ext4_utils: fix windows build by avoiding asprintf

asprintf is not available on windows.  Since it is only being used outside
operations.

Change-Id: I79c3a3934f6de7a3cd3f17db5ae7731e9a68387c

diff --git a/ext4_utils/make_ext4fs.c b/ext4_utils/make_ext4fs.c
index c3e242a..64fcc84 100644 (file)
--- a/ext4_utils/make_ext4fs.c
+++ b/ext4_utils/make_ext4fs.c
@@ -374,6 +374,63 @@ int make_ext4fs(const char *filename, s64 len,
        return status;
 }
 
+/* return a newly-malloc'd string that is a copy of str.  The new string
+   is guaranteed to have a trailing slash.  If absolute is true, the new string
+   is also guaranteed to have a leading slash.
+*/
+static char *canonicalize_slashes(const char *str, bool absolute)
+{
+       char *ret;
+       int len = strlen(str);
+       int newlen = len;
+       char *ptr;
+
+       if (len == 0 && absolute) {
+               return strdup("/");
+       }
+
+       if (str[0] != '/' && absolute) {
+               newlen++;
+       }
+       if (str[len - 1] != '/') {
+               newlen++;
+       }
+       ret = malloc(newlen + 1);
+       if (!ret) {
+               critical_error("malloc");
+       }
+
+       ptr = ret;
+       if (str[0] != '/' && absolute) {
+               *ptr++ = '/';
+       }
+
+       strcpy(ptr, str);
+       ptr += len;
+
+       if (str[len - 1] != '/') {
+               *ptr++ = '/';
+       }
+
+       if (ptr != ret + newlen) {
+               critical_error("assertion failed\n");
+       }
+
+       *ptr = '\0';
+
+       return ret;
+}
+
+static char *canonicalize_abs_slashes(const char *str)
+{
+       return canonicalize_slashes(str, true);
+}
+
+static char *canonicalize_rel_slashes(const char *str)
+{
+       return canonicalize_slashes(str, false);
+}
+
 int make_ext4fs_internal(int fd, const char *_directory,
                          const char *_mountpoint, fs_config_func_t fs_config_func, int gzip,
                          int sparse, int crc, int wipe, int init_itabs,
@@ -390,23 +447,12 @@ int make_ext4fs_internal(int fd, const char *_directory,
 
        if (_mountpoint == NULL) {
                mountpoint = strdup("");
-       } else if (_mountpoint[0] == '\0') {
-               mountpoint = strdup("/");
        } else {
-               ret = asprintf(&mountpoint, "%s%s%s",
-                              _mountpoint[0] == '/' ? "" : "/",
-                              _mountpoint,
-                              _mountpoint[strlen(_mountpoint) - 1] == '/' ? "" : "/");
-               if (ret < 0)
-                       critical_error_errno("asprintf");
+               mountpoint = canonicalize_abs_slashes(_mountpoint);
        }
 
        if (_directory) {
-               ret = asprintf(&directory, "%s%s",
-                              _directory,
-                              _directory[strlen(_directory) - 1] == '/' ? "" : "/");
-               if (ret < 0)
-                       critical_error_errno("asprintf");
+               directory = canonicalize_rel_slashes(_directory);
        }
 
        if (info.len <= 0)