Pass the dest place into write function

Author: tiif

src/shims/unix/fd.rs

@@ -593,7 +593,8 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         buf: Pointer,
         count: u64,
         offset: Option<i128>,
-    ) -> InterpResult<'tcx, Scalar> {
+        dest: &MPlaceTy<'tcx>,
+    ) -> InterpResult<'tcx> {
         let this = self.eval_context_mut();
 
         // Isolation check is done via `FileDescription` trait.
@@ -611,7 +612,9 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         let bytes = this.read_bytes_ptr_strip_provenance(buf, Size::from_bytes(count))?.to_owned();
         // We temporarily dup the FD to be able to retain mutable access to `this`.
         let Some(fd) = this.machine.fds.get(fd_num) else {
-            return Ok(Scalar::from_target_isize(this.fd_not_found()?, this));
+            let res = this.fd_not_found()?;
+            this.write_scalar(Scalar::from_target_isize(res, this), dest)?;
+            return Ok(());
         };
 
         let result = match offset {
@@ -620,17 +623,19 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 let Ok(offset) = u64::try_from(offset) else {
                     let einval = this.eval_libc("EINVAL");
                     this.set_last_error(einval)?;
-                    return Ok(Scalar::from_target_isize(-1, this));
+                    this.write_scalar(Scalar::from_target_isize(-1, this), dest)?;
+                    return Ok(());
                 };
                 fd.pwrite(communicate, &bytes, offset, this)
             }
         };
 
         let result = result?.map(|c| i64::try_from(c).unwrap());
-        Ok(Scalar::from_target_isize(this.try_unwrap_io_result(result)?, this))
+        let res = this.try_unwrap_io_result(result)?;
+        this.write_scalar(Scalar::from_target_isize(res, this), dest)?;
+        Ok(())
     }
 }
-// TODO: move this as a free function later
 fn write_byte_helper<'tcx>(
     buf: Pointer,
     bytes: Vec<u8>,

src/shims/unix/foreign_items.rs

@@ -100,9 +100,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 let buf = this.read_pointer(buf)?;
                 let count = this.read_target_usize(n)?;
                 trace!("Called write({:?}, {:?}, {:?})", fd, buf, count);
-                let result = this.write(fd, buf, count, None)?;
-                // Now, `result` is the value we return back to the program.
-                this.write_scalar(result, dest)?;
+                this.write(fd, buf, count, None, dest)?;
             }
             "pread" => {
                 let [fd, buf, count, offset] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
@@ -119,9 +117,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 let count = this.read_target_usize(n)?;
                 let offset = this.read_scalar(offset)?.to_int(this.libc_ty_layout("off_t").size)?;
                 trace!("Called pwrite({:?}, {:?}, {:?}, {:?})", fd, buf, count, offset);
-                let result = this.write(fd, buf, count, Some(offset))?;
-                // Now, `result` is the value we return back to the program.
-                this.write_scalar(result, dest)?;
+                this.write(fd, buf, count, Some(offset), dest)?;
             }
             "pread64" => {
                 let [fd, buf, count, offset] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
@@ -138,9 +134,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 let count = this.read_target_usize(n)?;
                 let offset = this.read_scalar(offset)?.to_int(this.libc_ty_layout("off64_t").size)?;
                 trace!("Called pwrite64({:?}, {:?}, {:?}, {:?})", fd, buf, count, offset);
-                let result = this.write(fd, buf, count, Some(offset))?;
-                // Now, `result` is the value we return back to the program.
-                this.write_scalar(result, dest)?;
+                this.write(fd, buf, count, Some(offset), dest)?;
             }
             "close" => {
                 let [fd] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;