This patch makes sure that the routine Check_For_BOM cannot
read past the end of file. In practice it is probably the
case that this cannot cause a real error, but valgrind can
see that this is happening. So this change will avoid the
annoying false positive from valgrind. It's not worth setting
up a valgrind test for this very minor issue, and there is
no way to generate a real test that fails, so no test.
Tested on x86_64-pc-linux-gnu, committed on trunk
2013-09-10 Robert Dewar <[email protected]>
* sinput.adb (Check_For_BOM): Avoid reading past end of file.
Index: sinput.adb
===================================================================
--- sinput.adb (revision 202451)
+++ sinput.adb (working copy)
@@ -6,7 +6,7 @@
-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2012, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2013, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
@@ -258,10 +258,20 @@
BOM : BOM_Kind;
Len : Natural;
Tst : String (1 .. 5);
+ C : Character;
begin
for J in 1 .. 5 loop
- Tst (J) := Source (Scan_Ptr + Source_Ptr (J) - 1);
+ C := Source (Scan_Ptr + Source_Ptr (J) - 1);
+
+ -- Definitely no BOM if EOF character marks either end of file, or
+ -- an illegal non-BOM character if not at the end of file.
+
+ if C = EOF then
+ return;
+ end if;
+
+ Tst (J) := C;
end loop;
Read_BOM (Tst, Len, BOM, False);
