From 025c264448de771ceb130d4d01aacbb9ca8453ea Mon Sep 17 00:00:00 2001
From: Uwe Hermann <uwe@hermann-uwe.de>
Date: Sun, 19 Apr 2015 18:36:58 +0200
Subject: [PATCH] autotools: Don't set/override "user variables".

This fixes bug #577.
---
 Makefile.am  | 11 ++++++++---
 configure.ac |  4 ----
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/Makefile.am b/Makefile.am
index 58185e9..8c0276c 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -22,6 +22,9 @@ ACLOCAL_AMFLAGS = -I autostuff
 
 AM_CPPFLAGS = -I$(top_srcdir)
 
+# Enable more compiler warnings.
+AM_CFLAGS = -std=c99 -Wall -Wextra -pedantic -Wmissing-prototypes -Wshadow
+
 lib_LTLIBRARIES = libserialport.la
 
 libserialport_la_SOURCES = serialport.c libserialport_internal.h
@@ -39,13 +42,15 @@ libserialport_la_SOURCES += freebsd.c
 endif
 
 libserialport_la_LIBADD = $(LIBOBJS)
-
-libserialport_la_LDFLAGS = $(SP_LIB_LDFLAGS) -no-undefined
-
 if WIN32
 libserialport_la_LIBADD += $(SP_LIBS)
 endif
 
+libserialport_la_LDFLAGS = $(SP_LIB_LDFLAGS) -no-undefined
+if MACOSX
+libserialport_la_LDFLAGS += -framework IOKit -framework CoreFoundation
+endif
+
 library_includedir = $(includedir)
 library_include_HEADERS = libserialport.h
 
diff --git a/configure.ac b/configure.ac
index 0662eb6..e569ee0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -42,9 +42,6 @@ AM_INIT_AUTOMAKE([1.11 -Wall -Werror check-news])
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
 m4_ifdef([AM_PROG_AR], [AM_PROG_AR])
 
-# Enable more compiler warnings.
-CFLAGS="$CFLAGS -std=c99 -Wall -Wextra -pedantic -Wmissing-prototypes -Wshadow"
-
 # Checks for programs.
 AC_PROG_CC
 AC_PROG_CPP
@@ -89,7 +86,6 @@ case $host_os in
 	AM_CONDITIONAL([WIN32], false)
 	AM_CONDITIONAL([MACOSX], true)
 	AM_CONDITIONAL([FREEBSD], false)
-	LDFLAGS="$LDFLAGS -Wl,-framework -Wl,IOKit -Wl,-framework -Wl,CoreFoundation"
 	AC_CHECK_HEADER(IOKit/IOKitLib.h, [], [AC_MSG_ERROR([IOKit/IOKitLib.h not found])])
 	;;
 mingw* | cygwin*)