From patchwork Fri Aug  6 12:58:44 2010
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Subject: [Ada] Do not build useless allocators
Date: Fri, 06 Aug 2010 02:58:44 -0000
From: Eric Botcazou <ebotcazou@adacore.com>
X-Patchwork-Id: 61109
Message-Id: <201008061458.44429.ebotcazou@adacore.com>
To: gcc-patches@gcc.gnu.org

When an object is too large to be allocated on the stack, gigi builds an 
allocator so that Storage_Error is raised at run time.  It was doing that 
even for imported objects, which is useless since the allocator is ditched 
afterward for them.

Fixed thusly, tested on x86-64-suse-linux, applied on the mainline.


2010-08-06  Eric Botcazou  <ebotcazou@adacore.com>

	* gcc-interface/decl.c (gnat_to_gnu_entity) <object>: Do not build an
	allocator for large imported objects.


Index: gcc-interface/decl.c
===================================================================
--- gcc-interface/decl.c	(revision 162897)
+++ gcc-interface/decl.c	(working copy)
@@ -1180,7 +1180,6 @@ gnat_to_gnu_entity (Entity_Id gnat_entit
 	    gnu_type = build_reference_type (gnu_type);
 	    gnu_size = NULL_TREE;
 	    used_by_ref = true;
-	    const_flag = true;
 
 	    /* In case this was a aliased object whose nominal subtype is
 	       unconstrained, the pointer above will be a thin pointer and
@@ -1194,7 +1193,7 @@ gnat_to_gnu_entity (Entity_Id gnat_entit
 	       If we are elaborating a mutable object, tell build_allocator to
 	       ignore a possibly simpler size from the initializer, if any, as
 	       we must allocate the maximum possible size in this case.  */
-	    if (definition)
+	    if (definition && !imported_p)
 	      {
 		tree gnu_alloc_type = TREE_TYPE (gnu_type);
 
@@ -1217,14 +1216,14 @@ gnat_to_gnu_entity (Entity_Id gnat_entit
 		  }
 
 		if (TREE_CODE (TYPE_SIZE_UNIT (gnu_alloc_type)) == INTEGER_CST
-		    && TREE_OVERFLOW (TYPE_SIZE_UNIT (gnu_alloc_type))
-		    && !Is_Imported (gnat_entity))
+		    && TREE_OVERFLOW (TYPE_SIZE_UNIT (gnu_alloc_type)))
 		  post_error ("?`Storage_Error` will be raised at run time!",
 			      gnat_entity);
 
 		gnu_expr
 		  = build_allocator (gnu_alloc_type, gnu_expr, gnu_type,
 				     Empty, Empty, gnat_entity, mutable_p);
+		const_flag = true;
 	      }
 	    else
 	      {