From bug-octave-request at bevo dot che dot wisc dot edu  Thu Apr 19 14:43:30 2001
Subject: eval() tramples on __error_text__
From: "John W. Eaton" <jwe at bevo dot che dot wisc dot edu>
To: Christoph Spiel <cspiel at hammersmith-consulting dot com>
Cc: bug-octave at bevo dot che dot wisc dot edu
Date: Thu, 19 Apr 2001 14:43:18 -0500

On 19-Apr-2001, Christoph Spiel <cspiel at hammersmith-consulting dot com> wrote:

| After John provided such a magnificent fix for
| setting __error_text__ in a catch block, I have
| looked at the behavior of the catch-string in
| eval().  While
| 
|     try clear a; a; catch e=__error_text__; end_try_catch; e
| 
| now works,
| 
|     eval("clear a; a;", "e=__error_text__"); e
| 
| does not:
| 
|     octave:1> try clear a; a; catch e=__error_text__; end_try_catch; e
|     e = `a' undefined near line 1 column 14
| 
|     octave:2> eval("clear a; a;", "e=__error_text__;"); e
|     e = 
|     octave:3> 

Please try the following patch.

Thanks,

jwe


2001-04-19  John W. Eaton  <jwe at bevo dot che dot wisc dot edu>

	* parse.y (fold (tree_binary_expression *)):
	Set discard_error_messages here instead of buffer_error_messages.
	Don't add clear_global_error_variable to the unwind_protect stack.
	(fold (tree_unary_expression *)): Likewise.
	(finish_colon_expression): Likewise.
	(finish_matrix): Likewise.

	* error.cc (panic): Set discard_error_messages to false here.
	(verror): Return immediately if discard_error_messages is true.

	* error.cc (discard_error_messages): New global variable.
	* error.h: Provide declaration.


Index: error.h
===================================================================
RCS file: /usr/local/cvsroot/octave/src/error.h,v
retrieving revision 1.27
diff -u -r1.27 error.h
--- error.h	2001/04/18 03:44:30	1.27
+++ error.h	2001/04/19 19:40:53
 at @ -47,6 +47,9 @@
 // the `unwind_protect' statement.
 extern bool buffer_error_messages;
 
+// TRUE means error messages are turned off.
+extern bool discard_error_messages;
+
 #endif
 
 /*
Index: error.cc
===================================================================
RCS file: /usr/local/cvsroot/octave/src/error.cc,v
retrieving revision 1.81
diff -u -r1.81 error.cc
--- error.cc	2001/04/18 03:44:30	1.81
+++ error.cc	2001/04/19 19:40:58
 at @ -68,6 +68,9 @@
 // the `unwind_protect' statement.
 bool buffer_error_messages = false;
 
+// TRUE means error messages are turned off.
+bool discard_error_messages = false;
+
 // The message buffer.
 static std::ostrstream *error_message_buffer = 0;
 
 at @ -99,6 +102,9 @@
 static void
 verror (const char *name, const char *fmt, va_list args)
 {
+  if (discard_error_messages)
+    return;
+
   if (! buffer_error_messages)
     flush_octave_stdout ();
 
 at @ -358,6 +364,7 @@
   va_list args;
   va_start (args, fmt);
   buffer_error_messages = false;
+  discard_error_messages = false;
   verror ("panic", fmt, args);
   va_end (args);
   abort ();
Index: parse.y
===================================================================
RCS file: /usr/local/cvsroot/octave/src/parse.y,v
retrieving revision 1.164
diff -u -r1.164 parse.y
--- parse.y	2001/02/26 20:26:15	1.164
+++ parse.y	2001/04/19 19:41:21
 at @ -1654,11 +1654,9 @@
 
   unwind_protect_int (error_state);
 
-  unwind_protect_bool (buffer_error_messages);
-  buffer_error_messages = true;
+  unwind_protect_bool (discard_error_messages);
+  discard_error_messages = true;
 
-  unwind_protect::add (clear_global_error_variable, 0);
-
   tree_expression *op1 = e->lhs ();
   tree_expression *op2 = e->rhs ();
 
 at @ -1703,11 +1701,9 @@
   unwind_protect::begin_frame ("fold_unary_expression");
 
   unwind_protect_int (error_state);
-
-  unwind_protect_bool (buffer_error_messages);
-  buffer_error_messages = true;
 
-  unwind_protect::add (clear_global_error_variable, 0);
+  unwind_protect_bool (discard_error_messages);
+  discard_error_messages = true;
 
   tree_expression *op = e->operand ();
 
 at @ -1754,11 +1750,9 @@
   unwind_protect::begin_frame ("finish_colon_expression");
 
   unwind_protect_int (error_state);
-
-  unwind_protect_bool (buffer_error_messages);
-  buffer_error_messages = true;
 
-  unwind_protect::add (clear_global_error_variable, 0);
+  unwind_protect_bool (discard_error_messages);
+  discard_error_messages = true;
 
   tree_expression *base = e->base ();
   tree_expression *limit = e->limit ();
 at @ -2633,11 +2627,9 @@
 
   unwind_protect_int (error_state);
 
-  unwind_protect_bool (buffer_error_messages);
-  buffer_error_messages = true;
+  unwind_protect_bool (discard_error_messages);
+  discard_error_messages = true;
 
-  unwind_protect::add (clear_global_error_variable, 0);
-
   if (m->all_elements_are_constant ())
     {
       octave_value tmp = m->rvalue ();
 at @ -3528,7 +3520,9 @@
 	  // errors that occurred in the first part of this eval().
 
 	  buffer_error_messages = false;
+
 	  bind_global_error_variable ();
+
 	  unwind_protect::add (clear_global_error_variable, 0);
 
 	  eval_string (args(1), 0, parse_status, nargout);



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