[PATCH 1/6] Add check-gdbarch.py

[Tom Tromey <tom@tromey.com>]

This adds a new check-gdbarch.py script.  This script checks the
sources to see which gdbarch methods are set but never called, and
which ones are called but never set.
---
 gdb/check-gdbarch.py | 90 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)

diff --git a/gdb/check-gdbarch.py b/gdb/check-gdbarch.py
new file mode 100755
index 0000000000000000000000000000000000000000..1f7479e7d1bdfc177e62ae9f58d971b8b8e34ce9
--- /dev/null
+++ b/gdb/check-gdbarch.py
@@ -0,0 +1,90 @@
+#!/usr/bin/env python3
+
+# gdbarch checker.
+#
+# Copyright (C) 2024 Free Software Foundation, Inc.
+#
+# This file is part of GDB.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import fileinput
+import glob
+import re
+import sys
+
+# gdbarch_components is imported only for its side-effect of filling
+# `gdbarch_types.components`.
+import gdbarch_components  # noqa: F401 # type: ignore
+from gdbarch_types import Component, Function, Info, Value, components
+
+
+def not_info(c: Component):
+    "Filter function to omit Info components."
+    return type(c) is not Info
+
+
+if len(sys.argv) != 1:
+    # Must be run in gdb srcdir.
+    print("usage: check-gdbarch.py")
+    sys.exit(1)
+
+
+# Make a hash holding all the gdbarch customization names.
+defined_names = set()
+set_names = set()
+called_names = set()
+for c in filter(not_info, components):
+    if c.implement:
+        defined_names.add(c.name)
+    if c.predicate:
+        # Predicates are always "set".
+        pname = c.name + "_p"
+        set_names.add(pname)
+        defined_names.add(pname)
+
+
+def find_local_files():
+    result = []
+    for name in glob.glob("*.[chyl]"):
+        if "gdbarch" not in name:
+            result.append(name)
+    return result
+
+
+files = find_local_files()
+files.extend(glob.glob("*/*.[ch]"))
+
+# FIXME could keep counts here and then look for deletion
+# opportunities.
+rx = re.compile(r"\b(set_)?gdbarch_([a-zA-Z0-9_]+)\b")
+for line in fileinput.input(files=files):
+    m = rx.search(line)
+    if m:
+        if m[0] == "gdbarch_p":
+            # There are a few variables with this name, exclude them.
+            pass
+        elif m[1]:
+            set_names.add(m[2])
+        else:
+            called_names.add(m[2])
+
+
+for elt in defined_names - set_names:
+    print(f"never set: {elt}")
+for elt in defined_names - called_names:
+    # Don't report _p functions here, predicate=True is sometimes used
+    # to allow optional functions.
+    if not elt.endswith("_p"):
+        print(f"never called: {elt}")

-- 
2.46.1