From da7a6f48757918088fe24db7d2cce23726f654df Mon Sep 17 00:00:00 2001
From: Kaushal Modi <kaushal.modi@gmail.com>
Date: Thu, 14 May 2020 01:27:57 -0400
Subject: [PATCH] Fail quickly if re or nre module is attempted to be compiled
 with js [backport] (#14341)

Fixes https://github.com/nim-lang/Nim/issues/14338 .

(cherry picked from commit a2a3fa10397bc96020a19936daf76b12e9ba9763)
---
 lib/impure/nre.nim | 3 +++
 lib/impure/re.nim  | 4 +++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/lib/impure/nre.nim b/lib/impure/nre.nim
index f0b3074f9d..5129c210f2 100644
--- a/lib/impure/nre.nim
+++ b/lib/impure/nre.nim
@@ -6,6 +6,9 @@
 #    distribution, for details about the copyright.
 #
 
+when defined(js):
+  {.error: "This library needs to be compiled with a c-like backend, and depends on PCRE.".}
+
 ## What is NRE?
 ## ============
 ##
diff --git a/lib/impure/re.nim b/lib/impure/re.nim
index 652a92d55d..af4cb71643 100644
--- a/lib/impure/re.nim
+++ b/lib/impure/re.nim
@@ -7,6 +7,9 @@
 #    distribution, for details about the copyright.
 #
 
+when defined(js):
+  {.error: "This library needs to be compiled with a c-like backend, and depends on PCRE.".}
+
 ## Regular expression support for Nim.
 ##
 ## This module is implemented by providing a wrapper around the
@@ -665,4 +668,3 @@ when isMainModule:
     doAssert replace("bar", re"^", "foo") == "foobar"
     doAssert replace("foo", re"", "-") == "-foo"
     doAssert replace("foo", re"$", "bar") == "foobar"
-