dtoc: Updates BytesToValue() for Python 3

The difference between the bytes and str types in Python 3 requires a
number of minor changes to this function. Update it to handle the input
data using the 'bytes' type. Create two useful helper functions which can
be used by other modules too.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 25 insertions, 16 deletions

diff --git a/tools/dtoc/fdt.py b/tools/dtoc/fdt.py
index 35453fbed9..2e74bc15be 100644
--- a/tools/dtoc/fdt.py
+++ b/tools/dtoc/fdt.py
@@ -30,50 +30,59 @@ def CheckErr(errnum, msg):
             (errnum, libfdt.fdt_strerror(errnum), msg))
 
 
-def BytesToValue(bytes):
+def BytesToValue(data):
     """Converts a string of bytes into a type and value
 
     Args:
-        A string containing bytes
+        A bytes value (which on Python 2 is an alias for str)
 
     Return:
         A tuple:
             Type of data
             Data, either a single element or a list of elements. Each element
             is one of:
-                TYPE_STRING: string value from the property
-                TYPE_INT: a byte-swapped integer stored as a 4-byte string
-                TYPE_BYTE: a byte stored as a single-byte string
+                TYPE_STRING: str/bytes value from the property
+                TYPE_INT: a byte-swapped integer stored as a 4-byte str/bytes
+                TYPE_BYTE: a byte stored as a single-byte str/bytes
     """
-    bytes = str(bytes)
-    size = len(bytes)
-    strings = bytes.split('\0')
+    data = bytes(data)
+    size = len(data)
+    strings = data.split(b'\0')
     is_string = True
     count = len(strings) - 1
-    if count > 0 and not strings[-1]:
+    if count > 0 and not len(strings[-1]):
         for string in strings[:-1]:
             if not string:
                 is_string = False
                 break
             for ch in string:
-                if ch < ' ' or ch > '~':
+                # Handle Python 2 treating bytes as str
+                if type(ch) == str:
+                    ch = ord(ch)
+                if ch < 32 or ch > 127:
                     is_string = False
                     break
     else:
         is_string = False
     if is_string:
-        if count == 1:
-            return TYPE_STRING, strings[0]
+        if count == 1: 
+            if sys.version_info[0] >= 3:  # pragma: no cover
+                return TYPE_STRING, strings[0].decode()
+            else:
+                return TYPE_STRING, strings[0]
         else:
-            return TYPE_STRING, strings[:-1]
+            if sys.version_info[0] >= 3:  # pragma: no cover
+                return TYPE_STRING, [s.decode() for s in strings[:-1]]
+            else:
+                return TYPE_STRING, strings[:-1]
     if size % 4:
         if size == 1:
-            return TYPE_BYTE, bytes[0]
+            return TYPE_BYTE, tools.ToChar(data[0])
         else:
-            return TYPE_BYTE, list(bytes)
+            return TYPE_BYTE, [tools.ToChar(ch) for ch in list(data)]
     val = []
     for i in range(0, size, 4):
-        val.append(bytes[i:i + 4])
+        val.append(data[i:i + 4])
     if size == 4:
         return TYPE_INT, val[0]
     else: