configure.ac: Clean up redundancy and fix LIBS on Linux

LIBS, AM_LDFLAGS, OS_ conditionals and THREADS_POSIX had a bit of
redundancy throughout the file, and on Linux LIBS ended up missing
the -pthread flag.

diff --git a/configure.ac b/configure.ac
index 2a13003..bd1f006 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -40,27 +40,22 @@ case $host in
 *-linux*)
        AC_DEFINE(OS_LINUX, [], [Linux backend])
        AC_SUBST(OS_LINUX)
-       AC_DEFINE([THREADS_POSIX], [], [Use Posix Threads])
        AC_MSG_RESULT([Linux])
        backend="linux"
        AC_CHECK_LIB(rt, clock_gettime, PC_LIBS_PRIVATE="-lrt")
-       LIBS="${LIBS} ${PC_LIBS_PRIVATE}"
        threads="posix"
        THREAD_CFLAGS="-pthread"
        PC_LIBS_PRIVATE="${PC_LIBS_PRIVATE} -pthread"
-       AM_LDFLAGS=""
        AC_CHECK_HEADERS([poll.h])
        AC_DEFINE([POLL_NFDS_TYPE],[nfds_t],[type of second poll() argument])
        ;;
 *-darwin*)
        AC_DEFINE(OS_DARWIN, [], [Darwin backend])
        AC_SUBST(OS_DARWIN)
-       AC_DEFINE([THREADS_POSIX], [], [Use Posix Threads])
        AC_MSG_RESULT([Darwin/Mac OS X])
        backend="darwin"
        threads="posix"
        PC_LIBS_PRIVATE="-Wl,-framework,IOKit -Wl,-framework,CoreFoundation -Wl,-prebind -no-undefined"
-       AM_LDFLAGS=${PC_LIBS_PRIVATE}
        AC_CHECK_HEADERS([poll.h])
        AC_CHECK_TYPE([nfds_t],
                [AC_DEFINE([POLL_NFDS_TYPE],[nfds_t],[type of second poll() argument])],
@@ -72,10 +67,7 @@ case $host in
        AC_SUBST(OS_WINDOWS)
        AC_MSG_RESULT([Windows])
        backend="windows"
-       threads="windows"
        PC_LIBS_PRIVATE="-lsetupapi -lole32 -ladvapi32"
-       LIBS="${LIBS} ${PC_LIBS_PRIVATE}"
-       # -avoid-version to avoid a naming scheme such as libusb-0.dll
        AM_LDFLAGS="-no-undefined -avoid-version --add-stdcall-alias"
        AC_CHECK_TOOL(RC, windres, no)
        AC_DEFINE([POLL_NFDS_TYPE],[unsigned int],[type of second poll() argument])
@@ -83,12 +75,10 @@ case $host in
 *-cygwin*)
        AC_DEFINE(OS_WINDOWS, [], [Windows backend])
        AC_SUBST(OS_WINDOWS)
-       AC_DEFINE([THREADS_POSIX], [], [Use Posix Threads])
        AC_MSG_RESULT([Cygwin (using Windows backend)])
        backend="windows"
        threads="posix"
        PC_LIBS_PRIVATE="-lsetupapi -lole32 -ladvapi32"
-       LIBS="${LIBS} ${PC_LIBS_PRIVATE}"
        AM_LDFLAGS="-no-undefined -avoid-version"
        AC_CHECK_TOOL(RC, windres, no)
        AC_DEFINE([POLL_NFDS_TYPE],[unsigned int],[type of second poll() argument])
@@ -97,11 +87,15 @@ case $host in
        AC_MSG_ERROR([unsupported operating system])
 esac
 AC_SUBST(PC_LIBS_PRIVATE)
-
-AM_CONDITIONAL([OS_LINUX], [test "x$backend" = "xlinux"])
-AM_CONDITIONAL([OS_DARWIN], [test "x$backend" = "xdarwin"])
-AM_CONDITIONAL([OS_WINDOWS], [test "x$backend" = "xwindows"])
-AM_CONDITIONAL([THREADS_POSIX], [test "x$threads" = "xposix"])
+LIBS="${LIBS} ${PC_LIBS_PRIVATE}"
+
+AM_CONDITIONAL(OS_LINUX, test "x$backend" = xlinux)
+AM_CONDITIONAL(OS_DARWIN, test "x$backend" = xdarwin)
+AM_CONDITIONAL(OS_WINDOWS, test "x$backend" = xwindows)
+AM_CONDITIONAL(THREADS_POSIX, test "x$threads" = xposix)
+if test "$threads" = posix; then
+       AC_DEFINE(THREADS_POSIX, 1, [Use POSIX Threads])
+fi
 
 # timerfd
 AC_CHECK_HEADER([sys/timerfd.h], [timerfd_h=1], [timerfd_h=0])