[RFAv2,1/3] New "info sources" args [-dirname | -basename] [--] [REGEXP]

diff --git a/gdb/symtab.c b/gdb/symtab.c
index 4920d94a24..854af63651 100644
--- a/gdb/symtab.c
+++ b/gdb/symtab.c
@@ -4114,10 +4114,28 @@  operator_chars (const char *p, const char **end)
 }
 
 
+/* What part to match in a file name.  */
+
+struct filename_partial_match_opts
+{
+  /* Only match the directory name part.   */
+  int dirname = false;
+
+  /* Only match the basename part.  */
+  int basename = false;
+};
+
 /* Data structure to maintain printing state for output_source_filename.  */
 
 struct output_source_filename_data
 {
+  /* Output only filenames matching REGEXP.  */
+  std::string regexp;
+  gdb::optional<compiled_regex> c_regexp;
+  /* Possibly only match a part of the filename.  */
+  filename_partial_match_opts partial_match;
+
+
   /* Cache of what we've seen so far.  */
   struct filename_seen_cache *filename_seen_cache;
 
@@ -4149,7 +4167,27 @@  output_source_filename (const char *name,
       return;
     }
 
-  /* No; print it and reset *FIRST.  */
+  /* Does it match data->regexp?  */
+  if (data->c_regexp.has_value ())
+    {
+      const char *to_match;
+      std::string dirname;
+
+      if (data->partial_match.dirname)
+	{
+	  dirname = ldirname (name);
+	  to_match = dirname.c_str ();
+	}
+      else if (data->partial_match.basename)
+	to_match = lbasename (name);
+      else
+	to_match = name;
+
+      if (data->c_regexp->exec (to_match, 0, NULL, 0) != 0)
+	return;
+    }
+
+  /* Print it and reset *FIRST.  */
   if (! data->first)
     printf_filtered (", ");
   data->first = 0;
@@ -4168,8 +4206,73 @@  output_partial_symbol_filename (const char *filename, const char *fullname,
 			  (struct output_source_filename_data *) data);
 }
 
+using isrc_flag_option_def
+  = gdb::option::flag_option_def<filename_partial_match_opts>;
+
+static const gdb::option::option_def info_sources_option_defs[] = {
+
+  isrc_flag_option_def {
+    "dirname",
+    [] (filename_partial_match_opts *opts) { return &opts->dirname; },
+    N_("Show only the files having a dirname matching REGEXP."),
+  },
+
+  isrc_flag_option_def {
+    "basename",
+    [] (filename_partial_match_opts *opts) { return &opts->basename; },
+    N_("Show only the files having a basename matching REGEXP."),
+  },
+
+};
+
+/* Create an option_def_group for the "info sources" options, with
+   ISRC_OPTS as context.  */
+
+static inline gdb::option::option_def_group
+make_info_sources_options_def_group (filename_partial_match_opts *isrc_opts)
+{
+  return {{info_sources_option_defs}, isrc_opts};
+}
+
+/* Prints the header message for the source files that will be printed
+   with the matching info present in DATA.  SYMBOL_MSG is a message
+   that tells what will or has been done with the symbols of the
+   matching source files.  */
+
+static void
+print_info_sources_header (const char *symbol_msg,
+			   const struct output_source_filename_data *data)
+{
+  printf_filtered ("Source files ");
+  if (!data->regexp.empty ())
+    {
+      if (data->partial_match.dirname)
+	printf_filtered ("(dirname ");
+      else if (data->partial_match.basename)
+	printf_filtered ("(basename ");
+      else
+	printf_filtered ("(filename ");
+      printf_filtered ("matching regular expression \"%s\") ",
+		       data->regexp.c_str ());
+    }
+  printf_filtered ("for which symbols %s:\n\n", symbol_msg);
+}
+
+/* Completer for "info sources".  */
+
+static void
+info_sources_command_completer (cmd_list_element *ignore,
+				completion_tracker &tracker,
+				const char *text, const char *word)
+{
+  const auto group = make_info_sources_options_def_group (nullptr);
+  if (gdb::option::complete_options
+      (tracker, &text, gdb::option::PROCESS_OPTIONS_UNKNOWN_IS_OPERAND, group))
+    return;
+}
+
 static void
-info_sources_command (const char *ignore, int from_tty)
+info_sources_command (const char *args, int from_tty)
 {
   struct output_source_filename_data data;
 
@@ -4180,11 +4283,37 @@  info_sources_command (const char *ignore, int from_tty)
 
   filename_seen_cache filenames_seen;
 
-  data.filename_seen_cache = &filenames_seen;
+  auto group = make_info_sources_options_def_group (&data.partial_match);
+
+  gdb::option::process_options
+    (&args, gdb::option::PROCESS_OPTIONS_UNKNOWN_IS_ERROR, group);
 
-  printf_filtered ("Source files for which symbols have been read in:\n\n");
+  if (args != NULL && *args != '\000')
+    data.regexp = args;
 
+  data.filename_seen_cache = &filenames_seen;
   data.first = 1;
+
+  if (data.partial_match.dirname && data.partial_match.basename)
+    error (_("You cannot give both -basename and -dirname to 'info sources'."));
+  if ((data.partial_match.dirname || data.partial_match.basename)
+      && data.regexp.empty ())
+     error (_("Missing REGEXP for 'info sources'."));
+
+  if (data.regexp.empty ())
+    data.c_regexp.reset ();
+  else
+    {
+      int cflags = REG_NOSUB;
+#ifdef HAVE_CASE_INSENSITIVE_FILE_SYSTEM
+      cflags |= REG_ICASE;
+#endif
+      data.c_regexp.emplace (data.regexp.c_str (), cflags,
+			     _("Invalid regexp"));
+    }
+
+  print_info_sources_header ("have been read in", &data);
+
   for (objfile *objfile : current_program_space->objfiles ())
     {
       for (compunit_symtab *cu : objfile->compunits ())
@@ -4199,8 +4328,7 @@  info_sources_command (const char *ignore, int from_tty)
     }
   printf_filtered ("\n\n");
 
-  printf_filtered ("Source files for which symbols "
-		   "will be read in on demand:\n\n");
+  print_info_sources_header ("will be read in on demand", &data);
 
   filenames_seen.clear ();
   data.first = 1;
@@ -6008,6 +6136,8 @@  symbol_set_symtab (struct symbol *symbol, struct symtab *symtab)
 void
 _initialize_symtab (void)
 {
+  struct cmd_list_element *c;
+
   initialize_ordinary_address_classes ();
 
   add_info ("variables", info_variables_command,
@@ -6042,8 +6172,20 @@  Prints the functions.\n"),
   add_info ("types", info_types_command,
 	    _("All type names, or those matching REGEXP."));
 
-  add_info ("sources", info_sources_command,
-	    _("Source files in the program."));
+  const auto info_sources_opts = make_info_sources_options_def_group (nullptr);
+
+  static std::string info_sources_help
+    = gdb::option::build_help (_("\
+All source files in the program or those matching REGEXP.\n\
+Usage: info sources [OPTION]... [REGEXP]\n\
+By default, REGEXP is used to match anywhere in the filename.\n\
+\n\
+Options:\n\
+%OPTIONS%"),
+			       info_sources_opts);
+
+  c = add_info ("sources", info_sources_command, info_sources_help.c_str ());
+  set_cmd_completer_handle_brkchars (c, info_sources_command_completer);
 
   add_com ("rbreak", class_breakpoint, rbreak_command,
 	   _("Set a breakpoint for all functions matching REGEXP."));