From 55cd2433dc2f5025137a96d65bf681dd64b6f7f7 Mon Sep 17 00:00:00 2001
From: Rich Kadel <richkadel@google.com>
Date: Thu, 27 Aug 2020 12:27:18 -0700
Subject: [PATCH] Adds --bless support to test/run-make-fulldeps

The ability to "bless" output for some of these tests is critical to
making it practical to adapt tests to unrelated changes.

This is needed for new coverage tests, as shown in PR #75828 (or its
derivative).
---
 src/tools/compiletest/src/runtest.rs | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
index 124a9adcab91a..965b20f5202e0 100644
--- a/src/tools/compiletest/src/runtest.rs
+++ b/src/tools/compiletest/src/runtest.rs
@@ -2782,6 +2782,18 @@ impl<'test> TestCx<'test> {
             cmd.env("RUSTFLAGS", "-Ctarget-feature=-crt-static").env("IS_MUSL_HOST", "1");
         }
 
+        if self.config.bless {
+            cmd.env("RUSTC_BLESS_TEST", "--bless");
+            // Assume this option is active if the environment variable is "defined", with _any_ value.
+            // As an example, a `Makefile` can use this option by:
+            //
+            //   ifdef RUSTC_BLESS_TEST
+            //       cp "$(TMPDIR)"/actual_something.ext expected_something.ext
+            //   else
+            //       $(DIFF) expected_something.ext "$(TMPDIR)"/actual_something.ext
+            //   endif
+        }
+
         if self.config.target.contains("msvc") && self.config.cc != "" {
             // We need to pass a path to `lib.exe`, so assume that `cc` is `cl.exe`
             // and that `lib.exe` lives next to it.