For VxWorks:

fix building errors
use wr-c++ as linker

src/bootstrap/cc_detect.rs

@@ -132,7 +132,8 @@ pub fn find(build: &mut Build) {
             false
         };
 
-        if cxx_configured {
+        // for VxWorks, record CXX compiler which will be used in lib.rs:linker()
+        if cxx_configured || target.contains("vxworks") {
             let compiler = cfg.get_compiler();
             build.cxx.insert(target, compiler);
         }

src/bootstrap/lib.rs

@@ -857,6 +857,10 @@ fn linker(&self, target: TargetSelection, can_use_lld: bool) -> Option<&Path> {
         if let Some(linker) = self.config.target_config.get(&target).and_then(|c| c.linker.as_ref())
         {
             Some(linker)
+        } else if target.contains("vxworks") {
+            // need to use CXX compiler as linker to resolve the exception functions
+            // that are only existed in CXX libraries
+            Some(self.cxx[&target].path())
         } else if target != self.config.build
             && util::use_host_linker(target)
             && !target.contains("msvc")