subprocess-win: update to mp_subprocess2

This fixes the "run" and "subprocess" commands on Windows, including
youtube-dl support.

Unix-like FD inheritance is emulated on Windows by using an undocumented
data structure[1] that gets passed to the newly created process in
STARTUPINFO.lpReserved2. It consists of two sparse arrays listing the
HANDLE and internal CRT flags corresponding to each FD. This structure
is used and understood primarily by MSVCRT, but there are other runtimes
and frameworks that can write it, like libuv.

The code for creating asynchronous "anonymous" pipes in Windows has been
enhanced and moved into windows_utils.c. This is mainly an artifact of
an unfinished future change to support anonymous IPC clients in Windows.
Right now, it's still only used in subprocess-win.c

[1]: https://www.catch22.net/tuts/undocumented-createprocess

1 files changed, 16 insertions, 0 deletions

diff --git a/osdep/windows_utils.h b/osdep/windows_utils.h
index a20a558709..a8a5e947b8 100644
--- a/osdep/windows_utils.h
+++ b/osdep/windows_utils.h
@@ -19,6 +19,7 @@
 #define MP_WINDOWS_UTILS_H_
 
 #include <windows.h>
+#include <stdbool.h>
 
 // Conditionally release a COM interface and set the pointer to NULL
 #define SAFE_RELEASE(u) \
@@ -30,4 +31,19 @@ char *mp_HRESULT_to_str_buf(char *buf, size_t buf_size, HRESULT hr);
 #define mp_HRESULT_to_str(hr) mp_HRESULT_to_str_buf((char[256]){0}, 256, (hr))
 #define mp_LastError_to_str() mp_HRESULT_to_str(HRESULT_FROM_WIN32(GetLastError()))
 
+struct w32_create_anon_pipe_opts {
+    DWORD server_flags;
+    DWORD server_mode;
+    bool server_inheritable;
+    DWORD out_buf_size;
+    DWORD in_buf_size;
+
+    DWORD client_flags;
+    DWORD client_mode;
+    bool client_inheritable;
+};
+
+bool mp_w32_create_anon_pipe(HANDLE *server, HANDLE *client,
+                             struct w32_create_anon_pipe_opts *opts);
+
 #endif