cli: extract out default_globals()

Drgn has a set of globals provided in interactive mode, but they can be
useful to other modes (e.g. for executing statements directly). They may
also be useful to client code. Make this a separate, public helper. It
does make the globals_func argument to run_interactive() a bit much, but
that's ok.

Signed-off-by: Stephen Brennan <[email protected]>

Author: brenns10

drgn/cli.py

@@ -21,10 +21,27 @@
 from drgn.internal.rlcompleter import Completer
 from drgn.internal.sudohelper import open_via_sudo
 
-__all__ = ("run_interactive", "version_header")
+__all__ = ("default_globals", "run_interactive", "version_header")
 
 logger = logging.getLogger("drgn")
 
+# The list of attributes from the drgn module which are imported and inserted
+# into the global namespace for interactive debugging.
+_DRGN_GLOBALS = [
+    "FaultError",
+    "NULL",
+    "Object",
+    "alignof",
+    "cast",
+    "container_of",
+    "execscript",
+    "implicit_convert",
+    "offsetof",
+    "reinterpret",
+    "sizeof",
+    "stack_trace",
+]
+
 
 class _LogFormatter(logging.Formatter):
     _LEVELS = (
@@ -89,6 +106,33 @@ def version_header() -> str:
     return f"drgn {drgn.__version__} (using Python {python_version}, elfutils {drgn._elfutils_version}, {libkdumpfile})"
 
 
+def default_globals(prog: drgn.Program) -> Dict[str, Any]:
+    """
+    Return the default globals for an interactive drgn session
+
+    :param prog: the program which will be debugged
+    :return: a dict of globals
+    """
+    # Don't forget to update the default banner in run_interactive()
+    # with any new additions.
+    init_globals: Dict[str, Any] = {
+        "prog": prog,
+        "drgn": drgn,
+        "__name__": "__main__",
+        "__doc__": None,
+    }
+    for attr in _DRGN_GLOBALS:
+        init_globals[attr] = getattr(drgn, attr)
+    module = importlib.import_module("drgn.helpers.common")
+    for name in module.__dict__["__all__"]:
+        init_globals[name] = getattr(module, name)
+    if prog.flags & drgn.ProgramFlags.IS_LINUX_KERNEL:
+        module = importlib.import_module("drgn.helpers.linux")
+        for name in module.__dict__["__all__"]:
+            init_globals[name] = getattr(module, name)
+    return init_globals
+
+
 def _identify_script(path: str) -> str:
     EI_NIDENT = 16
     SIZEOF_E_TYPE = 2
@@ -566,44 +610,14 @@ def run_interactive(
         function, applications should restore their history and settings before
         using ``readline``.
     """
-    init_globals: Dict[str, Any] = {
-        "prog": prog,
-        "drgn": drgn,
-        "__name__": "__main__",
-        "__doc__": None,
-    }
-    drgn_globals = [
-        "FaultError",
-        "NULL",
-        "Object",
-        "alignof",
-        "cast",
-        "container_of",
-        "execscript",
-        "implicit_convert",
-        "offsetof",
-        "reinterpret",
-        "sizeof",
-        "stack_trace",
-    ]
-    for attr in drgn_globals:
-        init_globals[attr] = getattr(drgn, attr)
-
+    init_globals = default_globals(prog)
     banner = f"""\
 For help, type help(drgn).
 >>> import drgn
->>> from drgn import {", ".join(drgn_globals)}
+>>> from drgn import {", ".join(_DRGN_GLOBALS)}
 >>> from drgn.helpers.common import *"""
-
-    module = importlib.import_module("drgn.helpers.common")
-    for name in module.__dict__["__all__"]:
-        init_globals[name] = getattr(module, name)
     if prog.flags & drgn.ProgramFlags.IS_LINUX_KERNEL:
         banner += "\n>>> from drgn.helpers.linux import *"
-        module = importlib.import_module("drgn.helpers.linux")
-        for name in module.__dict__["__all__"]:
-            init_globals[name] = getattr(module, name)
-
     if banner_func:
         banner = banner_func(banner)
     if globals_func: