[dexter] Require python >= 3.6

[djtodoro]

Summary

I see the doc says we need python >= 3.6. Running it with an older version, I get verbose output from python interpreter, so I think that should simple be handled.

For example:

python2 dexter.py list-debuggers
You need python 3.6 or later to run DExTer

[djtodoro]

-using the same indentation

[Orlando]

LGTM pending no other comments, thanks for the patch!

debuginfo-tests/dexter/dexter.py

14

Could use sys.exit(ReturnCode._ERROR) here for consistency.

[djtodoro]

@Orlando Thanks!

debuginfo-tests/dexter/dexter.py

14

I can add a comment here. If we import something from dex.* that will cause calling of some __init__ constructors where the newer python syntax was used, so we would end up with the interpreter failing again.

[djtodoro]

-adding a comment

[jmorse]

LGTM, and thanks for the patch; ideally a similar test would also go into debuginfo-tests/CMakeLists.txt to avoid people adding debuginfo-tests to their configuration with a version of python that will definitely fail.

[djtodoro]

In D78621#1996517, @jmorse wrote:

LGTM, and thanks for the patch; ideally a similar test would also go into debuginfo-tests/CMakeLists.txt to avoid people adding debuginfo-tests to their configuration with a version of python that will definitely fail.

Oh, yes, that is good idea. We should do that.

Out of this topic, have you thought about adding a (CMAKE) build target for the dexter, so we have it with in the final $build/bin? Something similar we did for llvm-locstatsutil (written in python as well).

[Orlando]

debuginfo-tests/dexter/dexter.py

14

Makes sense, SGTM.

[TWeaver]

thanks for this, LGTM.

[TWeaver]

@jmorse I believe there's already a test in the cmake/config that checks the python version when generating the build.

if you don't provide a -DPYTHON_EXECUTABLE options on the cmake command line that points at a version 3.6 or higher, the build gen fails.

[TWeaver]

in ./debuginfo-tests/CMakeLists.txt we have the following on line 27:

if (NOT DEFINED PYTHON_EXECUTABLE)
  message(FATAL_ERROR "Cannot run debuginfo-tests without python")
elseif(PYTHON_VERSION_MAJOR LESS 3)
  message(FATAL_ERROR "Cannot run debuginfo-tests without python 3")

Perhaps we should add a minor check too.

debuginfo-tests/dexter/dexter.py

 #!/usr/bin/python
 # DExTer : Debugging Experience Tester
 # ~~~~~~   ~         ~~         ~   ~~
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 # See https://llvm.org/LICENSE.txt for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 """DExTer entry point. This is the only non-module file."""
 
 import sys
 
+if sys.version_info < (3,6,0):
+    sys.stderr.write("You need python 3.6 or later to run DExTer\n")
+    # Equivalent to sys.exit(ReturnCode._ERROR).
+    sys.exit(1)
+
 from dex.tools import main
 
 if __name__ == '__main__':
     return_code = main()
     sys.exit(return_code.value)