diff options
| -rw-r--r-- | tvix/eval/src/vm.rs | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/tvix/eval/src/vm.rs b/tvix/eval/src/vm.rs index 75fe8b32acda..4d049c6d71b0 100644 --- a/tvix/eval/src/vm.rs +++ b/tvix/eval/src/vm.rs @@ -1,6 +1,7 @@ //! This module implements the virtual (or abstract) machine that runs //! Tvix bytecode. +use serde_json::json; use std::{ops::DerefMut, path::PathBuf, rc::Rc}; use crate::{ @@ -818,7 +819,22 @@ impl<'o> VM<'o> { match self.inc_ip() { OpCode::DataLocalIdx(StackIdx(local_idx)) => { let idx = self.frame().stack_offset + local_idx; - upvalues.deref_mut().push(self.stack[idx].clone()); + + let val = match self.stack.get(idx) { + Some(val) => val.clone(), + None => { + return Err(self.error(ErrorKind::TvixBug { + msg: "upvalue to be captured was missing on stack", + metadata: Some(Rc::new(json!({ + "ip": format!("{:#x}", self.frame().ip.0 - 1), + "local_idx": local_idx, + "stack_idx": idx, + }))), + })) + } + }; + + upvalues.deref_mut().push(val); } OpCode::DataUpvalueIdx(upv_idx) => { |