Add support for windows builds

For allowing python and rust users to develop OSDP apps on windows,
we need to fix this repo in multiple places. Some of it looks uglier
than it ought to be but that's the cost of usability :(

Signed-off-by: Siddharth <Siddharth.Chandrasekaran@huawei.com>

Author: sidcha

include/utils/utils.h

@@ -119,9 +119,23 @@ extern "C" {
 #define __packed        __attribute__((__packed__))
 #endif
 
+#ifdef __GNUC__
+#define PACK( __Declaration__ ) __Declaration__ __attribute__((__packed__))
+#endif
+
+#ifdef _MSC_VER
+#define PACK( __Declaration__ ) __pragma( pack(push, 1) ) __Declaration__ __pragma( pack(pop))
+#endif
+
 #undef __weak
 #define __weak          __attribute__((weak))
 
+#if (defined(_WIN32) || defined(_WIN64))
+#define __format_printf(x, y)
+#else
+#define __format_printf(x, y) __attribute__((format(printf, x, y)))
+#endif
+
 /**
  * @brief Return random number between 0 and `limit` both inclusive.
  *
@@ -193,7 +207,7 @@ void dump_trace(void);
 
 static inline bool char_is_space(int c)
 {
-	unsigned char d = c - 9;
+	unsigned char d = (unsigned char)(c - 9);
 	return (0x80001FU >> (d & 31)) & (1U >> (d >> 5));
 }
 

src/disjoint_set.c

@@ -49,8 +49,12 @@ void disjoint_set_union(struct disjoint_set *set, int a, int b)
 	if (a == b)
 		return;
 
-	if (set->rank[a] < set->rank[b])
-		SWAP(a, b);
+	if (set->rank[a] < set->rank[b]) {
+		int tmp;
+		tmp = a;
+		a = b;
+		b = tmp;
+	}
 
 	set->parent[b] = a;
 	if (set->rank[a] == set->rank[b])

src/logger.c

@@ -6,10 +6,12 @@
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <unistd.h>
 #include <string.h>
 #include <assert.h>
 #include <time.h>
+#if (!defined(_WIN32) && !defined(_WIN64))
+#include <unistd.h>
+#endif
 
 #include <utils/logger.h>
 
@@ -98,7 +100,7 @@ static int terminate_log_line(char *buf, int len)
 
 #define LOG_BUF_LEN 192
 
-__attribute__((format(printf, 5, 6)))
+__format_printf(5, 6)
 int __logger_log(logger_t *ctx, int log_level, const char *file, unsigned long line,
 		 const char *fmt, ...)
 {

src/slab.c

@@ -10,11 +10,11 @@
 
 #include <utils/slab.h>
 
-struct slab_unit {
+PACK(struct slab_unit {
 	uint32_t leased;
 	uint32_t canary;
 	uint8_t data[];
-} __packed;
+});
 
 int slab_init(slab_t *slab, size_t slab_size,
 	      uint8_t *blob, size_t blob_size)

src/utils.c

@@ -9,8 +9,6 @@
 #include <stddef.h>
 #include <ctype.h>
 #include <stdlib.h>
-#include <time.h>
-#include <sys/time.h>
 
 #include <utils/utils.h>
 
@@ -49,7 +47,7 @@ int num_digits_in_number(int num)
 	return digits;
 }
 
-__attribute__((format(printf, 3, 4)))
+__format_printf(3, 4)
 void hexdump(const void *p, size_t len, const char *fmt, ...)
 {
 	size_t i;
@@ -87,6 +85,43 @@ void hexdump(const void *p, size_t len, const char *fmt, ...)
 	printf("\n");
 }
 
+#if (defined(_WIN32) || defined(_WIN64))
+#define WIN32_LEAN_AND_MEAN
+#include <Windows.h>
+#include <stdint.h> // portable: uint64_t   MSVC: __int64
+
+// MSVC defines this in winsock2.h!?
+typedef struct timeval {
+	long tv_sec;
+	long tv_usec;
+} timeval;
+
+int gettimeofday(struct timeval * tp, struct timezone * tzp)
+{
+	// Note: some broken versions only have 8 trailing zero's, the correct
+	// epoch has 9 trailing zero's This magic number is the number of 100
+	// nanosecond intervals since January 1, 1601 (UTC) until 00:00:00
+	// January 1, 1970
+	static const uint64_t EPOCH = ((uint64_t) 116444736000000000ULL);
+
+	SYSTEMTIME  system_time;
+	FILETIME    file_time;
+	uint64_t    time;
+
+	GetSystemTime( &system_time );
+	SystemTimeToFileTime( &system_time, &file_time );
+	time =  ((uint64_t)file_time.dwLowDateTime )      ;
+	time += ((uint64_t)file_time.dwHighDateTime) << 32;
+
+	tp->tv_sec  = (long) ((time - EPOCH) / 10000000L);
+	tp->tv_usec = (long) (system_time.wMilliseconds * 1000);
+	return 0;
+}
+#else
+#include <sys/time.h>
+#include <time.h>
+#endif
+
 int64_t usec_now()
 {
 	int64_t usec;