* Documentation/user/tutorial.itely: Revised (continued).

[lilypond.git] / lily / parse-scm.cc

diff --git a/lily/parse-scm.cc b/lily/parse-scm.cc
index e65e4455110faf1510620829e6466ebf259ce920..c30547f71f92fcdd90421df9461331d8411c602c 100644 (file)
--- a/lily/parse-scm.cc
+++ b/lily/parse-scm.cc
@@ -1,23 +1,22 @@
 #include <stdio.h>
 
+#include "ly-module.hh"
 #include "lily-guile.hh"
+#include "main.hh"
+#include "paper-book.hh"
 #include "parse-scm.hh"
 #include "string.hh"
 #include "source-file.hh"
 
-/*
-  Pass string to scm parser, evaluate one expression.
-  Return result value and #chars read.
-
-  Thanks to Gary Houston <ghouston@freewire.co.uk>
-
-  Need guile-1.3.4 (>1.3 anyway) for ftell on str ports -- jcn
-*/
+/* Pass string to scm parser, evaluate one expression.
+   Return result value and #chars read.
+   
+   Thanks to Gary Houston <ghouston@freewire.co.uk>  */
 SCM
-internal_ly_parse_scm (Parse_start * ps)
+internal_ly_parse_scm (Parse_start * ps, bool safe)
 {
   Source_file* sf =ps->start_location_.source_file_;
-  SCM port = sf->get_port();
+  SCM port = sf->get_port ();
 
   int off = ps->start_location_.defined_str0_ - sf->to_str0();
   
@@ -29,25 +28,24 @@ internal_ly_parse_scm (Parse_start * ps)
 
   /* Read expression from port */
   if (!SCM_EOF_OBJECT_P (form = scm_read (port)))
-    answer = scm_primitive_eval (form);
+    {
+      if (safe)
+       {
+         static SCM safe_module;
+         if (!safe_module)
+           {
+             safe_module = scm_primitive_eval (ly_symbol2scm ("safe-module"));
+             if (output_format_global == PAGE_LAYOUT)
+               ly_import_module (safe_module, scm_c_resolve_module ("lily"));
+           }
+         answer = scm_eval (form, safe_module);
+       }
+      else
+       answer = scm_primitive_eval (form);
+    }
  
-  /*
-   After parsing
-
- (begin (foo 1 2))
-
-   all seems fine, but after parsing
-
- (foo 1 2)
-
-   read_buf has been advanced to read_pos - 1,
-   so that scm_ftell returns 1, instead of #parsed chars
-   */
-  
-  /*
-    urg: reset read_buf for scm_ftell
-    shouldn't scm_read () do this for us?
-  */
+  /* Reset read_buf for scm_ftell.
+     Shouldn't scm_read () do this for us?  */
   scm_fill_input (port);
   SCM to = scm_ftell (port);
   ps->nchars = gh_scm2int (to) - gh_scm2int (from);
@@ -55,31 +53,36 @@ internal_ly_parse_scm (Parse_start * ps)
   /* Don't close the port here; if we re-enter this function via a
      continuation, then the next time we enter it, we'll get an error.
      It's a string port anyway, so there's no advantage to closing it
-     early.
-
-     scm_close_port (port);
-  */
+     early. */
+  // scm_close_port (port);
 
   return answer;
 }
 
-
 SCM
 catch_protected_parse_body (void *p)
 {
   Parse_start *ps = (Parse_start*) p;
-  return internal_ly_parse_scm (ps);
+  return internal_ly_parse_scm (ps, false);
+}
+
+SCM
+safe_catch_protected_parse_body (void *p)
+{
+  Parse_start *ps = (Parse_start*) p;
+  return internal_ly_parse_scm (ps, true);
 }
 
 SCM 
 parse_handler (void * data, SCM tag, SCM args)
 {
   Parse_start* ps = (Parse_start*) data;
-
-  ps->start_location_.error (_("GUILE signaled an error for the expression begining here"));
+  (void) tag;                  // prevent warning
+  
+  ps->start_location_.error (_("GUILE signaled an error for the expression beginning here"));
 
   if (scm_ilength (args) > 2)
-    scm_display_error_message (gh_cadr (args), gh_caddr(args), scm_current_error_port());
+    scm_display_error_message (gh_cadr (args), gh_caddr (args), scm_current_error_port ());
 
   /*
     The following is a kludge; we should probably search for
@@ -103,29 +106,27 @@ parse_handler (void * data, SCM tag, SCM args)
 #endif
 
 SCM
-protected_ly_parse_scm (Parse_start *ps)
+protected_ly_parse_scm (Parse_start *ps, bool safe)
 {
   return scm_internal_catch (ly_symbol2scm (READ_ERROR),
-                            &catch_protected_parse_body,
-                            (void*)ps,
-                            &parse_handler, (void*)ps);
+                            (safe ? &safe_catch_protected_parse_body
+                             : catch_protected_parse_body),
+                            (void*) ps,
+                            &parse_handler, (void*) ps);
 }
 
-bool  parse_protect_global  = true; 
+bool parse_protect_global = true; 
 
-/*
-  Try parsing. If failure, then return SCM_UNDEFINED.
- */
+/* Try parsing.  Upon failure return SCM_UNDEFINED. */
 SCM
-ly_parse_scm (char const* s, int *n, Input i)
+ly_parse_scm (char const* s, int *n, Input i, bool safe)
 {
-  
   Parse_start ps ;
   ps.str = s;
   ps.start_location_ = i;
 
-  SCM ans = parse_protect_global ? protected_ly_parse_scm (&ps)
-    : internal_ly_parse_scm (&ps);
+  SCM ans = parse_protect_global ? protected_ly_parse_scm (&ps, safe)
+    : internal_ly_parse_scm (&ps, safe);
   *n = ps.nchars;
 
   return ans;