while and until loops support

This commit is contained in:
BVK Chaitanya 2010-01-23 11:19:26 +05:30
parent 3babea95bb
commit 10523df478
5 changed files with 100 additions and 5 deletions

View File

@ -121,6 +121,21 @@ struct grub_script_cmdfor
struct grub_script_cmd *list;
};
/* A while/until command. */
struct grub_script_cmdwhile
{
struct grub_script_cmd cmd;
/* The command list used as condition. */
struct grub_script_cmd *cond;
/* The command list executed in each loop. */
struct grub_script_cmd *list;
/* The flag to indicate this as "until" loop. */
int until;
};
/* A menu entry generate statement. */
struct grub_script_cmd_menuentry
{
@ -234,6 +249,12 @@ grub_script_create_cmdfor (struct grub_parser_param *state,
struct grub_script_arglist *words,
struct grub_script_cmd *list);
struct grub_script_cmd *
grub_script_create_cmdwhile (struct grub_parser_param *state,
struct grub_script_cmd *cond,
struct grub_script_cmd *list,
int is_an_until_loop);
struct grub_script_cmd *
grub_script_create_cmdmenu (struct grub_parser_param *state,
struct grub_script_arglist *arglist,
@ -283,6 +304,7 @@ grub_err_t grub_script_execute_cmdline (struct grub_script_cmd *cmd);
grub_err_t grub_script_execute_cmdblock (struct grub_script_cmd *cmd);
grub_err_t grub_script_execute_cmdif (struct grub_script_cmd *cmd);
grub_err_t grub_script_execute_cmdfor (struct grub_script_cmd *cmd);
grub_err_t grub_script_execute_cmdwhile (struct grub_script_cmd *cmd);
grub_err_t grub_script_execute_menuentry (struct grub_script_cmd *cmd);
/* Execute any GRUB pre-parsed command or script. */

View File

@ -308,6 +308,26 @@ grub_script_execute_cmdfor (struct grub_script_cmd *cmd)
return result;
}
/* Execute a "while" or "until" command. */
grub_err_t
grub_script_execute_cmdwhile (struct grub_script_cmd *cmd)
{
int cond;
int result;
struct grub_script_cmdwhile *cmdwhile = (struct grub_script_cmdwhile *) cmd;
result = 0;
do {
cond = grub_script_execute_cmd (cmdwhile->cond);
if ((cmdwhile->until && !cond) || (!cmdwhile->until && cond))
break;
result = grub_script_execute_cmd (cmdwhile->list);
} while (1); /* XXX Put a check for ^C here */
return result;
}
/* Execute the menu entry generate statement. */
grub_err_t
grub_script_execute_menuentry (struct grub_script_cmd *cmd)

View File

@ -76,8 +76,9 @@
%token <arg> GRUB_PARSER_TOKEN_WORD "word"
%type <arglist> word argument arguments0 arguments1
%type <cmd> script_init script grubcmd ifcmd forcmd command
%type <cmd> commands1 menuentry statement
%type <cmd> script_init script
%type <cmd> grubcmd ifcmd forcmd whilecmd untilcmd
%type <cmd> command commands1 menuentry statement
%pure-parser
%lex-param { struct grub_parser_param *state };
@ -173,9 +174,11 @@ grubcmd: word arguments0
;
/* A single command. */
command: grubcmd { $$ = $1; }
| ifcmd { $$ = $1; }
| forcmd { $$ = $1; }
command: grubcmd { $$ = $1; }
| ifcmd { $$ = $1; }
| forcmd { $$ = $1; }
| whilecmd { $$ = $1; }
| untilcmd { $$ = $1; }
;
/* A list of commands. */
@ -250,3 +253,25 @@ forcmd: "for" "name"
grub_script_lexer_deref (state->lexerstate);
}
;
whilecmd: "while"
{
grub_script_lexer_ref (state->lexerstate);
}
commands1 delimiters1 "do" commands1 delimiters1 "done"
{
$$ = grub_script_create_cmdwhile (state, $3, $6, 0);
grub_script_lexer_deref (state->lexerstate);
}
;
untilcmd: "until"
{
grub_script_lexer_ref (state->lexerstate);
}
commands1 delimiters1 "do" commands1 delimiters1 "done"
{
$$ = grub_script_create_cmdwhile (state, $3, $6, 1);
grub_script_lexer_deref (state->lexerstate);
}
;

View File

@ -245,6 +245,28 @@ grub_script_create_cmdfor (struct grub_parser_param *state,
return (struct grub_script_cmd *) cmd;
}
/* Create a "while" or "until" command. */
struct grub_script_cmd *
grub_script_create_cmdwhile (struct grub_parser_param *state,
struct grub_script_cmd *cond,
struct grub_script_cmd *list,
int is_an_until_loop)
{
struct grub_script_cmdwhile *cmd;
cmd = grub_script_malloc (state, sizeof (*cmd));
if (! cmd)
return 0;
cmd->cmd.exec = grub_script_execute_cmdwhile;
cmd->cmd.next = 0;
cmd->cond = cond;
cmd->list = list;
cmd->until = is_an_until_loop;
return (struct grub_script_cmd *) cmd;
}
/* Create a command that adds a menu entry to the menu. Title is an
argument that is parsed to generate a string that can be used as
the title. The sourcecode for this entry is passed in SOURCECODE.

View File

@ -87,6 +87,12 @@ grub_script_execute_cmdfor (struct grub_script_cmd *cmd __attribute__ ((unused))
return 0;
}
grub_err_t
grub_script_execute_cmdwhile (struct grub_script_cmd *cmd __attribute__ ((unused)))
{
return 0;
}
grub_err_t
grub_script_execute_menuentry (struct grub_script_cmd *cmd __attribute__ ((unused)))
{