gdb/make-target-delegates.py

   1 #!/usr/bin/env python3
   2
   3 # Copyright (C) 2013-2024 Free Software Foundation, Inc.
   4 #
   5 # This file is part of GDB.
   6 #
   7 # This program is free software; you can redistribute it and/or modify
   8 # it under the terms of the GNU General Public License as published by
   9 # the Free Software Foundation; either version 3 of the License, or
  10 # (at your option) any later version.
  11 #
  12 # This program is distributed in the hope that it will be useful,
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 # GNU General Public License for more details.
  16 #
  17 # You should have received a copy of the GNU General Public License
  18 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19
  20 # Usage:
  21 #    make-target-delegates.py
  22
  23 import re
  24 from typing import Dict, List, TextIO
  25
  26 import gdbcopyright
  27
  28 # The line we search for in target.h that marks where we should start
  29 # looking for methods.
  30 TRIGGER = re.compile(r"^struct target_ops$")
  31 # The end of the methods part.
  32 ENDER = re.compile(r"^\s*};$")
  33
  34 # Match a C symbol.
  35 SYMBOL = "[a-zA-Z_][a-zA-Z0-9_]*"
  36 # Match the name part of a method in struct target_ops.
  37 NAME_PART = r"(?P<name>" + SYMBOL + r")\s"
  38 # Match the arguments to a method.
  39 ARGS_PART = r"(?P<args>\(.*\))"
  40 # We strip the indentation so here we only need the caret.
  41 INTRO_PART = r"^"
  42
  43 POINTER_PART = r"\s*(\*|\&)?\s*"
  44
  45 # Match a C++ symbol, including scope operators and template
  46 # parameters.  E.g., 'std::vector<something>'.
  47 CP_SYMBOL = r"[a-zA-Z_][a-zA-Z0-9_<>:]*"
  48 # Match the return type when it is "ordinary".
  49 SIMPLE_RETURN_PART = r"((struct|class|enum|union)\s+)?" + CP_SYMBOL
  50
  51 # Match a return type.
  52 RETURN_PART = r"((const|volatile)\s+)?(" + SIMPLE_RETURN_PART + ")" + POINTER_PART
  53
  54 # Match "virtual".
  55 VIRTUAL_PART = r"virtual\s"
  56
  57 # Match the TARGET_DEFAULT_* attribute for a method.
  58 TARGET_DEFAULT_PART = r"TARGET_DEFAULT_(?P<style>[A-Z_]+)\s*\((?P<default_arg>.*)\)"
  59
  60 # Match the arguments and trailing attribute of a method definition.
  61 # Note we don't match the trailing ";".
  62 METHOD_TRAILER = r"\s*" + TARGET_DEFAULT_PART + "$"
  63
  64 # Match an entire method definition.
  65 METHOD = re.compile(
  66     INTRO_PART
  67     + VIRTUAL_PART
  68     + "(?P<return_type>"
  69     + RETURN_PART
  70     + ")"
  71     + NAME_PART
  72     + ARGS_PART
  73     + METHOD_TRAILER
  74 )
  75
  76 # Space-separated symbols.
  77 CP_SYMBOLS = CP_SYMBOL + r"(\s+" + CP_SYMBOL + r")*"
  78
  79 # Regular expression used to dissect argument types.
  80 ARGTYPES = re.compile(
  81     "^("
  82     + r"(?P<E>enum\s+"
  83     + SYMBOL
  84     + r")"
  85     + r"|(?P<T>"
  86     + CP_SYMBOLS
  87     + r"(\s|\*|&)+)"
  88     + SYMBOL
  89     + ")$"
  90 )
  91
  92 # Match TARGET_DEBUG_PRINTER in an argument type.
  93 # This must match the whole "sub-expression" including the parens.
  94 TARGET_DEBUG_PRINTER = r"\s*TARGET_DEBUG_PRINTER\s*\((?P<arg>[^)]*)\)\s*"
  95
  96
  97 class Entry:
  98     def __init__(
  99         self, argtypes: List[str], return_type: str, style: str, default_arg: str
 100     ):
 101         self.argtypes = argtypes
 102         self.return_type = return_type
 103         self.style = style
 104         self.default_arg = default_arg
 105
 106
 107 def scan_target_h():
 108     found_trigger = False
 109     all_the_text = ""
 110     with open("target.h", "r") as target_h:
 111         for line in target_h:
 112             line = line.strip()
 113             if not found_trigger:
 114                 if TRIGGER.match(line):
 115                     found_trigger = True
 116             elif "{" in line:
 117                 # Skip the open brace.
 118                 pass
 119             elif ENDER.match(line):
 120                 break
 121             else:
 122                 # Strip // comments.
 123                 line = re.split("//", line)[0]
 124                 all_the_text = all_the_text + " " + line
 125     if not found_trigger:
 126         raise RuntimeError("Could not find trigger line")
 127     # Now strip out the C comments.
 128     all_the_text = re.sub(r"/\*(.*?)\*/", "", all_the_text)
 129     # Replace sequences whitespace with a single space character.
 130     # We need the space because the method may have been split
 131     # between multiple lines, like e.g.:
 132     #
 133     #  virtual std::vector<long_type_name>
 134     #    my_long_method_name ()
 135     #    TARGET_DEFAULT_IGNORE ();
 136     #
 137     # If we didn't preserve the space, then we'd end up with:
 138     #
 139     #  virtual std::vector<long_type_name>my_long_method_name ()TARGET_DEFAULT_IGNORE ()
 140     #
 141     # ... which wouldn't later be parsed correctly.
 142     all_the_text = re.sub(r"\s+", " ", all_the_text)
 143     return all_the_text.split(";")
 144
 145
 146 # Parse arguments into a list.
 147 def parse_argtypes(typestr: str):
 148     # Remove the outer parens.
 149     typestr = re.sub(r"^\((.*)\)$", r"\1", typestr)
 150     result: list[str] = []
 151     for item in re.split(r",\s*", typestr):
 152         if item == "":
 153             continue
 154
 155         m = ARGTYPES.match(item)
 156         if m:
 157             if m.group("E"):
 158                 onetype = m.group("E")
 159             else:
 160                 onetype = m.group("T")
 161         else:
 162             onetype = item
 163         result.append(onetype.strip())
 164     return result
 165
 166
 167 # Write function header given name, return type, and argtypes.
 168 # Returns a list of actual argument names.
 169 def write_function_header(
 170     f: TextIO, decl: bool, name: str, return_type: str, argtypes: List[str]
 171 ):
 172     print(return_type, file=f, end="")
 173     if decl:
 174         if not return_type.endswith("*"):
 175             print(" ", file=f, end="")
 176     else:
 177         print("", file=f)
 178     print(name + " (", file=f, end="")
 179     argdecls: list[str] = []
 180     actuals: list[str] = []
 181     for i in range(len(argtypes)):
 182         val = re.sub(TARGET_DEBUG_PRINTER, "", argtypes[i])
 183         if not val.endswith("*") and not val.endswith("&"):
 184             val = val + " "
 185         vname = "arg" + str(i)
 186         val = val + vname
 187         argdecls.append(val)
 188         actuals.append(vname)
 189     print(", ".join(argdecls) + ")", file=f, end="")
 190     if decl:
 191         print(" override;", file=f)
 192     else:
 193         print("\n{", file=f)
 194     return actuals
 195
 196
 197 # Write out a declaration.
 198 def write_declaration(f: TextIO, name: str, return_type: str, argtypes: List[str]):
 199     write_function_header(f, True, name, return_type, argtypes)
 200
 201
 202 # Write out a delegation function.
 203 def write_delegator(f: TextIO, name: str, return_type: str, argtypes: List[str]):
 204     print("", file=f)
 205     names = write_function_header(
 206         f, False, "target_ops::" + name, return_type, argtypes
 207     )
 208     print("  ", file=f, end="")
 209     if return_type != "void":
 210         print("return ", file=f, end="")
 211     print("this->beneath ()->" + name + " (", file=f, end="")
 212     print(", ".join(names), file=f, end="")
 213     print(");", file=f)
 214     print("}", file=f)
 215
 216
 217 # Write out a default function.
 218 def write_tdefault(
 219     f: TextIO,
 220     content: str,
 221     style: str,
 222     name: str,
 223     return_type: str,
 224     argtypes: List[str],
 225 ):
 226     print("", file=f)
 227     name = "dummy_target::" + name
 228     names = write_function_header(f, False, name, return_type, argtypes)
 229     if style == "FUNC":
 230         print("  ", file=f, end="")
 231         if return_type != "void":
 232             print("return ", file=f, end="")
 233         print(content + " (", file=f, end="")
 234         names.insert(0, "this")
 235         print(", ".join(names) + ");", file=f)
 236     elif style == "RETURN":
 237         print("  return " + content + ";", file=f)
 238     elif style == "NORETURN":
 239         print("  " + content + ";", file=f)
 240     elif style == "IGNORE":
 241         # Nothing.
 242         pass
 243     else:
 244         raise RuntimeError("unrecognized style: " + style)
 245     print("}", file=f)
 246
 247
 248 def munge_type(typename: str):
 249     m = re.search(TARGET_DEBUG_PRINTER, typename)
 250     if m:
 251         return m.group("arg")
 252     typename = typename.rstrip()
 253     # There's no reason to have these keywords in the name, and their
 254     # presence makes it harder to change styles.
 255     typename = re.sub("\\b(struct|enum|class|union) ", "", typename)
 256     typename = re.sub("[ ()<>:]", "_", typename)
 257     typename = re.sub("[*]", "p", typename)
 258     typename = re.sub("&", "r", typename)
 259     # Identifiers with double underscores are reserved to the C++
 260     # implementation.
 261     typename = re.sub("_+", "_", typename)
 262     # Avoid ending the function name with underscore, for
 263     # cosmetics.  Trailing underscores appear after munging types
 264     # with template parameters, like e.g. "foo<int>".
 265     typename = re.sub("_+$", "", typename)
 266     return "target_debug_print_" + typename
 267
 268
 269 # Write out a debug method.
 270 def write_debugmethod(
 271     f: TextIO, content: str, name: str, return_type: str, argtypes: List[str]
 272 ):
 273     print("", file=f)
 274     debugname = "debug_target::" + name
 275     names = write_function_header(f, False, debugname, return_type, argtypes)
 276     print(
 277         f'  target_debug_printf_nofunc ("-> %s->{name} (...)", this->beneath ()->shortname ());',
 278         file=f,
 279     )
 280
 281     # Delegate to the beneath target.
 282     if return_type != "void":
 283         print("  " + return_type + " result", file=f)
 284         print("    = ", file=f, end="")
 285     else:
 286         print("  ", file=f, end="")
 287     print("this->beneath ()->" + name + " (", file=f, end="")
 288     print(", ".join(names), file=f, end="")
 289     print(");", file=f)
 290
 291     # Generate the debug printf call.
 292     args_fmt = ", ".join(["%s"] * len(argtypes))
 293     args = "".join(
 294         [
 295             (",\n\t      {printer} (arg{i}).c_str ()").format(
 296                 printer=munge_type(t), i=i
 297             )
 298             for i, t in enumerate(argtypes)
 299         ]
 300     )
 301
 302     if return_type != "void":
 303         ret_fmt = " = %s"
 304         ret = ",\n\t      {printer} (result).c_str ()".format(
 305             printer=munge_type(return_type)
 306         )
 307     else:
 308         ret_fmt = ""
 309         ret = ""
 310
 311     print(
 312         f'  target_debug_printf_nofunc ("<- %s->{name} ({args_fmt}){ret_fmt}",\n'
 313         f"\t      this->beneath ()->shortname (){args}{ret});",
 314         file=f,
 315     )
 316
 317     if return_type != "void":
 318         print("  return result;", file=f)
 319
 320     print("}", file=f)
 321
 322
 323 def print_class(
 324     f: TextIO,
 325     class_name: str,
 326     delegators: List[str],
 327     entries: Dict[str, Entry],
 328 ):
 329     print("", file=f)
 330     print("struct " + class_name + " : public target_ops", file=f)
 331     print("{", file=f)
 332     print("  const target_info &info () const override;", file=f)
 333     print("", file=f)
 334     print("  strata stratum () const override;", file=f)
 335     print("", file=f)
 336
 337     for name in delegators:
 338         print("  ", file=f, end="")
 339         entry = entries[name]
 340         write_declaration(f, name, entry.return_type, entry.argtypes)
 341
 342     print("};", file=f)
 343
 344
 345 delegators: List[str] = []
 346 entries: Dict[str, Entry] = {}
 347
 348 for current_line in scan_target_h():
 349     # See comments in scan_target_h.  Here we strip away the leading
 350     # and trailing whitespace.
 351     current_line = current_line.strip()
 352     m = METHOD.match(current_line)
 353     if not m:
 354         continue
 355     data = m.groupdict()
 356     name = data["name"]
 357     argtypes = parse_argtypes(data["args"])
 358     return_type = data["return_type"].strip()
 359     style = data["style"]
 360     default_arg = data["default_arg"]
 361     entries[name] = Entry(argtypes, return_type, style, default_arg)
 362
 363     delegators.append(name)
 364
 365 with open("target-delegates-gen.c", "w") as f:
 366     print(
 367         gdbcopyright.copyright(
 368             "make-target-delegates.py", "Boilerplate target methods for GDB"
 369         ),
 370         file=f,
 371     )
 372     print_class(f, "dummy_target", delegators, entries)
 373     print_class(f, "debug_target", delegators, entries)
 374
 375     for name in delegators:
 376         entry = entries[name]
 377
 378         write_delegator(f, name, entry.return_type, entry.argtypes)
 379         write_tdefault(
 380             f,
 381             entry.default_arg,
 382             entry.style,
 383             name,
 384             entry.return_type,
 385             entry.argtypes,
 386         )
 387         write_debugmethod(
 388             f,
 389             entry.default_arg,
 390             name,
 391             entry.return_type,
 392             entry.argtypes,
 393         )