Auto merge of #39199 - alexcrichton:rollup, r=alexcrichton

Rollup of 28 pull requests

- Successful merges: #38603, #38761, #38842, #38847, #38955, #38966, #39062, #39068, #39077, #39111, #39112, #39114, #39118, #39120, #39132, #39135, #39138, #39142, #39143, #39146, #39157, #39166, #39167, #39168, #39179, #39184, #39195, #39197
- Failed merges: #39060, #39145

4 files changed, 18 insertions, 6 deletions

diff --git a/src/bootstrap/cc.rs b/src/bootstrap/cc.rs
index aa70e24d952..54c8194678e 100644
--- a/src/bootstrap/cc.rs
+++ b/src/bootstrap/cc.rs
@@ -121,10 +121,14 @@ fn set_compiler(cfg: &mut gcc::Config,
         }
 
         "mips-unknown-linux-musl" => {
-            cfg.compiler("mips-linux-musl-gcc");
+            if cfg.get_compiler().path().to_str() == Some("gcc") {
+                cfg.compiler("mips-linux-musl-gcc");
+            }
         }
         "mipsel-unknown-linux-musl" => {
-            cfg.compiler("mipsel-linux-musl-gcc");
+            if cfg.get_compiler().path().to_str() == Some("gcc") {
+                cfg.compiler("mipsel-linux-musl-gcc");
+            }
         }
 
         t if t.contains("musl") => {
diff --git a/src/bootstrap/compile.rs b/src/bootstrap/compile.rs
index 0eeb799672c..079f93e7331 100644
--- a/src/bootstrap/compile.rs
+++ b/src/bootstrap/compile.rs
@@ -213,7 +213,11 @@ pub fn rustc(build: &Build, target: &str, compiler: &Compiler) {
     if let Some(s) = target_config.and_then(|c| c.llvm_config.as_ref()) {
         cargo.env("CFG_LLVM_ROOT", s);
     }
-    if build.config.llvm_static_stdcpp {
+    // Building with a static libstdc++ is only supported on linux right now,
+    // not for MSVC or OSX
+    if build.config.llvm_static_stdcpp &&
+       !target.contains("windows") &&
+       !target.contains("apple") {
         cargo.env("LLVM_STATIC_STDCPP",
                   compiler_file(build.cxx(target), "libstdc++.a"));
     }
diff --git a/src/bootstrap/flags.rs b/src/bootstrap/flags.rs
index 1be823417d7..c5bbfd89b27 100644
--- a/src/bootstrap/flags.rs
+++ b/src/bootstrap/flags.rs
@@ -287,8 +287,8 @@ To learn more about a subcommand, run `./x.py <command> -h`
             build: m.opt_str("build").unwrap_or_else(|| {
                 env::var("BUILD").unwrap()
             }),
-            host: m.opt_strs("host"),
-            target: m.opt_strs("target"),
+            host: split(m.opt_strs("host")),
+            target: split(m.opt_strs("target")),
             config: cfg_file,
             src: m.opt_str("src").map(PathBuf::from),
             jobs: m.opt_str("jobs").map(|j| j.parse().unwrap()),
@@ -309,3 +309,7 @@ impl Subcommand {
         }
     }
 }
+
+fn split(s: Vec<String>) -> Vec<String> {
+    s.iter().flat_map(|s| s.split(',')).map(|s| s.to_string()).collect()
+}
diff --git a/src/bootstrap/sanity.rs b/src/bootstrap/sanity.rs
index 66bdd5e00f4..8e79c2d27d1 100644
--- a/src/bootstrap/sanity.rs
+++ b/src/bootstrap/sanity.rs
@@ -45,7 +45,7 @@ pub fn check(build: &mut Build) {
             let target = path.join(cmd);
             let mut cmd_alt = cmd.to_os_string();
             cmd_alt.push(".exe");
-            if target.exists() ||
+            if target.is_file() ||
                target.with_extension("exe").exists() ||
                target.join(cmd_alt).exists() {
                 return Some(target);