From 401614b75a1d653786fd527546d288e4cba3a58e Mon Sep 17 00:00:00 2001
From: Venkata Giri Reddy <venkatagirireddy@gmail.com>
Date: Fri, 30 Jun 2017 16:55:32 +0000
Subject: [PATCH 1/2] rustc_llvm: re-run build script when env var LLVM_CONFIG
 changes

---
 src/bootstrap/compile.rs   | 4 ----
 src/librustc_llvm/build.rs | 6 +-----
 2 files changed, 1 insertion(+), 9 deletions(-)

diff --git a/src/bootstrap/compile.rs b/src/bootstrap/compile.rs
index c8ab3a8fc1d99..b2bd792e93ba6 100644
--- a/src/bootstrap/compile.rs
+++ b/src/bootstrap/compile.rs
@@ -276,10 +276,6 @@ pub fn rustc(build: &Build, target: &str, compiler: &Compiler) {
     if build.is_rust_llvm(target) {
         cargo.env("LLVM_RUSTLLVM", "1");
     }
-    if let Some(ref cfg_file) = build.flags.config {
-        let cfg_path = t!(PathBuf::from(cfg_file).canonicalize());
-        cargo.env("CFG_LLVM_TOML", cfg_path.into_os_string());
-    }
     cargo.env("LLVM_CONFIG", build.llvm_config(target));
     let target_config = build.config.target_config.get(target);
     if let Some(s) = target_config.and_then(|c| c.llvm_config.as_ref()) {
diff --git a/src/librustc_llvm/build.rs b/src/librustc_llvm/build.rs
index 01b37a55f4fe7..3f0f5369607e5 100644
--- a/src/librustc_llvm/build.rs
+++ b/src/librustc_llvm/build.rs
@@ -60,11 +60,7 @@ fn main() {
         });
 
     println!("cargo:rerun-if-changed={}", llvm_config.display());
-
-    if let Some(cfg_toml) = env::var_os("CFG_LLVM_TOML") {
-        let cfg_path = PathBuf::from(cfg_toml);
-        println!("cargo:rerun-if-changed={}", cfg_path.display());
-    }
+    println!("cargo:rerun-if-env-changed=LLVM_CONFIG");
 
     // Test whether we're cross-compiling LLVM. This is a pretty rare case
     // currently where we're producing an LLVM for a different platform than

From 4f13da736220fc0d5f3218ac2763617f20b10b89 Mon Sep 17 00:00:00 2001
From: Venkata Giri Reddy <venkatagirireddy@gmail.com>
Date: Fri, 30 Jun 2017 17:35:00 +0000
Subject: [PATCH 2/2] rustc_{a,l,m,t}san: re-run build script if env var
 LLVM_CONFIG changes

---
 src/librustc_asan/build.rs | 1 +
 src/librustc_lsan/build.rs | 1 +
 src/librustc_msan/build.rs | 1 +
 src/librustc_tsan/build.rs | 1 +
 4 files changed, 4 insertions(+)

diff --git a/src/librustc_asan/build.rs b/src/librustc_asan/build.rs
index 3a80baa0485f5..cb7721affe761 100644
--- a/src/librustc_asan/build.rs
+++ b/src/librustc_asan/build.rs
@@ -32,4 +32,5 @@ fn main() {
             .build_target("asan")
             .build();
     }
+    println!("cargo:rerun-if-env-changed=LLVM_CONFIG");
 }
diff --git a/src/librustc_lsan/build.rs b/src/librustc_lsan/build.rs
index da53571a24390..3d2ae480de6df 100644
--- a/src/librustc_lsan/build.rs
+++ b/src/librustc_lsan/build.rs
@@ -32,4 +32,5 @@ fn main() {
             .build_target("lsan")
             .build();
     }
+    println!("cargo:rerun-if-env-changed=LLVM_CONFIG");
 }
diff --git a/src/librustc_msan/build.rs b/src/librustc_msan/build.rs
index dcadbe86966e7..7e2a82dd0ab94 100644
--- a/src/librustc_msan/build.rs
+++ b/src/librustc_msan/build.rs
@@ -32,4 +32,5 @@ fn main() {
             .build_target("msan")
             .build();
     }
+    println!("cargo:rerun-if-env-changed=LLVM_CONFIG");
 }
diff --git a/src/librustc_tsan/build.rs b/src/librustc_tsan/build.rs
index 5ea52f17a0fde..641d9c3647d39 100644
--- a/src/librustc_tsan/build.rs
+++ b/src/librustc_tsan/build.rs
@@ -32,4 +32,5 @@ fn main() {
             .build_target("tsan")
             .build();
     }
+    println!("cargo:rerun-if-env-changed=LLVM_CONFIG");
 }