add set_last_error_and_return_i32 helper and use it in a few places

Author: RalfJung

src/tools/miri/src/shims/io_error.rs

@@ -119,6 +119,28 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
  this.write_scalar(errno,&errno_place)
 }
 
+/// Sets the last OS error and writes -1 to dest place.
+fnset_last_error_and_return(
+&mutself,
+err:implInto<IoError>,
+dest:&MPlaceTy<'tcx>,
+) -> InterpResult<'tcx>{
+let this = self.eval_context_mut();
+ this.set_last_error(err)?;
+ this.write_int(-1, dest)?;
+Ok(())
+}
+
+/// Sets the last OS error and return `-1` as a `i32`-typed Scalar
+fnset_last_error_and_return_i32(
+&mutself,
+err:implInto<IoError>,
+) -> InterpResult<'tcx,Scalar>{
+let this = self.eval_context_mut();
+ this.set_last_error(err)?;
+Ok(Scalar::from_i32(-1))
+}
+
 /// Gets the last error variable.
 fnget_last_error(&mutself) -> InterpResult<'tcx,Scalar>{
 let this = self.eval_context_mut();
@@ -185,18 +207,6 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
 }
 }
 
-/// Sets the last OS error using a `std::io::ErrorKind` and writes -1 to dest place.
-fnset_last_error_and_return(
-&mutself,
-err:implInto<IoError>,
-dest:&MPlaceTy<'tcx>,
-) -> InterpResult<'tcx>{
-let this = self.eval_context_mut();
- this.set_last_error(err)?;
- this.write_int(-1, dest)?;
-Ok(())
-}
-
 /// Helper function that consumes an `std::io::Result<T>` and returns an
 /// `InterpResult<'tcx,T>::Ok` instead. In case the result is an error, this function returns
 /// `Ok(-1)` and sets the last OS error accordingly.

src/tools/miri/src/shims/unix/env.rs

@@ -177,8 +177,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
 Ok(Scalar::from_i32(0))// return zero on success
 }else{
 // name argument is a null pointer, points to an empty string, or points to a string containing an '=' character.
- this.set_last_error(LibcError("EINVAL"))?;
-Ok(Scalar::from_i32(-1))
+ this.set_last_error_and_return_i32(LibcError("EINVAL"))
 }
 }
 
@@ -202,8 +201,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
 Ok(Scalar::from_i32(0))
 }else{
 // name argument is a null pointer, points to an empty string, or points to a string containing an '=' character.
- this.set_last_error(LibcError("EINVAL"))?;
-Ok(Scalar::from_i32(-1))
+ this.set_last_error_and_return_i32(LibcError("EINVAL"))
 }
 }
 
@@ -242,9 +240,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
 
 ifletIsolatedOp::Reject(reject_with) = this.machine.isolated_op{
  this.reject_in_isolation("`chdir`", reject_with)?;
- this.set_last_error(ErrorKind::PermissionDenied)?;
-
-returnOk(Scalar::from_i32(-1));
+return this.set_last_error_and_return_i32(ErrorKind::PermissionDenied);
 }
 
 let result = env::set_current_dir(path).map(|()| 0);

src/tools/miri/src/shims/unix/fd.rs

@@ -524,8 +524,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
 // Reject if isolation is enabled.
 ifletIsolatedOp::Reject(reject_with) = this.machine.isolated_op{
  this.reject_in_isolation("`fcntl`", reject_with)?;
- this.set_last_error(ErrorKind::PermissionDenied)?;
-returnOk(Scalar::from_i32(-1));
+return this.set_last_error_and_return_i32(ErrorKind::PermissionDenied);
 }
 
  this.ffullsync_fd(fd_num)
@@ -606,9 +605,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
 None => fd.read(&fd, communicate, buf, count, dest, this)?,
 Some(offset) => {
 letOk(offset) = u64::try_from(offset)else{
- this.set_last_error(LibcError("EINVAL"))?;
- this.write_int(-1, dest)?;
-returnOk(());
+return this.set_last_error_and_return(LibcError("EINVAL"), dest);
 };
  fd.pread(communicate, offset, buf, count, dest, this)?
 }
@@ -650,9 +647,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
 None => fd.write(&fd, communicate, buf, count, dest, this)?,
 Some(offset) => {
 letOk(offset) = u64::try_from(offset)else{
- this.set_last_error(LibcError("EINVAL"))?;
- this.write_int(-1, dest)?;
-returnOk(());
+return this.set_last_error_and_return(LibcError("EINVAL"), dest);
 };
  fd.pwrite(communicate, buf, count, offset, dest, this)?
 }