Re: Compilation warning in simple-object-xcoff.c

[Eli Zaretskii <eliz@gnu.org>]

> From: Andreas Schwab <schwab@linux-m68k.org>
> Cc: Eli Zaretskii <eliz@gnu.org>,  gcc-patches@gcc.gnu.org,  gdb-patches@sourceware.org
> Date: Tue, 16 Jan 2018 23:00:55 +0100
> 
> On Jan 16 2018, DJ Delorie <dj@redhat.com> wrote:
> 
> > And it's not the host's bit size that counts; there are usually ways to
> > get 64-bit file operations on 32-bit hosts.
> 
> If ACX_LARGEFILE doesn't succeed in enabling those 64-bit file
> operations (thus making off_t a 64-bit type) then you are out of luck
> (or AC_SYS_LARGEFILE doesn't support your host yet).

Yes, AC_SYS_LARGEFILE doesn't support MinGW.

DJ, would the following semi-kludgey workaround be acceptable?

--- libiberty/simple-object-xcoff.c~0	2018-01-12 05:31:04.000000000 +0200
+++ libiberty/simple-object-xcoff.c	2018-01-17 12:21:08.496186000 +0200
@@ -596,13 +596,19 @@ simple_object_xcoff_find_sections (simpl
 	      aux = (unsigned char *) auxent;
 	      if (u64)
 		{
+		  /* Use an intermediate 64-bit type to avoid
+		     compilation warning about 32-bit shift below on
+		     hosts with 32-bit off_t which aren't supported by
+		     AC_SYS_LARGEFILE.  */
+		  ulong_type x_scnlen64;
+
 		  if ((auxent->u.xcoff64.x_csect.x_smtyp & 0x7) != XTY_SD
 		      || auxent->u.xcoff64.x_csect.x_smclas != XMC_XO)
 		    continue;
 
-		  x_scnlen = fetch_32 (aux + offsetof (union external_auxent,
-						       u.xcoff64.x_csect.x_scnlen_hi));
-		  x_scnlen = x_scnlen << 32
+		  x_scnlen64 = fetch_32 (aux + offsetof (union external_auxent,
+							 u.xcoff64.x_csect.x_scnlen_hi));
+		  x_scnlen = x_scnlen64 << 32
 			   | fetch_32 (aux + offsetof (union external_auxent,
 						       u.xcoff64.x_csect.x_scnlen_lo));
 		}