added Workaround for MinGW-w64 multilib bug

* current MinGW-w64 32 bit headers (winbase.h) are missing the WINAPI qualifier on Interlocked### calls
* this results in missing decorations on symbols and failed linking as a result
* this workaround hooks into kernel32.dll for these function calls to alleviate the issue

3 files changed, 38 insertions, 5 deletions

diff --git a/libusb/os/poll_windows.c b/libusb/os/poll_windows.c
index 9ae9895..6941164 100644
--- a/libusb/os/poll_windows.c
+++ b/libusb/os/poll_windows.c
@@ -95,6 +95,14 @@ static inline int _open_osfhandle(intptr_t osfhandle, int flags)
 
 #define CHECK_INIT_POLLING do {if(!is_polling_set) init_polling();} while(0)
 
+// Workaround for MinGW-w64 multilib bug
+static LONG (WINAPI *pInterlockedExchange)(LONG volatile *, LONG) = NULL;
+#define INIT_INTERLOCKEDEXCHANGE if (pInterlockedExchange == NULL) {		\
+	pInterlockedExchange = (LONG (WINAPI *)(LONG volatile *, LONG))			\
+		GetProcAddress(GetModuleHandle("KERNEL32"), "InterlockedExchange");	\
+	if (pInterlockedExchange == NULL) return;								\
+	}
+
 // public fd data
 const struct winfd INVALID_WINFD = {-1, INVALID_HANDLE_VALUE, NULL, RW_NONE};
 struct winfd poll_fd[MAX_FDS];
@@ -147,7 +155,8 @@ void init_polling(void)
 {
 	int i;
 
-	while (InterlockedExchange((LONG *)&compat_spinlock, 1) == 1) {
+	INIT_INTERLOCKEDEXCHANGE;
+	while (pInterlockedExchange((LONG *)&compat_spinlock, 1) == 1) {
 		SleepEx(0, TRUE);
 	}
 	if (!is_polling_set) {
@@ -242,7 +251,8 @@ void exit_polling(void)
 {
 	int i;
 
-	while (InterlockedExchange((LONG *)&compat_spinlock, 1) == 1) {
+	INIT_INTERLOCKEDEXCHANGE;
+	while (pInterlockedExchange((LONG *)&compat_spinlock, 1) == 1) {
 		SleepEx(0, TRUE);
 	}
 	if (is_polling_set) {
diff --git a/libusb/os/threads_windows.c b/libusb/os/threads_windows.c
index 8a29920..9d64fb0 100644
--- a/libusb/os/threads_windows.c
+++ b/libusb/os/threads_windows.c
@@ -25,6 +25,13 @@
 
 #include "libusbi.h"
 
+// Workaround for MinGW-w64 multilib bug
+static LONG (WINAPI *pInterlockedExchange)(LONG volatile *, LONG) = NULL;
+#define INIT_INTERLOCKEDEXCHANGE if (pInterlockedExchange == NULL) {		\
+	pInterlockedExchange = (LONG (WINAPI *)(LONG volatile *, LONG))			\
+		GetProcAddress(GetModuleHandle("KERNEL32"), "InterlockedExchange");	\
+	if (pInterlockedExchange == NULL) return ((errno=ENOENT));				\
+	}
 
 int usbi_mutex_init(usbi_mutex_t *mutex,
 					const usbi_mutexattr_t *attr) {
@@ -68,7 +75,8 @@ int usbi_mutex_unlock(usbi_mutex_t *mutex) {
 
 int usbi_mutex_static_lock(usbi_mutex_static_t *mutex) {
 	if(!mutex)               return ((errno=EINVAL));
-	while (InterlockedExchange((LONG *)mutex, 1) == 1) {
+	INIT_INTERLOCKEDEXCHANGE;
+	while (pInterlockedExchange((LONG *)mutex, 1) == 1) {
 		SleepEx(0, TRUE);
 	}
 	return 0;
diff --git a/libusb/os/windows_usb.c b/libusb/os/windows_usb.c
index f41f064..bb37572 100644
--- a/libusb/os/windows_usb.c
+++ b/libusb/os/windows_usb.c
@@ -111,6 +111,19 @@ static int composite_abort_control(struct usbi_transfer *itransfer);
 static int composite_reset_device(struct libusb_device_handle *dev_handle);
 static int composite_copy_transfer_data(struct usbi_transfer *itransfer, uint32_t io_size);
 
+// Workaround for MinGW-w64 multilib bug
+static LONG (WINAPI *pInterlockedExchange)(LONG volatile *, LONG) = NULL;
+#define INIT_INTERLOCKEDEXCHANGE if (pInterlockedExchange == NULL) {		\
+	pInterlockedExchange = (LONG (WINAPI *)(LONG volatile *, LONG))			\
+		GetProcAddress(GetModuleHandle("KERNEL32"), "InterlockedExchange");	\
+	if (pInterlockedExchange == NULL) return 1;								\
+	}
+static LONG (WINAPI *pInterlockedIncrement)(LONG volatile *) = NULL;
+#define INIT_INTERLOCKEDINCREMENT if (pInterlockedIncrement == NULL) {		\
+	pInterlockedIncrement = (LONG (WINAPI *)(LONG volatile *))				\
+		GetProcAddress(GetModuleHandle("KERNEL32"), "InterlockedIncrement");\
+	if (pInterlockedIncrement == NULL) return LIBUSB_ERROR_NOT_FOUND;		\
+	}
 
 // Global variables
 struct windows_hcd_priv* hcd_root = NULL;
@@ -2121,7 +2134,8 @@ unsigned __stdcall windows_clock_gettime_threaded(void* param)
 			}
 			ReleaseMutex(timer_mutex);
 
-			nb_responses = InterlockedExchange((LONG*)&request_count[0], 0);
+			INIT_INTERLOCKEDEXCHANGE;
+			nb_responses = pInterlockedExchange((LONG*)&request_count[0], 0);
 			if ( (nb_responses)
 			  && (ReleaseSemaphore(timer_response, nb_responses, NULL) == 0) ) {
 				usbi_dbg("unable to release timer semaphore %d: %s", windows_error_str(0));
@@ -2144,8 +2158,9 @@ static int windows_clock_gettime(int clk_id, struct timespec *tp)
 	switch(clk_id) {
 	case USBI_CLOCK_MONOTONIC:
 		if (hires_frequency != 0) {
+			INIT_INTERLOCKEDINCREMENT;
 			while (1) {
-				InterlockedIncrement((LONG*)&request_count[0]);
+				pInterlockedIncrement((LONG*)&request_count[0]);
 				SetEvent(timer_request[0]);
 				r = WaitForSingleObject(timer_response, TIMER_REQUEST_RETRY_MS);
 				switch(r) {