[committed][PATCH] Trivial cleanups to new classes

[Jeff Law <law at redhat dot com>]

As has been discussed on-list.  This patch adds a virtual destructor to 
the new classes in tree-ssa-propagate.h per our coding conventions and 
what are considered best practices.  It doesn't matter for any code I'm 
aware of today -- it's a defensive measure.

This also drops the "virtual" keyword on the FINAL OVERRIDE member 
functions in gimple-ssa-sprintf's sprintf_dom_walker class.  Opinions 
here are more mixed.  It's agreed that the keyword is redundant in this 
context.  The question is whether or not it adds confusion or reduces 
confusion.

The virtual keyword intuitively implies to me the member can be 
overridden by a derived class, but that's in direct conflict with the 
FINAL keyword.

Others focus more on the fact that the virtual keyword implies that the 
calls are typically indirect.   But in the case of a FINAL, one of the 
hopes is that devirt can use the information to change the indirect call 
into a direct call.

In the end the arguments for dropping the "virtual" seemed stronger to me.

Bootstrapped and regression tested on x86.  Installing on the trunk.

Jeff

ps. I suspect there's similar cleanups we ought to be doing on other 
classes used within GCC.

	* gimple-ssa-sprintf.c (sprintf_dom_walker): Remove
	virtual keyword on FINAL OVERRIDE members.

	* tree-ssa-propagate.h (ssa_propagation_engine): Group
	virtuals together.  Add virtual destructor.
	(substitute_and_fold_engine): Similarly.

diff --git a/gcc/gimple-ssa-sprintf.c b/gcc/gimple-ssa-sprintf.c
index 7415413..35ceb2c 100644
--- a/gcc/gimple-ssa-sprintf.c
+++ b/gcc/gimple-ssa-sprintf.c
@@ -120,7 +120,7 @@ class sprintf_dom_walker : public dom_walker
   sprintf_dom_walker () : dom_walker (CDI_DOMINATORS) {}
   ~sprintf_dom_walker () {}
 
-  virtual edge before_dom_children (basic_block) FINAL OVERRIDE;
+  edge before_dom_children (basic_block) FINAL OVERRIDE;
   bool handle_gimple_call (gimple_stmt_iterator *);
 
   struct call_info;
diff --git a/gcc/tree-ssa-propagate.h b/gcc/tree-ssa-propagate.h
index 629ae77..be4500b 100644
--- a/gcc/tree-ssa-propagate.h
+++ b/gcc/tree-ssa-propagate.h
@@ -81,14 +81,16 @@ class ssa_propagation_engine
 {
  public:
 
-  /* Main interface into the propagation engine.  */
-  void ssa_propagate (void);
+  virtual ~ssa_propagation_engine (void) { }
 
   /* Virtual functions the clients must provide to visit statements
      and phi nodes respectively.  */
   virtual enum ssa_prop_result visit_stmt (gimple *, edge *, tree *) = 0;
   virtual enum ssa_prop_result visit_phi (gphi *) = 0;
 
+  /* Main interface into the propagation engine.  */
+  void ssa_propagate (void);
+
  private:
   /* Internal implementation details.  */
   void simulate_stmt (gimple *stmt);
@@ -100,10 +102,12 @@ class ssa_propagation_engine
 class substitute_and_fold_engine
 {
  public:
-  bool substitute_and_fold (void);
-  bool replace_uses_in (gimple *);
+  virtual ~substitute_and_fold_engine (void) { }
   virtual bool fold_stmt (gimple_stmt_iterator *) { return false; }
   virtual tree get_value (tree) { return NULL_TREE; }
+
+  bool substitute_and_fold (void);
+  bool replace_uses_in (gimple *);
   bool replace_phi_args_in (gphi *);
 };