diff options
| author | Paolo Bonzini <bonzini@gnu.org> | 2016-10-31 18:08:07 +0100 |
|---|---|---|
| committer | Eric Blake <eblake@redhat.com> | 2016-12-21 08:32:45 -0600 |
| commit | 0e2eecedb12dd472c9a008748be6edd6ea68fa0e (patch) | |
| tree | 13be775a0fb6f6e778f5d7658a00da8fdccc89ec | |
| parent | c54beb85aa855ce2c817d4f7738748841bf6ad30 (diff) | |
| download | autoconf-0e2eecedb12dd472c9a008748be6edd6ea68fa0e.tar.gz | |
autoconf: prefer an unrolled loop for trivial AC_CHECK_HEADERS
An unrolled loop avoids the cost of spawning sed in AS_TR_SH and
AS_TR_CPP. Prefer it if there is nothing in the second and third
argument of AC_CHECK_HEADERS and the first argument is a literal.
* lib/autoconf/headers.m4 (AC_CHECK_HEADERS): Unroll loop if safe.
(_AC_CHECK_HEADERS): Move basic implementation here.
(AC_CHECK_INCLUDES_DEFAULT): Remove unnecessary arguments after the first.
Signed-off-by: Paolo Bonzini <bonzini@gnu.org>
Message-Id: <1477933688-4884-3-git-send-email-bonzini@gnu.org>
[eblake: perform AC_CHECK_HEADERS_ONCE changes separately, use
dnl to reduce generated blank lines]
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
| -rw-r--r-- | lib/autoconf/headers.m4 | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/lib/autoconf/headers.m4 b/lib/autoconf/headers.m4 index 5f4ab4a8..8e2dbb02 100644 --- a/lib/autoconf/headers.m4 +++ b/lib/autoconf/headers.m4 @@ -185,12 +185,17 @@ m4_define([AH_CHECK_HEADERS], # header. Either ACTION may include `break' to stop the search. AC_DEFUN([AC_CHECK_HEADERS], [m4_map_args_w([$1], [_AH_CHECK_HEADER(], [)])]dnl -[AS_FOR([AC_header], [ac_header], [$1], -[AC_CHECK_HEADER(AC_header, - [AC_DEFINE_UNQUOTED(AS_TR_CPP([HAVE_]AC_header)) $2], - [$3], [$4])dnl]) +[m4_if([$2$3]AS_LITERAL_IF([$1], [[yes]], [[no]]), [yes], + [m4_map_args_w([$1], [_$0(], [, [], [], [$4])])], + [AS_FOR([AC_header], [ac_header], [$1], [_$0(AC_header, [$2], [$3], [$4])])])dnl ])# AC_CHECK_HEADERS +m4_define([_AC_CHECK_HEADERS], +[AC_CHECK_HEADER([$1], + [AC_DEFINE_UNQUOTED(AS_TR_CPP([HAVE_]$1)) $2], + [$3], [$4])dnl +]) + # _AC_CHECK_HEADER_ONCE(HEADER-FILE) # ---------------------------------- @@ -285,8 +290,7 @@ ac_includes_default="\ #endif" ])]dnl [_AC_CHECK_HEADERS_ONCE( - [sys/types.h sys/stat.h strings.h inttypes.h stdint.h unistd.h], - [], [], [$ac_includes_default])]dnl + [sys/types.h sys/stat.h strings.h inttypes.h stdint.h unistd.h])]dnl dnl For backward compatibility, provide unconditional AC_DEFINEs of dnl HAVE_STDLIB_H, HAVE_STRING_H, and STDC_HEADERS. [AC_DEFINE([HAVE_STDLIB_H], [1], |