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 3e9a701eb0c209ebb8a1bca270934fd93e64fa3e..31dd4f2b1203a4aca52d44837d2ed87288578bf7 100644 (file)
--- 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 23c63485da428bc811cda88d75732e4af6afb47e..ebd7403ff87680e6241fb9c0412250b47b0c9649 100644 (file)
--- 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 eb6bc0171a90119ac2732acce1f7d4afef35ac4a..bf2cb7a13b3e4215d15f301192d414599385d4a5 100644 (file)
--- 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)