Add/remove `rerun-if-changed` when necessary

src/Cargo.lock

@@ -221,6 +221,7 @@ dependencies = [
 name = "compiler_builtins"
 version = "0.0.0"
 dependencies = [
+ "build_helper 0.1.0",
  "core 0.0.0",
  "gcc 0.3.43 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

src/liballoc_jemalloc/build.rs

@@ -21,8 +21,6 @@ use std::process::Command;
 use build_helper::{run, rerun_if_changed_anything_in_dir, up_to_date};
 
 fn main() {
-    println!("cargo:rerun-if-changed=build.rs");
-
     // FIXME: This is a hack to support building targets that don't
     // support jemalloc alongside hosts that do. The jemalloc build is
     // controlled by a feature of the std crate, and if that feature

src/libcompiler_builtins/Cargo.toml

@@ -15,4 +15,5 @@ doc = false
 core = { path = "../libcore" }
 
 [build-dependencies]
+build_helper = { path = "../build_helper" }
 gcc = "0.3.27"

src/libcompiler_builtins/build.rs

@@ -33,6 +33,7 @@
 //! error (if any) and then we just add it to the list. Overall, that cost is
 //! far far less than working with compiler-rt's build system over time.
 
+extern crate build_helper;
 extern crate gcc;
 
 use std::collections::BTreeMap;
@@ -404,5 +405,8 @@ fn main() {
         cfg.file(Path::new("../compiler-rt/lib/builtins").join(src));
     }
 
+    // Can't reuse `sources` list becuse it doesn't contain header files.
+    build_helper::rerun_if_changed_anything_in_dir(Path::new("../compiler-rt"));
+
     cfg.compile("libcompiler-rt.a");
 }

src/libflate/build.rs

@@ -11,6 +11,7 @@
 extern crate gcc;
 
 fn main() {
+    println!("cargo:rerun-if-changed=../rt/miniz.c");
     gcc::Config::new()
         .file("../rt/miniz.c")
         .compile("libminiz.a");

src/librustc_asan/build.rs

@@ -34,6 +34,4 @@ fn main() {
                 .unwrap())
             .join("../compiler-rt"));
     }
-
-    println!("cargo:rerun-if-changed=build.rs");
 }

src/librustc_llvm/build.rs

@@ -144,9 +144,7 @@ fn main() {
         cfg.flag("-DLLVM_RUSTLLVM");
     }
 
-    println!("cargo:rerun-if-changed=../rustllvm/PassWrapper.cpp");
-    println!("cargo:rerun-if-changed=../rustllvm/RustWrapper.cpp");
-    println!("cargo:rerun-if-changed=../rustllvm/ArchiveWrapper.cpp");
+    build_helper::rerun_if_changed_anything_in_dir(Path::new("../rustllvm"));
     cfg.file("../rustllvm/PassWrapper.cpp")
        .file("../rustllvm/RustWrapper.cpp")
        .file("../rustllvm/ArchiveWrapper.cpp")

src/librustc_lsan/build.rs

@@ -34,6 +34,4 @@ fn main() {
                 .unwrap())
             .join("../compiler-rt"));
     }
-
-    println!("cargo:rerun-if-changed=build.rs");
 }

src/librustc_msan/build.rs

@@ -34,6 +34,4 @@ fn main() {
                 .unwrap())
             .join("../compiler-rt"));
     }
-
-    println!("cargo:rerun-if-changed=build.rs");
 }

src/librustc_tsan/build.rs

@@ -34,6 +34,4 @@ fn main() {
                 .unwrap())
             .join("../compiler-rt"));
     }
-
-    println!("cargo:rerun-if-changed=build.rs");
 }

src/librustdoc/build.rs

@@ -8,9 +8,12 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+extern crate build_helper;
 extern crate gcc;
 
 fn main() {
+    let src_dir = std::path::Path::new("../rt/hoedown/src");
+    build_helper::rerun_if_changed_anything_in_dir(src_dir);
     let mut cfg = gcc::Config::new();
     cfg.file("../rt/hoedown/src/autolink.c")
        .file("../rt/hoedown/src/buffer.c")
@@ -21,6 +24,6 @@ fn main() {
        .file("../rt/hoedown/src/html_smartypants.c")
        .file("../rt/hoedown/src/stack.c")
        .file("../rt/hoedown/src/version.c")
-       .include("../rt/hoedown/src")
+       .include(src_dir)
        .compile("libhoedown.a");
 }

src/libstd/build.rs

@@ -21,8 +21,6 @@ use std::process::Command;
 use build_helper::{run, rerun_if_changed_anything_in_dir, up_to_date};
 
 fn main() {
-    println!("cargo:rerun-if-changed=build.rs");
-
     let target = env::var("TARGET").expect("TARGET was not set");
     let host = env::var("HOST").expect("HOST was not set");
     if cfg!(feature = "backtrace") && !target.contains("apple") && !target.contains("msvc") &&

src/libunwind/build.rs

@@ -11,6 +11,7 @@
 use std::env;
 
 fn main() {
+    println!("cargo:rerun-if-changed=build.rs");
     let target = env::var("TARGET").expect("TARGET was not set");
 
     if target.contains("linux") {