[RFAv2 1/6] 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]

cli-utils.c has a new static function extract_arg_maybe_quoted
that extracts an argument, possibly single quoted.

gdb/ChangeLog
2018-08-26  Philippe Waroquiers  <philippe.waroquiers@skynet.be>

	* cli-utils.c (extract_arg_maybe_quoted): New function.
	(extract_info_print_args): New function.
	* cli-utils.h (extract_arg_maybe_quoted): New function.
	(extract_info_print_args): New function.
	(INFO_PRINT_ARGS_HELP): new macro.
---
 gdb/cli/cli-utils.c | 113 ++++++++++++++++++++++++++++++++++++++++++++
 gdb/cli/cli-utils.h |  20 ++++++++
 2 files changed, 133 insertions(+)

diff --git a/gdb/cli/cli-utils.c b/gdb/cli/cli-utils.c
index 98b7414991..7adbab46a1 100644
--- a/gdb/cli/cli-utils.c
+++ b/gdb/cli/cli-utils.c
@@ -23,6 +23,9 @@
 
 #include <ctype.h>
 
+static std::string
+extract_arg_maybe_quoted (const char **arg);
+
 /* See documentation in cli-utils.h.  */
 
 int
@@ -125,6 +128,56 @@ 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 = extract_arg (args);
+
+}
+
+
 /* See documentation in cli-utils.h.  */
 
 number_or_range_parser::number_or_range_parser (const char *string)
@@ -282,6 +335,66 @@ 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 using
+   single quote characters.  The return value is empty if no argument
+   was found.  */
+
+static std::string
+extract_arg_maybe_quoted (const char **arg)
+{
+  if (!*arg)
+    return std::string ();
+
+  /* Find the start of the argument.  */
+  *arg = skip_spaces (*arg);
+  if (!**arg)
+    return std::string ();
+
+  if (**arg == '\'')
+    {
+      /* Quoted argument.  */
+      const char *orig_arg = *arg;
+      std::string result;
+      const char *p;
+
+      (*arg)++; /* Skip starting quote.  */
+
+      /* Find the end of the quoted argument.  */
+      for (p = *arg; *p != '\0'; p++)
+	{
+	  if (*p == '\'')
+	    {
+	      (*arg)++; /* Skip ending quote.  */
+	      return result;
+	    }
+
+	  if (*p == '\\' && p[1] == '\'')
+	    {
+	      /* Escaped quote.  */
+	      p++;      /* Skip escape char.  */
+	      (*arg)++; /* Skip escape char.  */
+	    }
+
+	  result = result + *p;
+	  (*arg)++;
+	}
+      error (_("Unterminated quoted argument in %s"), orig_arg);
+    }
+  else
+    {
+      const char *result = *arg;
+
+      /* Find the end of the argument.  */
+      *arg = skip_to_space (*arg + 1);
+
+      if (result == *arg)
+	return std::string ();
+
+      return std::string (result, *arg - 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..602a36314d 100644
--- a/gdb/cli/cli-utils.h
+++ b/gdb/cli/cli-utils.h
@@ -39,6 +39,26 @@ 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);
+
+#define INFO_PRINT_ARGS_HELP(entity_kind) \
+"If NAMEREGEXP is provided, only prints the " entity_kind " whose name\n\
+matches NAMEREGEXP.\n\
+If -t TYPEREGEXP is provided, only prints the " entity_kind " 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 " entity_kind " can be printed.\n\
+The flag -q disables the production of these headers and messages."
+
 /* 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