Keysyms: improve generator (#364)

Motivation: normalization of keysyms header files in `xorgproto`. See:
https://gitlab.freedesktop.org/xorg/proto/xorgproto/-/merge_requests/80

Improve `scripts/makeheader`:
- Simplify `evdev` and `XK_` substitution and improve alignment. Also, perform
  some additional `XK_` substitutions in comments.
- Format with `black`.

scripts/makeheader

@@ -3,20 +3,63 @@ from __future__ import print_function
 import re
 import os
 
-# expected format:
+# Expected format:
-# #define XF86XK_FooBar _EVDEVK(0x123) /* some optional comment */
+#     #define XF86XK_FooBar 0x1234         /* some optional comment */
-evdev_pattern = re.compile(r'^#define\s+XF86XK_(?P<name>\w+)\s+_EVDEVK\((?P<value>0x[0-9A-Fa-f]+)\)')
+# or:
+#     #define XF86XK_FooBar _EVDEVK(0x123) /* some optional comment */
+# We also need to match commented evdev entries:
+#     /* Use: XF86XK_FooBar _EVDEVK(0x123)    some optional comment */
+keysym_entry_pattern = re.compile(
+    r"""^
+    (?P<define>\#define|/\*\s+Use:)\s+
+    (?P<prefix>\w*)XK_(?P<name>\w+)(?P<spacing>\s+)
+    (?P<evdev>_EVDEVK\()?(?P<value>0x[0-9A-Fa-f]+)(?(evdev)\))
+    """,
+    re.VERBOSE,
+)
 
-prefix = os.environ.get('X11_HEADERS_PREFIX', '/usr')
+# Match remaining XK_ references in the comments, e.g we will replace:
+#       XF86XK_CamelCaseKernelName	_EVDEVK(kernel value)
+#       #define XKB_KEY_SunCompose		0x0000FF20	/* Same as XK_Multi_key */
+# with:
+#       XKB_KEY_XF86CamelCaseKernelName	_EVDEVK(kernel value)
+#       #define XKB_KEY_SunCompose		0x0000FF20	/* Same as XKB_KEY_Multi_key */
+xorgproto_keysym_prefix_pattern = re.compile(r"\b(?P<prefix>\w*)XK_(?!KOREAN\b)")
+
+
+def make_keysym_entry(m: re.Match[str]) -> str:
+    """
+    Perform the substitutions
+    """
+    if m.group("evdev"):
+        if m.group("define").startswith("#"):
+            # Replace the xorgproto _EVDEVK macro with the actual value:
+            # 0x10081000 is the base, the evdev hex code is added to that.
+            # We replace to make parsing of the keys later easier.
+            value = 0x10081000 + int(m.group("value"), 16)
+            value_str = f"{value:#x}    "
+        else:
+            value_str = f"""_EVDEVK({m.group('value')})"""
+    else:
+        value_str = m.group("value")
+    define = m.group("define")
+    prefix = m.group("prefix") or ""
+    name = m.group("name")
+    spacing = m.group("spacing")
+    return f"""{define} XKB_KEY_{prefix}{name}{spacing}{value_str}"""
+
+
+prefix = os.environ.get("X11_HEADERS_PREFIX", "/usr")
 HEADERS = [
-    prefix + '/include/X11/keysymdef.h',
+    prefix + "/include/X11/keysymdef.h",
-    prefix + '/include/X11/XF86keysym.h',
+    prefix + "/include/X11/XF86keysym.h",
-    prefix + '/include/X11/Sunkeysym.h',
+    prefix + "/include/X11/Sunkeysym.h",
-    prefix + '/include/X11/DECkeysym.h',
+    prefix + "/include/X11/DECkeysym.h",
-    prefix + '/include/X11/HPkeysym.h',
+    prefix + "/include/X11/HPkeysym.h",
 ]
 
-print('''#ifndef _XKBCOMMON_KEYSYMS_H
+print(
+    """#ifndef _XKBCOMMON_KEYSYMS_H
 #define _XKBCOMMON_KEYSYMS_H
 
 /* This file is autogenerated; please do not commit directly. */
@@ -27,31 +70,26 @@ print('''#ifndef _XKBCOMMON_KEYSYMS_H
  */
 
 #define XKB_KEY_NoSymbol                    0x000000  /* Special KeySym */
-''')
+"""
+)
 for path in HEADERS:
     with open(path) as header:
         for line in header:
-            if '#ifdef' in line or '#ifndef' in line or '#endif' in line:
+            if "#ifdef" in line or "#ifndef" in line or "#endif" in line:
                 continue
 
             # Remove #define _OSF_Keysyms and such.
-            if '#define _' in line:
+            if "#define _" in line:
                 continue
 
             # Handle a duplicate definition in HPkeysyms.h which kicks in if
             # it's not already defined.
-            if 'XK_Ydiaeresis' in line and '0x100000ee' in line:
+            if "XK_Ydiaeresis" in line and "0x100000ee" in line:
                 continue
 
-            # Replace the xorgproto _EVDEVK macro with the actual value
+            # Perform _EVDEV and XK_ substitutions
-            # 0x10081000 is the base, the evdev hex code is added to that.
+            line = keysym_entry_pattern.sub(make_keysym_entry, line)
-            # We replace to make parsing of the keys later easier.
+            line = xorgproto_keysym_prefix_pattern.sub(r"XKB_KEY_\1", line)
-            match = re.match(evdev_pattern, line)
-            if match:
-                value = 0x10081000 + int(match.group('value'), 16)
-                line = re.sub(r'_EVDEVK\(0x([0-9A-Fa-f]+)\)', '{:#x}'.format(value), line)
 
-            line = re.sub(r'#define\s*(\w*)XK_', r'#define XKB_KEY_\1', line)
+            print(line, end="")
-
+print("\n\n#endif")
-            print(line, end='')
-print('\n\n#endif')