Implement file cloning on Windows

src/shims/windows/foreign_items.rs

@@ -572,6 +572,14 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 let ret = this.WaitForSingleObject(handle, timeout)?;
                 this.write_scalar(ret, dest)?;
             }
+            "GetCurrentProcess" => {
+                let [] = this.check_shim(abi, sys_conv, link_name, args)?;
+
+                this.write_scalar(
+                    Handle::Pseudo(PseudoHandle::CurrentProcess).to_scalar(this),
+                    dest,
+                )?;
+            }
             "GetCurrentThread" => {
                 let [] = this.check_shim(abi, sys_conv, link_name, args)?;
 
@@ -693,6 +701,20 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 let res = this.GetStdHandle(which)?;
                 this.write_scalar(res, dest)?;
             }
+            "DuplicateHandle" => {
+                let [src_proc, src_handle, target_proc, target_handle, access, inherit, options] =
+                    this.check_shim(abi, sys_conv, link_name, args)?;
+                let res = this.DuplicateHandle(
+                    src_proc,
+                    src_handle,
+                    target_proc,
+                    target_handle,
+                    access,
+                    inherit,
+                    options,
+                )?;
+                this.write_scalar(res, dest)?;
+            }
             "CloseHandle" => {
                 let [handle] = this.check_shim(abi, sys_conv, link_name, args)?;
 

src/shims/windows/handle.rs

@@ -9,6 +9,7 @@ use crate::*;
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub enum PseudoHandle {
     CurrentThread,
+    CurrentProcess,
 }
 
 /// Miri representation of a Windows `HANDLE`
@@ -23,16 +24,19 @@ pub enum Handle {
 
 impl PseudoHandle {
     const CURRENT_THREAD_VALUE: u32 = 0;
+    const CURRENT_PROCESS_VALUE: u32 = 1;
 
     fn value(self) -> u32 {
         match self {
             Self::CurrentThread => Self::CURRENT_THREAD_VALUE,
+            Self::CurrentProcess => Self::CURRENT_PROCESS_VALUE,
         }
     }
 
     fn from_value(value: u32) -> Option<Self> {
         match value {
             Self::CURRENT_THREAD_VALUE => Some(Self::CurrentThread),
+            Self::CURRENT_PROCESS_VALUE => Some(Self::CurrentProcess),
             _ => None,
         }
     }
@@ -244,6 +248,76 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         interp_ok(handle.to_scalar(this))
     }
 
+    fn DuplicateHandle(
+        &mut self,
+        src_proc: &OpTy<'tcx>,       // HANDLE
+        src_handle: &OpTy<'tcx>,     // HANDLE
+        target_proc: &OpTy<'tcx>,    // HANDLE
+        target_handle: &OpTy<'tcx>,  // LPHANDLE
+        desired_access: &OpTy<'tcx>, // DWORD
+        inherit: &OpTy<'tcx>,        // BOOL
+        options: &OpTy<'tcx>,        // DWORD
+    ) -> InterpResult<'tcx, Scalar> {
+        // ^ Returns BOOL (i32 on Windows)
+        let this = self.eval_context_mut();
+
+        let src_proc = this.read_handle(src_proc, "DuplicateHandle")?;
+        let src_handle = this.read_handle(src_handle, "DuplicateHandle")?;
+        let target_proc = this.read_handle(target_proc, "DuplicateHandle")?;
+        let target_handle_ptr = this.read_pointer(target_handle)?;
+        // Since we only support DUPLICATE_SAME_ACCESS, this value is ignored, but should be valid
+        let _ = this.read_scalar(desired_access)?.to_u32()?;
+        // We don't support the CreateProcess API, so inheritable or not means nothing.
+        // If we ever add CreateProcess support, this will need to be implemented.
+        let _ = this.read_scalar(inherit)?;
+        let options = this.read_scalar(options)?;
+
+        if src_proc != Handle::Pseudo(PseudoHandle::CurrentProcess) {
+            throw_unsup_format!(
+                "`DuplicateHandle` `hSourceProcessHandle` parameter is not the current process, which is unsupported"
+            );
+        }
+
+        if target_proc != Handle::Pseudo(PseudoHandle::CurrentProcess) {
+            throw_unsup_format!(
+                "`DuplicateHandle` `hSourceProcessHandle` parameter is not the current process, which is unsupported"
+            );
+        }
+
+        if this.ptr_is_null(target_handle_ptr)? {
+            throw_unsup_format!(
+                "`DuplicateHandle` `lpTargetHandle` parameter is null, which is unsupported"
+            );
+        }
+
+        if options != this.eval_windows("c", "DUPLICATE_SAME_ACCESS") {
+            throw_unsup_format!(
+                "`DuplicateHandle` `dwOptions` parameter is not `DUPLICATE_SAME_ACCESS`, which is unsupported"
+            );
+        }
+
+        let new_handle = match src_handle {
+            Handle::File(old_fd_num) => {
+                let Some(fd) = this.machine.fds.get(old_fd_num) else {
+                    this.invalid_handle("DuplicateHandle")?
+                };
+                Handle::File(this.machine.fds.insert(fd))
+            }
+            Handle::Thread(_) => {
+                throw_unsup_format!(
+                    "`DuplicateHandle` called on a thread handle, which is unsupported"
+                );
+            }
+            Handle::Pseudo(pseudo) => Handle::Pseudo(pseudo),
+            Handle::Null | Handle::Invalid => this.invalid_handle("DuplicateHandle")?,
+        };
+
+        let target_place = this.deref_pointer_as(target_handle, this.machine.layouts.usize)?;
+        this.write_scalar(new_handle.to_scalar(this), &target_place)?;
+
+        interp_ok(this.eval_windows("c", "TRUE"))
+    }
+
     fn CloseHandle(&mut self, handle_op: &OpTy<'tcx>) -> InterpResult<'tcx, Scalar> {
         let this = self.eval_context_mut();
 

tests/pass/shims/fs.rs

@@ -23,9 +23,9 @@ fn main() {
     test_seek();
     test_errors();
     test_from_raw_os_error();
+    test_file_clone();
     // Windows file handling is very incomplete.
     if cfg!(not(windows)) {
-        test_file_clone();
         test_file_set_len();
         test_file_sync();
         test_rename();