Updated by Shantanu Goel, to accept action keywords only inside $(...) and

only variable values inside ${...}.

2 files changed, 118 insertions, 140 deletions

diff --git a/boot/boot_script.c b/boot/boot_script.c
index ca71ccc3..64548d4f 100644
--- a/boot/boot_script.c
+++ b/boot/boot_script.c
@@ -1,4 +1,6 @@
-/* Script parser for Mach.  */
+/* Boot script parser for Mach.  */
+
+/* Written by Shantanu Goel (goel@cs.columbia.edu).  */
 
 #include <mach/mach_types.h>
 #include <mach/message.h>
@@ -36,11 +38,7 @@ struct cmd
 struct sym
 {
   /* Symbol name.  */
-  char *name;
-
-  /* Pointer to function that returns symbol value.
-     The function should return 0 on success, non-zero otherwise.  */
-  int (*func) (struct cmd *cmd, int *val);
+  const char *name;
 
   /* Type of value returned by function.  */
   int type;
@@ -48,22 +46,21 @@ struct sym
   /* Symbol value.  */
   int val;
 
-  /* If set, don't create an argument if the symbol
-     appears by itself in an expression.  */
-  int no_arg;
+  /* For function symbols; type of value returned by function.  */
+  int ret_type;
 
-  /* If set, execute function at the time of command execution,
-     not during parsing.  A function with this field set must
-     also have `no_arg' set.  Also, the function's `val' argument
-     will always be NULL.  */
+  /* For function symbols; if set, execute function at the time
+     of command execution, not during parsing.  A function with
+     this field set must also have `no_arg' set.  Also, the function's
+     `val' argument will always be NULL.  */
   int run_on_exec;
 };
 
-/* Type of values symbols can have.  */
+/* Additional values symbols can take.
+   These are only used internally.  */
 #define VAL_NONE	0	/* none */
-#define VAL_STR		1	/* string */
-#define VAL_PORT	2	/* port */
 #define VAL_SYM		3	/* symbol table entry */
+#define VAL_FUNC	4	/* function pointer */
 
 /* This structure describes an argument.  */
 struct arg
@@ -119,47 +116,11 @@ resume_task (struct cmd *cmd, int *val)
   return 0;
 }
 
-/* Return a send right to the host port.  */
-static int
-get_host_port (struct cmd *cmd, int *val)
-{
-  *val = (int) boot_script_host_port;
-  return 0;
-}
-
-/* Return a send right to the master device port.  */
-static int
-get_device_port (struct cmd *cmd, int *val)
-{
-  *val = (int) boot_script_device_port;
-  return 0;
-}
-
-/* Return the root device name.  */
-static int
-get_root_device (struct cmd *cmd, int *val)
-{
-  *val = (int) boot_script_root_device;
-  return 0;
-}
-
-/* Set the bootstrap port for a task.  */
-static int
-set_bootstrap_port (struct cmd *cmd, int *val)
-{
-  boot_script_set_bootstrap_port (cmd->task, boot_script_bootstrap_port);
-  return 0;
-}
-
 /* List of builtin symbols.  */
 static struct sym builtin_symbols[] =
 {
-  { "task-create", create_task, VAL_PORT, 0, 1, 0 },
-  { "task-resume", resume_task, VAL_NONE, 0, 1, 1 },
-  { "host-port", get_host_port, VAL_PORT, 0, 0, 0 },
-  { "device-port", get_device_port, VAL_PORT, 0, 0, 0 },
-  { "bootstrap-port", set_bootstrap_port, VAL_NONE, 0, 1, 0 },
-  { "root-device", get_root_device, VAL_STR, 0, 0, 0 }
+  { "task-create", VAL_FUNC, (int) create_task, VAL_PORT, 0 },
+  { "task-resume", VAL_FUNC, (int) resume_task, VAL_NONE, 1 }
 };
 #define NUM_BUILTIN (sizeof (builtin_symbols) / sizeof (builtin_symbols[0]))
 
@@ -266,7 +227,7 @@ add_arg (struct cmd *cmd, char *text, int type, int val)
 
 /* Search for the symbol NAME in the symbol table.  */
 static struct sym *
-sym_lookup (char *name)
+sym_lookup (const char *name)
 {
   int i;
 
@@ -278,7 +239,7 @@ sym_lookup (char *name)
 
 /* Create an entry for symbol NAME in the symbol table.  */
 static struct sym *
-sym_enter (char *name)
+sym_enter (const char *name)
 {
   struct sym *sym;
 
@@ -345,9 +306,9 @@ boot_script_parse_line (char *cmdline)
 	}
 
       /* Look for a symbol.  */
-      if (arg || (*p == '$' && *(p + 1) == '{'))
+      if (arg || (*p == '$' && (*(p + 1) == '{' || *(p + 1) == '(')))
 	{
-	  int saw_assignment = 0;
+	  char end_char = (*(p + 1) == '{') ? '}' : ')';
 	  struct sym *sym = 0;
 
 	  for (p += 2;;)
@@ -357,9 +318,10 @@ boot_script_parse_line (char *cmdline)
 	      struct sym *s;
 
 	      /* Parse symbol name.  */
-	      for (q = p; *q && *q != '\n' && *q != '}' && *q != '='; q++)
+	      for (q = p; *q && *q != '\n' && *q != end_char && *q != '='; q++)
 		;
-	      if (p == q || ! *q || *q == '\n')
+	      if (p == q || ! *q || *q == '\n'
+		  || (end_char == '}' && *q != '}'))
 		{
 		  error = BOOT_SCRIPT_SYNTAX_ERROR;
 		  goto bad;
@@ -377,31 +339,51 @@ boot_script_parse_line (char *cmdline)
 		  is_builtin = 1;
 		  s = &builtin_symbols[i];
 
+		  /* Only values are allowed in ${...} constructs.  */
+		  if (end_char == '}' && s->type == VAL_FUNC)
+		    return BOOT_SCRIPT_INVALID_SYM;
+
 		  /* Check that assignment is valid.  */
-		  if (c != '}' || ((arg || sym) && s->type == VAL_NONE))
+		  if (end_char == ')'
+		      && (c != end_char
+			  || ((arg || sym)
+			      && s->type == VAL_FUNC
+			      && (s->run_on_exec
+				  || s->ret_type == VAL_NONE))))
 		    {
 		      error = BOOT_SCRIPT_INVALID_ASG;
 		      goto bad;
 		    }
 
-		  if (! s->run_on_exec)
+		  /* For function symbols, execute the function.  */
+		  if (s->type == VAL_FUNC)
 		    {
-		      error = (*s->func) (cmd, &val);
-		      if (error)
-			goto bad;
-		      type = s->type;
+		      if (! s->run_on_exec)
+			{
+			  (error
+			   = ((*((int (*) (struct cmd *, int *)) s->val))
+			      (cmd, &val)));
+			  if (error)
+			    goto bad;
+			  type = s->ret_type;
+			}
+		      else
+			{
+			  if (add_list (s, (void ***) &cmd->exec_funcs,
+					&cmd->exec_funcs_alloc,
+					&cmd->exec_funcs_index, 5))
+			    {
+			      error = BOOT_SCRIPT_NOMEM;
+			      goto bad;
+			    }
+			  type = VAL_NONE;
+			  goto out;
+			}
 		    }
 		  else
 		    {
-		      if (add_list (s, (void ***) &cmd->exec_funcs,
-				    &cmd->exec_funcs_alloc,
-				    &cmd->exec_funcs_index, 5))
-			{
-			  error = BOOT_SCRIPT_NOMEM;
-			  goto bad;
-			}
-		      type = VAL_NONE;
-		      goto out;
+		      type = s->type;
+		      val = s->val;
 		    }
 		}
 	      else
@@ -435,26 +417,19 @@ boot_script_parse_line (char *cmdline)
 
 	    out:
 	      p = q + 1;
-	      if (c == '}')
+	      if (c == end_char)
 		{
 		  /* Create an argument if necessary.
 		     We create an argument if the symbol appears
-		     in the expression by itself, and it's `no_arg'
-		     field is 0.
+		     in the expression by itself.
 
 		     NOTE: This is temporary till the boot filesystem
 		     servers support arguments.  When that happens,
 		     symbol values will only be printed if they're
 		     associated with an argument.  */
-		  if (! arg && ! saw_assignment && ! s->no_arg)
+		  if (! arg && end_char == '}')
 		    {
-		      struct arg *a;
-
-		      if (is_builtin)
-			a = add_arg (cmd, 0, type, val);
-		      else
-			a = add_arg (cmd, 0, VAL_SYM, (int) s);
-		      if (! a)
+		      if (! add_arg (cmd, 0, type, val))
 			{
 			  error = BOOT_SCRIPT_NOMEM;
 			  goto bad;
@@ -463,8 +438,6 @@ boot_script_parse_line (char *cmdline)
 		  arg = 0;
 		  break;
 		}
-	      else
-		saw_assignment = 1;
 	      if (! is_builtin)
 		sym = s;
 	    }
@@ -473,7 +446,7 @@ boot_script_parse_line (char *cmdline)
 	{
 	  char c;
 
-	  /* Command argument.  Just copy the text.  */
+	  /* Command argument; just copy the text.  */
 	  for (q = p;; q++)
 	    {
 	      if (! *q || *q == ' ' || *q == '\t' || *q == '\n')
@@ -560,7 +533,7 @@ boot_script_exec ()
       memcpy (cmdline, cmd->path, cmdline_index);
 
       /* Allocate argument vector.  */
-      argv = boot_script_malloc (sizeof (char *) * (cmd->args_index + 1));
+      argv = boot_script_malloc (sizeof (char *) * (cmd->args_index + 2));
       if (! argv)
 	{
 	  boot_script_free (cmdline, cmdline_alloc);
@@ -591,8 +564,8 @@ boot_script_exec ()
 	  /* Add value of any symbol associated with this argument.  */
 	  if (arg->type != VAL_NONE)
 	    {
-	      char *p = 0, buf[50];
-	      int len = 0;
+	      char *p, buf[50];
+	      int len;
 
 	      if (arg->type == VAL_SYM)
 		{
@@ -638,6 +611,10 @@ boot_script_exec ()
 		    }
 		  while (i /= 10);
 		  break;
+
+		default:
+		  error = BOOT_SCRIPT_BAD_TYPE;
+		  goto done;
 		}
 	      len++;
 	      CHECK_CMDLINE_LEN (len);
@@ -664,7 +641,7 @@ boot_script_exec ()
 
     done:
       boot_script_free (cmdline, cmdline_alloc);
-      boot_script_free (argv, (cmd->args_index + 1) * sizeof (char *));
+      boot_script_free (argv, (cmd->args_index + 2) * sizeof (char *));
       if (error)
 	{
 	  cleanup (1);
@@ -682,7 +659,8 @@ boot_script_exec ()
 	for (i = 0; i < cmd->exec_funcs_index; i++)
 	  {
 	    struct sym *sym = cmd->exec_funcs[i];
-	    int error = (*sym->func) (cmd, 0);
+	    int error = ((*((int (*) (struct cmd *, int *)) sym->val))
+			 (cmd, 0));
 	    if (error)
 	      {
 		cleanup (1);
@@ -694,6 +672,21 @@ boot_script_exec ()
   cleanup (0);
   return 0;
 }
+
+/* Create an entry for the variable NAME with TYPE and value VAL,
+   in the symbol table.  */
+int
+boot_script_set_variable (const char *name, int type, int val)
+{
+  struct sym *sym = sym_enter (name);
+
+  if (sym)
+    {
+      sym->type = type;
+      sym->val = val;
+    }
+  return sym ? 0 : 1;
+}
 
 /* Return a string describing ERR.  */
 char *
@@ -718,22 +711,23 @@ boot_script_error_string (int err)
 
     case BOOT_SCRIPT_EXEC_ERROR:
       return "exec error";
+
+    case BOOT_SCRIPT_INVALID_SYM:
+      return "invalid variable in expression";
+
+    case BOOT_SCRIPT_BAD_TYPE:
+      return "invalid value type";
     }
   return 0;
 }
 
 #ifdef BOOT_SCRIPT_TEST
-#include <mach.h>
 #include <stdio.h>
 
 extern void *malloc (int size);
 extern void free (void *ptr);
 
-char *boot_script_root_device = "hd0a";
 mach_port_t boot_script_task_port;
-mach_port_t boot_script_host_port;
-mach_port_t boot_script_device_port;
-mach_port_t boot_script_bootstrap_port = MACH_PORT_NULL;
 
 void *
 boot_script_malloc (int size)
@@ -750,32 +744,24 @@ boot_script_free (void *ptr, int size)
 mach_port_t
 boot_script_task_create ()
 {
-  mach_port_t task;
+  static mach_port_t task = 10;
 
-  if (task_create (mach_task_self (), FALSE, &task))
-    return 0;
-  return task;
+  return task++;
 }
 
 void
 boot_script_task_terminate (mach_port_t task)
 {
-  task_terminate (task);
 }
 
 void
 boot_script_task_suspend (mach_port_t task)
 {
-  task_suspend (task);
 }
 
 int
 boot_script_task_resume (mach_port_t task)
 {
-  mach_port_t bootport;
-
-  task_get_bootstrap_port (task, &bootport);
-  printf ("bootstrap port %d\n", bootport);
   printf ("boot_script_task_resume()\n");
   return 0;
 }
@@ -783,30 +769,22 @@ boot_script_task_resume (mach_port_t task)
 void
 boot_script_port_deallocate (mach_port_t task, mach_port_t port)
 {
-  mach_port_deallocate (task, port);
 }
 
 int
 boot_script_port_insert_right (mach_port_t task, mach_port_t name,
 			       mach_port_t port, mach_msg_type_name_t right)
 {
-  if (mach_port_insert_right (task, name, port, right))
-    return 1;
   return 0;
 }
 
-void
-boot_script_set_bootstrap_port (mach_port_t task, mach_port_t port)
-{
-  task_set_bootstrap_port (task, port);
-}
-
 int
 boot_script_exec_cmd (mach_port_t task, char *path, int argc,
 		      char **argv, char *strings, int stringlen)
 {
   int i;
 
+  printf ("port = %d: ", (int) task);
   for (i = 0; i < argc; i++)
     printf ("%s ", argv[i]);
   printf ("\n");
@@ -819,6 +797,7 @@ main (int argc, char **argv)
   char buf[500], *p;
   int len;
   FILE *fp;
+  mach_port_t host_port, device_port;
 
   if (argc < 2)
     {
@@ -831,14 +810,12 @@ main (int argc, char **argv)
       fprintf (stderr, "Can't open %s\n", argv[1]);
       exit (1);
     }
-  boot_script_task_port = mach_task_self ();
-  boot_script_host_port = task_by_pid (-1);
-  boot_script_device_port = task_by_pid (-2);
-  if (! boot_script_host_port || ! boot_script_device_port)
-    {
-      fprintf (stderr, "Unable to get privileged ports\n");
-      exit (1);
-    }
+  host_port = 1;
+  device_port = 2;
+  boot_script_set_variable ("host-port", VAL_PORT, (int) host_port);
+  boot_script_set_variable ("device-port", VAL_PORT, (int) device_port);
+  boot_script_set_variable ("root-device", VAL_STR, (int) "hd0a");
+  boot_script_set_variable ("boot-args", VAL_STR, (int) "-ad");
   p = buf;
   len = sizeof (buf);
   while (fgets (p, len, fp))
diff --git a/boot/boot_script.h b/boot/boot_script.h
index 88a6bf49..1166232b 100644
--- a/boot/boot_script.h
+++ b/boot/boot_script.h
@@ -1,3 +1,7 @@
+/* Definitions for boot script parser for Mach.  */
+
+/* Written by Shantanu Goel (goel@cs.columbia.edu).  */
+
 /* Error codes returned by boot_script_parse_line()
    and boot_script_exec_cmd().  */
 #define BOOT_SCRIPT_NOMEM		1
@@ -6,25 +10,17 @@
 #define BOOT_SCRIPT_MACH_ERROR		4
 #define BOOT_SCRIPT_UNDEF_SYM		5
 #define BOOT_SCRIPT_EXEC_ERROR		6
+#define BOOT_SCRIPT_INVALID_SYM		7
+#define BOOT_SCRIPT_BAD_TYPE		8
 
-/* The user must define this variable.  The root device name.
-   This must be initialized prior to calling the parser.  */
-extern char *boot_script_root_device;
+/* Legal values for argument `type' to function
+   boot_script_set_variable().  */
+#define VAL_STR		1	/* string */
+#define VAL_PORT	2	/* port */
 
 /* The user must define this variable.  The task port of the program.  */
 extern mach_port_t boot_script_task_port;
 
-/* The user must define this variable.  Send right to the host port.  */
-extern mach_port_t boot_script_host_port;
-
-/* The user must define this variable.  Send right to the
-   master device port.  */
-extern mach_port_t boot_script_device_port;
-
-/* The user must define this variable.  Send right to the
-   the bootstrap port.  */
-extern mach_port_t boot_script_bootstrap_port;
-
 /* The user must define this function.  Allocate SIZE bytes of memory
    and return a pointer to it.  */
 void *boot_script_malloc (int size);
@@ -87,5 +83,10 @@ int boot_script_parse_line (char *cmdline);
    Returns 0 for success, non-zero otherwise.  */
 int boot_script_exec (void);
 
+/* Create an entry in the symbol table for variable NAME,
+   whose type is TYPE and value is VAL.  Returns 0 on success,
+   non-zero otherwise.  */
+int boot_script_set_variable (const char *name, int type, int val);
+
 /* Returns a string describing the error ERR.  */
 char *boot_script_error_string (int err);