SL-15742: Convert build scripts to Python 3

This changeset makes it possible to build the Second Life viewer using
Python 3. It is designed to be used with an equivalent Autobuild branch
so that a developer can compile without needing Python 2 on their
machine.

Breaking change: Python 2 support ending

Rather than supporting two versions of Python, including one that was
discontinued at the beginning of the year, this branch focuses on
pouring future effort into Python 3 only. As a result, scripts do not
need to be backwards compatible. This means that build environments,
be they on personal computers and on build agents, need to have a
compatible interpreter.

Notes

- SLVersionChecker will still use Python 2 on macOS
- Fixed the message template url used by template_verifier.py

1 files changed, 7 insertions, 8 deletions

diff --git a/indra/llcommon/tests/llsdserialize_test.cpp b/indra/llcommon/tests/llsdserialize_test.cpp
index 642c1c3879..c246f5ee56 100644
--- a/indra/llcommon/tests/llsdserialize_test.cpp
+++ b/indra/llcommon/tests/llsdserialize_test.cpp
@@ -1795,7 +1795,7 @@ namespace tut
         set_test_name("verify NamedTempFile");
         python("platform",
                "import sys\n"
-               "print 'Running on', sys.platform\n");
+               "print('Running on', sys.platform)\n");
     }
 
     // helper for test<3>
@@ -1825,14 +1825,14 @@ namespace tut
         const char pydata[] =
             "def verify(iterable):\n"
             "    it = iter(iterable)\n"
-            "    assert it.next() == 17\n"
-            "    assert abs(it.next() - 3.14) < 0.01\n"
-            "    assert it.next() == '''\\\n"
+            "    assert next(it) == 17\n"
+            "    assert abs(next(it) - 3.14) < 0.01\n"
+            "    assert next(it) == '''\\\n"
             "This string\n"
             "has several\n"
             "lines.'''\n"
             "    try:\n"
-            "        it.next()\n"
+            "        next(it)\n"
             "    except StopIteration:\n"
             "        pass\n"
             "    else:\n"
@@ -1855,7 +1855,7 @@ namespace tut
                "        yield llsd.parse(item)\n" <<
                pydata <<
                // Don't forget raw-string syntax for Windows pathnames.
-               "verify(parse_each(open(r'" << file.getName() << "')))\n");
+               "verify(parse_each(open(r'" << file.getName() << "', 'rb')))\n");
     }
 
     template<> template<>
@@ -1870,7 +1870,6 @@ namespace tut
 
         python("write Python notation",
                placeholders::arg1 <<
-               "from __future__ import with_statement\n" <<
                import_llsd <<
                "DATA = [\n"
                "    17,\n"
@@ -1884,7 +1883,7 @@ namespace tut
                // N.B. Using 'print' implicitly adds newlines.
                "with open(r'" << file.getName() << "', 'w') as f:\n"
                "    for item in DATA:\n"
-               "        print >>f, llsd.format_notation(item)\n");
+               "        print(llsd.format_notation(item).decode(), file=f)\n");
 
         std::ifstream inf(file.getName().c_str());
         LLSD item;