[binutils-gdb] Rewrite make-target-delegates in Python

[Tom Tromey <tromey@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=fb079cb5c419e03d400a0a139c3ccc4eedc33bef

commit fb079cb5c419e03d400a0a139c3ccc4eedc33bef
Author: Tom Tromey <tromey@adacore.com>
Date:   Mon Feb 14 10:19:06 2022 -0700

    Rewrite make-target-delegates in Python
    
    I think gdb is probably better off having fewer languages involved
    when generating code.  'sh' is unavoidable for build-time generation,
    but for other things, let's use Python.
    
    This rewrites make-target-delegates in Python.  I've stuck pretty
    closely to the original code in this rewrite, so it may look slightly
    weird from a Python perspective.
    
    The only output difference is that a copyright header is now
    generated, using the code introduced in the previous patch.
    
    make-target-delegates.py is simpler to invoke, as it knows the correct
    input file to scan and it creates the output file itself.

Diff:
---
 gdb/make-target-delegates    | 421 -------------------------------------------
 gdb/make-target-delegates.py | 340 ++++++++++++++++++++++++++++++++++
 gdb/target-delegates.c       |  26 ++-
 3 files changed, 363 insertions(+), 424 deletions(-)

diff --git a/gdb/make-target-delegates b/gdb/make-target-delegates
deleted file mode 100755
index f759b5507ca..00000000000
--- a/gdb/make-target-delegates
+++ /dev/null
@@ -1,421 +0,0 @@
-#!/usr/bin/perl
-
-# Copyright (C) 2013-2022 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/>.
-
-
-# Usage:
-#    make-target-delegates target.h > target-delegates.c
-
-# The line we search for in target.h that marks where we should start
-# looking for methods.
-$TRIGGER = qr,^struct target_ops$,;
-# The end of the methods part.
-$ENDER = qr,^\s*};$,;
-
-# Match a C symbol.
-$SYMBOL = qr,[a-zA-Z_][a-zA-Z0-9_]*,;
-# Match the name part of a method in struct target_ops.
-$NAME_PART = qr,(?<name>${SYMBOL}+)\s,;
-# Match the arguments to a method.
-$ARGS_PART = qr,(?<args>\(.*\)),;
-# We strip the indentation so here we only need the caret.
-$INTRO_PART = qr,^,;
-
-$POINTER_PART = qr,\s*(\*)?\s*,;
-
-# Match a C++ symbol, including scope operators and template
-# parameters.  E.g., 'std::vector<something>'.
-$CP_SYMBOL = qr,[a-zA-Z_][a-zA-Z0-9_<>:]*,;
-# Match the return type when it is "ordinary".
-$SIMPLE_RETURN_PART = qr,((struct|class|enum|union)\s+)?${CP_SYMBOL}+,;
-
-# Match a return type.
-$RETURN_PART = qr,((const|volatile)\s+)?(${SIMPLE_RETURN_PART})${POINTER_PART},;
-
-# Match "virtual".
-$VIRTUAL_PART = qr,virtual\s,;
-
-# Match the TARGET_DEFAULT_* attribute for a method.
-$TARGET_DEFAULT_PART = qr,TARGET_DEFAULT_(?<style>[A-Z_]+)\s*\((?<default_arg>.*)\),;
-
-# Match the arguments and trailing attribute of a method definition.
-# Note we don't match the trailing ";".
-$METHOD_TRAILER = qr,\s*${TARGET_DEFAULT_PART}$,;
-
-# Match an entire method definition.
-$METHOD = ($INTRO_PART . $VIRTUAL_PART . "(?<return_type>" . $RETURN_PART . ")"
-	   . $NAME_PART . $ARGS_PART
-	   . $METHOD_TRAILER);
-
-# Match TARGET_DEBUG_PRINTER in an argument type.
-# This must match the whole "sub-expression" including the parens.
-# Reference $1 must refer to the function argument.
-$TARGET_DEBUG_PRINTER = qr,\s*TARGET_DEBUG_PRINTER\s*\(([^)]*)\)\s*,;
-
-sub trim($) {
-    my ($result) = @_;
-
-    $result =~ s,^\s+,,;
-    $result =~ s,\s+$,,;
-
-    return $result;
-}
-
-# Read from the input files until we find the trigger line.
-# Die if not found.
-sub find_trigger() {
-    while (<>) {
-	chomp;
-	return if m/$TRIGGER/;
-    }
-
-    die "could not find trigger line\n";
-}
-
-# Scan target.h and return a list of possible target_ops method entries.
-sub scan_target_h() {
-    my $all_the_text = '';
-
-    find_trigger();
-    while (<>) {
-	chomp;
-	# Skip the open brace.
-	next if /{/;
-	last if m/$ENDER/;
-
-	# Strip // comments.
-	$_ =~ s,//.*$,,;
-
-	$all_the_text .= $_;
-    }
-
-    # Now strip out the C comments.
-    $all_the_text =~ s,/\*(.*?)\*/,,g;
-
-    # Replace sequences of tabs and/or whitespace with a single
-    # whitespace character.  We need the whitespace because the method
-    # may have been split between multiple lines, like e.g.:
-    #
-    #  virtual std::vector<long_type_name>
-    #    my_long_method_name ()
-    #    TARGET_DEFAULT_IGNORE ();
-    #
-    # If we didn't preserve the whitespace, then we'd end up with:
-    #
-    #  virtual std::vector<long_type_name>my_long_method_name ()TARGET_DEFAULT_IGNORE ()
-    #
-    # ... which wouldn't later be parsed correctly.
-    $all_the_text =~ s/[\t\s]+/ /g;
-
-    return split (/;/, $all_the_text);
-}
-
-# Parse arguments into a list.
-sub parse_argtypes($) {
-    my ($typestr) = @_;
-
-    $typestr =~ s/^\((.*)\)$/\1/;
-
-    my (@typelist) = split (/,\s*/, $typestr);
-    my (@result, $iter, $onetype);
-
-    foreach $iter (@typelist) {
-	if ($iter =~ m/^(enum\s+${SYMBOL}\s*)(${SYMBOL})?$/) {
-	    $onetype = $1;
-	} elsif ($iter =~ m/^(.*(enum\s+)?${SYMBOL}.*(\s|\*|&))${SYMBOL}+$/) {
-	    $onetype = $1;
-	} elsif ($iter eq 'void') {
-	    next;
-	} else {
-	    $onetype = $iter;
-	}
-	push @result, trim ($onetype);
-    }
-
-    return @result;
-}
-
-sub dname($) {
-    my ($name) = @_;
-    return "target_ops::" . $name;
-}
-
-# Write function header given name, return type, and argtypes.
-# Returns a list of actual argument names.
-sub write_function_header($$$@) {
-    my ($decl, $name, $return_type, @argtypes) = @_;
-
-    print $return_type;
-
-    if ($decl) {
-	if ($return_type !~ m,\*$,) {
-	    print " ";
-	}
-    } else {
-	print "\n";
-    }
-
-    print $name . ' (';
-
-    my $iter;
-    my @argdecls;
-    my @actuals;
-    my $i = 0;
-    foreach $iter (@argtypes) {
-	my $val = $iter;
-
-	$val =~ s/$TARGET_DEBUG_PRINTER//;
-
-	if ($iter !~ m,(\*|&)$,) {
-	    $val .= ' ';
-	}
-
-	my $vname;
-	$vname .= "arg$i";
-	$val .= $vname;
-
-	push @argdecls, $val;
-	push @actuals, $vname;
-	++$i;
-    }
-
-    print join (', ', @argdecls) . ")";
-
-    if ($decl) {
-	print " override;\n";
-    } else {
-	print "\n{\n";
-    }
-
-    return @actuals;
-}
-
-# Write out a declaration.
-sub write_declaration($$@) {
-    my ($name, $return_type, @argtypes) = @_;
-
-    write_function_header (1, $name, $return_type, @argtypes);
-}
-
-# Write out a delegation function.
-sub write_delegator($$@) {
-    my ($name, $return_type, @argtypes) = @_;
-
-    my (@names) = write_function_header (0, dname ($name),
-					 $return_type, @argtypes);
-
-    print "  ";
-    if ($return_type ne 'void') {
-	print "return ";
-    }
-    print "this->beneath ()->" . $name . " (";
-    print join (', ', @names);
-    print ");\n";
-    print "}\n\n";
-}
-
-sub tdname ($) {
-    my ($name) = @_;
-    return "dummy_target::" . $name;
-}
-
-# Write out a default function.
-sub write_tdefault($$$$@) {
-    my ($content, $style, $name, $return_type, @argtypes) = @_;
-
-    my (@names) = write_function_header (0, tdname ($name),
-					 $return_type, @argtypes);
-
-    if ($style eq 'FUNC') {
-	print "  ";
-	if ($return_type ne 'void') {
-	    print "return ";
-	}
-	print $content . " (this";
-	if (@names) {
-	    print ", ";
-	}
-	print join (', ', @names);
-	print ");\n";
-    } elsif ($style eq 'RETURN') {
-	print "  return $content;\n";
-    } elsif ($style eq 'NORETURN') {
-	print "  $content;\n";
-    } elsif ($style eq 'IGNORE') {
-	# Nothing.
-    } else {
-	die "unrecognized style: $style\n";
-    }
-
-    print "}\n\n";
-
-    return tdname ($name);
-}
-
-sub munge_type($) {
-    my ($typename) = @_;
-    my ($result);
-
-    if ($typename =~ m/$TARGET_DEBUG_PRINTER/) {
-	$result = $1;
-    } else {
-	($result = $typename) =~ s/\s+$//;
-	$result =~ s/[ ()<>:]/_/g;
-	$result =~ s/[*]/p/g;
-	$result =~ s/&/r/g;
-
-	# Identifers with double underscores are reserved to the C++
-	# implementation.
-	$result =~ s/_+/_/g;
-
-	# Avoid ending the function name with underscore, for
-	# cosmetics.  Trailing underscores appear after munging types
-	# with template parameters, like e.g. "foo<int>".
-	$result =~ s/_$//g;
-
-	$result = 'target_debug_print_' . $result;
-    }
-
-    return $result;
-}
-
-# Write out a debug method.
-sub write_debugmethod($$$@) {
-    my ($content, $name, $return_type, @argtypes) = @_;
-
-    my ($debugname) = "debug_target::" . $name;
-    my ($targetname) = $name;
-
-    my (@names) = write_function_header (0, $debugname, $return_type, @argtypes);
-
-    if ($return_type ne 'void') {
-	print "  $return_type result;\n";
-    }
-
-    print "  fprintf_unfiltered (gdb_stdlog, \"-> %s->$name (...)\\n\", this->beneath ()->shortname ());\n";
-
-    # Delegate to the beneath target.
-    print "  ";
-    if ($return_type ne 'void') {
-	print "result = ";
-    }
-    print "this->beneath ()->" . $name . " (";
-    print join (', ', @names);
-    print ");\n";
-
-    # Now print the arguments.
-    print "  fprintf_unfiltered (gdb_stdlog, \"<- %s->$name (\", this->beneath ()->shortname ());\n";
-    for my $i (0 .. $#argtypes) {
-	if ($i > 0) {
-	    print "  fputs_unfiltered (\", \", gdb_stdlog);\n"
-	}
-	my $printer = munge_type ($argtypes[$i]);
-	print "  $printer ($names[$i]);\n";
-    }
-    if ($return_type ne 'void') {
-	print "  fputs_unfiltered (\") = \", gdb_stdlog);\n";
-	my $printer = munge_type ($return_type);
-	print "  $printer (result);\n";
-	print "  fputs_unfiltered (\"\\n\", gdb_stdlog);\n";
-    } else {
-	print "  fputs_unfiltered (\")\\n\", gdb_stdlog);\n";
-    }
-
-    if ($return_type ne 'void') {
-	print "  return result;\n";
-    }
-
-    print "}\n\n";
-
-    return $debugname;
-}
-
-print "/* THIS FILE IS GENERATED -*- buffer-read-only: t -*- */\n";
-print "/* vi:set ro: */\n\n";
-print "/* To regenerate this file, run:*/\n";
-print "/*      make-target-delegates target.h > target-delegates.c */\n";
-print "\n";
-
-@lines = scan_target_h();
-
-@delegators = ();
-@return_types = ();
-@tdefaults = ();
-@styles = ();
-@argtypes_array = ();
-
-foreach $current_line (@lines) {
-    # See comments in scan_target_h.  Here we strip away the leading
-    # and trailing whitespace.
-    $current_line = trim ($current_line);
-
-    next unless $current_line =~ m/$METHOD/;
-
-    my $name = $+{name};
-    my $current_line = $+{args};
-    my $return_type = trim ($+{return_type});
-    my $current_args = $+{args};
-    my $tdefault = $+{default_arg};
-    my $style = $+{style};
-
-    my @argtypes = parse_argtypes ($current_args);
-
-    push @delegators, $name;
-
-    $return_types{$name} = $return_type;
-    $tdefaults{$name} = $tdefault;
-    $styles{$name} = $style;
-    $argtypes_array{$name} = \@argtypes;
-}
-
-sub print_class($) {
-    my ($name) = @_;
-
-    print "struct " . $name . " : public target_ops\n";
-    print "{\n";
-    print "  const target_info &info () const override;\n";
-    print "\n";
-    print "  strata stratum () const override;\n";
-    print "\n";
-
-    for $name (@delegators) {
-	my $return_type = $return_types{$name};
-	my @argtypes = @{$argtypes_array{$name}};
-
-	print "  ";
-	write_declaration ($name, $return_type, @argtypes);
-    }
-
-    print "};\n\n";
-}
-
-print_class ("dummy_target");
-print_class ("debug_target");
-
-for $name (@delegators) {
-    my $tdefault = $tdefaults{$name};
-    my $return_type = $return_types{$name};
-    my $style = $styles{$name};
-    my @argtypes = @{$argtypes_array{$name}};
-
-    write_delegator ($name, $return_type, @argtypes);
-
-    write_tdefault ($tdefault, $style, $name, $return_type, @argtypes);
-
-    write_debugmethod ($tdefault, $name, $return_type, @argtypes);
-}
diff --git a/gdb/make-target-delegates.py b/gdb/make-target-delegates.py
new file mode 100755
index 00000000000..97178072a37
--- /dev/null
+++ b/gdb/make-target-delegates.py
@@ -0,0 +1,340 @@
+#!/usr/bin/env python3
+
+# Copyright (C) 2013-2022 Free Software Foundation, Inc.
+#
+# This file is part of GDB.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Usage:
+#    make-target-delegates.py
+
+import re
+import gdbcopyright
+
+
+# The line we search for in target.h that marks where we should start
+# looking for methods.
+TRIGGER = re.compile(r"^struct target_ops$")
+# The end of the methods part.
+ENDER = re.compile(r"^\s*};$")
+
+# Match a C symbol.
+SYMBOL = "[a-zA-Z_][a-zA-Z0-9_]*"
+# Match the name part of a method in struct target_ops.
+NAME_PART = r"(?P<name>" + SYMBOL + ")\s"
+# Match the arguments to a method.
+ARGS_PART = r"(?P<args>\(.*\))"
+# We strip the indentation so here we only need the caret.
+INTRO_PART = r"^"
+
+POINTER_PART = r"\s*(\*)?\s*"
+
+# Match a C++ symbol, including scope operators and template
+# parameters.  E.g., 'std::vector<something>'.
+CP_SYMBOL = r"[a-zA-Z_][a-zA-Z0-9_<>:]*"
+# Match the return type when it is "ordinary".
+SIMPLE_RETURN_PART = r"((struct|class|enum|union)\s+)?" + CP_SYMBOL
+
+# Match a return type.
+RETURN_PART = r"((const|volatile)\s+)?(" + SIMPLE_RETURN_PART + ")" + POINTER_PART
+
+# Match "virtual".
+VIRTUAL_PART = r"virtual\s"
+
+# Match the TARGET_DEFAULT_* attribute for a method.
+TARGET_DEFAULT_PART = r"TARGET_DEFAULT_(?P<style>[A-Z_]+)\s*\((?P<default_arg>.*)\)"
+
+# Match the arguments and trailing attribute of a method definition.
+# Note we don't match the trailing ";".
+METHOD_TRAILER = r"\s*" + TARGET_DEFAULT_PART + "$"
+
+# Match an entire method definition.
+METHOD = re.compile(
+    INTRO_PART
+    + VIRTUAL_PART
+    + "(?P<return_type>"
+    + RETURN_PART
+    + ")"
+    + NAME_PART
+    + ARGS_PART
+    + METHOD_TRAILER
+)
+
+# Regular expression used to dissect argument types.
+ARGTYPES = re.compile(
+    "^("
+    + r"(?P<E>enum\s+"
+    + SYMBOL
+    + r"\s*)("
+    + SYMBOL
+    + ")?"
+    + r"|(?P<T>.*(enum\s+)?"
+    + SYMBOL
+    + r".*(\s|\*|&))"
+    + SYMBOL
+    + ")$"
+)
+
+# Match TARGET_DEBUG_PRINTER in an argument type.
+# This must match the whole "sub-expression" including the parens.
+TARGET_DEBUG_PRINTER = r"\s*TARGET_DEBUG_PRINTER\s*\((?P<arg>[^)]*)\)\s*"
+
+
+def scan_target_h():
+    found_trigger = False
+    all_the_text = ""
+    with open("target.h", "r") as target_h:
+        for line in target_h:
+            line = line.strip()
+            if not found_trigger:
+                if TRIGGER.match(line):
+                    found_trigger = True
+            elif "{" in line:
+                # Skip the open brace.
+                pass
+            elif ENDER.match(line):
+                break
+            else:
+                # Strip // comments.
+                line = re.split("//", line)[0]
+                all_the_text = all_the_text + " " + line
+    if not found_trigger:
+        raise "Could not find trigger line"
+    # Now strip out the C comments.
+    all_the_text = re.sub(r"/\*(.*?)\*/", "", all_the_text)
+    # Replace sequences whitespace with a single space character.
+    # We need the space because the method may have been split
+    # between multiple lines, like e.g.:
+    #
+    #  virtual std::vector<long_type_name>
+    #    my_long_method_name ()
+    #    TARGET_DEFAULT_IGNORE ();
+    #
+    # If we didn't preserve the space, then we'd end up with:
+    #
+    #  virtual std::vector<long_type_name>my_long_method_name ()TARGET_DEFAULT_IGNORE ()
+    #
+    # ... which wouldn't later be parsed correctly.
+    all_the_text = re.sub(r"\s+", " ", all_the_text)
+    return all_the_text.split(";")
+
+
+# Parse arguments into a list.
+def parse_argtypes(typestr):
+    # Remove the outer parens.
+    typestr = re.sub(r"^\((.*)\)$", r"\1", typestr)
+    result = []
+    for item in re.split(r",\s*", typestr):
+        if item == "void" or item == "":
+            continue
+        m = ARGTYPES.match(item)
+        if m:
+            if m.group("E"):
+                onetype = m.group("E")
+            else:
+                onetype = m.group("T")
+        else:
+            onetype = item
+        result.append(onetype.strip())
+    return result
+
+
+# Write function header given name, return type, and argtypes.
+# Returns a list of actual argument names.
+def write_function_header(f, decl, name, return_type, argtypes):
+    print(return_type, file=f, end="")
+    if decl:
+        if not return_type.endswith("*"):
+            print(" ", file=f, end="")
+    else:
+        print("", file=f)
+    print(name + " (", file=f, end="")
+    argdecls = []
+    actuals = []
+    for i in range(len(argtypes)):
+        val = re.sub(TARGET_DEBUG_PRINTER, "", argtypes[i])
+        if not val.endswith("*") and not val.endswith("&"):
+            val = val + " "
+        vname = "arg" + str(i)
+        val = val + vname
+        argdecls.append(val)
+        actuals.append(vname)
+    print(", ".join(argdecls) + ")", file=f, end="")
+    if decl:
+        print(" override;", file=f)
+    else:
+        print("\n{", file=f)
+    return actuals
+
+
+# Write out a declaration.
+def write_declaration(f, name, return_type, argtypes):
+    write_function_header(f, True, name, return_type, argtypes)
+
+
+# Write out a delegation function.
+def write_delegator(f, name, return_type, argtypes):
+    names = write_function_header(
+        f, False, "target_ops::" + name, return_type, argtypes
+    )
+    print("  ", file=f, end="")
+    if return_type != "void":
+        print("return ", file=f, end="")
+    print("this->beneath ()->" + name + " (", file=f, end="")
+    print(", ".join(names), file=f, end="")
+    print(");", file=f)
+    print("}\n", file=f)
+
+
+# Write out a default function.
+def write_tdefault(f, content, style, name, return_type, argtypes):
+    name = "dummy_target::" + name
+    names = write_function_header(f, False, name, return_type, argtypes)
+    if style == "FUNC":
+        print("  ", file=f, end="")
+        if return_type != "void":
+            print("return ", file=f, end="")
+        print(content + " (", file=f, end="")
+        names.insert(0, "this")
+        print(", ".join(names) + ");", file=f)
+    elif style == "RETURN":
+        print("  return " + content + ";", file=f)
+    elif style == "NORETURN":
+        print("  " + content + ";", file=f)
+    elif style == "IGNORE":
+        # Nothing.
+        pass
+    else:
+        raise "unrecognized style: " + style
+    print("}\n", file=f)
+
+
+def munge_type(typename):
+    m = re.search(TARGET_DEBUG_PRINTER, typename)
+    if m:
+        return m.group("arg")
+    typename = typename.rstrip()
+    typename = re.sub("[ ()<>:]", "_", typename)
+    typename = re.sub("[*]", "p", typename)
+    typename = re.sub("&", "r", typename)
+    # Identifers with double underscores are reserved to the C++
+    # implementation.
+    typename = re.sub("_+", "_", typename)
+    # Avoid ending the function name with underscore, for
+    # cosmetics.  Trailing underscores appear after munging types
+    # with template parameters, like e.g. "foo<int>".
+    typename = re.sub("_+$", "", typename)
+    return "target_debug_print_" + typename
+
+
+# Write out a debug method.
+def write_debugmethod(f, content, name, return_type, argtypes):
+    debugname = "debug_target::" + name
+    names = write_function_header(f, False, debugname, return_type, argtypes)
+    if return_type != "void":
+        print("  " + return_type + " result;", file=f)
+    print(
+        '  fprintf_unfiltered (gdb_stdlog, "-> %s->'
+        + name
+        + ' (...)\\n", this->beneath ()->shortname ());',
+        file=f,
+    )
+
+    # Delegate to the beneath target.
+    print("  ", file=f, end="")
+    if return_type != "void":
+        print("result = ", file=f, end="")
+    print("this->beneath ()->" + name + " (", file=f, end="")
+    print(", ".join(names), file=f, end="")
+    print(");", file=f)
+
+    # Now print the arguments.
+    print(
+        '  fprintf_unfiltered (gdb_stdlog, "<- %s->'
+        + name
+        + ' (", this->beneath ()->shortname ());',
+        file=f,
+    )
+    for i in range(len(argtypes)):
+        if i > 0:
+            print('  fputs_unfiltered (", ", gdb_stdlog);', file=f)
+        printer = munge_type(argtypes[i])
+        print("  " + printer + " (" + names[i] + ");", file=f)
+    if return_type != "void":
+        print('  fputs_unfiltered (") = ", gdb_stdlog);', file=f)
+        printer = munge_type(return_type)
+        print("  " + printer + " (result);", file=f)
+        print('  fputs_unfiltered ("\\n", gdb_stdlog);', file=f)
+    else:
+        print('  fputs_unfiltered (")\\n", gdb_stdlog);', file=f)
+
+    if return_type != "void":
+        print("  return result;", file=f)
+
+    print("}\n", file=f)
+
+
+def print_class(f, class_name, delegators, entries):
+    print("struct " + class_name + " : public target_ops", file=f)
+    print("{", file=f)
+    print("  const target_info &info () const override;", file=f)
+    print("", file=f)
+    print("  strata stratum () const override;", file=f)
+    print("", file=f)
+
+    for name in delegators:
+        return_type = entries[name]["return_type"]
+        argtypes = entries[name]["argtypes"]
+        print("  ", file=f, end="")
+        write_declaration(f, name, return_type, argtypes)
+
+    print("};\n", file=f)
+
+
+delegators = []
+entries = {}
+for current_line in scan_target_h():
+    # See comments in scan_target_h.  Here we strip away the leading
+    # and trailing whitespace.
+    current_line = current_line.strip()
+    m = METHOD.match(current_line)
+    if not m:
+        continue
+    data = m.groupdict()
+    data["argtypes"] = parse_argtypes(data["args"])
+    data["return_type"] = data["return_type"].strip()
+    entries[data["name"]] = data
+
+    delegators.append(data["name"])
+
+with open("target-delegates.c", "w") as f:
+    print(
+        gdbcopyright.copyright(
+            "make-target-delegates.py", "Boilerplate target methods for GDB"
+        ),
+        file=f,
+    )
+    print_class(f, "dummy_target", delegators, entries)
+    print_class(f, "debug_target", delegators, entries)
+
+    for name in delegators:
+        tdefault = entries[name]["default_arg"]
+        return_type = entries[name]["return_type"]
+        style = entries[name]["style"]
+        argtypes = entries[name]["argtypes"]
+
+        write_delegator(f, name, return_type, argtypes)
+        write_tdefault(f, tdefault, style, name, return_type, argtypes)
+        write_debugmethod(f, tdefault, name, return_type, argtypes)
diff --git a/gdb/target-delegates.c b/gdb/target-delegates.c
index ca1734f86ba..fd01b640f7c 100644
--- a/gdb/target-delegates.c
+++ b/gdb/target-delegates.c
@@ -1,8 +1,28 @@
-/* THIS FILE IS GENERATED -*- buffer-read-only: t -*- */
+/* *INDENT-OFF* */ /* THIS FILE IS GENERATED -*- buffer-read-only: t -*- */
 /* vi:set ro: */
 
-/* To regenerate this file, run:*/
-/*      make-target-delegates target.h > target-delegates.c */
+/* Boilerplate target methods for GDB
+
+   Copyright (C) 2013-2022 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/>.  */
+
+/* To regenerate this file, run:
+   ./make-target-delegates.py
+*/
 
 struct dummy_target : public target_ops
 {