobj_get_attributes (const struct varobj *var)
 {
   int attributes = 0;
 
@@ -1068,7 +1068,7 @@ varobj_get_attributes (struct varobj *var)
 /* Return true if VAR is a dynamic varobj.  */
 
 int
-varobj_is_dynamic_p (struct varobj *var)
+varobj_is_dynamic_p (const struct varobj *var)
 {
   return var->dynamic->pretty_printer != NULL;
 }
@@ -1517,7 +1517,7 @@ install_new_value (struct varobj *var, struct value *value, int initial)
    selected sub-range of VAR.  If no range was selected using
    -var-set-update-range, then both will be -1.  */
 void
-varobj_get_child_range (struct varobj *var, int *from, int *to)
+varobj_get_child_range (const struct varobj *var, int *from, int *to)
 {
   *from = var->from;
   *to = var->to;
@@ -1579,7 +1579,7 @@ varobj_set_visualizer (struct varobj *var, const char *visualizer)
    NEW_VALUE may be NULL, if the varobj is now out of scope.  */
 
 static int
-varobj_value_has_mutated (struct varobj *var, struct value *new_value,
+varobj_value_has_mutated (const struct varobj *var, struct value *new_value,
 			  struct type *new_type)
 {
   /* If we haven't previously computed the number of children in var,
@@ -2209,7 +2209,7 @@ make_cleanup_free_variable (struct varobj *var)
 
    For example, top-level references are always stripped.  */
 struct type *
-varobj_get_value_type (struct varobj *var)
+varobj_get_value_type (const struct varobj *var)
 {
   struct type *type;
 
@@ -2278,7 +2278,7 @@ cppop (struct cpstack **pstack)
    is the number of children that the user will see in the variable
    display.  */
 static int
-number_of_children (struct varobj *var)
+number_of_children (const struct varobj *var)
 {
   return (*var->root->lang_ops->number_of_children) (var);
 }
@@ -2286,7 +2286,7 @@ number_of_children (struct varobj *var)
 /* What is the expression for the root varobj VAR? Returns a malloc'd
    string.  */
 static char *
-name_of_variable (struct varobj *var)
+name_of_variable (const struct varobj *var)
 {
   return (*var->root->lang_ops->name_of_variable) (var);
 }
@@ -2303,7 +2303,7 @@ name_of_child (struct varobj *var, int index)
    to it and return 1.  Otherwise, return 0.  */
 
 static int
-check_scope (struct varobj *var)
+check_scope (const struct varobj *var)
 {
   struct frame_info *fi;
   int scope;
@@ -2514,7 +2514,7 @@ varobj_formatted_print_options (struct value_print_options *opts,
 char *
 varobj_value_get_print_value (struct value *value,
 			      enum varobj_display_formats format,
-			      struct varobj *var)
+			      const struct varobj *var)
 {
   struct ui_file *stb;
   struct cleanup *old_chain;
@@ -2645,7 +2645,7 @@ varobj_value_get_print_value (struct value *value,
 }
 
 int
-varobj_editable_p (struct varobj *var)
+varobj_editable_p (const struct varobj *var)
 {
   struct type *type;
 
@@ -2673,7 +2673,7 @@ varobj_editable_p (struct varobj *var)
 /* Call VAR's value_is_changeable_p language-specific callback.  */
 
 int
-varobj_value_is_changeable_p (struct varobj *var)
+varobj_value_is_changeable_p (const struct varobj *var)
 {
   return var->root->lang_ops->value_is_changeable_p (var);
 }
@@ -2682,7 +2682,7 @@ varobj_value_is_changeable_p (struct varobj *var)
    selected frame, and not bound to thread/frame.  Such variable objects
    are created using '@' as frame specifier to -var-create.  */
 int
-varobj_floating_p (struct varobj *var)
+varobj_floating_p (const struct varobj *var)
 {
   return var->root->floating;
 }
@@ -2691,7 +2691,7 @@ varobj_floating_p (struct varobj *var)
    languages.  */
 
 int
-varobj_default_value_is_changeable_p (struct varobj *var)
+varobj_default_value_is_changeable_p (const struct varobj *var)
 {
   int r;
   struct type *type;