[RFA 1/5] Explicit linespecs - refactor linespec parsing

[Keith Seitz <keiths at redhat dot com>]

Hi,

This first patch refactors a bunch of code in linespec.c to allow for a 
different parsing function. This is mainly to facilitate sharing code 
with decode_line_full.  In the end, regardless of what the actual 
parsing function is, the results must be the same.

Questions/comments/concerns?
Keith

ChangeLog
2012-07-26  Keith Seitz  <keiths@redhat.com>

        * linespec.c (linespec_parse_func): New typedef.
        (struct ls_parser): Add PARSE_IT.
        (undefined_label_error): New function.
        (source_file_not_found_error): New function.
        (linespec_parse_basic): Use undefined_label_error.
        (parse_linespec): Add/use DATA parameter instead of previous
        ARGPTR parameter.
        (linespec_parser_new): Add FUNC parameter.
        (do_decode_line): Move most of decode_line_full here to here.
        Use the parser's PARSE_IT function to do the actual parsing.
        (decode_line_full): Use do_decode_line.
        (decode_line_1): Pass parsing function name to
        linespec_parser_new and call it to do the parsing.
        (symtabs_from_filename): Use source_file_not_found_error.

diff --git a/gdb/linespec.c b/gdb/linespec.c
index 3d7f62f..2b84515 100644
--- a/gdb/linespec.c
+++ b/gdb/linespec.c
@@ -265,6 +265,12 @@ typedef struct ls_token linespec_token;
 #define LS_TOKEN_STOKEN(TOK) (TOK).data.string
 #define LS_TOKEN_KEYWORD(TOK) (TOK).data.keyword
 
+/* A parser function definition used by do_decode_line.  */
+
+struct ls_parser;
+typedef struct symtabs_and_lines (*linespec_parse_func) (struct ls_parser *,
+							 void *client_data);
+
 /* An instance of the linespec parser.  */
 
 struct ls_parser
@@ -293,6 +299,9 @@ struct ls_parser
   /* The result of the parse.  */
   struct linespec result;
 #define PARSER_RESULT(PPTR) (&(PPTR)->result)
+
+  /* The function to actually do the parsing.  */
+  linespec_parse_func parse_it;
 };
 typedef struct ls_parser linespec_parser;
 
@@ -1433,6 +1442,29 @@ unexpected_linespec_error (linespec_parser *parser)
 		 token_type_strings[token.type]);
 }
 
+/* Throw an undefined label error.  */
+
+static void ATTRIBUTE_NORETURN
+undefined_label_error (const char *function, const char *label)
+{
+  if (function != NULL)
+    throw_error (NOT_FOUND_ERROR,
+                _("No label \"%s\" defined in function \"%s\"."),
+                label, function);
+  else
+    throw_error (NOT_FOUND_ERROR,
+                _("No label \"%s\" defined in current function."), label);
+}
+
+/* Throw a source file not found error.  */
+
+static void ATTRIBUTE_NORETURN
+source_file_not_found_error (const char *name)
+{
+  throw_error (NOT_FOUND_ERROR,
+              _("No source file named %s."), name);
+}
+
 /* Parse and return a line offset in STRING.  */
 
 static struct line_offset
@@ -1587,9 +1619,8 @@ linespec_parse_basic (linespec_parser *parser)
 	  else
 	    {
 	      /* We don't know what it was, but it isn't a label.  */
-	      throw_error (NOT_FOUND_ERROR,
-			   _("No label \"%s\" defined in function \"%s\"."),
-			   name, PARSER_RESULT (parser)->function_name);
+	      undefined_label_error (PARSER_RESULT (parser)->function_name,
+				     name);
 	    }
 
 	  /* Check for a line offset.  */
@@ -1995,15 +2026,16 @@ convert_linespec_to_sals (struct linespec_state *state, linespec_p ls)
    if no file is validly specified.  Callers must check that.
    Also, the line number returned may be invalid.  */
 
-/* Parse the linespec in ARGPTR.  */
+/* Parse the linespec in DATA.  */
 
 static struct symtabs_and_lines
-parse_linespec (linespec_parser *parser, char **argptr)
+parse_linespec (linespec_parser *parser, void *data)
 {
   linespec_token token;
   struct symtabs_and_lines values;
   volatile struct gdb_exception file_exception;
   struct cleanup *cleanup;
+  char **argptr = (char **) data;
 
   /* A special case to start.  It has become quite popular for
      IDEs to work around bugs in the previous parser by quoting
@@ -2210,7 +2242,7 @@ linespec_state_constructor (struct linespec_state *self,
 /* Initialize a new linespec parser.  */
 
 static void
-linespec_parser_new (linespec_parser *parser,
+linespec_parser_new (linespec_parser *parser, linespec_parse_func func,
 		     int flags, const struct language_defn *language,
 		     struct symtab *default_symtab,
 		     int default_line,
@@ -2219,6 +2251,7 @@ linespec_parser_new (linespec_parser *parser,
   parser->lexer.current.type = LSTOKEN_CONSUMED;
   memset (PARSER_RESULT (parser), 0, sizeof (struct linespec));
   PARSER_RESULT (parser)->line_offset.sign = LINE_OFFSET_UNKNOWN;
+  parser->parse_it = func;
   linespec_state_constructor (PARSER_STATE (parser), flags, language,
 			      default_symtab, default_line, canonical);
 }
@@ -2261,42 +2294,35 @@ linespec_parser_delete (void *arg)
   linespec_state_destructor (PARSER_STATE (parser));
 }
 
-/* See linespec.h.  */
+/* Decode the linespec given in DATA with the PARSER.
+   SELECT_MODE and FILTER are from decode_line_full.  */
 
-void
-decode_line_full (char **argptr, int flags,
-		  struct symtab *default_symtab,
-		  int default_line, struct linespec_result *canonical,
-		  const char *select_mode,
-		  const char *filter)
+static void
+do_decode_line (linespec_parser *parser, void *data,
+		const char *select_mode, const char *filter)
 {
   struct symtabs_and_lines result;
   struct cleanup *cleanups;
-  char *arg_start = *argptr;
   VEC (const_char_ptr) *filters = NULL;
-  linespec_parser parser;
   struct linespec_state *state;
 
-  gdb_assert (canonical != NULL);
   /* The filter only makes sense for 'all'.  */
   gdb_assert (filter == NULL || select_mode == multiple_symbols_all);
   gdb_assert (select_mode == NULL
 	      || select_mode == multiple_symbols_all
 	      || select_mode == multiple_symbols_ask
 	      || select_mode == multiple_symbols_cancel);
-  gdb_assert ((flags & DECODE_LINE_LIST_MODE) == 0);
 
-  linespec_parser_new (&parser, flags, current_language, default_symtab,
-		       default_line, canonical);
-  cleanups = make_cleanup (linespec_parser_delete, &parser);
+  cleanups = make_cleanup (null_cleanup, NULL);
   save_current_program_space ();
 
-  result = parse_linespec (&parser, argptr);
-  state = PARSER_STATE (&parser);
+  result = (*parser->parse_it) (parser, data);
+  state = PARSER_STATE (parser);
 
-  gdb_assert (result.nelts == 1 || canonical->pre_expanded);
-  gdb_assert (canonical->addr_string != NULL);
-  canonical->pre_expanded = 1;
+  gdb_assert (result.nelts == 1 || state->canonical->pre_expanded);
+  gdb_assert (state->canonical->addr_string != NULL);
+  gdb_assert (result.nelts == 0 || state->canonical_names != NULL);
+  state->canonical->pre_expanded = 1;
 
   /* Arrange for allocated canonical names to be freed.  */
   if (result.nelts > 0)
@@ -2336,6 +2362,29 @@ decode_line_full (char **argptr, int flags,
   do_cleanups (cleanups);
 }
 
+/* See linespec.h.
+   All of the real work is done in do_decode_line.  */
+
+void
+decode_line_full (char **argptr, int flags,
+		  struct symtab *default_symtab,
+		  int default_line, struct linespec_result *canonical,
+		  const char *select_mode,
+		  const char *filter)
+{
+  linespec_parser parser;
+  struct cleanup *cleanups;
+
+  gdb_assert (canonical != NULL);
+  gdb_assert ((flags & DECODE_LINE_LIST_MODE) == 0);
+
+  linespec_parser_new (&parser, parse_linespec, flags, current_language,
+		       default_symtab, default_line, canonical);
+  cleanups = make_cleanup (linespec_parser_delete, &parser);
+  do_decode_line (&parser, argptr, select_mode, filter);
+  do_cleanups (cleanups);
+}
+
 /* See linespec.h.  */
 
 struct symtabs_and_lines
@@ -2347,12 +2396,12 @@ decode_line_1 (char **argptr, int flags,
   linespec_parser parser;
   struct cleanup *cleanups;
 
-  linespec_parser_new (&parser, flags, current_language, default_symtab,
-		       default_line, NULL);
+  linespec_parser_new (&parser, parse_linespec, flags, current_language,
+		       default_symtab, default_line, NULL);
   cleanups = make_cleanup (linespec_parser_delete, &parser);
   save_current_program_space ();
 
-  result = parse_linespec (&parser, argptr);
+  result = (*parser.parse_it) (&parser, argptr);
 
   do_cleanups (cleanups);
   return result;
@@ -2879,7 +2928,7 @@ symtabs_from_filename (const char *filename)
 	throw_error (NOT_FOUND_ERROR,
 		     _("No symbol table is loaded.  "
 		       "Use the \"file\" command."));
-      throw_error (NOT_FOUND_ERROR, _("No source file named %s."), filename);
+      source_file_not_found_error (filename);
     }
 
   return result;