vlib: debug CLI macro expander, part deux

Deal with circular macro definitions instead of crashing due to stack
overflow.

Separate macro tables, per CLI session

Add documentation to the Sphinx docs

Type: improvement

Signed-off-by: Dave Barach <dave@barachs.net>
Change-Id: I55fc9152bd37ad0c15fa3959f38b07b63100e634

1 files changed, 34 insertions, 11 deletions

diff --git a/src/vlib/unix/cli.c b/src/vlib/unix/cli.c
index 6b02fdf9bf5..5979dbdbd6a 100644
--- a/src/vlib/unix/cli.c
+++ b/src/vlib/unix/cli.c
@@ -242,6 +242,8 @@ typedef struct
    */
   u8 cursor_direction;
 
+  /** Macro tables for this session */
+  clib_macro_main_t macro_main;
 } unix_cli_file_t;
 
 /** Resets the pager buffer and other data.
@@ -493,7 +495,7 @@ typedef struct
   /** List of new sessions */
   unix_cli_new_session_t *new_sessions;
 
-  /* Macro expander */
+  /** system default macro table */
   clib_macro_main_t macro_main;
 
 } unix_cli_main_t;
@@ -501,6 +503,24 @@ typedef struct
 /** CLI global state */
 static unix_cli_main_t unix_cli_main;
 
+/** Return the macro main / tables we should use for this session
+ */
+static clib_macro_main_t *
+get_macro_main (void)
+{
+  unix_cli_main_t *cm = &unix_cli_main;
+  vlib_main_t *vm = vlib_get_main ();
+  vlib_process_t *cp = vlib_get_current_process (vm);
+  unix_cli_file_t *cf;
+
+  if (pool_is_free_index (cm->cli_file_pool, cp->output_function_arg))
+    return (&cm->macro_main);
+
+  cf = pool_elt_at_index (cm->cli_file_pool, cp->output_function_arg);
+
+  return (&cf->macro_main);
+}
+
 /**
  * @brief Search for a byte sequence in the action list.
  *
@@ -2575,9 +2595,11 @@ more:
       vec_validate (cf->current_command, vec_len (cf->current_command));
       cf->current_command[vec_len (cf->current_command) - 1] = 0;
       /* The macro expander expects proper C-strings, not vectors */
-      expanded = (u8 *) clib_macro_eval (&cm->macro_main,
+      expanded = (u8 *) clib_macro_eval (&cf->macro_main,
 					 (i8 *) cf->current_command,
-					 1 /* complain */ );
+					 1 /* complain */ ,
+					 0 /* level */ ,
+					 8 /* max_level */ );
       /* Macro processor NULL terminates the return */
       _vec_len (expanded) -= 1;
       vec_reset_length (cf->current_command);
@@ -2689,6 +2711,7 @@ unix_cli_kill (unix_cli_main_t * cm, uword cli_file_index)
   clib_file_del (fm, uf);
 
   unix_cli_file_free (cf);
+  clib_macro_free (&cf->macro_main);
   pool_put (cm->cli_file_pool, cf);
 }
 
@@ -2906,6 +2929,7 @@ unix_cli_file_add (unix_cli_main_t * cm, char *name, int fd)
 
   pool_get (cm->cli_file_pool, cf);
   clib_memset (cf, 0, sizeof (*cf));
+  clib_macro_init (&cf->macro_main);
 
   template.read_function = unix_cli_read_ready;
   template.write_function = unix_cli_write_ready;
@@ -3962,7 +3986,7 @@ define_cmd_fn (vlib_main_t * vm,
 {
   u8 *macro_name;
   unformat_input_t _line_input, *line_input = &_line_input;
-  unix_cli_main_t *cm = &unix_cli_main;
+  clib_macro_main_t *mm = get_macro_main ();
   clib_error_t *error;
 
   if (!unformat (input, "%s", &macro_name))
@@ -3980,8 +4004,7 @@ define_cmd_fn (vlib_main_t * vm,
     }
   /* the macro expander expects c-strings, not vectors... */
   vec_add1 (line_input->buffer, 0);
-  clib_macro_set_value (&cm->macro_main, (char *) macro_name,
-			(char *) line_input->buffer);
+  clib_macro_set_value (mm, (char *) macro_name, (char *) line_input->buffer);
   vec_free (macro_name);
   unformat_free (line_input);
   return 0;
@@ -4001,12 +4024,12 @@ undefine_cmd_fn (vlib_main_t * vm,
 		 unformat_input_t * input, vlib_cli_command_t * cmd)
 {
   u8 *macro_name;
-  unix_cli_main_t *cm = &unix_cli_main;
+  clib_macro_main_t *mm = get_macro_main ();
 
   if (!unformat (input, "%s", &macro_name))
     return clib_error_return (0, "missing variable name...");
 
-  if (clib_macro_unset (&cm->macro_main, (char *) macro_name))
+  if (clib_macro_unset (mm, (char *) macro_name))
     vlib_cli_output (vm, "%s wasn't set...", macro_name);
 
   vec_free (macro_name);
@@ -4025,7 +4048,7 @@ static clib_error_t *
 show_macro_cmd_fn (vlib_main_t * vm,
 		   unformat_input_t * input, vlib_cli_command_t * cmd)
 {
-  unix_cli_main_t *cm = &unix_cli_main;
+  clib_macro_main_t *mm = get_macro_main ();
   int evaluate = 1;
 
   if (unformat (input, "noevaluate %=", &evaluate, 0))
@@ -4033,8 +4056,7 @@ show_macro_cmd_fn (vlib_main_t * vm,
   else if (unformat (input, "noeval %=", &evaluate, 0))
     ;
 
-  vlib_cli_output (vm, "%U", format_clib_macro_main, &cm->macro_main,
-		   evaluate);
+  vlib_cli_output (vm, "%U", format_clib_macro_main, mm, evaluate);
   return 0;
 }
 
@@ -4055,6 +4077,7 @@ unix_cli_init (vlib_main_t * vm)
    * has not been started */
   cm->new_session_process_node_index = ~0;
   clib_macro_init (&cm->macro_main);
+
   return 0;
 }