patman: Adjust 'command' to return strings instead of bytes

At present all the 'command' methods return bytes. Most of the time we
actually want strings, so change this. We still need to keep the internal
representation as bytes since otherwise unicode strings might break over
a read() boundary (e.g. 4KB), causing errors. But we can convert the end
result to strings.

Add a 'binary' parameter to cover the few cases where bytes are needed.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/cbfs_util_test.py b/tools/binman/cbfs_util_test.py
index 772c794..ddc2e09 100755
--- a/tools/binman/cbfs_util_test.py
+++ b/tools/binman/cbfs_util_test.py
@@ -56,7 +56,7 @@
         cls.have_lz4 = True
         try:
             tools.Run('lz4', '--no-frame-crc', '-c',
-                      tools.GetInputFilename('u-boot.bin'))
+                      tools.GetInputFilename('u-boot.bin'), binary=True)
         except:
             cls.have_lz4 = False
 
diff --git a/tools/binman/ftest.py b/tools/binman/ftest.py
index 494e218..9350799 100644
--- a/tools/binman/ftest.py
+++ b/tools/binman/ftest.py
@@ -174,7 +174,7 @@
         cls.have_lz4 = True
         try:
             tools.Run('lz4', '--no-frame-crc', '-c',
-                      os.path.join(cls._indir, 'u-boot.bin'))
+                      os.path.join(cls._indir, 'u-boot.bin'), binary=True)
         except:
             cls.have_lz4 = False
 
diff --git a/tools/patman/command.py b/tools/patman/command.py
index 16299f3..5fbd2c4 100644
--- a/tools/patman/command.py
+++ b/tools/patman/command.py
@@ -4,6 +4,7 @@
 
 import os
 import cros_subprocess
+import tools
 
 """Shell command ease-ups for Python."""
 
@@ -31,6 +32,13 @@
         self.return_code = return_code
         self.exception = exception
 
+    def ToOutput(self, binary):
+        if not binary:
+            self.stdout = tools.ToString(self.stdout)
+            self.stderr = tools.ToString(self.stderr)
+            self.combined = tools.ToString(self.combined)
+        return self
+
 
 # This permits interception of RunPipe for test purposes. If it is set to
 # a function, then that function is called with the pipe list being
@@ -41,7 +49,7 @@
 
 def RunPipe(pipe_list, infile=None, outfile=None,
             capture=False, capture_stderr=False, oneline=False,
-            raise_on_error=True, cwd=None, **kwargs):
+            raise_on_error=True, cwd=None, binary=False, **kwargs):
     """
     Perform a command pipeline, with optional input/output filenames.
 
@@ -67,7 +75,7 @@
         else:
             return test_result
         # No result: fall through to normal processing
-    result = CommandResult()
+    result = CommandResult(b'', b'', b'')
     last_pipe = None
     pipeline = list(pipe_list)
     user_pipestr =  '|'.join([' '.join(pipe) for pipe in pipe_list])
@@ -93,29 +101,36 @@
             if raise_on_error:
                 raise Exception("Error running '%s': %s" % (user_pipestr, str))
             result.return_code = 255
-            return result
+            return result.ToOutput(binary)
 
     if capture:
         result.stdout, result.stderr, result.combined = (
                 last_pipe.CommunicateFilter(None))
         if result.stdout and oneline:
-            result.output = result.stdout.rstrip('\r\n')
+            result.output = result.stdout.rstrip(b'\r\n')
         result.return_code = last_pipe.wait()
     else:
         result.return_code = os.waitpid(last_pipe.pid, 0)[1]
     if raise_on_error and result.return_code:
         raise Exception("Error running '%s'" % user_pipestr)
-    return result
+    return result.ToOutput(binary)
 
 def Output(*cmd, **kwargs):
     kwargs['raise_on_error'] = kwargs.get('raise_on_error', True)
     return RunPipe([cmd], capture=True, **kwargs).stdout
 
 def OutputOneLine(*cmd, **kwargs):
+    """Run a command and output it as a single-line string
+
+    The command us expected to produce a single line of output
+
+    Returns:
+        String containing output of command
+    """
     raise_on_error = kwargs.pop('raise_on_error', True)
-    return (RunPipe([cmd], capture=True, oneline=True,
-            raise_on_error=raise_on_error,
-            **kwargs).stdout.strip())
+    result = RunPipe([cmd], capture=True, oneline=True,
+                     raise_on_error=raise_on_error, **kwargs).stdout.strip()
+    return result
 
 def Run(*cmd, **kwargs):
     return RunPipe([cmd], **kwargs).stdout
diff --git a/tools/patman/tools.py b/tools/patman/tools.py
index 4a7fcda..3feddb2 100644
--- a/tools/patman/tools.py
+++ b/tools/patman/tools.py
@@ -186,7 +186,7 @@
             return True
     return False
 
-def Run(name, *args):
+def Run(name, *args, **kwargs):
     """Run a tool with some arguments
 
     This runs a 'tool', which is a program used by binman to process files and
@@ -201,13 +201,14 @@
         CommandResult object
     """
     try:
+        binary = kwargs.get('binary')
         env = None
         if tool_search_paths:
             env = dict(os.environ)
             env['PATH'] = ':'.join(tool_search_paths) + ':' + env['PATH']
         all_args = (name,) + args
         result = command.RunPipe([all_args], capture=True, capture_stderr=True,
-                                 env=env, raise_on_error=False)
+                                 env=env, raise_on_error=False, binary=binary)
         if result.return_code:
             raise Exception("Error %d running '%s': %s" %
                (result.return_code,' '.join(all_args),
@@ -375,7 +376,7 @@
     """Convert a str type into a bytes type
 
     Args:
-        string: string to convert value
+        string: string to convert
 
     Returns:
         Python 3: A bytes type
@@ -385,6 +386,18 @@
         return string.encode('utf-8')
     return string
 
+def ToString(bval):
+    """Convert a bytes type into a str type
+
+    Args:
+        bval: bytes value to convert
+
+    Returns:
+        Python 3: A bytes type
+        Python 2: A string type
+    """
+    return bval.decode('utf-8')
+
 def Compress(indata, algo, with_header=True):
     """Compress some data using a given algorithm
 
@@ -406,14 +419,14 @@
     fname = GetOutputFilename('%s.comp.tmp' % algo)
     WriteFile(fname, indata)
     if algo == 'lz4':
-        data = Run('lz4', '--no-frame-crc', '-c', fname)
+        data = Run('lz4', '--no-frame-crc', '-c', fname, binary=True)
     # cbfstool uses a very old version of lzma
     elif algo == 'lzma':
         outfname = GetOutputFilename('%s.comp.otmp' % algo)
         Run('lzma_alone', 'e', fname, outfname, '-lc1', '-lp0', '-pb0', '-d8')
         data = ReadFile(outfname)
     elif algo == 'gzip':
-        data = Run('gzip', '-c', fname)
+        data = Run('gzip', '-c', fname, binary=True)
     else:
         raise ValueError("Unknown algorithm '%s'" % algo)
     if with_header:
@@ -446,13 +459,13 @@
     with open(fname, 'wb') as fd:
         fd.write(indata)
     if algo == 'lz4':
-        data = Run('lz4', '-dc', fname)
+        data = Run('lz4', '-dc', fname, binary=True)
     elif algo == 'lzma':
         outfname = GetOutputFilename('%s.decomp.otmp' % algo)
         Run('lzma_alone', 'd', fname, outfname)
-        data = ReadFile(outfname)
+        data = ReadFile(outfname, binary=True)
     elif algo == 'gzip':
-        data = Run('gzip', '-cd', fname)
+        data = Run('gzip', '-cd', fname, binary=True)
     else:
         raise ValueError("Unknown algorithm '%s'" % algo)
     return data