chore(tvix/eval): clean up remains of previous disassembler impl

Change-Id: Ib402ea23a58dc52ed0c5a97178cb5d0e53d69300
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6454
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI

tvix/eval/src/disassembler.rs

@@ -1,41 +0,0 @@
-//! Implements methods for disassembling and printing a representation
-//! of compiled code, as well as tracing the runtime stack during
-//! execution.
-use std::io::{Stderr, Write};
-use tabwriter::TabWriter;
-
-use crate::opcode::OpCode;
-use crate::value::Value;
-
-/// Helper struct to trace runtime values and automatically flush the
-/// output after the value is dropped (i.e. in both success and
-/// failure exits from the VM).
-pub struct Tracer(TabWriter<Stderr>);
-
-impl Default for Tracer {
-    fn default() -> Self {
-        Tracer(TabWriter::new(std::io::stderr()))
-    }
-}
-
-impl Tracer {
-    pub fn trace(&mut self, op: &OpCode, ip: usize, stack: &[Value]) {
-        let _ = write!(&mut self.0, "{:04} {:?}\t[ ", ip, op);
-
-        for val in stack {
-            let _ = write!(&mut self.0, "{} ", val);
-        }
-
-        let _ = writeln!(&mut self.0, "]");
-    }
-
-    pub fn literal(&mut self, line: &str) {
-        let _ = writeln!(&mut self.0, "{}", line);
-    }
-}
-
-impl Drop for Tracer {
-    fn drop(&mut self) {
-        let _ = self.0.flush();
-    }
-}

tvix/eval/src/eval.rs

@@ -3,7 +3,7 @@ use std::{path::PathBuf, rc::Rc};
 use crate::{
     builtins::global_builtins,
     errors::{Error, ErrorKind, EvalResult},
-    observer::{DisassemblingObserver, NoOpObserver},
+    observer::{DisassemblingObserver, TracingObserver},
     value::Value,
 };
 
@@ -41,7 +41,7 @@ pub fn interpret(code: &str, location: Option<PathBuf>) -> EvalResult<Value> {
         println!("{:?}", root_expr);
     }
 
-    let mut observer = DisassemblingObserver::new(codemap.clone(), std::io::stderr());
+    let mut observer = DisassemblingObserver::new(codemap, std::io::stderr());
 
     let result =
         crate::compiler::compile(root_expr, location, &file, global_builtins(), &mut observer)?;
@@ -68,6 +68,6 @@ pub fn interpret(code: &str, location: Option<PathBuf>) -> EvalResult<Value> {
         return Err(err.clone());
     }
 
-    let mut tracer = NoOpObserver::default();
+    let mut tracer = TracingObserver::new(std::io::stderr());
     crate::vm::run_lambda(&mut tracer, result.lambda)
 }

tvix/eval/src/lib.rs

@@ -1,7 +1,6 @@
 mod builtins;
 mod chunk;
 mod compiler;
-mod disassembler;
 mod errors;
 mod eval;
 pub mod observer;