Fix some issues with bytes and strings in Python 3.

SBProcess::ReadMemory and other related functions such as
WriteMemory are returning Python string() objects.  This means
that in Python 3 that are returning Unicode objects.  In reality
they should be returning bytes objects which is the same as a string
in Python 2, but different in Python 3.  This patch updates the
generated SWIG code to return Python bytes objects for all
memory related functions.

One quirk of this patch is that the C++ signature of ReadCStringFromMemory
has it writing c-string data into a void*.  This confuses our swig
typemaps which expect that a void* means byte data.  So I hacked up
a custom typemap which maps this specific function to treat the
void* as string data instead of byte data.

llvm-svn: 258743

lldb/packages/Python/lldbsuite/test/python_api/process/TestProcessAPI.py

@@ -56,7 +56,7 @@ class ProcessAPITestCase(TestBase):
 
         self.expect(content, "Result from SBProcess.ReadMemory() matches our expected output: 'x'",
                     exe=False,
-            startstr = 'x')
+            startstr = b'x')
 
         # Read (char *)my_char_ptr.
         val = frame.FindValue("my_char_ptr", lldb.eValueTypeVariableGlobal)
@@ -154,7 +154,7 @@ class ProcessAPITestCase(TestBase):
 
         self.expect(content, "Result from SBProcess.ReadMemory() matches our expected output: 'a'",
                     exe=False,
-            startstr = 'a')
+            startstr = b'a')
 
     @add_test_categories(['pyapi'])
     def test_access_my_int(self):
@@ -206,9 +206,8 @@ class ProcessAPITestCase(TestBase):
         # But we want to use the WriteMemory() API to assign 256 to the variable.
 
         # Now use WriteMemory() API to write 256 into the global variable.
-        new_value = str(bytes)
         error = lldb.SBError()
-        result = process.WriteMemory(location, new_value, error)
+        result = process.WriteMemory(location, bytes, error)
         if not error.Success() or result != byteSize:
             self.fail("SBProcess.WriteMemory() failed")
 
@@ -230,14 +229,11 @@ class ProcessAPITestCase(TestBase):
         if not error.Success():
             self.fail("SBProcess.ReadMemory() failed")
 
-        # Use "ascii" as the encoding because each element of 'content' is in the range [0..255].
-        new_bytes = bytearray(content, "ascii")
-
         # The bytearray_to_int utility function expects a little endian bytearray.
         if byteOrder == lldb.eByteOrderBig:
             new_bytes.reverse()
 
-        new_value = bytearray_to_int(new_bytes, byteSize)
+        new_value = bytearray_to_int(content, byteSize)
         if new_value != 256:
             self.fail("Memory content read from 'my_int' does not match (int)256")