r76: added cygwin support

- use AM_CFLAGS instead of CFLAGS (configure.ac)
- added -Werror in visibility attribute test to properly detect on cygwin (configure.ac)
- moved -Wshadow to AM_CFLAGS and disabled it on cygwin (configure.ac)
- emulated _open_osfhandle in windows_compat.c
- removed unneeded <tchar> include in windows_usb.c

3 files changed, 39 insertions, 6 deletions

diff --git a/configure.ac b/configure.ac
index 441370f..5aea8b2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -20,7 +20,7 @@ case $host in
 	AC_MSG_RESULT([Linux])
 	backend="linux"
 	AC_CHECK_LIB(rt, clock_gettime)
-	CFLAGS="-pthread"
+	AM_CFLAGS="-pthread -Wshadow"
 	AM_LDFLAGS=""
 	;;
 *-darwin*)
@@ -29,7 +29,7 @@ case $host in
 	AC_DEFINE(USBI_OS_HANDLES_TIMEOUT, [], [Backend handles timeout])
 	AC_MSG_RESULT([Darwin/MacOS X])
 	backend="darwin"
-	CFLAGS="-pthread"
+	AM_CFLAGS="-pthread -Wshadow"
 	AM_LDFLAGS="-Wl,-framework -Wl,IOKit -Wl,-framework -Wl,CoreFoundation -Wl,-prebind -no-undefined"
 	;;
 *-mingw*)
@@ -38,9 +38,18 @@ case $host in
 	AC_MSG_RESULT([Windows])
 	backend="windows"
 	LIBS="-lpthreadGC2 -lsetupapi -lole32"
-	CFLAGS=""	
+	AM_CFLAGS="-Wshadow"	
 	AM_LDFLAGS=""
 	;;
+*-cygwin*)
+	AC_DEFINE(OS_WINDOWS, [], [Windows backend])
+	AC_SUBST(OS_WINDOWS)
+	AC_MSG_RESULT([Windows])
+	backend="windows"
+	LIBS="-lpthread -lsetupapi -lole32"
+	AM_CFLAGS=""	
+	AM_LDFLAGS=""
+	;;	
 *)
 	AC_MSG_ERROR([unsupported operating system])
 esac
@@ -116,7 +125,8 @@ CFLAGS="$saved_cflags"
 
 # check for -fvisibility=hidden compiler support (GCC >= 3.4)
 saved_cflags="$CFLAGS"
-CFLAGS="$CFLAGS -fvisibility=hidden"
+# -Werror required for cygwin
+CFLAGS="$CFLAGS -Werror -fvisibility=hidden"
 AC_COMPILE_IFELSE(AC_LANG_PROGRAM([]),
 	[VISIBILITY_CFLAGS="-fvisibility=hidden"
 	 AC_DEFINE([API_EXPORTED], [__attribute__((visibility("default")))], [Default visibility]) ],
@@ -132,7 +142,7 @@ AC_COMPILE_IFELSE(AC_LANG_PROGRAM([]),
 	nopointersign_cflags="-Wno-pointer-sign", nopointersign_cflags="")
 CFLAGS="$saved_cflags"
 
-AM_CFLAGS="-std=gnu99 $inline_cflags -Wall -Wundef -Wunused -Wstrict-prototypes -Werror-implicit-function-declaration $nopointersign_cflags -Wshadow"
+AM_CFLAGS="$AM_CFLAGS -std=gnu99 $inline_cflags -Wall -Wundef -Wunused -Wstrict-prototypes -Werror-implicit-function-declaration $nopointersign_cflags"
 
 AC_SUBST(VISIBILITY_CFLAGS)
 AC_SUBST(AM_CFLAGS)
diff --git a/libusb/os/windows_compat.c b/libusb/os/windows_compat.c
index 641ef15..711d553 100644
--- a/libusb/os/windows_compat.c
+++ b/libusb/os/windows_compat.c
@@ -88,6 +88,30 @@
 #endif
 #endif
 
+#if defined(__CYGWIN__ )
+// _open_osfhandle() is not available on cygwin, but we can emulate
+// it for our needs with cygwin_attach_handle_to_fd()
+static inline int _open_osfhandle(intptr_t osfhandle, int flags)
+{
+	int access;
+	switch (flags) {
+	case _O_RDONLY:
+		access = GENERIC_READ;
+		break;
+	case _O_WRONLY:
+		access = GENERIC_WRITE;
+		break;
+	case _O_RDWR:
+		access = GENERIC_READ|GENERIC_WRITE;
+		break;
+	default:
+		printb("_open_osfhandle (emulated): unuspported access mode\n");
+		return -1;
+	}
+	return cygwin_attach_handle_to_fd("/dev/null", -1, osfhandle, -1, access);
+}
+#endif
+
 #define CHECK_INIT_POLLING do {if(!is_polling_set) init_polling();} while(0)
 
 // public fd data
diff --git a/libusb/os/windows_usb.c b/libusb/os/windows_usb.c
index fb14cd0..d628e1f 100644
--- a/libusb/os/windows_usb.c
+++ b/libusb/os/windows_usb.c
@@ -37,7 +37,6 @@
 #include <pthread.h>
 #include <stdio.h>
 #include <windows.h>
-#include <tchar.h>
 #include <setupapi.h>
 #if defined(_MSC_VER)
 // Fixes DDK errors