[gcc(refs/vendors/ARM/heads/morello)] Avoid losing __capability when adding later attributes

[gcc(refs/vendors/ARM/heads/morello)] Avoid losing __capability when adding later attributes

[Matthew Malcomson]

https://gcc.gnu.org/g:f33457b9832988e34fb7e5bb6f5b1261aeb3637a

commit f33457b9832988e34fb7e5bb6f5b1261aeb3637a
Author: Richard Sandiford <richard.sandiford@arm.com>
Date:   Wed Apr 27 19:41:22 2022 +0100

    Avoid losing __capability when adding later attributes
    
    This patch fixes three cases in which applying an attribute
    to a function pointer type would lose any previous attributes
    attached to the pointer (rather than the function) type.
    This includes the __capability attribute, but it seems like
    a general bug.

Diff:
---
 gcc/attribs.c                                      | 10 ++++------
 gcc/c-family/c-attribs.c                           | 22 ++++++++++------------
 .../gcc.target/aarch64/morello/func-attrs-1.c      | 22 ++++++++++++++++++++++
 3 files changed, 36 insertions(+), 18 deletions(-)

diff --git a/gcc/attribs.c b/gcc/attribs.c
index c2b5962e466..5e8ec4b4326 100644
--- a/gcc/attribs.c
+++ b/gcc/attribs.c
@@ -555,7 +555,7 @@ decl_attributes (tree *node, tree attributes, int flags,
       tree *anode = node;
       const struct attribute_spec *spec
 	= lookup_scoped_attribute_spec (ns, name);
-      int fn_ptr_quals = 0;
+      tree orig_fn_ptr = NULL_TREE;
       tree fn_ptr_tmp = NULL_TREE;
       const bool cxx11_attr_p = cxx11_attribute_p (attr);
 
@@ -638,8 +638,8 @@ decl_attributes (tree *node, tree attributes, int flags,
 
 		 This would all be simpler if attributes were part of the
 		 declarator, grumble grumble.  */
-	      fn_ptr_tmp = TREE_TYPE (*anode);
-	      fn_ptr_quals = TYPE_QUALS (*anode);
+	      orig_fn_ptr = *anode;
+	      fn_ptr_tmp = TREE_TYPE (orig_fn_ptr);
 	      anode = &fn_ptr_tmp;
 	      flags &= ~(int) ATTR_FLAG_TYPE_IN_PLACE;
 	    }
@@ -790,9 +790,7 @@ decl_attributes (tree *node, tree attributes, int flags,
 	{
 	  /* Rebuild the function pointer type and put it in the
 	     appropriate place.  */
-	  fn_ptr_tmp = build_pointer_type (fn_ptr_tmp);
-	  if (fn_ptr_quals)
-	    fn_ptr_tmp = build_qualified_type (fn_ptr_tmp, fn_ptr_quals);
+	  fn_ptr_tmp = change_pointer_target_type (orig_fn_ptr, fn_ptr_tmp);
 	  if (DECL_P (*node))
 	    TREE_TYPE (*node) = fn_ptr_tmp;
 	  else
diff --git a/gcc/c-family/c-attribs.c b/gcc/c-family/c-attribs.c
index 9852ed35889..a5996eaf0d2 100644
--- a/gcc/c-family/c-attribs.c
+++ b/gcc/c-family/c-attribs.c
@@ -878,12 +878,11 @@ handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args),
     TREE_THIS_VOLATILE (*node) = 1;
   else if (TREE_CODE (type) == POINTER_TYPE
 	   && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
-    TREE_TYPE (*node)
-      = (build_qualified_type
-	 (build_pointer_type
-	  (build_type_variant (TREE_TYPE (type),
-			       TYPE_READONLY (TREE_TYPE (type)), 1)),
-	  TYPE_QUALS (type)));
+    {
+      tree target = build_type_variant (TREE_TYPE (type),
+					TYPE_READONLY (TREE_TYPE (type)), 1);
+      TREE_TYPE (*node) = change_pointer_target_type (type, target);
+    }
   else
     {
       warning (OPT_Wattributes, "%qE attribute ignored", name);
@@ -1465,12 +1464,11 @@ handle_const_attribute (tree *node, tree name, tree ARG_UNUSED (args),
     TREE_READONLY (*node) = 1;
   else if (TREE_CODE (type) == POINTER_TYPE
 	   && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
-    TREE_TYPE (*node)
-      = (build_qualified_type
-	 (build_pointer_type
-	  (build_type_variant (TREE_TYPE (type), 1,
-			       TREE_THIS_VOLATILE (TREE_TYPE (type)))),
-	  TYPE_QUALS (type)));
+    {
+      tree target = build_type_variant (TREE_TYPE (type), 1,
+					TREE_THIS_VOLATILE (TREE_TYPE (type)));
+      TREE_TYPE (*node) = change_pointer_target_type (type, target);
+    }
   else
     {
       warning (OPT_Wattributes, "%qE attribute ignored", name);
diff --git a/gcc/testsuite/gcc.target/aarch64/morello/func-attrs-1.c b/gcc/testsuite/gcc.target/aarch64/morello/func-attrs-1.c
new file mode 100644
index 00000000000..069ca4c6fe5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/morello/func-attrs-1.c
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+
+void (*__capability nonnull1) (void) __attribute__((nonnull));
+void (*nonnull2) (void) __attribute__((nonnull));
+
+void (*__capability noreturn1) (void) __attribute__((noreturn));
+void (*noreturn2) (void) __attribute__((noreturn));
+
+void (*__capability const1) (void) __attribute__((const));
+void (*const2) (void) __attribute__((const));
+
+void (*__capability callable1) (void) __attribute__((transaction_callable));
+void (*callable2) (void) __attribute__((transaction_callable));
+
+int
+foo (void)
+{
+  nonnull1 = nonnull2;
+  noreturn1 = noreturn2;
+  const1 = const2;
+  callable1 = callable2;
+}