From 8b7d2bc270af4bc873303e7c43000e49a0d5fa5a Mon Sep 17 00:00:00 2001
From: Dylan MacKenzie <ecstaticmorse@gmail.com>
Date: Wed, 6 Nov 2019 11:41:27 -0800
Subject: [PATCH] Add E0744 for control flow in consts

---
 src/librustc_passes/error_codes.rs | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/librustc_passes/error_codes.rs b/src/librustc_passes/error_codes.rs
index e22e69a0697..3f5b0dcab74 100644
--- a/src/librustc_passes/error_codes.rs
+++ b/src/librustc_passes/error_codes.rs
@@ -626,6 +626,28 @@ async fn foo() {}
 Switch to the Rust 2018 edition to use `async fn`.
 "##,
 
+E0744: r##"
+Control-flow expressions are not allowed inside a const context.
+
+At the moment, `if` and `match`, as well as the looping constructs `for`,
+`while`, and `loop`, are forbidden inside a `const`, `static`, or `const fn`.
+
+```compile_fail,E0744
+const _: {
+    let mut x = 0;
+    loop {
+        x += 1;
+        if x == 4 {
+            break;
+        }
+    }
+
+    x
+};
+```
+
+"##,
+
 ;
     E0226, // only a single explicit lifetime bound is permitted
     E0472, // asm! is unsupported on this target