From 94e7a55b97211092845d4bf4365700f38a68f300 Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Tue, 18 May 2021 20:02:56 +0300
Subject: [PATCH] builtin: implement -d trace_error

With debugger backtraces, it can help pinpoint the original source of a
bubbled error, until we can store stacktraces in the errors in an
efficient way.
---
 vlib/builtin/option.v | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/vlib/builtin/option.v b/vlib/builtin/option.v
index 6ab693ac2f..90a352ffaa 100644
--- a/vlib/builtin/option.v
+++ b/vlib/builtin/option.v
@@ -35,10 +35,16 @@ fn (_ None__) str() string {
 	return 'none'
 }
 
+[if trace_error]
+fn trace_error(x string) {
+	eprintln('> ${@FN} | $x')
+}
+
 // error returns a default error instance containing the error given in `message`.
 // Example: `if ouch { return error('an error occurred') }`
 [inline]
 pub fn error(message string) IError {
+	trace_error(message)
 	return &Error{
 		msg: message
 	}
@@ -48,6 +54,7 @@ pub fn error(message string) IError {
 // `if ouch { return error_with_code('an error occurred', 1) }`
 [inline]
 pub fn error_with_code(message string, code int) IError {
+	trace_error('$message | code: $code')
 	return &Error{
 		msg: message
 		code: code