[Bug middle-end/97373] missing warning on sprintf into allocated destination

[msebor at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97373

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Blocks|                            |85741
           Keywords|                            |diagnostic

--- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> ---
The simplest change to diagnose the overflow in comment #0 goes like this:

diff --git a/gcc/gimple-ssa-sprintf.c b/gcc/gimple-ssa-sprintf.c
index fff034fac4d..ed35eccebf3 100644
--- a/gcc/gimple-ssa-sprintf.c
+++ b/gcc/gimple-ssa-sprintf.c
@@ -4047,9 +4047,13 @@ get_destination_size (tree dest)
      use type-zero object size to determine the size of the enclosing
      object (the function fails without optimization in this type).  */
   int ost = optimize > 0;
-  unsigned HOST_WIDE_INT size;
-  if (compute_builtin_object_size (dest, ost, &size))
-    return size;
+  access_ref ref;
+  if (compute_objsize (dest, ost, &ref))
+    {
+      offset_int size = ref.size_remaining ();
+      if (wi::fits_uhwi_p (size))
+       return size.to_uhwi ();
+    }

   return HOST_WIDE_INT_MAX;
 }


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85741
[Bug 85741] [meta-bug] bogus/missing -Wformat-overflow