misc: Text vs Byte string in python3

Python 3 uses the concepts of two different types:
text and binary strings.
Those cannot be implicilty combined (as it was happening in python2) and
in order to be used together one of them must be converted to the other
type:

* Text can be encoded into Bytes via the encode() method
* Bytes can be decoded to Text using the decode() method

By default encode/decode will assume UTF-8 format

JIRA: https://gem5.atlassian.net/browse/GEM5-345

Change-Id: I1bdf7db17b49cc109239fd5f44791769370853f8
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/26250
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

SConstruct

@@ -1013,7 +1013,7 @@ export_vars += ['USE_FENV', 'TARGET_ISA', 'TARGET_GPU_ISA', 'CP_ANNOTATE',
 # operands are the name of the variable and a Value node containing the
 # value of the variable.
 def build_config_file(target, source, env):
-    (variable, value) = [s.get_contents() for s in source]
+    (variable, value) = [s.get_contents().decode('utf-8') for s in source]
     with open(str(target[0]), 'w') as f:
         print('#define', variable, value, file=f)
     return None

src/SConscript

@@ -621,7 +621,7 @@ for opt in export_vars:
     env.ConfigFile(opt)
 
 def makeTheISA(source, target, env):
-    isas = [ src.get_contents() for src in source ]
+    isas = [ src.get_contents().decode('utf-8') for src in source ]
     target_isa = env['TARGET_ISA']
     def define(isa):
         return isa.upper() + '_ISA'
@@ -823,7 +823,7 @@ depends.sort(key = lambda x: x.name)
 # Generate Python file containing a dict specifying the current
 # buildEnv flags.
 def makeDefinesPyFile(target, source, env):
-    build_env = source[0].get_contents()
+    build_env = source[0].get_contents().decode('utf-8')
 
     code = code_formatter()
     code("""
@@ -882,7 +882,7 @@ def createSimObjectCxxConfig(is_header):
     def body(target, source, env):
         assert len(target) == 1 and len(source) == 1
 
-        name = str(source[0].get_contents())
+        name = source[0].get_contents().decode('utf-8')
         obj = sim_objects[name]
 
         code = code_formatter()

src/python/m5/util/__init__.py

@@ -43,6 +43,8 @@ import os
 import re
 import sys
 
+from six import string_types
+
 from . import convert
 from . import jobfile
 
@@ -122,7 +124,7 @@ def compareVersions(v1, v2):
     def make_version_list(v):
         if isinstance(v, (list,tuple)):
             return v
-        elif isinstance(v, str):
+        elif isinstance(v, string_types):
             return map(lambda x: int(re.match('\d+', x).group()), v.split('.'))
         else:
             raise TypeError()
@@ -196,7 +198,7 @@ def readCommand(cmd, **kwargs):
             return exception
         raise
 
-    return subp.communicate()[0]
+    return subp.communicate()[0].decode('utf-8')
 
 def makeDir(path):
     """Make a directory if it doesn't exist.  If the path does exist,