X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/mLib/blobdiff_plain/4ce6f42e899799bff22c1378deaa4a1a7ece7e91..ba9edb26cc236748197a91bb0a0ee960ab6d910c:/traceopt.c

diff --git a/traceopt.c b/traceopt.c
index 08cdd57..e1c2624 100644
--- a/traceopt.c
+++ b/traceopt.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: traceopt.c,v 1.1 1999/10/22 22:40:08 mdw Exp $
+ * $Id: traceopt.c,v 1.2 2001/02/03 16:25:43 mdw Exp $
  *
  * Parsing tracing options
  *
@@ -30,6 +30,10 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: traceopt.c,v $
+ * Revision 1.2  2001/02/03 16:25:43  mdw
+ * Various bug fixes: understand requests for help properly, and fix the
+ * logic for flag letters with `bad' flags.
+ *
  * Revision 1.1  1999/10/22 22:40:08  mdw
  * Separate function for parsing user trace specs.
  *
@@ -48,7 +52,7 @@
 
 /* --- @traceopt@ --- *
  *
- * Arguments:	@trace_opt *t@ = pointer to trace options table
+ * Arguments:	@const trace_opt *t@ = pointer to trace options table
  *		@const char *p@ = option string supplied by user
  *		@unsigned f@ = initial tracing flags
  *		@unsigned bad@ = forbidden tracing flags
@@ -60,18 +64,20 @@
  *		`?' character, a help message is displayed.
  */
 
-unsigned traceopt(trace_opt *t, const char *p, unsigned f, unsigned bad)
+unsigned traceopt(const trace_opt *t, const char *p,
+		  unsigned f, unsigned bad)
 {
   unsigned sense = 1;
 
   /* --- Dump out help text --- */
 
-  if (!p || strcmp(p, "?")) {
+  if (!p || !strcmp(p, "?")) {
+    const trace_opt *tt;
     puts("Trace options:");
-    while (t->ch) {
-      if (t->f & bad || !t->help)
+    for (tt = t; tt->ch; tt++) {
+      if (!(tt->f & ~bad) || !tt->help)
 	continue;
-      printf("  `%c': %s\n", t->ch, t->help);
+      printf("  `%c': %s\n", tt->ch, tt->help);
     }
     return (f);
   }
@@ -88,17 +94,17 @@ unsigned traceopt(trace_opt *t, const char *p, unsigned f, unsigned bad)
 	sense = 0;
 	break;
       default: {
-	trace_opt *tt;
+	const trace_opt *tt;
 	for (tt = t; tt->ch; tt++) {
-	  if (tt->f & bad)
+	  if (!(tt->f & ~bad))
 	    continue;
 	  if (tt->ch == *p) {
 	    if (sense)
 	      f |= (tt->f & ~bad);
 	    else
 	      f &= ~(tt->f & ~bad);
+	    goto ok;
 	  }
-	  goto ok;
 	}
 	moan("unknown trace option `%c'", *p);
       ok:;