2013-01-03 Robert Dewar <dewar@adacore.com>

	* exp_intr.adb: Minor reformatting.

2013-01-03  Robert Dewar  <dewar@adacore.com>

	* einfo.adb: Minor reformatting.

2013-01-03  Pascal Obry  <obry@adacore.com>

	* adaint.c, adaint.h (__gnat_get_module_name): Removed.
	(__gnat_is_module_name_supported): Removed.
	* s-win32.ads: Add some needed definitions.
	* g-trasym.ads: Update comments.

2013-01-03  Robert Dewar  <dewar@adacore.com>

	* layout.adb (Set_Composite_Alignment): Fix problems of
	interactions with Optimize_Alignment set to Space.

2013-01-03  Thomas Quinot  <quinot@adacore.com>

	* exp_disp.adb: Minor reformatting.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@194842 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 47 insertions, 6 deletions

diff --git a/gcc/ada/layout.adb b/gcc/ada/layout.adb
index 3ac620ca4ca..55fe37812ce 100644
--- a/gcc/ada/layout.adb
+++ b/gcc/ada/layout.adb
@@ -2873,22 +2873,63 @@ package body Layout is
       --  Alignment is not known, see if we can set it, taking into account
       --  the setting of the Optimize_Alignment mode.
 
-      --  If Optimize_Alignment is set to Space, then packed records always
-      --  have an alignment of 1. But don't do anything for atomic records
-      --  since we may need higher alignment for indivisible access.
+      --  If Optimize_Alignment is set to Space, then we try to give packed
+      --  records an aligmment of 1, unless there is some reason we can't.
 
       if Optimize_Alignment_Space (E)
         and then Is_Record_Type (E)
         and then Is_Packed (E)
-        and then not Is_Atomic (E)
       then
+         --  No effect for record with atomic components
+
+         if Is_Atomic (E) then
+            Error_Msg_N ("Optimize_Alignment has no effect for &??", E);
+            Error_Msg_N ("\pragma ignored for atomic record??", E);
+            return;
+         end if;
+
+         --  No effect if independent components
+
+         if Has_Independent_Components (E) then
+            Error_Msg_N ("Optimize_Alignment has no effect for &??", E);
+            Error_Msg_N
+              ("\pragma ignored for record with independent components??", E);
+            return;
+         end if;
+
+         --  No effect if any component is atomic or is a by reference type
+
+         declare
+            Ent : Entity_Id;
+         begin
+            Ent := First_Component_Or_Discriminant (E);
+            while Present (Ent) loop
+               if Is_By_Reference_Type (Etype (Ent))
+                 or else Is_Atomic (Etype (Ent))
+                 or else Is_Atomic (Ent)
+               then
+                  Error_Msg_N ("Optimize_Alignment has no effect for &??", E);
+                  Error_Msg_N
+                    ("\pragma is ignored if atomic components present??", E);
+                  return;
+               else
+                  Next_Component_Or_Discriminant (Ent);
+               end if;
+            end loop;
+         end;
+
+         --  Optimize_Alignment has no effect on variable length record
+
          if not Size_Known_At_Compile_Time (E) then
             Error_Msg_N ("Optimize_Alignment has no effect for &??", E);
             Error_Msg_N ("\pragma is ignored for variable length record??", E);
-         else
-            Align := 1;
+            return;
          end if;
 
+         --  All tests passed, we can set alignment to 1
+
+         Align := 1;
+
       --  Not a record, or not packed
 
       else