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Date: Wed, 04 Jul 2007 23:31:00 -0000
Subject: [Bug c/32628]  New: bogus integer overflow warning
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From: "ak at muc dot de" <gcc-bugzilla@gcc.gnu.org>
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gcc version 4.3.0 20070704 (experimental)

Following test case derived from the Linux ACPI code warns

toverflow.c: In function 'f':
toverflow.c:8: warning: integer overflow in expression

but the warning is not correct because 0 + ULONG_MAX doesn't really overflow.

typedef void *acpi_handle;
typedef unsigned long long UINT64;
typedef unsigned long long acpi_native_uint;
typedef unsigned char u8;

int f(acpi_handle device)
{
        if (device == ((acpi_handle *) (void *) ((((u8 *) (void *) ((((void
*)0)))) + (acpi_native_uint)((UINT64)(~((UINT64) 0)))))))
                return 1;
        return 0;
}


-- 
           Summary: bogus integer overflow warning
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ak at muc dot de
 GCC build triplet: x86_64-linux
  GCC host triplet: x86_64-linux
GCC target triplet: x86_64-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32628