From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-428760-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 31014 invoked by alias); 1 Sep 2013 05:33:27 -0000
Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Id: <gcc-bugs.gcc.gnu.org>
List-Archive: <http://gcc.gnu.org/ml/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-help@gcc.gnu.org>
Sender: gcc-bugs-owner@gcc.gnu.org
Received: (qmail 30993 invoked by uid 48); 1 Sep 2013 05:33:24 -0000
From: "jklowden at schemamania dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug bootstrap/58289] New: gcc/gengtype.c includes gcc/double-int.h, which uses C++ constructs
Date: Sun, 01 Sep 2013 05:33:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: bootstrap
X-Bugzilla-Version: unknown
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: jklowden at schemamania dot org
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags:
X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status bug_severity priority component assigned_to reporter
Message-ID: <bug-58289-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-SW-Source: 2013-09/txt/msg00000.txt.bz2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58289

            Bug ID: 58289
           Summary: gcc/gengtype.c includes gcc/double-int.h, which uses
                    C++ constructs
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jklowden at schemamania dot org

I pulled from svn://gcc.gnu.org/svn/gcc/trunk today to build gcc on OS X using
Clang.  Some header files use C++ syntax, but are included in C files.  The
error I'm seeing is:

/Developer/usr/bin/clang [...options omitted...]
                -o build/gengtype.o ../../gcc/gengtype.c
[...warnings ommitted...]
In file included from ../../gcc/gengtype.c:28:
../../gcc/double-int.h:58:10: error: must use 'struct' tag to refer to type
'double_int'
  static double_int from_uhwi (unsigned HOST_WIDE_INT cst);


The error stems from this construct in double-int.h:

==snip==
struct double_int
{
  /* Normally, we would define constructors to create instances.
     Two things prevent us from doing so.
     First, defining a constructor makes the class non-POD in C++03,
     and we certainly want double_int to be a POD.
     Second, the GCC conding conventions prefer explicit conversion,
     and explicit conversion operators are not available until C++11.  */

  static double_int from_uhwi (unsigned HOST_WIDE_INT cst);
==pins==

Comment not withstanding, the file could easily be converted to C; there are no
classes declared, for instance.  All that's needed is say,

    static struct double-int from_uhwi = cst;

perhaps with a cast.  

I found similar problems in two other files that were small enough to repair or
work around.  This file seems to be a pupa determined to become C++, and I'm
not quite sure what should be done.