g-dyntab.adb, [...]: (Set_Item): Suppress Range_Check on Allocated_Table.

2007-08-16  Thomas Quinot  <quinot@adacore.com>

	* g-dyntab.adb, g-table.adb, table.adb: (Set_Item): Suppress
	Range_Check on Allocated_Table.

From-SVN: r127541

1 files changed, 10 insertions, 1 deletions

diff --git a/gcc/ada/table.adb b/gcc/ada/table.adb
index 273be81..db64c4c 100644
--- a/gcc/ada/table.adb
+++ b/gcc/ada/table.adb
@@ -287,11 +287,20 @@ package body Table is
 
          Allocated_Table : Allocated_Table_T;
          pragma Import (Ada, Allocated_Table);
+         pragma Suppress (Range_Check, On => Allocated_Table);
          for Allocated_Table'Address use Allocated_Table_Address;
          --  Allocated_Table represents the currently allocated array, plus one
          --  element (the supplementary element is used to have a convenient
          --  way of computing the address just past the end of the current
-         --  allocation).
+         --  allocation). Range checks are suppressed because this unit
+         --  uses direct calls to System.Memory for allocation, and this can
+         --  yield misaligned storage (and we cannot rely on the bootstrap
+         --  compiler supporting specifically disabling alignment cheks, so we
+         --  need to suppress all range checks). It is safe to suppress this
+         --  check here because we know that a (possibly misaligned) object
+         --  of that type does actually exist at that address.
+         --  ??? We should really improve the allocation circuitry here to
+         --  guarantee proper alignment.
 
          Need_Realloc : constant Boolean := Int (Index) > Max;
          --  True if this operation requires storage reallocation (which may