Revert ALIGN changes

Reverts a2c59f28 and e474ab13.  Since the unary form of ALIGN only
references "dot" implicitly, there isn't really a strong argument for
making ALIGN use a relative value when inside an output section.

	* ldexp.c (align_dot_val): Delete.
	(fold_unary <ALIGN_K, NEXT>): Revert 2015-07-10 change.
	(is_align_conditional): Revert 2015-07-20 change.
	(exp_fold_tree_1): Likewise, but keep expanded comment.
	* scripttempl/elf.sc (.ldata, .bss): Revert 2015-07-20 change.
	* ld.texinfo (<ALIGN>): Correct description.

1 files changed, 31 insertions, 49 deletions

diff --git a/ld/ldexp.c b/ld/ldexp.c
index f02f576..642f8d6 100644
--- a/ld/ldexp.c
+++ b/ld/ldexp.c
@@ -257,14 +257,6 @@ new_rel_from_abs (bfd_vma value)
   expld.result.section = s;
 }
 
-static void
-align_dot_val (bfd_vma align)
-{
-  bfd_vma base = expld.section->vma;
-
-  new_rel_from_abs (base + align_n (expld.dot - base, align));
-}
-
 /* New-function for the definedness hash table.  */
 
 static struct bfd_hash_entry *
@@ -343,7 +335,7 @@ fold_unary (etree_type *tree)
 	{
 	case ALIGN_K:
 	  if (expld.phase != lang_first_phase_enum)
-	    align_dot_val (expld.result.value);
+	    new_rel_from_abs (align_n (expld.dot, expld.result.value));
 	  else
 	    expld.result.valid_p = FALSE;
 	  break;
@@ -373,7 +365,7 @@ fold_unary (etree_type *tree)
 	  if (expld.phase != lang_first_phase_enum)
 	    {
 	      make_abs ();
-	      align_dot_val (expld.result.value);
+	      expld.result.value = align_n (expld.dot, expld.result.value);
 	    }
 	  else
 	    expld.result.valid_p = FALSE;
@@ -951,28 +943,20 @@ is_dot_plus_0 (const etree_type *tree)
 	      || is_sym_value (tree->binary.rhs, 0)));
 }
 
-/* Return true if TREE is "ALIGN (. != 0 ? some_expression : 1)",
-   or equivalent binary ALIGN expressions.  */
+/* Return true if TREE is "ALIGN (. != 0 ? some_expression : 1)".  */
 
 static bfd_boolean
 is_align_conditional (const etree_type *tree)
 {
-  if (tree->type.node_code != ALIGN_K)
-    return 0;
-  else if (tree->type.node_class == etree_unary)
-    tree = tree->unary.child;
-  else if (tree->type.node_class == etree_binary
-	   && (is_dot (tree->binary.lhs)
-	       || (tree->binary.lhs->type.node_class == etree_unary
-		   && tree->binary.lhs->type.node_code == ABSOLUTE
-		   && is_dot (tree->binary.lhs->unary.child))))
-    tree = tree->binary.rhs;
-  else
-    return 0;
-
-  return (tree->type.node_class == etree_trinary
-	  && is_dot_ne_0 (tree->trinary.cond)
-	  && is_value (tree->trinary.rhs, 1));
+  if (tree->type.node_class == etree_unary
+      && tree->type.node_code == ALIGN_K)
+    {
+      tree = tree->unary.child;
+      return (tree->type.node_class == etree_trinary
+	      && is_dot_ne_0 (tree->trinary.cond)
+	      && is_value (tree->trinary.rhs, 1));
+    }
+  return 0;
 }
 
 static void
@@ -1039,13 +1023,30 @@ exp_fold_tree_1 (etree_type *tree)
 	      exp_fold_tree_1 (tree->assign.src);
 	      expld.assigning_to_dot = FALSE;
 
+	      /* If we are assigning to dot inside an output section
+		 arrange to keep the section, except for certain
+		 expressions that evaluate to zero.  We ignore . = 0,
+		 . = . + 0, and . = ALIGN (. != 0 ? expr : 1).
+		 We can't ignore all expressions that evaluate to zero
+		 because an otherwise empty section might have padding
+		 added by an alignment expression that changes with
+		 relaxation.  Such a section might have zero size
+		 before relaxation and so be stripped incorrectly.  */
+	      if (expld.phase == lang_mark_phase_enum
+		  && expld.section != bfd_abs_section_ptr
+		  && !(expld.result.valid_p
+		       && expld.result.value == 0
+		       && (is_value (tree->assign.src, 0)
+			   || is_sym_value (tree->assign.src, 0)
+			   || is_dot_plus_0 (tree->assign.src)
+			   || is_align_conditional (tree->assign.src))))
+		expld.section->flags |= SEC_KEEP;
+
 	      if (!expld.result.valid_p)
 		{
 		  if (expld.phase != lang_mark_phase_enum)
 		    einfo (_("%F%S invalid assignment to"
 			     " location counter\n"), tree);
-		  else if (expld.section != bfd_abs_section_ptr)
-		    expld.section->flags |= SEC_KEEP;
 		}
 	      else if (expld.dotp == NULL)
 		einfo (_("%F%S assignment to location counter"
@@ -1065,25 +1066,6 @@ exp_fold_tree_1 (etree_type *tree)
 		    nextdot += expld.result.section->vma;
 		  else
 		    nextdot += expld.section->vma;
-
-		  /* If we are assigning to dot inside an output
-		     section arrange to keep the section, except for
-		     certain expressions that evaluate to zero.  We
-		     can't ignore all expressions that evaluate to
-		     zero because an otherwise empty section might
-		     have padding added by an alignment expression
-		     that changes with relaxation.  Such a section
-		     might have zero size before relaxation and so be
-		     stripped incorrectly.  */
-		  if (expld.phase == lang_mark_phase_enum
-		      && expld.section != bfd_abs_section_ptr
-		      && !(nextdot == expld.section->vma
-			   && (is_value (tree->assign.src, 0)
-			       || is_sym_value (tree->assign.src, 0)
-			       || is_dot_plus_0 (tree->assign.src)
-			       || is_align_conditional (tree->assign.src))))
-		    expld.section->flags |= SEC_KEEP;
-
 		  if (nextdot < expld.dot
 		      && expld.section != bfd_abs_section_ptr)
 		    einfo (_("%F%S cannot move location counter backwards"