[Dexter] Normalise the "tools directory" into a list of tools

AFAIUI the original rationale behind having tools abstracted behind the
directory that they live is was to ease development -- create a new tool by
creating a new directory. However it also puts in awkward abstractions
whereby you can't know what's going to be run without first loading a
module. There's also effectively no authoritative list of tools, because
you can load one from anywhere. And the tool names are affected by pythons
normalisation of module names!

Instead: move the tools into named files in the tools directory, have a
list of them, and create the tool object from that list when needed. No
module wrangling requried at all, and there can be certainty about what's
going on. We can also delete some name-normalisation that happens now that
it's not subject to module-loading-normalisation.

Author: jmorse

cross-project-tests/debuginfo-tests/dexter/dex/debugger/Debuggers.py

@@ -47,7 +47,7 @@ def _get_potential_debuggers():  # noqa
 
 
 def _warn_meaningless_option(context, option):
-    if hasattr(context.options, "list_debuggers"):
+    if hasattr(context.options, "list-debuggers"):
         return
 
     context.logger.warning(

cross-project-tests/debuginfo-tests/dexter/dex/tools/Main.py

@@ -54,27 +54,6 @@ def _output_bug_report_message(context):
     )
 
 
-def get_tools_directory():
-    """Returns directory path where DExTer tool imports can be
-    found.
-    """
-    tools_directory = os.path.join(get_root_directory(), "tools")
-    assert os.path.isdir(tools_directory), tools_directory
-    return tools_directory
-
-
-def get_tool_names():
-    """Returns a list of expected DExTer Tools"""
-    return [
-        "help",
-        "list-debuggers",
-        "no-tool-",
-        "run-debugger-internal-",
-        "test",
-        "view",
-    ]
-
-
 def _set_auto_highlights(context):
     """Flag some strings for auto-highlighting."""
     context.o.auto_reds.extend(
@@ -118,6 +97,7 @@ def _is_valid_tool_name(tool_name):
     """check tool name matches a tool directory within the dexter tools
     directory.
     """
+    from . import get_tool_names
     valid_tools = get_tool_names()
     if tool_name not in valid_tools:
         raise Error(
@@ -127,17 +107,6 @@ def _is_valid_tool_name(tool_name):
         )
 
 
-def _import_tool_module(tool_name):
-    """Imports the python module at the tool directory specificed by
-    tool_name.
-    """
-    # format tool argument to reflect tool directory form.
-    tool_name = tool_name.replace("-", "_")
-
-    tools_directory = get_tools_directory()
-    return load_module(tool_name, tools_directory)
-
-
 def tool_main(context, tool, args):
     with Timer(tool.name):
         options, defaults = tool.parse_command_line(args)
@@ -190,6 +159,7 @@ def __init__(self):
 
 
 def main() -> ReturnCode:
+    from . import get_tools
     context = Context()
     with PrettyOutput() as context.o:
         context.logger = Logger(context.o)
@@ -200,8 +170,8 @@ def main() -> ReturnCode:
             options, args = _get_options_and_args(context)
             # raises 'Error' if command line tool is invalid.
             tool_name = _get_tool_name(options)
-            module = _import_tool_module(tool_name)
-            return tool_main(context, module.Tool(context), args)
+            T = get_tools()[tool_name]
+            return tool_main(context, T(context), args)
         except Error as e:
             context.logger.error(str(e))
             try:

cross-project-tests/debuginfo-tests/dexter/dex/tools/__init__.py

@@ -5,6 +5,32 @@
 # See https://llvm.org/LICENSE.txt for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-from dex.tools.Main import Context, get_tool_names, get_tools_directory, main, tool_main
+from dex.tools.Main import Context, main, tool_main
 from dex.tools.TestToolBase import TestToolBase
 from dex.tools.ToolBase import ToolBase
+
+def get_tool_names():
+    """Returns a list of expected DExTer Tools"""
+    return ["help", "list-debuggers", "no-tool-", "run-debugger-internal-", "test", "view"]
+
+def get_tools():
+    """Returns a dictionary of expected DExTer Tools"""
+    return _the_tools
+
+
+from .help import Tool as help_tool
+from .list_debuggers import Tool as list_debuggers_tool
+from .no_tool_ import Tool as no_tool_tool
+from .run_debugger_internal_ import Tool as run_debugger_internal_tool
+from .test import Tool as test_tool
+from .view import Tool as view_tool
+
+_the_tools = {
+      "help" : help_tool,
+      "list-debuggers" : list_debuggers_tool,
+      "no_tool_" : no_tool_tool,
+      "run-debugger-internal-" : run_debugger_internal_tool,
+      "test" : test_tool,
+      "view" : view_tool
+}
+

cross-project-tests/debuginfo-tests/dexter/dex/tools/help/Tool.py renamed to cross-project-tests/debuginfo-tests/dexter/dex/tools/help.py

@@ -8,7 +8,7 @@
 
 import textwrap
 
-from dex.tools import ToolBase, get_tool_names, get_tools_directory, tool_main
+from dex.tools import ToolBase, get_tool_names, get_tools, tool_main
 from dex.utils.Imports import load_module
 from dex.utils.ReturnCode import ReturnCode
 
@@ -36,10 +36,8 @@ def handle_options(self, defaults):
     @property
     def _default_text(self):
         s = "\n<b>The following subtools are available:</>\n\n"
-        tools_directory = get_tools_directory()
         for tool_name in sorted(self._visible_tool_names):
-            internal_name = tool_name.replace("-", "_")
-            tool_doc = load_module(internal_name, tools_directory).Tool.__doc__
+            tool_doc = get_tools()[tool_name].__doc__
             tool_doc = tool_doc.strip() if tool_doc else ""
             tool_doc = textwrap.fill(" ".join(tool_doc.split()), 80)
             s += "<g>{}</>\n{}\n\n".format(tool_name, tool_doc)
@@ -50,7 +48,5 @@ def go(self) -> ReturnCode:
             self.context.o.auto(self._default_text)
             return ReturnCode.OK
 
-        tool_name = self.context.options.tool.replace("-", "_")
-        tools_directory = get_tools_directory()
-        module = load_module(tool_name, tools_directory)
-        return tool_main(self.context, module.Tool(self.context), ["--help"])
+        T = get_tools()[tool_name]
+        return tool_main(self.context, T(self.context), ["--help"])