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sched-vis: prevent visual_tbl overflow


While playing with scheduling, I introduced an insn with a huge
ready-delay, and this exercised a latent bug in sched-vis.c.  Tested
on i686-pc-linux-gnu with -dap.  Ok to install?

Index: gcc/ChangeLog
from  Alexandre Oliva  <aoliva@redhat.com>

	* sched-vis.c (visual_tbl_line_length): New variable.
	(get_visual_tbl_length): Set it.
	(visualize_stall_cycles): Don't let stalls overrun
	visual_tbl_line_length.

Index: gcc/sched-vis.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/sched-vis.c,v
retrieving revision 1.2
diff -u -p -r1.2 sched-vis.c
--- gcc/sched-vis.c 2000/12/05 16:51:13 1.2
+++ gcc/sched-vis.c 2000/12/05 21:41:18
@@ -82,6 +82,7 @@ insn_print_units (insn)
 #define MAX_VISUAL_LINES 100
 #define INSN_LEN 30
 int n_visual_lines;
+static int visual_tbl_line_length;
 char *visual_tbl;
 int n_vis_no_unit;
 rtx vis_no_unit[10];
@@ -133,6 +134,8 @@ get_visual_tbl_length ()
   n += n1;
   n += strlen ("\n") + 2;
 
+  visual_tbl_line_length = n;
+
   /* Compute length of visualization string.  */
   return (MAX_VISUAL_LINES * n);
 }
@@ -897,6 +900,8 @@ visualize_stall_cycles (stalls)
      int stalls;
 {
   int i;
+  const char *prefix = ";;       ";
+  const char *suffix = "\n";
 
   /* If no more room, split table into two.  */
   if (n_visual_lines >= MAX_VISUAL_LINES)
@@ -906,11 +911,19 @@ visualize_stall_cycles (stalls)
     }
 
   n_visual_lines++;
+
+  sprintf (visual_tbl + strlen (visual_tbl), "%s", prefix);
 
-  sprintf (visual_tbl + strlen (visual_tbl), ";;       ");
+  if (stalls > visual_tbl_line_length - strlen (prefix) - strlen (suffix))
+    {
+      suffix = "[...]\n";
+      stalls = visual_tbl_line_length - strlen (prefix) - strlen (suffix);
+    }
+
   for (i = 0; i < stalls; i++)
     sprintf (visual_tbl + strlen (visual_tbl), ".");
-  sprintf (visual_tbl + strlen (visual_tbl), "\n");
+
+  sprintf (visual_tbl + strlen (visual_tbl), "%s", suffix);
 }
 
 /* Allocate data used for visualization during scheduling.  */

-- 
Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Red Hat GCC Developer                  aoliva@{cygnus.com, redhat.com}
CS PhD student at IC-Unicamp        oliva@{lsd.ic.unicamp.br, gnu.org}
Free Software Evangelist    *Please* write to mailing lists, not to me

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