[C++ PATCH] PR c++/90171 - reorganize usual_deallocation_fn_p

[C++ PATCH] PR c++/90171 - reorganize usual_deallocation_fn_p

[Jason Merrill]

When fixing 90171 it struck me as undesirable to have so many separate
functions that all needed to know about the definition of a usual
deallocation function.  So this patch condenses them into one.  I left
destroying_delete_p because it is used by other files as well.

Tested x86_64-pc-linux-gnu, applying to trunk.

	* call.c (struct dealloc_info): New.
	(usual_deallocation_fn_p): Take a dealloc_info*.
	(aligned_deallocation_fn_p, sized_deallocation_fn_p): Remove.
	(build_op_delete_call): Adjust.
---
 gcc/cp/call.c    | 144 ++++++++++++++++++++---------------------------
 gcc/cp/ChangeLog |   8 +++
 2 files changed, 70 insertions(+), 82 deletions(-)

diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 1a79017eff4..20db2974b56 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -6348,63 +6348,22 @@ destroying_delete_p (tree t)
   return std_destroying_delete_t_p (type) ? type : NULL_TREE;
 }
 
-/* Returns true iff T, an element of an OVERLOAD chain, is a usual deallocation
-   function (3.7.4.2 [basic.stc.dynamic.deallocation]) with a parameter of
-   std::align_val_t.  */
-
-static bool
-aligned_deallocation_fn_p (tree t)
+struct dealloc_info
 {
-  if (!aligned_new_threshold)
-    return false;
-
-  /* A template instance is never a usual deallocation function,
-     regardless of its signature.  */
-  if (TREE_CODE (t) == TEMPLATE_DECL
-      || primary_template_specialization_p (t))
-    return false;
-
-  tree a = FUNCTION_ARG_CHAIN (t);
-  if (destroying_delete_p (t))
-    a = TREE_CHAIN (a);
-  if (same_type_p (TREE_VALUE (a), align_type_node)
-      && TREE_CHAIN (a) == void_list_node)
-    return true;
-  if (!same_type_p (TREE_VALUE (a), size_type_node))
-    return false;
-  a = TREE_CHAIN (a);
-  if (a && same_type_p (TREE_VALUE (a), align_type_node)
-      && TREE_CHAIN (a) == void_list_node)
-    return true;
-  return false;
-}
+  bool sized;
+  bool aligned;
+  tree destroying;
+};
 
-/* Returns true if FN is a usual deallocation fn with a size_t parameter.  */
+/* Returns true iff T, an element of an OVERLOAD chain, is a usual deallocation
+   function (3.7.4.2 [basic.stc.dynamic.deallocation]).  If so, and DI is
+   non-null, also set *DI. */
 
 static bool
-sized_deallocation_fn_p (tree fn)
+usual_deallocation_fn_p (tree t, dealloc_info *di)
 {
-  tree t = FUNCTION_ARG_CHAIN (fn);
-  if (destroying_delete_p (fn))
-    t = TREE_CHAIN (t);
-  if (!t || !same_type_p (TREE_VALUE (t), size_type_node))
-    return false;
-  t = TREE_CHAIN (t);
-  if (t == void_list_node)
-    return true;
-  if (aligned_new_threshold && t
-      && same_type_p (TREE_VALUE (t), align_type_node)
-      && TREE_CHAIN (t) == void_list_node)
-    return true;
-  return false;
-}
+  if (di) *di = dealloc_info();
 
-/* Returns true iff T, an element of an OVERLOAD chain, is a usual
-   deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]).  */
-
-bool
-usual_deallocation_fn_p (tree t)
-{
   /* A template instance is never a usual deallocation function,
      regardless of its signature.  */
   if (TREE_CODE (t) == TEMPLATE_DECL
@@ -6418,17 +6377,33 @@ usual_deallocation_fn_p (tree t)
      - optionally, a parameter of type std::align_val_t.  */
   bool global = DECL_NAMESPACE_SCOPE_P (t);
   tree chain = FUNCTION_ARG_CHAIN (t);
-  if (!chain)
-    return false;
-  if (destroying_delete_p (t))
-    chain = TREE_CHAIN (chain);
-  if (chain == void_list_node
-      || ((!global || flag_sized_deallocation)
-	  && sized_deallocation_fn_p (t)))
-    return true;
-  if (aligned_deallocation_fn_p (t))
-    return true;
-  return false;
+  if (chain && destroying_delete_p (t))
+    {
+      if (di) di->destroying = TREE_VALUE (chain);
+      chain = TREE_CHAIN (chain);
+    }
+  if (chain
+      && (!global || flag_sized_deallocation)
+      && same_type_p (TREE_VALUE (chain), size_type_node))
+    {
+      if (di) di->sized = true;
+      chain = TREE_CHAIN (chain);
+    }
+  if (chain && aligned_new_threshold
+      && same_type_p (TREE_VALUE (chain), align_type_node))
+    {
+      if (di) di->aligned = true;
+      chain = TREE_CHAIN (chain);
+    }
+  return (chain == void_list_node);
+}
+
+/* Just return whether FN is a usual deallocation function.  */
+
+bool
+usual_deallocation_fn_p (tree fn)
+{
+  return usual_deallocation_fn_p (fn, NULL);
 }
 
 /* Build a call to operator delete.  This has to be handled very specially,
@@ -6457,6 +6432,7 @@ build_op_delete_call (enum tree_code code, tree addr, tree size,
 {
   tree fn = NULL_TREE;
   tree fns, fnname, type, t;
+  dealloc_info di_fn = { };
 
   if (addr == error_mark_node)
     return error_mark_node;
@@ -6575,11 +6551,13 @@ build_op_delete_call (enum tree_code code, tree addr, tree size,
     for (lkp_iterator iter (MAYBE_BASELINK_FUNCTIONS (fns)); iter; ++iter)
       {
 	tree elt = *iter;
-	if (usual_deallocation_fn_p (elt))
+	dealloc_info di_elt;
+	if (usual_deallocation_fn_p (elt, &di_elt))
 	  {
 	    if (!fn)
 	      {
 		fn = elt;
+		di_fn = di_elt;
 		continue;
 	      }
 
@@ -6587,12 +6565,13 @@ build_op_delete_call (enum tree_code code, tree addr, tree size,
 	       operator delete, all deallocation functions that are not
 	       destroying operator deletes are eliminated from further
 	       consideration.  */
-	    bool fn_destroying = destroying_delete_p (fn);
-	    bool elt_destroying = destroying_delete_p (elt);
-	    if (elt_destroying != fn_destroying)
+	    if (di_elt.destroying != di_fn.destroying)
 	      {
-		if (elt_destroying)
-		  fn = elt;
+		if (di_elt.destroying)
+		  {
+		    fn = elt;
+		    di_fn = di_elt;
+		  }
 		continue;
 	      }
 
@@ -6606,13 +6585,13 @@ build_op_delete_call (enum tree_code code, tree addr, tree size,
 	    if (aligned_new_threshold)
 	      {
 		bool want_align = type_has_new_extended_alignment (type);
-		bool fn_align = aligned_deallocation_fn_p (fn);
-		bool elt_align = aligned_deallocation_fn_p (elt);
-
-		if (elt_align != fn_align)
+		if (di_elt.aligned != di_fn.aligned)
 		  {
-		    if (want_align == elt_align)
-		      fn = elt;
+		    if (want_align == di_elt.aligned)
+		      {
+			fn = elt;
+			di_fn = di_elt;
+		      }
 		    continue;
 		  }
 	      }
@@ -6639,11 +6618,12 @@ build_op_delete_call (enum tree_code code, tree addr, tree size,
 		  /* We need a cookie to determine the array size.  */
 		  want_size = false;
 	      }
-	    bool fn_size = sized_deallocation_fn_p (fn);
-	    bool elt_size = sized_deallocation_fn_p (elt);
-	    gcc_assert (fn_size != elt_size);
-	    if (want_size == elt_size)
-	      fn = elt;
+	    gcc_assert (di_fn.sized != di_elt.sized);
+	    if (want_size == di_elt.sized)
+	      {
+		fn = elt;
+		di_fn = di_elt;
+	      }
 	  }
       }
 
@@ -6678,7 +6658,7 @@ build_op_delete_call (enum tree_code code, tree addr, tree size,
 	}
       else
 	{
-	  tree destroying = destroying_delete_p (fn);
+	  tree destroying = di_fn.destroying;
 	  if (destroying)
 	    {
 	      /* Strip const and volatile from addr but retain the type of the
@@ -6696,9 +6676,9 @@ build_op_delete_call (enum tree_code code, tree addr, tree size,
 	  args->quick_push (addr);
 	  if (destroying)
 	    args->quick_push (destroying);
-	  if (sized_deallocation_fn_p (fn))
+	  if (di_fn.sized)
 	    args->quick_push (size);
-	  if (aligned_deallocation_fn_p (fn))
+	  if (di_fn.aligned)
 	    {
 	      tree al = build_int_cst (align_type_node, TYPE_ALIGN_UNIT (type));
 	      args->quick_push (al);
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index d90cc099767..dade3e0c8b9 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,11 @@
+2019-05-06  Jason Merrill  <jason@redhat.com>
+
+	PR c++/90171 - reorganize usual_deallocation_fn_p
+	* call.c (struct dealloc_info): New.
+	(usual_deallocation_fn_p): Take a dealloc_info*.
+	(aligned_deallocation_fn_p, sized_deallocation_fn_p): Remove.
+	(build_op_delete_call): Adjust.
+
 2019-05-07  Jason Merrill  <jason@redhat.com>
 
 	PR c++/86485 - -Wmaybe-unused with empty class ?:

base-commit: 57481cdfdc4aa2a0c61e732f9fff312a9ddfb7b6
prerequisite-patch-id: f9e234ae0c68beb8fed9e212e3da578a940c2995
prerequisite-patch-id: 855e2f35bd03f2879aa0288e383ea742b120135a
-- 
2.20.1