[clang-repl] Handle frontend options for clang-repl before calling executeAction

clang/lib/Interpreter/Interpreter.cpp

@@ -141,6 +141,48 @@ CreateCI(const llvm::opt::ArgStringList &Argv) {
   return std::move(Clang);
 }
 
+static llvm::Error HandleFrontendOptions(const CompilerInstance &CI) {
+  const auto &FrontendOpts = CI.getFrontendOpts();
+
+  if (FrontendOpts.ShowHelp) {
+    driver::getDriverOptTable().printHelp(
+        llvm::outs(), "clang -cc1 [options] file...",
+        "LLVM 'Clang' Compiler: http://clang.llvm.org",
+        /*ShowHidden=*/false, /*ShowAllAliases=*/false,
+        llvm::opt::Visibility(driver::options::CC1Option));
+    return llvm::createStringError(llvm::errc::not_supported, "Help displayed");
+  }
+
+  if (FrontendOpts.ShowVersion) {
+    llvm::cl::PrintVersionMessage();
+    return llvm::createStringError(llvm::errc::not_supported,
+                                   "Version displayed");
+  }
+
+  if (!FrontendOpts.LLVMArgs.empty()) {
+    unsigned NumArgs = FrontendOpts.LLVMArgs.size();
+    auto Args = std::make_unique<const char *[]>(NumArgs + 2);
+    Args[0] = "clang-repl (LLVM option parsing)";
+    for (unsigned i = 0; i != NumArgs; ++i) {
+      Args[i + 1] = FrontendOpts.LLVMArgs[i].c_str();
+      // remove the leading '-' from the option name
+      if (Args[i + 1][0] == '-') {
+        auto *option = static_cast<llvm::cl::opt<bool> *>(
+            llvm::cl::getRegisteredOptions()[Args[i + 1] + 1]);
+        if (option) {
+          option->setInitialValue(true);
+        } else {
+          llvm::errs() << "Unknown LLVM option: " << Args[i + 1] << "\n";
+        }
+      }
+    }
+    Args[NumArgs + 1] = nullptr;
+    llvm::cl::ParseCommandLineOptions(NumArgs + 1, Args.get());
+  }
+
+  return llvm::Error::success();
+}
+
 } // anonymous namespace
 
 namespace clang {
@@ -451,7 +493,12 @@ const char *const Runtimes = R"(
 
 llvm::Expected<std::unique_ptr<Interpreter>>
 Interpreter::create(std::unique_ptr<CompilerInstance> CI) {
-  llvm::Error Err = llvm::Error::success();
+
+  llvm::Error Err = HandleFrontendOptions(*CI);
+  if (Err) {
+    return std::move(Err);
+  }
+
   auto Interp =
       std::unique_ptr<Interpreter>(new Interpreter(std::move(CI), Err));
   if (Err)

clang/test/Interpreter/handlefrontendopts.cpp

@@ -0,0 +1,5 @@
+// RUN: not clang-repl --Xcc -Xclang --Xcc -help 2>&1 | FileCheck %s --check-prefix=HELP
+// RUN: not clang-repl --Xcc -Xclang --Xcc -version 2>&1 | FileCheck %s --check-prefix=VERSION
+
+// HELP: Help displayed
+// VERSION: Version displayed