eval_error.c: rb_error_write flags

* eval_error.c (rb_error_write): add highlight and reverse mode
  flags.  defaulted to rb_stderr_tty_p() if Qnil.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62548 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

error.c

@@ -977,7 +977,7 @@ exc_to_s(VALUE exc)
 }
 
 /* FIXME: Include eval_error.c */
-void rb_error_write(VALUE errinfo, VALUE errat, VALUE str);
+void rb_error_write(VALUE errinfo, VALUE errat, VALUE str, VALUE highlight, VALUE reverse);
 
 /*
  * call-seq:
@@ -994,7 +994,7 @@ exc_full_message(VALUE exc)
 {
     VALUE str = rb_str_new2("");
     VALUE errat = rb_get_backtrace(exc);
-    rb_error_write(exc, errat, str);
+    rb_error_write(exc, errat, str, Qnil, Qnil);
     return str;
 }
 

eval_error.c

@@ -79,12 +79,16 @@ error_print(rb_execution_context_t *ec)
     rb_ec_error_print(ec, ec->errinfo);
 }
 
+#define CSI_BEGIN "\033["
+#define CSI_SGR "m"
+
+static const char underline[] = CSI_BEGIN"1;4"CSI_SGR;
+static const char bold[] = CSI_BEGIN"1"CSI_SGR;
+static const char reset[] = CSI_BEGIN""CSI_SGR;
+
 static void
 print_errinfo(const VALUE eclass, const VALUE errat, const VALUE emesg, const VALUE str, int highlight)
 {
-    static const char underline[] = "\033[4;1m";
-    static const char bold[] = "\033[1m";
-    static const char reset[] = "\033[m";
     const char *einfo = "";
     long elen = 0;
     VALUE mesg;
@@ -199,7 +203,7 @@ print_backtrace(const VALUE eclass, const VALUE errat, const VALUE str, int reve
 }
 
 void
-rb_error_write(VALUE errinfo, VALUE errat, VALUE str)
+rb_error_write(VALUE errinfo, VALUE errat, VALUE str, VALUE highlight, VALUE reverse)
 {
     volatile VALUE eclass = Qundef, emesg = Qundef;
 
@@ -216,13 +220,33 @@ rb_error_write(VALUE errinfo, VALUE errat, VALUE str)
 	    emesg = e;
 	}
     }
-    if (rb_stderr_tty_p()) {
-	write_warn(str, "\033[1mTraceback \033[m(most recent call last):\n");
+    if (NIL_P(reverse) || NIL_P(highlight)) {
+	VALUE tty = (VALUE)rb_stderr_tty_p();
+	if (NIL_P(reverse)) reverse = tty;
+	if (NIL_P(highlight)) highlight = tty;
+    }
+    if (reverse) {
+	static const char traceback[] = "Traceback "
+	    "(most recent call last):\n";
+	const int bold_part = rb_strlen_lit("Traceback");
+	char buff[sizeof(traceback)+sizeof(bold)+sizeof(reset)-2], *p = buff;
+	const char *msg = traceback;
+	long len = sizeof(traceback) - 1;
+	if (highlight) {
+#define APPEND(s, l) (memcpy(p, s, l), p += (l))
+	    APPEND(bold, sizeof(bold)-1);
+	    APPEND(traceback, bold_part);
+	    APPEND(reset, sizeof(reset)-1);
+	    APPEND(traceback + bold_part, sizeof(traceback)-bold_part-1);
+#undef APPEND
+	    len = p - (msg = buff);
+	}
+	write_warn2(str, msg, len);
 	print_backtrace(eclass, errat, str, TRUE);
-	print_errinfo(eclass, errat, emesg, str, TRUE);
+	print_errinfo(eclass, errat, emesg, str, highlight!=0);
     }
     else {
-	print_errinfo(eclass, errat, emesg, str, FALSE);
+	print_errinfo(eclass, errat, emesg, str, highlight!=0);
 	print_backtrace(eclass, errat, str, FALSE);
     }
 }
@@ -242,7 +266,7 @@ rb_ec_error_print(rb_execution_context_t * volatile ec, volatile VALUE errinfo)
 	errat = rb_get_backtrace(errinfo);
     }
 
-    rb_error_write(errinfo, errat, Qnil);
+    rb_error_write(errinfo, errat, Qnil, Qnil, Qnil);
 
     EC_POP_TAG();
     ec->errinfo = errinfo;