[RFAv3 1/5] New cli-utils.h/.c function extract_info_print_args

[Philippe Waroquiers <philippe dot waroquiers at skynet dot be>]

New cli-utils.h/.c function extract_info_print_args factorises
the extraction of the args '[-q] [-t TYPEREGEXP] [NAMEREGEXP]'.

This function will be used by the commands
  info [args|functions|locals|variables]

As this function will be used for 'info functions|variables' which
already have the NAMEREGEXP arg, it provides a backward compatible
behaviour.

cli-utils.c has a new static function extract_arg_maybe_quoted
that extracts an argument, possibly quoted. The behaviour of this
function is similar to the parsing done by gdb_argv.

gdb/ChangeLog
2018-09-23  Philippe Waroquiers  <philippe.waroquiers@skynet.be>

	* cli-utils.c (extract_arg_maybe_quoted): New function.
	(extract_info_print_args): New function.
	(info_print_args_help): New function.
	* cli-utils.h (extract_arg_maybe_quoted): New function.
	(extract_info_print_args): New function.
	(info_print_args_help): New function.
---
 gdb/cli/cli-utils.c | 159 ++++++++++++++++++++++++++++++++++++++++++++
 gdb/cli/cli-utils.h |  15 +++++
 2 files changed, 174 insertions(+)

diff --git a/gdb/cli/cli-utils.c b/gdb/cli/cli-utils.c
index 98b7414991..ea4b4b6f61 100644
--- a/gdb/cli/cli-utils.c
+++ b/gdb/cli/cli-utils.c
@@ -23,6 +23,8 @@
 
 #include <ctype.h>
 
+static std::string extract_arg_maybe_quoted (const char **arg);
+
 /* See documentation in cli-utils.h.  */
 
 int
@@ -125,6 +127,84 @@ get_number (char **pp)
   return result;
 }
 
+/* See documentation in cli-utils.h.  */
+
+void
+extract_info_print_args (const char* command,
+			 const char **args,
+			 bool *quiet,
+			 std::string *regexp,
+			 std::string *t_regexp)
+{
+  *quiet = false;
+  *regexp = "";
+  *t_regexp = "";
+
+  while (*args != NULL)
+    {
+      if (check_for_argument (args, "--", 2))
+	{
+	  *args = skip_spaces (*args);
+	  break;
+	}
+
+      if (check_for_argument (args, "-t", 2))
+	{
+	  *t_regexp = extract_arg_maybe_quoted (args);
+	  *args = skip_spaces (*args);
+	  continue;
+	}
+
+      if (check_for_argument (args, "-q", 2))
+	{
+	  *quiet = true;
+	  *args = skip_spaces (*args);
+	  continue;
+	}
+
+      if (**args != '-')
+	break;
+
+      std::string option = extract_arg (args);
+      error (_("Unrecognized option '%s' to %s command.  "
+	       "Try \"help %s\"."), option.c_str (),
+	     command, command);
+    }
+
+  if (*args != NULL && **args != '\000')
+    *regexp = *args;
+
+}
+
+/* See documentation in cli-utils.h.  */
+
+const char*
+info_print_args_help (const char* prefix,
+		      const char* entity_kind)
+{
+  std::string h;
+
+  h = prefix;
+  h += _("If NAMEREGEXP is provided, only prints the ");
+  h += entity_kind;
+  h +=_(" whose name\n\
+matches NAMEREGEXP.\n\
+If -t TYPEREGEXP is provided, only prints the ");
+  h += entity_kind;
+  h +=_(" whose type\n\
+matches TYPEREGEXP.  Note that the matching is done with the type\n\
+printed by the 'whatis' command.\n\
+By default, the command might produce headers and/or messages indicating\n\
+why no ");
+  h += entity_kind;
+  h += _(" can be printed.\n\
+The flag -q disables the production of these headers and messages.");
+
+  return xstrdup (h.c_str ());
+}
+
+
+
 /* See documentation in cli-utils.h.  */
 
 number_or_range_parser::number_or_range_parser (const char *string)
@@ -282,6 +362,85 @@ remove_trailing_whitespace (const char *start, const char *s)
   return s;
 }
 
+/* A helper function to extract an argument from *ARG.  An argument is
+   delimited by whitespace, but it can also be optionally quoted.
+   The quoting and special characters are handled similarly to
+   the parsing done by gdb_argv.
+   The return value is empty if no argument was found.  */
+
+static std::string
+extract_arg_maybe_quoted (const char **arg)
+{
+  int squote = 0;
+  int dquote = 0;
+  int bsquote = 0;
+  std::string result = std::string ();
+
+  /* Find the start of the argument.  */
+  *arg = skip_spaces (*arg);
+
+  /* Parse *arg similarly to gdb_argv buildargv function.  */
+  while (**arg != '\0')
+    {
+      if (isspace (**arg) && !squote && !dquote && !bsquote)
+	{
+	  break;
+	}
+      else
+	{
+	  if (bsquote)
+	    {
+	      bsquote = 0;
+	      result += **arg;
+	    }
+	  else if (**arg == '\\')
+	    {
+	      bsquote = 1;
+	    }
+	  else if (squote)
+	    {
+	      if (**arg == '\'')
+		{
+		  squote = 0;
+		}
+	      else
+		{
+		  result += **arg;
+		}
+	    }
+	  else if (dquote)
+	    {
+	      if (**arg == '"')
+		{
+		  dquote = 0;
+		}
+	      else
+		{
+		  result += **arg;
+		}
+	    }
+	  else
+	    {
+	      if (**arg == '\'')
+		{
+		  squote = 1;
+		}
+	      else if (**arg == '"')
+		{
+		  dquote = 1;
+		}
+	      else
+		{
+		  result += **arg;
+		}
+	    }
+	  (*arg)++;
+	}
+    }
+
+  return result;
+}
+
 /* See documentation in cli-utils.h.  */
 
 std::string
diff --git a/gdb/cli/cli-utils.h b/gdb/cli/cli-utils.h
index fa7d02d719..8ce8db1860 100644
--- a/gdb/cli/cli-utils.h
+++ b/gdb/cli/cli-utils.h
@@ -39,6 +39,21 @@ extern int get_number (const char **);
 
 extern int get_number (char **);
 
+/* Extract from args the arguments [-q] [-t TYPEREGEXP] [--] NAMEREGEXP.
+   Only the above flags are accepted.  Any other flag will raise an error.
+   COMMAND is used to produce the error message if an invalid flag is
+   given.  */
+extern void extract_info_print_args (const char* command,
+				     const char **args,
+				     bool *quiet,
+				     std::string *regexp,
+				     std::string *t_regexp);
+
+/* Builds the help string for a command documented by PREFIX,
+   followed by the extract_info_print_args help for ENTITY_KIND.  */
+extern const char* info_print_args_help (const char* prefix,
+					 const char* entity_kind);
+
 /* Parse a number or a range.
    A number will be of the form handled by get_number.
    A range will be of the form <number1> - <number2>, and
-- 
2.18.0