From 485697bf42cc6a03712e82e69c8f2357a2576454 Mon Sep 17 00:00:00 2001
From: Ximin Luo <infinity0@pwned.gg>
Date: Thu, 5 Sep 2019 00:14:09 -0700
Subject: [PATCH] Better way of conditioning the sanitizer builds

Previously the build would take the presence of the LLVM_CONFIG envvar to
mean that the sanitizers should be built, but this is a common envvar that
could be set for reasons unrelated to the rustc sanitizers.

This commit adds a new envvar RUSTC_BUILD_SANITIZERS and uses it instead.
---
 src/bootstrap/compile.rs   | 1 +
 src/librustc_asan/build.rs | 3 +++
 src/librustc_lsan/build.rs | 3 +++
 src/librustc_msan/build.rs | 3 +++
 src/librustc_tsan/build.rs | 3 +++
 5 files changed, 13 insertions(+)

diff --git a/src/bootstrap/compile.rs b/src/bootstrap/compile.rs
index 9d57a4f00d78..9a964457ef28 100644
--- a/src/bootstrap/compile.rs
+++ b/src/bootstrap/compile.rs
@@ -212,6 +212,7 @@ pub fn std_cargo(builder: &Builder<'_>,
                 emscripten: false,
             });
             cargo.env("LLVM_CONFIG", llvm_config);
+            cargo.env("RUSTC_BUILD_SANITIZERS", "1");
         }
 
         cargo.arg("--features").arg(features)
diff --git a/src/librustc_asan/build.rs b/src/librustc_asan/build.rs
index a2b4b090efb4..cc856ba68fbb 100644
--- a/src/librustc_asan/build.rs
+++ b/src/librustc_asan/build.rs
@@ -4,6 +4,9 @@ use build_helper::sanitizer_lib_boilerplate;
 use cmake::Config;
 
 fn main() {
+    if env::var("RUSTC_BUILD_SANITIZERS") != Ok("1".to_string()) {
+        return;
+    }
     if let Some(llvm_config) = env::var_os("LLVM_CONFIG") {
         build_helper::restore_library_path();
 
diff --git a/src/librustc_lsan/build.rs b/src/librustc_lsan/build.rs
index b8c7b7c2d553..d5f3e37dea51 100644
--- a/src/librustc_lsan/build.rs
+++ b/src/librustc_lsan/build.rs
@@ -4,6 +4,9 @@ use build_helper::sanitizer_lib_boilerplate;
 use cmake::Config;
 
 fn main() {
+    if env::var("RUSTC_BUILD_SANITIZERS") != Ok("1".to_string()) {
+        return;
+    }
     if let Some(llvm_config) = env::var_os("LLVM_CONFIG") {
         build_helper::restore_library_path();
 
diff --git a/src/librustc_msan/build.rs b/src/librustc_msan/build.rs
index 1c66b0a9cd3c..de1676f489a4 100644
--- a/src/librustc_msan/build.rs
+++ b/src/librustc_msan/build.rs
@@ -4,6 +4,9 @@ use build_helper::sanitizer_lib_boilerplate;
 use cmake::Config;
 
 fn main() {
+    if env::var("RUSTC_BUILD_SANITIZERS") != Ok("1".to_string()) {
+        return;
+    }
     if let Some(llvm_config) = env::var_os("LLVM_CONFIG") {
         build_helper::restore_library_path();
 
diff --git a/src/librustc_tsan/build.rs b/src/librustc_tsan/build.rs
index ed9c37087c7e..6df969125745 100644
--- a/src/librustc_tsan/build.rs
+++ b/src/librustc_tsan/build.rs
@@ -4,6 +4,9 @@ use build_helper::sanitizer_lib_boilerplate;
 use cmake::Config;
 
 fn main() {
+    if env::var("RUSTC_BUILD_SANITIZERS") != Ok("1".to_string()) {
+        return;
+    }
     if let Some(llvm_config) = env::var_os("LLVM_CONFIG") {
         build_helper::restore_library_path();