software: remove Python 3.7 compatibility shims.

We dropped support for Python 3.7 some time ago, so these shims were
completely unused.

software/glasgow/cli.py

@@ -11,10 +11,6 @@
 import importlib.metadata
 from vcd import VCDWriter
 from datetime import datetime
-try:
-    from ast import PyCF_ALLOW_TOP_LEVEL_AWAIT # Python 3.8+
-except ImportError:
-    PyCF_ALLOW_TOP_LEVEL_AWAIT = 0 # Python 3.7-
 
 from fx2 import FX2Config, FX2Device, FX2DeviceError, VID_CYPRESS, PID_FX2
 from fx2.format import input_data, diff_data
@@ -490,9 +486,6 @@ async def _main():
     args = get_argparser().parse_args()
     create_logger(args)
 
-    if sys.version_info < (3, 8) and os.name == "nt":
-        logger.warn("Ctrl+C on Windows is only supported on Python 3.8+")
-
     device = None
     try:
         if args.action not in ("build", "test", "tool", "factory", "list"):
@@ -637,10 +630,10 @@ async def run_applet():
                     elif args.action == "script":
                         if args.script_file:
                             code = compile(args.script_file.read(), filename=args.script_file.name,
-                                mode="exec", flags=PyCF_ALLOW_TOP_LEVEL_AWAIT)
+                                mode="exec", flags=ast.PyCF_ALLOW_TOP_LEVEL_AWAIT)
                         else:
                             code = compile(args.script_cmd, filename="<command>",
-                                mode="exec", flags=PyCF_ALLOW_TOP_LEVEL_AWAIT)
+                                mode="exec", flags=ast.PyCF_ALLOW_TOP_LEVEL_AWAIT)
                         future = eval(code, {"iface":iface, "device":device, "args":args})
                         if future is not None:
                             await future

software/glasgow/support/arepl.py

@@ -1,14 +1,11 @@
 import os
 import sys
+import ast
 import codeop
 import signal
 import asyncio
 import builtins
 import traceback
-try:
-    from ast import PyCF_ALLOW_TOP_LEVEL_AWAIT # Python 3.8+
-except ImportError:
-    PyCF_ALLOW_TOP_LEVEL_AWAIT = 0 # Python 3.7-
 try:
     import readline
     import rlcompleter
@@ -25,7 +22,7 @@ def __init__(self, locals, *, run_callback=None):
 
         self._buffer = []
         self._compile = codeop.CommandCompiler()
-        self._compile.compiler.flags |= PyCF_ALLOW_TOP_LEVEL_AWAIT
+        self._compile.compiler.flags |= ast.PyCF_ALLOW_TOP_LEVEL_AWAIT
 
         if readline is not None:
             self._init_readline()
@@ -48,13 +45,7 @@ def _save_readline(self):
     async def _run_code(self, code):
         try:
             future = eval(code, self.locals)
-            if PyCF_ALLOW_TOP_LEVEL_AWAIT == 0: # compat shim
-                future = getattr(builtins, "_", None)
-                if asyncio.iscoroutine(future):
-                    result = await future
-                    builtins._ = result
-                    print(repr(result))
-            elif asyncio.iscoroutine(future):
+            if asyncio.iscoroutine(future):
                 await future
             if self.run_callback is not None:
                 await self.run_callback()