[lldb/Test] Decode stdout and stderr in case it contains UTF-8

[JDevlieghere]

Summary

Fixes a UnicodeDecodeError when stdout or stderr contain non-ASCI characters.

    output += """Command Output (stdout):\n--\n%s\n--\n""" % (out,)
UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 in position 721: ordinal not in range(128)

[JDevlieghere]

Use single quotes for consistency

[friss]

I think this won't work with Python3, were out and err will be already "decoded" str objects

[JDevlieghere]

Right, I didn't check whether out and err were strings or bytes. I'll see if I can find a better solution or alternatively wrap it in a try-except.

[labath]

In D76955#1947160, @JDevlieghere wrote:

Right, I didn't check whether out and err were strings or bytes. I'll see if I can find a better solution or alternatively wrap it in a try-except.

It might be simplest to wrap that in if PY2 (when can we drop python2 support again?). I don't believe this can happen with py3 due to the try-catch here.

A lot of this stuff could be cleaned up when python2 is gone. Right now it's very confusing to reason about what is the type a thing in which python version.

lldb/test/API/lldbtest.py

85

replace or backslashreplace error strategy might be better, so that the presence/value of the erroneous character is not completely lost.

[JDevlieghere]

After looking at util.py I'm convinced that this should never happen, unless there's a bug in the to_string implementation in which case we'd need to fix it there.

[JDevlieghere]

Lit's to_string will just return the string when it's a str instance, which in Python can still contain UTF-8 characters:

>>> foo = "😀"
>>> isinstance(foo, str)
True
>>> foo.encode('utf-8')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
UnicodeDecodeError: 'ascii' codec can't decode byte 0xf0 in position 0: ordinal not in range(128)

[labath]

This seems like the simplest thing to do while we wait for py2 to die.

lldb/test/API/lldbtest.py

             timeoutInfo = 'Reached timeout of {} seconds'.format(
                 litConfig.maxIndividualTestTime)
 
+        if sys.version_info.major == 2:
+            # In Python 2, string objects can contain Unicode characters.
+            out = out.decode('utf-8')
+            err = err.decode('utf-8')
+
         output = """Script:\n--\n%s\n--\nExit Code: %d\n""" % (
             ' '.join(cmd), exitCode)
         if timeoutInfo is not None: