bootstrap: Allow to specify ranlib tool used when compiling C++ code.

config.toml.example

@@ -388,6 +388,10 @@
 # Note: an absolute path should be used, otherwise LLVM build will break.
 #ar = "ar"
 
+# Ranlib to be used to assemble static libraries compiled from C/C++ code.
+# Note: an absolute path should be used, otherwise LLVM build will break.
+#ranlib = "ranlib"
+
 # Linker to be used to link Rust code. Note that the
 # default value is platform specific, and if not specified it may also depend on
 # what platform is crossing to what platform.

src/bootstrap/config.rs

@@ -163,6 +163,7 @@ pub struct Target {
     pub cc: Option<PathBuf>,
     pub cxx: Option<PathBuf>,
     pub ar: Option<PathBuf>,
+    pub ranlib: Option<PathBuf>,
     pub linker: Option<PathBuf>,
     pub ndk: Option<PathBuf>,
     pub crt_static: Option<bool>,
@@ -327,6 +328,7 @@ struct TomlTarget {
     cc: Option<String>,
     cxx: Option<String>,
     ar: Option<String>,
+    ranlib: Option<String>,
     linker: Option<String>,
     android_ndk: Option<String>,
     crt_static: Option<bool>,
@@ -581,6 +583,7 @@ impl Config {
                 target.cc = cfg.cc.clone().map(PathBuf::from);
                 target.cxx = cfg.cxx.clone().map(PathBuf::from);
                 target.ar = cfg.ar.clone().map(PathBuf::from);
+                target.ranlib = cfg.ranlib.clone().map(PathBuf::from);
                 target.linker = cfg.linker.clone().map(PathBuf::from);
                 target.crt_static = cfg.crt_static.clone();
                 target.musl_root = cfg.musl_root.clone().map(PathBuf::from);

src/bootstrap/lib.rs

@@ -281,6 +281,7 @@ pub struct Build {
     cc: HashMap<Interned<String>, cc::Tool>,
     cxx: HashMap<Interned<String>, cc::Tool>,
     ar: HashMap<Interned<String>, PathBuf>,
+    ranlib: HashMap<Interned<String>, PathBuf>,
     // Misc
     crates: HashMap<Interned<String>, Crate>,
     is_sudo: bool,
@@ -406,6 +407,7 @@ impl Build {
             cc: HashMap::new(),
             cxx: HashMap::new(),
             ar: HashMap::new(),
+            ranlib: HashMap::new(),
             crates: HashMap::new(),
             lldb_version: None,
             lldb_python_dir: None,
@@ -772,6 +774,11 @@ impl Build {
         self.ar.get(&target).map(|p| &**p)
     }
 
+    /// Returns the path to the `ranlib` utility for the target specified.
+    fn ranlib(&self, target: Interned<String>) -> Option<&Path> {
+        self.ranlib.get(&target).map(|p| &**p)
+    }
+
     /// Returns the path to the C++ compiler for the target specified.
     fn cxx(&self, target: Interned<String>) -> Result<&Path, String> {
         match self.cxx.get(&target) {

src/bootstrap/native.rs

@@ -379,6 +379,14 @@ fn configure_cmake(builder: &Builder,
         }
     }
 
+    if let Some(ranlib) = builder.ranlib(target) {
+        if ranlib.is_absolute() {
+            // LLVM build breaks if `CMAKE_RANLIB` is a relative path, for some reason it
+            // tries to resolve this path in the LLVM build directory.
+            cfg.define("CMAKE_RANLIB", sanitize_cc(ranlib));
+        }
+    }
+
     if env::var_os("SCCACHE_ERROR_LOG").is_some() {
         cfg.env("RUST_LOG", "sccache=warn");
     }