Fix build failure of Ada runtime for Aarch64 targets

The Aarch64 back-end now asserts that the main variant of scalar types
has TYPE_USER_ALIGN cleared, and that's not the case for scalar types
declared with a confirming alignment clause in Ada.

gcc/ada/
	PR bootstrap/109510
	* gcc-interface/decl.cc (gnat_to_gnu_entity) <types>: Reset align
	to zero if its value is equal to TYPE_ALIGN and the type is scalar.
	Set TYPE_USER_ALIGN on the type only if align is positive.

diff --git a/gcc/ada/gcc-interface/decl.cc b/gcc/ada/gcc-interface/decl.cc
index d24adf33601cee00690766779829265843dcf3f2..851a6745f771822e020f463b4e39f413a22ab1a8 100644 (file)
--- a/gcc/ada/gcc-interface/decl.cc
+++ b/gcc/ada/gcc-interface/decl.cc
@@ -4364,13 +4364,17 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
       /* If the alignment has not already been processed and this is not
         an unconstrained array type, see if an alignment is specified.
         If not, we pick a default alignment for atomic objects.  */
-      if (align != 0 || TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE)
+      if (align > 0 || TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE)
        ;
       else if (Known_Alignment (gnat_entity))
        {
          align = validate_alignment (Alignment (gnat_entity), gnat_entity,
                                      TYPE_ALIGN (gnu_type));
 
+         /* Treat confirming clauses on scalar types like the default.  */
+         if (align == TYPE_ALIGN (gnu_type) && !AGGREGATE_TYPE_P (gnu_type))
+           align = 0;
+
          /* Warn on suspiciously large alignments.  This should catch
             errors about the (alignment,byte)/(size,bit) discrepancy.  */
          if (align > BIGGEST_ALIGNMENT && Has_Alignment_Clause (gnat_entity))
@@ -4666,7 +4670,7 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
            TYPE_BY_REFERENCE_P (gnu_type) = 1;
 
          /* Record whether an alignment clause was specified.  */
-         if (Present (Alignment_Clause (gnat_entity)))
+         if (align > 0 && Present (Alignment_Clause (gnat_entity)))
            TYPE_USER_ALIGN (gnu_type) = 1;
 
          /* Record whether a pragma Universal_Aliasing was specified.  */