windows: Simplify la_CreateSymbolicLinkW

The CreateSymbolicLinkW function is available since 0x0600 and is also
part of the Nano Server APIs. On earlier systems, don't even try.
Otherwise use it directly to simplify code.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>

diff --git a/libarchive/archive_write_disk_windows.c b/libarchive/archive_write_disk_windows.c
index bd6cff58aa934c45992dae190fcb6863c59c2280..6fda86f9c85e6159ffdaf390c3e34b5833305410 100644 (file)
--- a/libarchive/archive_write_disk_windows.c
+++ b/libarchive/archive_write_disk_windows.c
@@ -580,24 +580,6 @@ la_mktemp(struct archive_write_disk *a)
        return (fd);
 }
 
-#if _WIN32_WINNT < _WIN32_WINNT_VISTA
-static void *
-la_GetFunctionKernel32(const char *name)
-{
-       static HINSTANCE lib;
-       static int set;
-       if (!set) {
-               set = 1;
-               lib = LoadLibrary(TEXT("kernel32.dll"));
-       }
-       if (lib == NULL) {
-               fprintf(stderr, "Can't load kernel32.dll?!\n");
-               exit(1);
-       }
-       return (void *)GetProcAddress(lib, name);
-}
-#endif
-
 static int
 la_CreateHardLinkW(wchar_t *linkname, wchar_t *target)
 {
@@ -635,30 +617,18 @@ la_CreateHardLinkW(wchar_t *linkname, wchar_t *target)
 static int
 la_CreateSymbolicLinkW(const wchar_t *linkname, const wchar_t *target,
     int linktype) {
-       static BOOLEAN (WINAPI *f)(LPCWSTR, LPCWSTR, DWORD);
+       BOOL ret = 0;
+#if _WIN32_WINNT < _WIN32_WINNT_VISTA ||\
+    !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP | WINAPI_PARTITION_SYSTEM)
+       (void)linkname; /* UNUSED */
+       (void)target; /* UNUSED */
+       (void)linktype; /* UNUSED */
+#else
        wchar_t *ttarget, *p;
        size_t len;
        DWORD attrs = 0;
        DWORD flags = 0;
        DWORD newflags = 0;
-       BOOL ret = 0;
-
-#if _WIN32_WINNT < _WIN32_WINNT_VISTA
-/* CreateSymbolicLinkW is available since Vista and always loaded */
-       static int set;
-       if (!set) {
-               set = 1;
-               f = la_GetFunctionKernel32("CreateSymbolicLinkW");
-       }
-#else
-# if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP | WINAPI_PARTITION_SYSTEM)
-       f = CreateSymbolicLinkW;
-# else
-       f = NULL;
-# endif
-#endif
-       if (!f)
-               return (0);
 
        len = wcslen(target);
        if (len == 0) {
@@ -720,15 +690,16 @@ la_CreateSymbolicLinkW(const wchar_t *linkname, const wchar_t *target,
                        disk_unlink(linkname);
        }
 
-       ret = (*f)(linkname, ttarget, newflags);
+       ret = CreateSymbolicLinkW(linkname, ttarget, newflags);
        /*
         * Prior to Windows 10 calling CreateSymbolicLinkW() will fail
         * if SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE is set
         */
        if (!ret) {
-               ret = (*f)(linkname, ttarget, flags);
+               ret = CreateSymbolicLinkW(linkname, ttarget, flags);
        }
        free(ttarget);
+#endif
        return (ret);
 }