unix-cpy: Remove unix-cpy. It's no longer needed.

unix-cpy was originally written to get semantic equivalent with CPython
without writing functional tests.  When writing the initial
implementation of uPy it was a long way between lexer and functional
tests, so the half-way test was to make sure that the bytecode was
correct.  The idea was that if the uPy bytecode matched CPython 1-1 then
uPy would be proper Python if the bytecodes acted correctly.  And having
matching bytecode meant that it was less likely to miss some deep
subtlety in the Python semantics that would require an architectural
change later on.

But that is all history and it no longer makes sense to retain the
ability to output CPython bytecode, because:

1. It outputs CPython 3.3 compatible bytecode.  CPython's bytecode
changes from version to version, and seems to have changed quite a bit
in 3.5.  There's no point in changing the bytecode output to match
CPython anymore.

2. uPy and CPy do different optimisations to the bytecode which makes it
harder to match.

3. The bytecode tests are not run.  They were never part of Travis and
are not run locally anymore.

4. The EMIT_CPYTHON option needs a lot of extra source code which adds
heaps of noise, especially in compile.c.

5. Now that there is an extensive test suite (which tests functionality)
there is no need to match the bytecode.  Some very subtle behaviour is
tested with the test suite and passing these tests is a much better
way to stay Python-language compliant, rather than trying to match
CPy bytecode.

1 files changed, 0 insertions, 15 deletions

diff --git a/tests/bytecode/README.md b/tests/bytecode/README.md
deleted file mode 100644
index 0d5245cb7..000000000
--- a/tests/bytecode/README.md
+++ /dev/null
@@ -1,15 +0,0 @@
-This directory contains the framework and test files for testing the byte code
-output of the Micro Python compiler.
-
-You need to first build the 'cpy' executable in the directory micropython/unix-cpy/.
-This executable is a minimal version of Micro Python which compiles a single source
-file and outputs the corresponding byte code.
-
-The output of Micro Python is checked against CPython 3.4.
-
-To run the tests use:
-
-    ./run-tests
-
-Note that the tests in pylib-test/ are from the Python 3.3 library, and are licensed
-under the relevant license, as per pylib-test/LICENSE.txt.