From: Eric Blake <ebb9@byu.net>
Date: Wed, 17 Jun 2009 12:26:48 +0000 (-0600)
Subject: Fix AC_CHECK_HEADER infloop for gcc.
X-Git-Tag: v2.64~40
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=01660aaecc22ce7ca6b5ee88851916bf2f36e74c;p=thirdparty%2Fautoconf.git

Fix AC_CHECK_HEADER infloop for gcc.

* lib/autoconf/headers.m4 (_AC_CHECK_HEADER_NEW)
(_AC_CHECK_HEADER_OLD): Give up on AU_DEFUN, and manually warn
about obsoletion, to avoid infinite loop in gcc.
Reported by Ralf Wildenhues.

Signed-off-by: Eric Blake <ebb9@byu.net>
---

diff --git a/ChangeLog b/ChangeLog
index 4acbea59..e568c7fe 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2009-06-17  Eric Blake  <ebb9@byu.net>
+
+	Fix AC_CHECK_HEADER infloop for gcc.
+	* lib/autoconf/headers.m4 (_AC_CHECK_HEADER_NEW)
+	(_AC_CHECK_HEADER_OLD): Give up on AU_DEFUN, and manually warn
+	about obsoletion, to avoid infinite loop in gcc.
+	Reported by Ralf Wildenhues.
+
 2009-06-15  Eric Blake  <ebb9@byu.net>
 
 	Add m4_copy_force, m4_rename_force.
diff --git a/lib/autoconf/headers.m4 b/lib/autoconf/headers.m4
index 6ba0b91b..21b512c8 100644
--- a/lib/autoconf/headers.m4
+++ b/lib/autoconf/headers.m4
@@ -194,14 +194,6 @@ AC_DEFUN([_AC_CHECK_HEADER_COMPILE],
 AS_VAR_IF([ac_Header], [yes], [$2], [$3])
 AS_VAR_POPDEF([ac_Header])])# _AC_CHECK_HEADER_COMPILE
 
-# _AC_CHECK_HEADER_NEW(HEADER-FILE, [ACTION-IF-FOUND],
-#                      [ACTION-IF-NOT-FOUND])
-# ----------------------------------------------------
-# Some packages used this macro, even though it is undocumented.
-AU_DEFUN([_AC_CHECK_HEADER_NEW],
-[AC_CHECK_HEADER([$1], [$2], [$3], [AC_INCLUDES_DEFAULT])])
-
-
 # _AC_CHECK_HEADER_PREPROC_BODY
 # -----------------------------
 # Shell function body for _AC_CHECK_HEADER_PREPROC.
@@ -234,10 +226,23 @@ AS_VAR_POPDEF([ac_Header])dnl
 
 # _AC_CHECK_HEADER_OLD(HEADER-FILE, [ACTION-IF-FOUND],
 #                      [ACTION-IF-NOT-FOUND])
+# _AC_CHECK_HEADER_NEW(HEADER-FILE, [ACTION-IF-FOUND],
+#                      [ACTION-IF-NOT-FOUND])
 # ----------------------------------------------------
-# Some packages used this macro, even though it is undocumented.
-AU_DEFUN([_AC_CHECK_HEADER_OLD],
-[AC_CHECK_HEADER([$1], [$2], [$3], [-])])
+# Some packages used these undocumented macros.  Even worse, gcc
+# redefined AC_CHECK_HEADER in terms of _AC_CHECK_HEADER_OLD, so we
+# can't do the simpler:
+#   AU_DEFUN([_AC_CHECK_HEADER_OLD],
+#     [AC_CHECK_HEADER([$1], [$2], [$3], [-])])
+AC_DEFUN([_AC_CHECK_HEADER_OLD],
+[AC_DIAGNOSE([obsolete], [The macro `$0' is obsolete.
+You should use AC_CHECK_HEADER with a fourth argument.])]dnl
+[_AC_CHECK_HEADER_PREPROC($@)])
+
+AC_DEFUN([_AC_CHECK_HEADER_NEW],
+[AC_DIAGNOSE([obsolete], [The macro `$0' is obsolete.
+You should use AC_CHECK_HEADER with a fourth argument.])]dnl
+[_AC_CHECK_HEADER_COMPILE($@)])
 
 
 # _AH_CHECK_HEADER(HEADER-FILE)