LLDB fails to build

[stanblesk]

Summary

When trying to build swift on linux environment where Python 3 exists, and even if it's not set as default script uses Python 3 instead of Python 2.

Tested in Gentoo Linux

I don't knoe how to commit here, tried on github, but there is a read-only version of code there

[labath]

Looks good, however I should point out that the state of the lldb+python3+linux combo is unknown..

[stanblesk]

Well as long as this code is cross-platform I guess it won't damage anything on other platforms. It will still work on those platforms where Python 2 is default, and will work on platforms with Python 3. Nevertheless it will fix a huge compilation error on Linux. Right now after each Swift upgrade I have to manually change those lines in this script and continue building it.

There is still one problem exists with LLDB which requires me to restart the installation. I handle it this way:

$ cd ../build/buildbot_linux/lldb-linux-x86_64/lib
$ ln -s ../lib64/python3.5 python3.5

Thank you very much!

scripts/Python/python-swigsafecast.swig

 SBTypeToSWIGWrapper (const char* c_str)
 {
     if (c_str)
-        return PyString_FromString(c_str);
+        #if PY_MAJOR_VERSION > 2
+            return PyUnicode_FromString(c_str);
+        #else
+            return PyString_FromString(c_str);
+        #endif
     return NULL;
 }