From 96a6a5fec12a71b28db6cb8a22202e18a6ae9cf4 Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume1.gomez@gmail.com>
Date: Mon, 13 Jul 2020 15:34:38 +0200
Subject: [PATCH] Add color in rustdoc --test output

---
 src/librustdoc/doctest.rs | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/librustdoc/doctest.rs b/src/librustdoc/doctest.rs
index c79b2395d231..b49bbf3f8011 100644
--- a/src/librustdoc/doctest.rs
+++ b/src/librustdoc/doctest.rs
@@ -1,13 +1,14 @@
 use rustc_ast as ast;
 use rustc_data_structures::sync::Lrc;
-use rustc_errors::ErrorReported;
+use rustc_errors::{ColorConfig, ErrorReported};
+use rustc_feature::UnstableFeatures;
 use rustc_hir as hir;
 use rustc_hir::intravisit;
 use rustc_hir::{HirId, CRATE_HIR_ID};
 use rustc_interface::interface;
 use rustc_middle::hir::map::Map;
 use rustc_middle::ty::TyCtxt;
-use rustc_session::config::{self, CrateType};
+use rustc_session::config::{self, CrateType, ErrorOutputType};
 use rustc_session::{lint, DiagnosticOutput, Session};
 use rustc_span::edition::Edition;
 use rustc_span::source_map::SourceMap;
@@ -293,6 +294,18 @@ fn run_test(
             path.to_str().expect("target path must be valid unicode").to_string()
         }
     });
+    match options.error_format {
+        ErrorOutputType::HumanReadable(kind) => {
+            let (_, color_config) = kind.unzip();
+            match color_config {
+                ColorConfig::Never => {}
+                _ => {
+                    compiler.arg("--color").arg("always");
+                }
+            }
+        }
+        _ => {}
+    }
 
     compiler.arg("-");
     compiler.stdin(Stdio::piped());