[C++ PATCH] CONV_OP accessors

[Nathan Sidwell <nathan at acm dot org>]

the conv op accessor macros are overly conservative.  We never call 
DECL_CONV_FN_P when DECL_NAME is null, and we never call 
DECL_CONV_FN_TYPE when the fn isn't a conversion operator.  Removed 
those checks from these macros.

Further, we never use DECL_TEMPLATE_CONV_FN_P, execpt to set that flag. 
So that can simply be nuked.

We reuse the underlying bitfield for static data member arrays of 
unknown bound.  I renamed the field.

Applied to trunk.

nathan
--
Nathan Sidwell

2017-09-05  Nathan Sidwell  <nathan@acm.org>

	* cp-tree.h (lang_decl_base): Rename template_conv_p to
	unknown_bound_p.
	(DECL_CONV_FN_P): Don't check NULL DECL_NAME.
	(DECL_CONV_FN_TYPE): FN must be conv op.
	(DECL_TEMPLATE_CONV_FN_P): Delete.
	(VAR_HAD_UNKNOWN_BOUND, SET_VAR_HAD_UNKNOWN_BOUND): Adjust.
	* pt.c (push_template_decl_real): Delete DECL_TEMPLATE_CONV_FN_P
	setting.

Index: cp-tree.h
===================================================================
--- cp-tree.h	(revision 251722)
+++ cp-tree.h	(working copy)
@@ -2451,7 +2451,7 @@ struct GTY(()) lang_decl_base {
   unsigned anticipated_p : 1;		   /* fn, type or template */
   /* anticipated_p reused as DECL_OMP_PRIVATIZED_MEMBER in var */
   unsigned friend_or_tls : 1;		   /* var, fn, type or template */
-  unsigned template_conv_p : 1;		   /* var or template */
+  unsigned unknown_bound_p : 1;		   /* var */
   unsigned odr_used : 1;		   /* var or fn */
   unsigned u2sel : 1;
   unsigned concept_p : 1;                  /* applies to vars and functions */
@@ -2807,28 +2807,20 @@ struct GTY(()) lang_decl {
        || DECL_BASE_DESTRUCTOR_P (NODE)))
 
 /* Nonzero if NODE is a user-defined conversion operator.  */
-#define DECL_CONV_FN_P(NODE) \
-  (DECL_NAME (NODE) && IDENTIFIER_CONV_OP_P (DECL_NAME (NODE)))
+#define DECL_CONV_FN_P(NODE) IDENTIFIER_CONV_OP_P (DECL_NAME (NODE))
 
-/* If FN is a conversion operator, the type to which it converts.
-   Otherwise, NULL_TREE.  */
+/* The type to which conversion operator FN converts to.   */
 #define DECL_CONV_FN_TYPE(FN) \
-  (DECL_CONV_FN_P (FN) ? TREE_TYPE (DECL_NAME (FN)) : NULL_TREE)
-
-/* Nonzero if NODE, which is a TEMPLATE_DECL, is a template
-   conversion operator to a type dependent on the innermost template
-   args.  */
-#define DECL_TEMPLATE_CONV_FN_P(NODE) \
-  (DECL_LANG_SPECIFIC (TEMPLATE_DECL_CHECK (NODE))->u.base.template_conv_p)
+  TREE_TYPE ((gcc_checking_assert (DECL_CONV_FN_P (FN)), DECL_NAME (FN)))
 
 /* Nonzero if NODE, a static data member, was declared in its class as an
    array of unknown bound.  */
 #define VAR_HAD_UNKNOWN_BOUND(NODE)			\
   (DECL_LANG_SPECIFIC (VAR_DECL_CHECK (NODE))		\
-   ? DECL_LANG_SPECIFIC (NODE)->u.base.template_conv_p	\
+   ? DECL_LANG_SPECIFIC (NODE)->u.base.unknown_bound_p	\
    : false)
 #define SET_VAR_HAD_UNKNOWN_BOUND(NODE) \
-  (DECL_LANG_SPECIFIC (VAR_DECL_CHECK (NODE))->u.base.template_conv_p = true)
+  (DECL_LANG_SPECIFIC (VAR_DECL_CHECK (NODE))->u.base.unknown_bound_p = true)
 
 /* Set the overloaded operator code for NODE to CODE.  */
 #define SET_OVERLOADED_OPERATOR_CODE(NODE, CODE) \
Index: pt.c
===================================================================
--- pt.c	(revision 251724)
+++ pt.c	(working copy)
@@ -5608,25 +5608,13 @@ push_template_decl_real (tree decl, bool
   if (is_primary)
     {
       tree parms = DECL_TEMPLATE_PARMS (tmpl);
-      int i;
 
       DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
-      if (DECL_CONV_FN_P (tmpl))
-	{
-	  int depth = TMPL_PARMS_DEPTH (parms);
-
-	  /* It is a conversion operator. See if the type converted to
-	     depends on innermost template operands.  */
-
-	  if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
-					 depth))
-	    DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
-	}
 
       /* Give template template parms a DECL_CONTEXT of the template
 	 for which they are a parameter.  */
       parms = INNERMOST_TEMPLATE_PARMS (parms);
-      for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
+      for (int i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
 	{
 	  tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
 	  if (TREE_CODE (parm) == TEMPLATE_DECL)