[PATCH] Expand keyword lexing intelligence in the linespec parser.

[Joel Brobecker]

> gdb/ChangeLog
> 
> 	* breakpoint.c (parse_breakpoint_sals): Use
> 	linespec_lexer_lex_keyword to ascertain if the user specified
> 	a NULL location.
> 	* linespec.c [IF_KEYWORD_INDEX]: Define.
> 	(linespec_lexer_lex_keyword): Export.
> 	(struct ls_parser) <keyword_ok>: Remove.
> 	A keyword is only a keyword if not followed by another keyword.
> 	(linespec_lexer_lex_one): Remove keyword_ok handling.
> 	Add comment explaining why the parsing stream is not advanced
> 	when a keyword is seen.
> 	(parse_linespec): Remove parser->keyword_ok.
> 	* linespec.h (linespec_lexer_lex_keyword): Add declaration.
> 
> gdb/testsuite/ChangeLog
> 
> 	* gdb.linespec/keywords.c: New file.
> 	* gdb.linespec/keywords.exp: New file.

LGTM. A few minor comments, but otherwise pre-approved.

> +++ b/gdb/linespec.h
> @@ -152,4 +152,8 @@ extern struct symtabs_and_lines decode_line_with_current_source (char *, int);
>  
>  extern struct symtabs_and_lines decode_line_with_last_displayed (char *, int);
>  
> +/* Does P represent one of the keywords?  If so, return
> +   the keyword.  If not, return NULL.  */
> +
> +extern const char *linespec_lexer_lex_keyword (const char *p);

You already have the function documented in linespec.c, so no need
to duplicate it here.

> +gdb_test "break thread 123" "Unknown thread 123\."

I think that "\." should be "\\.", no? Likewise for the expected
output of the remaining tests.

> +gdb_test "break thread foo" "Junk after thread keyword\."
> +gdb_test "break task 123" "Unknown task 123\."
> +gdb_test "break task foo" "Junk after task keyword\."
> +gdb_breakpoint "thread if 0" "message"
> +
> +# These are also NULL locations, but using a subsequent keyword
> +# as the "junk".
> +gdb_test "break thread thread" "Junk after thread keyword\."
> +gdb_test "break thread task" "Junk after thread keyword\."
> +gdb_test "break thread if" "Junk after thread keyword\."
> +gdb_test "break task task" "Junk after task keyword\."
> +gdb_test "break task thread" "Junk after task keyword\."
> +gdb_test "break task if" "Junk after task keyword\."
> +
> +# Test locations containing keyword followed by keyword.
> +gdb_test "break thread thread 123" "Unknown thread 123\."
> +gdb_test "break task task 123" "Unknown task 123\."
> +
> +# Test NULL location with valid conditional containing a keyword.
> +gdb_breakpoint "thread if thread == 0"
> +gdb_breakpoint "task if task == 0"

-- 
Joel