adding a check to bootstrap script

configure

@@ -634,6 +634,7 @@ valopt datadir "${CFG_PREFIX}/share" "install data"
 valopt infodir "${CFG_PREFIX}/share/info" "install additional info"
 valopt llvm-root "" "set LLVM root"
 valopt python "" "set path to python"
+valopt nodejs "" "set path to nodejs"
 valopt jemalloc-root "" "set directory where libjemalloc_pic.a is located"
 valopt build "${DEFAULT_BUILD}" "GNUs ./configure syntax LLVM build triple"
 valopt android-cross-path "" "Android NDK standalone path (deprecated)"
@@ -749,6 +750,9 @@ if [ $(echo $python_version | grep -c '^Python 2\.7') -ne 1 ]; then
     err "Found $python_version, but Python 2.7 is required"
 fi
 
+# Checking for node, but not required
+probe CFG_NODEJS nodejs node
+
 # If we have no git directory then we are probably a tarball distribution
 # and shouldn't attempt to load submodules
 if [ ! -e ${CFG_SRC_DIR}.git ]

src/bootstrap/config.rs

@@ -79,6 +79,7 @@ pub struct Config {
     pub musl_root: Option<PathBuf>,
     pub prefix: Option<String>,
     pub codegen_tests: bool,
+    pub nodejs: Option<PathBuf>,
 }
 
 /// Per-target configuration stored in the global configuration structure.
@@ -391,6 +392,9 @@ impl Config {
                     self.rustc = Some(PathBuf::from(value).join("bin/rustc"));
                     self.cargo = Some(PathBuf::from(value).join("bin/cargo"));
                 }
+                "CFG_NODEJS" if value.len() > 0 => {
+                    self.nodejs = Some(PathBuf::from(value));
+                }
                 _ => {}
             }
         }

src/bootstrap/sanity.rs

@@ -75,6 +75,12 @@ pub fn check(build: &mut Build) {
 
     need_cmd("python".as_ref());
 
+    // If a manual nodejs was added to the config,
+    // of if a nodejs install is detected through config, use it.
+    if let Some(ref s) = build.config.nodejs {
+        need_cmd(s.as_ref());
+    }
+
     // We're gonna build some custom C code here and there, host triples
     // also build some C++ shims for LLVM so we need a C++ compiler.
     for target in build.config.target.iter() {