squash: move flag validation to c++

Author: not-an-aardvark

lib/internal/bootstrap_node.js

@@ -114,10 +114,6 @@
       }
 
       if (process._eval != null && !process._forceRepl) {
-        if (process._syntax_check_only != null) {
-          console.error('--check and --eval flags are mutually exclusive.');
-          process.exit(9);
-        }
         // User passed '-e' or '--eval' arguments to Node without '-i' or
         // '--interactive'
         preloadModules();

src/node.cc

@@ -3800,6 +3800,12 @@ static void ParseArgs(int* argc,
   }
 #endif
 
+  if (eval_string != nullptr && syntax_check_only) {
+    fprintf(stderr,
+            "%s: either --check or --eval can be used, not both\n", argv[0]);
+    exit(9);
+  }
+
   // Copy remaining arguments.
   const unsigned int args_left = nargs - index;
   memcpy(new_argv + new_argc, argv + index, args_left * sizeof(*argv));

test/parallel/test-cli-syntax.js

@@ -126,7 +126,7 @@ syntaxArgs.forEach(function(args) {
 
     assert.strictEqual(
       c.stderr,
-      '--check and --eval flags are mutually exclusive.\n'
+      `${node}: either --check or --eval can be used, not both\n`
     );
 
     assert.strictEqual(c.status, 9, 'code === ' + c.status);