Re: [RFA]: error_silent for use in pending breakpoint support

["J. Johnston" <jjohnstn at redhat dot com>]

Thanks.  I updated comments as asked.  The revised patch has been checked in.

-- Jeff J.

Andrew Cagney wrote:
> > Ok, patch revised.
> >
> > I chose to add a new version of catch_exceptions() called 
> > catch_exceptions_with_msg() which saves a copy of the error message 
> > (if an error occurs) for the caller to manually output if desired.  
> > The copy needs to be freed by the caller once the message is no longer 
> > needed.
> >
> > I removed error_last_output() and created a new function 
> > error_output_message() which takes pre_print text plus a message and 
> > outputs to gdb_stderr.
> >
> > Any other problems or ok to commit? 
>
>
> Much nicer - that nasty message buffer is better confied to top.c - 
> thank.  Just suggest more commentary here:
>
> > -      throw_exception (RETURN_ERROR);
> > +      error_silent ("No source file named %s.", copy);
>
> before committing (elena's already oked it from memory).
>
> tks.
> Andrew
Index: defs.h
===================================================================
RCS file: /cvs/src/src/gdb/defs.h,v
retrieving revision 1.137
diff -u -p -r1.137 defs.h
--- defs.h	17 Jan 2004 00:13:46 -0000	1.137
+++ defs.h	20 Jan 2004 02:03:33 -0000
@@ -1,7 +1,7 @@
 /* *INDENT-OFF* */ /* ATTR_FORMAT confuses indent, avoid running it for now */
 /* Basic, host-specific, and target-specific definitions for GDB.
    Copyright 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
-   1997, 1998, 1999, 2000, 2001, 2002, 2003
+   1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
    Free Software Foundation, Inc.
 
    This file is part of GDB.
@@ -911,6 +911,8 @@ extern NORETURN void verror (const char 
 
 extern NORETURN void error (const char *fmt, ...) ATTR_NORETURN ATTR_FORMAT (printf, 1, 2);
 
+extern NORETURN void error_silent (const char *fmt, ...) ATTR_NORETURN ATTR_FORMAT (printf, 1, 2);
+
 extern NORETURN void error_stream (struct ui_file *) ATTR_NORETURN;
 
 /* Initialize the error buffer.  */
@@ -920,6 +922,9 @@ extern void error_init (void);
    message.  */
 extern char *error_last_message (void);
 
+/* Output arbitrary error message.  */
+extern void error_output_message (char *pre_print, char *msg);
+
 extern NORETURN void internal_verror (const char *file, int line,
 				      const char *, va_list ap) ATTR_NORETURN;
 
@@ -982,6 +987,11 @@ extern NORETURN void throw_exception (en
    new cleanup_chain is established.  The old values are restored
    before catch_exceptions() returns.
 
+   The variant catch_exceptions_with_msg() is the same as
+   catch_exceptions() but adds the ability to return an allocated
+   copy of the gdb error message.  This is used when a silent error is 
+   issued and the caller wants to manually issue the error message.
+
    FIXME; cagney/2001-08-13: The need to override the global UIOUT
    builder variable should just go away.
 
@@ -994,6 +1004,11 @@ typedef int (catch_exceptions_ftype) (st
 extern int catch_exceptions (struct ui_out *uiout,
 			     catch_exceptions_ftype *func, void *func_args,
 			     char *errstring, return_mask mask);
+extern int catch_exceptions_with_msg (struct ui_out *uiout,
+			     	      catch_exceptions_ftype *func, 
+			     	      void *func_args,
+			     	      char *errstring, char **gdberrmsg,
+				      return_mask mask);
 
 /* If CATCH_ERRORS_FTYPE throws an error, catch_errors() returns zero
    otherwize the result from CATCH_ERRORS_FTYPE is returned. It is
Index: utils.c
===================================================================
RCS file: /cvs/src/src/gdb/utils.c,v
retrieving revision 1.111
diff -u -p -r1.111 utils.c
--- utils.c	2 Jan 2004 17:35:01 -0000	1.111
+++ utils.c	20 Jan 2004 02:03:33 -0000
@@ -1,7 +1,7 @@
 /* General utility routines for GDB, the GNU debugger.
 
    Copyright 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
-   1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003 Free Software
+   1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software
    Foundation, Inc.
 
    This file is part of GDB.
@@ -626,6 +626,38 @@ static void
 do_write (void *data, const char *buffer, long length_buffer)
 {
   ui_file_write (data, buffer, length_buffer);
+}
+
+/* Cause a silent error to occur.  Any error message is recorded
+   though it is not issued.  */
+NORETURN void
+error_silent (const char *string, ...)
+{
+  va_list args;
+  struct ui_file *tmp_stream = mem_fileopen ();
+  va_start (args, string);
+  make_cleanup_ui_file_delete (tmp_stream);
+  vfprintf_unfiltered (tmp_stream, string, args);
+  /* Copy the stream into the GDB_LASTERR buffer.  */
+  ui_file_rewind (gdb_lasterr);
+  ui_file_put (tmp_stream, do_write, gdb_lasterr);
+  va_end (args);
+
+  throw_exception (RETURN_ERROR);
+}
+
+/* Output an error message including any pre-print text to gdb_stderr.  */
+void
+error_output_message (char *pre_print, char *msg)
+{
+  target_terminal_ours ();
+  wrap_here ("");		/* Force out any buffered output */
+  gdb_flush (gdb_stdout);
+  annotate_error_begin ();
+  if (pre_print)
+    fputs_filtered (pre_print, gdb_stderr);
+  fputs_filtered (msg, gdb_stderr);
+  fprintf_filtered (gdb_stderr, "\n");
 }
 
 NORETURN void
Index: top.c
===================================================================
RCS file: /cvs/src/src/gdb/top.c,v
retrieving revision 1.86
diff -u -p -r1.86 top.c
--- top.c	2 Jan 2004 20:53:11 -0000	1.86
+++ top.c	20 Jan 2004 02:03:33 -0000
@@ -383,6 +383,7 @@ catcher (catch_exceptions_ftype *func,
 	 int *func_val,
 	 enum return_reason *func_caught,
 	 char *errstring,
+	 char **gdberrmsg,
 	 return_mask mask)
 {
   SIGJMP_BUF *saved_catch;
@@ -428,7 +429,14 @@ catcher (catch_exceptions_ftype *func,
   if (!caught)
     val = (*func) (func_uiout, func_args);
   else
-    val = 0;
+    {
+      val = 0;
+      /* If caller wants a copy of the low-level error message, make one.  
+         This is used in the case of a silent error whereby the caller
+         may optionally want to issue the message.  */
+      if (gdberrmsg)
+	*gdberrmsg = error_last_message ();
+    }
   catch_return = saved_catch;
 
   /* FIXME: cagney/1999-11-05: A correct FUNC implementation will
@@ -476,7 +484,25 @@ catch_exceptions (struct ui_out *uiout,
 {
   int val;
   enum return_reason caught;
-  catcher (func, uiout, func_args, &val, &caught, errstring, mask);
+  catcher (func, uiout, func_args, &val, &caught, errstring, NULL, mask);
+  gdb_assert (val >= 0);
+  gdb_assert (caught <= 0);
+  if (caught < 0)
+    return caught;
+  return val;
+}
+
+int
+catch_exceptions_with_msg (struct ui_out *uiout,
+		  	   catch_exceptions_ftype *func,
+		  	   void *func_args,
+		  	   char *errstring,
+			   char **gdberrmsg,
+		  	   return_mask mask)
+{
+  int val;
+  enum return_reason caught;
+  catcher (func, uiout, func_args, &val, &caught, errstring, gdberrmsg, mask);
   gdb_assert (val >= 0);
   gdb_assert (caught <= 0);
   if (caught < 0)
@@ -506,7 +532,8 @@ catch_errors (catch_errors_ftype *func, 
   struct catch_errors_args args;
   args.func = func;
   args.func_args = func_args;
-  catcher (do_catch_errors, uiout, &args, &val, &caught, errstring, mask);
+  catcher (do_catch_errors, uiout, &args, &val, &caught, errstring, 
+	   NULL, mask);
   if (caught != 0)
     return 0;
   return val;
Index: linespec.c
===================================================================
RCS file: /cvs/src/src/gdb/linespec.c,v
retrieving revision 1.53
diff -u -p -r1.53 linespec.c
--- linespec.c	17 Dec 2003 21:47:47 -0000	1.53
+++ linespec.c	20 Jan 2004 02:03:33 -0000
@@ -1,6 +1,6 @@
 /* Parser for linespec for the GNU debugger, GDB.
    Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
-   1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
+   1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
    Free Software Foundation, Inc.
 
    This file is part of GDB.
@@ -1469,7 +1469,14 @@ symtab_from_filename (char **argptr, cha
       if (not_found_ptr)
 	{
 	  *not_found_ptr = 1;
-	  throw_exception (RETURN_ERROR);
+	  /* The caller has indicated that it wishes quiet notification of any
+	     error where the function or file is not found.  A call to 
+	     error_silent causes an error to occur, but it does not issue 
+	     the supplied message.  The message can be manually output by
+	     the caller, if desired.  This is used, for example, when 
+	     attempting to set breakpoints for functions in shared libraries 
+	     that have not yet been loaded.  */
+	  error_silent ("No source file named %s.", copy);
 	}
       error ("No source file named %s.", copy);
     }
@@ -1684,7 +1691,14 @@ decode_variable (char *copy, int funfirs
   if (not_found_ptr)
     {
       *not_found_ptr = 1;
-      throw_exception (RETURN_ERROR);
+      /* The caller has indicated that it wishes quiet notification of any
+	 error where the function or file is not found.  A call to 
+	 error_silent causes an error to occur, but it does not issue 
+	 the supplied message.  The message can be manually output by
+	 the caller, if desired.  This is used, for example, when 
+	 attempting to set breakpoints for functions in shared libraries 
+	 that have not yet been loaded.  */
+      error_silent ("Function \"%s\" not defined.", copy);
     }
   
   error ("Function \"%s\" not defined.", copy);