From: Eric Blake <ebb9@byu.net>
Date: Thu, 13 Nov 2008 21:02:51 +0000 (-0700)
Subject: Optimize single-argument loop.
X-Git-Tag: v2.63b~106
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2db8890532465e3791268cf35d7844efe5d9748e;p=thirdparty%2Fautoconf.git

Optimize single-argument loop.

* lib/autoconf/functions.m4 (AC_CHECK_FUNCS): Avoid forks when
loop only has one argument.
* lib/autoconf/headers.m4 (AC_CHECK_HEADERS): Likewise.

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

diff --git a/ChangeLog b/ChangeLog
index 3e9a701eb..31dd4f2b1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2008-11-13  Eric Blake  <ebb9@byu.net>
+
+	Optimize single-argument loop.
+	* lib/autoconf/functions.m4 (AC_CHECK_FUNCS): Avoid forks when
+	loop only has one argument.
+	* lib/autoconf/headers.m4 (AC_CHECK_HEADERS): Likewise.
+
 2008-11-13  Eric Blake  <ebb9@byu.net>
 
 	Fix AS_ESCAPE usage bugs.
diff --git a/lib/autoconf/functions.m4 b/lib/autoconf/functions.m4
index 23c63485d..ebd7403ff 100644
--- a/lib/autoconf/functions.m4
+++ b/lib/autoconf/functions.m4
@@ -108,13 +108,15 @@ m4_define([_AH_CHECK_FUNC],
 # `break' to stop the search.
 AC_DEFUN([AC_CHECK_FUNCS],
 [m4_map_args_w([$1], [_AH_CHECK_FUNC(], [)])]dnl
+[m4_pushdef([AC_func], m4_if(m4_index(m4_translit([$1], [	][
+$`], [    ]), [ ]), [-1], [[$1]], [[$ac_func]]))]dnl
 [for ac_func in $1
 do
-AC_CHECK_FUNC($ac_func,
-	      [AC_DEFINE_UNQUOTED(AS_TR_CPP([HAVE_$ac_func])) $2],
+AC_CHECK_FUNC(AC_func,
+	      [AC_DEFINE_UNQUOTED(AS_TR_CPP([HAVE_]AC_func)) $2],
 	      [$3])dnl
 done
-])
+_m4_popdef([AC_func])])
 
 
 # _AC_CHECK_FUNC_ONCE(FUNCTION)
diff --git a/lib/autoconf/headers.m4 b/lib/autoconf/headers.m4
index eb6bc0171..bf2cb7a13 100644
--- a/lib/autoconf/headers.m4
+++ b/lib/autoconf/headers.m4
@@ -245,14 +245,16 @@ m4_define([_AH_CHECK_HEADER],
 # header.  Either ACTION may include `break' to stop the search.
 AC_DEFUN([AC_CHECK_HEADERS],
 [m4_map_args_w([$1], [_AH_CHECK_HEADER(], [)])]dnl
+[m4_pushdef([AC_header], m4_if(m4_index(m4_translit([$1], [	][
+$`], [    ]), [ ]), [-1], [[$1]], [[$ac_header]]))]dnl
 [for ac_header in $1
 do
-AC_CHECK_HEADER($ac_header,
-		[AC_DEFINE_UNQUOTED(AS_TR_CPP(HAVE_$ac_header)) $2],
+AC_CHECK_HEADER(AC_header,
+		[AC_DEFINE_UNQUOTED(AS_TR_CPP([HAVE_]AC_header)) $2],
 		[$3],
 		[$4])dnl
 done
-])# AC_CHECK_HEADERS
+_m4_popdef([AC_header])])# AC_CHECK_HEADERS
 
 
 # _AC_CHECK_HEADER_ONCE(HEADER-FILE)