Rename demangle.c to gdb-demangle.c, and some cleanup

In addition to renaming demangle.c to match the header file naming,
this also makes is_cplus_marker return a bool and removes a duplicate
declaration of "bool demangle" from symtab.h.

gdb/ChangeLog:

2019-11-21  Christian Biesinger  <cbiesinger@google.com>

	* Makefile.in: Update.
	* demangle.c: Rename to...
	* gdb-demangle.c: ..this.
	(is_cplus_marker): Change return type to bool.
	(_initialize_demangler): Rename to...
	(_initialize_gdb_demangle): ...this.
	* gdb-demangle.h (is_cplus_marker): Change return type to bool.
	* symtab.h (demangle): Remove declaration; instead include
	gdb-demangle.h.

Change-Id: I83c3b3f7ee71b2bf6f5b5d0f9eb1d4b5208f2a97

1 files changed, 268 insertions, 0 deletions

diff --git a/gdb/gdb-demangle.c b/gdb/gdb-demangle.c
new file mode 100644
index 0000000..2ed64d4
--- /dev/null
+++ b/gdb/gdb-demangle.c
@@ -0,0 +1,268 @@
+/* Basic C++ demangling support for GDB.
+
+   Copyright (C) 1991-2019 Free Software Foundation, Inc.
+
+   Written by Fred Fish at Cygnus Support.
+
+   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/>.  */
+
+
+/*  This file contains support code for C++ demangling that is common
+   to a styles of demangling, and GDB specific.  */
+
+#include "defs.h"
+#include "cli/cli-utils.h" /* for skip_to_space */
+#include "command.h"
+#include "gdbcmd.h"
+#include "demangle.h"
+#include "gdb-demangle.h"
+#include "language.h"
+
+/* Select the default C++ demangling style to use.  The default is "auto",
+   which allows gdb to attempt to pick an appropriate demangling style for
+   the executable it has loaded.  It can be set to a specific style ("gnu",
+   "lucid", "arm", "hp", etc.) in which case gdb will never attempt to do auto
+   selection of the style unless you do an explicit "set demangle auto".
+   To select one of these as the default, set DEFAULT_DEMANGLING_STYLE in
+   the appropriate target configuration file.  */
+
+#ifndef DEFAULT_DEMANGLING_STYLE
+#define DEFAULT_DEMANGLING_STYLE AUTO_DEMANGLING_STYLE_STRING
+#endif
+
+/* See documentation in gdb-demangle.h.  */
+bool demangle = true;
+
+static void
+show_demangle (struct ui_file *file, int from_tty,
+	       struct cmd_list_element *c, const char *value)
+{
+  fprintf_filtered (file,
+		    _("Demangling of encoded C++/ObjC names "
+		      "when displaying symbols is %s.\n"),
+		    value);
+}
+
+/* See documentation in gdb-demangle.h.  */
+bool asm_demangle = false;
+
+static void
+show_asm_demangle (struct ui_file *file, int from_tty,
+		   struct cmd_list_element *c, const char *value)
+{
+  fprintf_filtered (file,
+		    _("Demangling of C++/ObjC names in "
+		      "disassembly listings is %s.\n"),
+		    value);
+}
+
+/* String name for the current demangling style.  Set by the
+   "set demangle-style" command, printed as part of the output by the
+   "show demangle-style" command.  */
+
+static const char *current_demangling_style_string;
+
+/* The array of names of the known demangling styles.  Generated by
+   _initialize_demangler from libiberty_demanglers[] array.  */
+
+static const char **demangling_style_names;
+static void
+show_demangling_style_names(struct ui_file *file, int from_tty,
+			    struct cmd_list_element *c, const char *value)
+{
+  fprintf_filtered (file, _("The current C++ demangling style is \"%s\".\n"),
+		    value);
+}
+
+/* Set current demangling style.  Called by the "set demangle-style"
+   command after it has updated the current_demangling_style_string to
+   match what the user has entered.
+
+   If the user has entered a string that matches a known demangling style
+   name in the demanglers[] array then just leave the string alone and update
+   the current_demangling_style enum value to match.
+
+   If the user has entered a string that doesn't match, including an empty
+   string, then print a list of the currently known styles and restore
+   the current_demangling_style_string to match the current_demangling_style
+   enum value.
+
+   Note:  Assumes that current_demangling_style_string always points to
+   a malloc'd string, even if it is a null-string.  */
+
+static void
+set_demangling_command (const char *ignore,
+			int from_tty, struct cmd_list_element *c)
+{
+  const struct demangler_engine *dem;
+  int i;
+
+  /*  First just try to match whatever style name the user supplied with
+     one of the known ones.  Don't bother special casing for an empty
+     name, we just treat it as any other style name that doesn't match.
+     If we match, update the current demangling style enum.  */
+
+  for (dem = libiberty_demanglers, i = 0;
+       dem->demangling_style != unknown_demangling; 
+       dem++)
+    {
+      if (strcmp (current_demangling_style_string,
+		  dem->demangling_style_name) == 0)
+	{
+	  current_demangling_style = dem->demangling_style;
+	  current_demangling_style_string = demangling_style_names[i];
+	  break;
+	}
+      i++;
+    }
+
+  /* We should have found a match, given we only add known styles to
+     the enumeration list.  */
+  gdb_assert (dem->demangling_style != unknown_demangling);
+}
+
+/* G++ uses a special character to indicate certain internal names.  Which
+   character it is depends on the platform:
+   - Usually '$' on systems where the assembler will accept that
+   - Usually '.' otherwise (this includes most sysv4-like systems and most
+     ELF targets)
+   - Occasionally '_' if neither of the above is usable
+
+   We check '$' first because it is the safest, and '.' often has another
+   meaning.  We don't currently try to handle '_' because the precise forms
+   of the names are different on those targets.  */
+
+static char cplus_markers[] = {'$', '.', '\0'};
+
+/* See documentation in gdb-demangle.h.  */
+
+bool
+is_cplus_marker (int c)
+{
+  return c && strchr (cplus_markers, c) != NULL;
+}
+
+/* Demangle the given string in the current language.  */
+
+static void
+demangle_command (const char *args, int from_tty)
+{
+  char *demangled;
+  const char *name;
+  const char *arg_start;
+  int processing_args = 1;
+  const struct language_defn *lang;
+
+  std::string arg_buf = args != NULL ? args : "";
+  arg_start = arg_buf.c_str ();
+
+  std::string lang_name;
+  while (processing_args
+	 && *arg_start == '-')
+    {
+      const char *p = skip_to_space (arg_start);
+
+      if (strncmp (arg_start, "-l", p - arg_start) == 0)
+	lang_name = extract_arg (&p);
+      else if (strncmp (arg_start, "--", p - arg_start) == 0)
+	processing_args = 0;
+      else
+	report_unrecognized_option_error ("demangle", arg_start);
+
+      arg_start = skip_spaces (p);
+    }
+
+  name = arg_start;
+
+  if (*name == '\0')
+    error (_("Usage: demangle [-l LANGUAGE] [--] NAME"));
+
+  if (!lang_name.empty ())
+    {
+      enum language lang_enum;
+
+      lang_enum = language_enum (lang_name.c_str ());
+      if (lang_enum == language_unknown)
+	error (_("Unknown language \"%s\""), lang_name.c_str ());
+      lang = language_def (lang_enum);
+    }
+  else
+    lang = current_language;
+
+  demangled = language_demangle (lang, name, DMGL_ANSI | DMGL_PARAMS);
+  if (demangled != NULL)
+    {
+      printf_filtered ("%s\n", demangled);
+      xfree (demangled);
+    }
+  else
+    error (_("Can't demangle \"%s\""), name);
+}
+
+void
+_initialize_gdb_demangle (void)
+{
+  int i, ndems;
+
+  /* Fill the demangling_style_names[] array, and set the default
+     demangling style chosen at compilation time.  */
+  for (ndems = 0;
+       libiberty_demanglers[ndems].demangling_style != unknown_demangling; 
+       ndems++)
+    ;
+  demangling_style_names = XCNEWVEC (const char *, ndems + 1);
+  for (i = 0;
+       libiberty_demanglers[i].demangling_style != unknown_demangling; 
+       i++)
+    {
+      demangling_style_names[i]
+	= xstrdup (libiberty_demanglers[i].demangling_style_name);
+
+      if (current_demangling_style_string == NULL
+	  && strcmp (DEFAULT_DEMANGLING_STYLE, demangling_style_names[i]) == 0)
+	current_demangling_style_string = demangling_style_names[i];
+    }
+
+  add_setshow_boolean_cmd ("demangle", class_support, &demangle, _("\
+Set demangling of encoded C++/ObjC names when displaying symbols."), _("\
+Show demangling of encoded C++/ObjC names when displaying symbols."), NULL,
+			   NULL,
+			   show_demangle,
+			   &setprintlist, &showprintlist);
+
+  add_setshow_boolean_cmd ("asm-demangle", class_support, &asm_demangle, _("\
+Set demangling of C++/ObjC names in disassembly listings."), _("\
+Show demangling of C++/ObjC names in disassembly listings."), NULL,
+			   NULL,
+			   show_asm_demangle,
+			   &setprintlist, &showprintlist);
+
+  add_setshow_enum_cmd ("demangle-style", class_support,
+			demangling_style_names,
+			&current_demangling_style_string, _("\
+Set the current C++ demangling style."), _("\
+Show the current C++ demangling style."), _("\
+Use `set demangle-style' without arguments for a list of demangling styles."),
+			set_demangling_command,
+			show_demangling_style_names,
+			&setlist, &showlist);
+
+  add_cmd ("demangle", class_support, demangle_command, _("\
+Demangle a mangled name.\n\
+Usage: demangle [-l LANGUAGE] [--] NAME\n\
+If LANGUAGE is not specified, NAME is demangled in the current language."),
+	   &cmdlist);
+}