[Lldb-commits] [lldb] [lldb][windows] add a Windows FifoFile implementation (PR #185894)

[Charles Zablit via lldb-commits]

================
@@ -24,17 +28,83 @@ using namespace llvm;
 
 namespace lldb_dap {
 
-FifoFile::FifoFile(StringRef path) : m_path(path) {}
+FifoFile::FifoFile(StringRef path, lldb::pipe_t pipe) : m_path(path) {
+#ifdef _WIN32
+  if (pipe == INVALID_HANDLE_VALUE)
+    pipe = CreateFileA(m_path.c_str(), GENERIC_READ | GENERIC_WRITE, 0, NULL,
+                       OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
+#endif
+  m_pipe = pipe;
+}
 
 FifoFile::~FifoFile() {
-#if !defined(_WIN32)
+#ifdef _WIN32
+  if (m_pipe != INVALID_HANDLE_VALUE) {
+    DisconnectNamedPipe(m_pipe);
+    CloseHandle(m_pipe);
+  }
+#else
   unlink(m_path.c_str());
 #endif
 }
 
+void FifoFile::WriteLine(std::string line) {
+#ifdef _WIN32
+  DWORD written;
+  line += "\n";
+  WriteFile(m_pipe, line.c_str(), static_cast<DWORD>(line.size()), &written,
+            NULL);
+  FlushFileBuffers(m_pipe);
+#else
+  std::ofstream writer(m_path, std::ofstream::out);
+  writer << line << std::endl;
+#endif
+}
+
+void FifoFile::Connect() {
+#ifdef _WIN32
+  ConnectNamedPipe(m_pipe, NULL);
+#endif
+}
+
+std::string FifoFile::ReadLine() {
+#ifdef _WIN32
+  std::string buffer;
+  char read_buffer[4096];
+  DWORD bytes_read;
+
+  if (ReadFile(m_pipe, read_buffer, sizeof(read_buffer) - 1, &bytes_read,
+               NULL) &&
+      bytes_read > 0) {
+    read_buffer[bytes_read] = '\0';
+    buffer = read_buffer;
+  }
----------------
charles-zablit wrote:

For our usage in https://github.com/llvm/llvm-project/pull/174635 this will never be a problem given the size of the json data (100 chars at most).

I have added a read loop in case this ends up being used by something else later.

https://github.com/llvm/llvm-project/pull/185894