Re: getopt compilation failure on Darwin (gzip 1.3.13)

[Eric Blake]

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According to Eric Blake on 10/6/2009 11:04 AM:
> Ludovic Courtès <ludo <at> gnu.org> writes:
> 
>> GNU zip 1.3.13 fails to build on Darwin:
> This is a sign that our #include_next of darwin's <getopt.h> worked, but that 
> darwin's header recursively includes some other header that calls back to our 
> <getopt.h>, prior to the completion of the first use of the system's 
> <getopt.h>.

The circle was:
./getopt.h did include_next <getopt.h>
 <getopt.h> did include <unistd.h>, but found ./unistd.h
  ./unistd.h did include_next <unistd.h>
  <unistd.h> completed
  ./unistd.h did include <getopt.h>, and found ./getopt.h
   ./getopt.h declared things
  ./unistd.h completed
 <getopt.h> redeclared things

The solution is to teach ./unistd.h to skip <getopt.h> if the system
<getopt.h> was the guy including unistd.  That way, both the system
<getopt.h> and <unistd.h> can run to completion prior to ./getopt.h
declaring overrides.

I will be pushing this, if further testing proves that it doesn't break
Linux or FreeBSD.

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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From dd0ebefe4fe761f6f422a400430db53c64dbffd7 Mon Sep 17 00:00:00 2001
From: Eric Blake <address@hidden>
Date: Tue, 6 Oct 2009 20:44:13 -0600
Subject: [PATCH] getopt: fix compilation on darwin
MIME-Version: 1.0
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Content-Transfer-Encoding: 8bit

* lib/getopt.in.h (includes): Leave breadcrumbs during system
include.
* lib/unistd.in.h (getopt): Use them to avoid recursive include.
Reported by Ludovic Courtès.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog       |    5 +++++
 lib/getopt.in.h |    6 +++++-
 lib/unistd.in.h |    2 +-
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 19d34df..f330309 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2009-10-06  Eric Blake  <address@hidden>

+       getopt: fix compilation on darwin
+       * lib/getopt.in.h (includes): Leave breadcrumbs during system
+       include.
+       * lib/unistd.in.h (getopt): Use them to avoid recursive include.
+
        utimens: minor optimization
        * lib/utimens.c (gl_futimens): Use one less system call.
        * modules/utimens (Depends-on): Add dup2.
diff --git a/lib/getopt.in.h b/lib/getopt.in.h
index 9de467a..7377f3c 100644
--- a/lib/getopt.in.h
+++ b/lib/getopt.in.h
@@ -22,9 +22,13 @@
 @PRAGMA_SYSTEM_HEADER@
 #endif

-/* The include_next requires a split double-inclusion guard.  */
+/* The include_next requires a split double-inclusion guard.  We must
+   also inform the replacement unistd.h to not recursively use
+   <getopt.h>; our definitions will be present soon enough.  */
 #if @HAVE_GETOPT_H@
+# define _GL_SYSTEM_GETOPT
 # @INCLUDE_NEXT@ @NEXT_GETOPT_H@
+# undef _GL_SYSTEM_GETOPT
 #endif

 #ifndef _GL_GETOPT_H
diff --git a/lib/unistd.in.h b/lib/unistd.in.h
index 38e2e13..b6ea889 100644
--- a/lib/unistd.in.h
+++ b/lib/unistd.in.h
@@ -49,7 +49,7 @@
 #endif

 /* Get getopt(), optarg, optind, opterr, optopt.  */
-#if @GNULIB_UNISTD_H_GETOPT@
+#if @GNULIB_UNISTD_H_GETOPT@ && !defined _GL_SYSTEM_GETOPT
 # include <getopt.h>
 #endif

-- 
1.6.5.rc1