decl.c (gnat_to_gnu_field): Do not set the alignment of the enclosing record…

decl.c (gnat_to_gnu_field): Do not set the alignment of the enclosing record type if it is not already set.

	* gcc-interface/decl.c (gnat_to_gnu_field): Do not set the alignment
	of the enclosing record type if it is not already set.

From-SVN: r255645

gcc/ada/ChangeLog

 2017-12-14  Eric Botcazou  <ebotcazou@adacore.com>
 
+	* gcc-interface/decl.c (gnat_to_gnu_field): Do not set the alignment
+	of the enclosing record type if it is not already set.
+
+2017-12-14  Eric Botcazou  <ebotcazou@adacore.com>
+
 	* gcc-interface/gigi.h (pad_type_has_rm_size): Declare.
 	* gcc-interface/decl.c (gnat_to_gnu_entity) <E_Variable>: Do not build
 	a padding type for the alignment before validating the size.

gcc/ada/gcc-interface/decl.c

@@ -6890,7 +6890,8 @@ gnat_to_gnu_field (Entity_Id gnat_field, tree gnu_record_type, int packed,
 	{
 	  const unsigned int type_align = TYPE_ALIGN (gnu_field_type);
 
-	  if (TYPE_ALIGN (gnu_record_type) < type_align)
+	  if (TYPE_ALIGN (gnu_record_type)
+	      && TYPE_ALIGN (gnu_record_type) < type_align)
 	    SET_TYPE_ALIGN (gnu_record_type, type_align);
 
 	  /* If the position is not a multiple of the alignment of the type,

gcc/testsuite/ChangeLog

+2017-12-14  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gnat.dg/alignment13.adb: New test.
+
 2017-12-14  Jakub Jelinek  <jakub@redhat.com>
 
 	PR lto/81406

gcc/testsuite/gnat.dg/alignment13.adb

+-- { dg-do run }
+-- { dg-options "-gnatws" }
+
+procedure Alignment13 is
+
+  type Rec is record
+    I1 : aliased Short_Integer;
+    I2 : Integer;
+  end record;
+
+  for Rec use record
+    I1 at 0 range 0 .. 15;
+  end record;
+
+  R : Rec;
+
+begin
+  if R.I2'Bit_Position /= 32 then
+    raise Program_Error;
+  end if;
+end;