1 files changed, 56 insertions, 0 deletions
diff --git a/libc/utils/HdrGen/Main.cpp b/libc/utils/HdrGen/Main.cpp
new file mode 100644
index 00000000000..13ff5baa0e9
--- /dev/null
+++ b/libc/utils/HdrGen/Main.cpp
@@ -0,0 +1,56 @@
+//===---------------- "main" function of libc-hdrgen ------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "Generator.h"
+
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/TableGen/Main.h"
+
+#include <string>
+#include <unordered_map>
+
+namespace {
+
+llvm::cl::opt<std::string>
+    HeaderDefFile("def", llvm::cl::desc("Path to the .h.def file."),
+                  llvm::cl::value_desc("<filename>"), llvm::cl::Required);
+llvm::cl::opt<std::string> StandardHeader(
+    "header",
+    llvm::cl::desc("The standard header file which is to be generated."),
+    llvm::cl::value_desc("<header file>"));
+llvm::cl::list<std::string> ReplacementValues(
+    "args", llvm::cl::desc("Command seperated <argument name>=<value> pairs."),
+    llvm::cl::value_desc("<name=value>[,name=value]"));
+
+void ParseArgValuePairs(std::unordered_map<std::string, std::string> &Map) {
+  for (std::string &R : ReplacementValues) {
+    auto Pair = llvm::StringRef(R).split('=');
+    Map[Pair.first] = Pair.second;
+  }
+}
+
+} // anonymous namespace
+
+namespace llvm_libc {
+
+bool HeaderGeneratorMain(llvm::raw_ostream &OS, llvm::RecordKeeper &Records) {
+  std::unordered_map<std::string, std::string> ArgMap;
+  ParseArgValuePairs(ArgMap);
+  Generator G(HeaderDefFile, StandardHeader, ArgMap);
+  G.generate(OS, Records);
+
+  return false;
+}
+
+} // namespace llvm_libc
+
+int main(int argc, char *argv[]) {
+  llvm::cl::ParseCommandLineOptions(argc, argv);
+  return TableGenMain(argv[0], &llvm_libc::HeaderGeneratorMain);
+}