Proper fix utf8 command line arguments

build_defs/cpp_opts.bzl

@@ -35,7 +35,7 @@ LINK_OPTS = select({
     "//build_defs:config_msvc": [
         # Suppress linker warnings about files with no symbols defined.
         "-ignore:4221",
-        "/utf-8",
+        "Shell32.lib",
     ],
     "@platforms//os:macos": [
         "-lpthread",

src/google/protobuf/compiler/command_line_interface.cc

@@ -1764,10 +1764,23 @@ bool CommandLineInterface::MakeInputsBeProtoPathRelative(
 
 
 bool CommandLineInterface::ExpandArgumentFile(
-    const std::string& file, std::vector<std::string>* arguments) {
+    const char* file, std::vector<std::string>* arguments) {
+
+// On windows to force ifstream to handle proper utr-8, we need to convert to proper supported utf8 wstring.
+// If we dont then the file can't be opened.
+#ifdef _MSC_VER
+  // Convert the file name to wide chars.
+  int size = MultiByteToWideChar(CP_UTF8, 0, file, strlen(file), NULL, 0);
+  std::wstring file_str;
+  file_str.resize(size);
+  MultiByteToWideChar(CP_UTF8, 0, file, strlen(file), &file_str[0], file_str.size());
+#else
+  std::string file_str(file);
+#endif
+
   // The argument file is searched in the working directory only. We don't
   // use the proto import path here.
-  std::ifstream file_stream(file.c_str());
+  std::ifstream file_stream(file_str.c_str());
   if (!file_stream.is_open()) {
     return false;
   }

src/google/protobuf/compiler/command_line_interface.h

@@ -240,7 +240,7 @@ class PROTOC_EXPORT CommandLineInterface {
 
   // Read an argument file and append the file's content to the list of
   // arguments. Return false if the file cannot be read.
-  bool ExpandArgumentFile(const std::string& file,
+  bool ExpandArgumentFile(const char* file,
                           std::vector<std::string>* arguments);
 
   // Parses a command-line argument into a name/value pair.  Returns

src/google/protobuf/compiler/main.cc

@@ -21,6 +21,10 @@
 // Must be included last.
 #include "google/protobuf/port_def.inc"
 
+#ifdef _MSC_VER
+#include <windows.h>
+#endif
+
 namespace google {
 namespace protobuf {
 namespace compiler {
@@ -101,6 +105,29 @@ int ProtobufMain(int argc, char* argv[]) {
 }  // namespace protobuf
 }  // namespace google
 
-int main(int argc, char* argv[]) {
+#ifdef _MSC_VER
+std::string ToMultiByteUtf8String(const wchar_t* input)
+{
+    int size = WideCharToMultiByte(CP_UTF8, 0, input, wcslen(input), 0, 0, NULL, NULL);
+    std::string result(size, 0);
+    if (size) WideCharToMultiByte(CP_UTF8, 0, input, wcslen(input), &result[0], size, NULL, NULL);
+    return result;
+}
+
+int main(int argc, char* argv[]) 
+{
+  wchar_t** wargv = CommandLineToArgvW(GetCommandLineW(), &argc);
+  char** argv_mbcs = new char* [argc];
+  for (int i = 0; i < argc; i++)
+  {
+      std::string* multibyte_string = new auto(ToMultiByteUtf8String(wargv[i]));
+      argv_mbcs[i] = const_cast<char*>(multibyte_string->c_str());
+  }
+  return google::protobuf::compiler::ProtobufMain(argc, argv_mbcs);
+}
+#else
+int main(int argc, char* argv[]) 
+{
   return google::protobuf::compiler::ProtobufMain(argc, argv);
 }
+#endif