mingw: move common functionality to win32.h

Some small Win32 specific functions will be shared by MinGW and
Cygwin compatibility layer. Place them into a separate header.

Signed-off-by: Dmitry Potapov <dpotapov@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

compat/mingw.c

@@ -1,4 +1,5 @@
 #include "../git-compat-util.h"
+#include "win32.h"
 #include "../strbuf.h"
 
 unsigned int _CRT_fmode = _O_BINARY;
@@ -39,46 +40,19 @@ static int do_lstat(const char *file_name, struct stat *buf)
 {
 	WIN32_FILE_ATTRIBUTE_DATA fdata;
 
-	if (GetFileAttributesExA(file_name, GetFileExInfoStandard, &fdata)) {
-		int fMode = S_IREAD;
-		if (fdata.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
-			fMode |= S_IFDIR;
-		else
-			fMode |= S_IFREG;
-		if (!(fdata.dwFileAttributes & FILE_ATTRIBUTE_READONLY))
-			fMode |= S_IWRITE;
-
+	if (!(errno = get_file_attr(file_name, &fdata))) {
 		buf->st_ino = 0;
 		buf->st_gid = 0;
 		buf->st_uid = 0;
 		buf->st_nlink = 1;
-		buf->st_mode = fMode;
+		buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes);
 		buf->st_size = fdata.nFileSizeLow; /* Can't use nFileSizeHigh, since it's not a stat64 */
 		buf->st_dev = buf->st_rdev = 0; /* not used by Git */
 		buf->st_atime = filetime_to_time_t(&(fdata.ftLastAccessTime));
 		buf->st_mtime = filetime_to_time_t(&(fdata.ftLastWriteTime));
 		buf->st_ctime = filetime_to_time_t(&(fdata.ftCreationTime));
-		errno = 0;
 		return 0;
 	}
-
-	switch (GetLastError()) {
-	case ERROR_ACCESS_DENIED:
-	case ERROR_SHARING_VIOLATION:
-	case ERROR_LOCK_VIOLATION:
-	case ERROR_SHARING_BUFFER_EXCEEDED:
-		errno = EACCES;
-		break;
-	case ERROR_BUFFER_OVERFLOW:
-		errno = ENAMETOOLONG;
-		break;
-	case ERROR_NOT_ENOUGH_MEMORY:
-		errno = ENOMEM;
-		break;
-	default:
-		errno = ENOENT;
-		break;
-	}
 	return -1;
 }
 
@@ -130,19 +104,11 @@ int mingw_fstat(int fd, struct stat *buf)
 		return fstat(fd, buf);
 
 	if (GetFileInformationByHandle(fh, &fdata)) {
-		int fMode = S_IREAD;
-		if (fdata.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
-			fMode |= S_IFDIR;
-		else
-			fMode |= S_IFREG;
-		if (!(fdata.dwFileAttributes & FILE_ATTRIBUTE_READONLY))
-			fMode |= S_IWRITE;
-
 		buf->st_ino = 0;
 		buf->st_gid = 0;
 		buf->st_uid = 0;
 		buf->st_nlink = 1;
-		buf->st_mode = fMode;
+		buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes);
 		buf->st_size = fdata.nFileSizeLow; /* Can't use nFileSizeHigh, since it's not a stat64 */
 		buf->st_dev = buf->st_rdev = 0; /* not used by Git */
 		buf->st_atime = filetime_to_time_t(&(fdata.ftLastAccessTime));

compat/win32.h

@@ -0,0 +1,34 @@
+/* common Win32 functions for MinGW and Cygwin */
+#include <windows.h>
+
+static inline int file_attr_to_st_mode (DWORD attr)
+{
+	int fMode = S_IREAD;
+	if (attr & FILE_ATTRIBUTE_DIRECTORY)
+		fMode |= S_IFDIR;
+	else
+		fMode |= S_IFREG;
+	if (!(attr & FILE_ATTRIBUTE_READONLY))
+		fMode |= S_IWRITE;
+	return fMode;
+}
+
+static inline int get_file_attr(const char *fname, WIN32_FILE_ATTRIBUTE_DATA *fdata)
+{
+	if (GetFileAttributesExA(fname, GetFileExInfoStandard, fdata))
+		return 0;
+
+	switch (GetLastError()) {
+	case ERROR_ACCESS_DENIED:
+	case ERROR_SHARING_VIOLATION:
+	case ERROR_LOCK_VIOLATION:
+	case ERROR_SHARING_BUFFER_EXCEEDED:
+		return EACCES;
+	case ERROR_BUFFER_OVERFLOW:
+		return ENAMETOOLONG;
+	case ERROR_NOT_ENOUGH_MEMORY:
+		return ENOMEM;
+	default:
+		return ENOENT;
+	}
+}