miden_debug_engine/exec/
host.rs

1use std::{
2    collections::{BTreeMap, VecDeque},
3    num::NonZeroU32,
4    sync::Arc,
5};
6
7use miden_assembly::SourceManager;
8use miden_core::{
9    Word,
10    events::{EventId, EventName},
11};
12use miden_debug_types::{Location, SourceFile, SourceSpan};
13use miden_processor::{
14    ExecutionError, FutureMaybeSend, Host, MastForestStore, MemMastForestStore, ProcessorState,
15    TraceError,
16    advice::AdviceMutation,
17    event::{EventError, EventHandler, EventHandlerRegistry},
18    mast::MastForest,
19    trace::RowIndex,
20};
21
22use super::{TraceEvent, TraceHandler};
23
24/// This is an implementation of [Host] which is essentially [miden_processor::DefaultHost],
25/// but extended with additional functionality for debugging, in particular it manages trace
26/// events that record the entry or exit of a procedure call frame.
27pub struct DebuggerHost<S: SourceManager + ?Sized> {
28    store: MemMastForestStore,
29    event_handlers: EventHandlerRegistry,
30    tracing_callbacks: BTreeMap<u32, Vec<Box<TraceHandler>>>,
31    on_assert_failed: Option<Box<TraceHandler>>,
32    source_manager: Arc<S>,
33    event_replay: VecDeque<Vec<AdviceMutation>>,
34}
35impl<S> DebuggerHost<S>
36where
37    S: SourceManager + ?Sized,
38{
39    /// Construct a new instance of [DebuggerHost] with the given source manager.
40    pub fn new(source_manager: Arc<S>) -> Self {
41        Self {
42            store: Default::default(),
43            event_handlers: EventHandlerRegistry::default(),
44            tracing_callbacks: Default::default(),
45            on_assert_failed: None,
46            source_manager,
47            event_replay: VecDeque::new(),
48        }
49    }
50
51    /// Set the event replay queue.
52    ///
53    /// When non-empty, `on_event()` will pop mutations from this queue instead of
54    /// returning empty results. This is used for transaction debugging where events
55    /// were recorded during a prior execution.
56    pub fn set_event_replay(&mut self, events: VecDeque<Vec<AdviceMutation>>) {
57        self.event_replay = events;
58    }
59
60    /// Register a trace handler for `event`
61    pub fn register_trace_handler<F>(&mut self, event: TraceEvent, callback: F)
62    where
63        F: FnMut(RowIndex, TraceEvent) + 'static,
64    {
65        let key = match event {
66            TraceEvent::AssertionFailed(None) => u32::MAX,
67            ev => ev.into(),
68        };
69        self.tracing_callbacks.entry(key).or_default().push(Box::new(callback));
70    }
71
72    /// Register a handler to be called when an assertion in the VM fails
73    pub fn register_assert_failed_tracer<F>(&mut self, callback: F)
74    where
75        F: FnMut(RowIndex, TraceEvent) + 'static,
76    {
77        self.on_assert_failed = Some(Box::new(callback));
78    }
79
80    /// Invoke the assert-failed handler, if registered.
81    ///
82    /// This is called externally when `step()` returns an assertion error, since
83    /// `on_assert_failed` no longer exists on the Host trait in 0.21.
84    pub fn handle_assert_failed(&mut self, clk: RowIndex, err_code: Option<NonZeroU32>) {
85        if let Some(handler) = self.on_assert_failed.as_mut() {
86            handler(clk, TraceEvent::AssertionFailed(err_code));
87        }
88    }
89
90    /// Load `forest` into the MAST store for this host
91    pub fn load_mast_forest(&mut self, forest: Arc<MastForest>) {
92        self.store.insert(forest);
93    }
94
95    /// Registers an event handler for use during program execution.
96    pub fn register_event_handler(
97        &mut self,
98        event: EventName,
99        handler: Arc<dyn EventHandler>,
100    ) -> Result<(), ExecutionError> {
101        self.event_handlers.register(event, handler)
102    }
103}
104
105impl<S> Host for DebuggerHost<S>
106where
107    S: SourceManager + ?Sized,
108{
109    fn get_label_and_source_file(
110        &self,
111        location: &Location,
112    ) -> (SourceSpan, Option<Arc<SourceFile>>) {
113        let maybe_file = self.source_manager.get_by_uri(location.uri());
114        let span = self.source_manager.location_to_span(location.clone()).unwrap_or_default();
115        (span, maybe_file)
116    }
117
118    fn get_mast_forest(&self, node_digest: &Word) -> impl FutureMaybeSend<Option<Arc<MastForest>>> {
119        std::future::ready(self.store.get(node_digest))
120    }
121
122    fn on_event(
123        &mut self,
124        process: &ProcessorState<'_>,
125    ) -> impl FutureMaybeSend<Result<Vec<AdviceMutation>, EventError>> {
126        if !self.event_replay.is_empty() {
127            let mutations = self.event_replay.pop_front().unwrap_or_default();
128            return std::future::ready(Ok(mutations));
129        }
130
131        let event_id = EventId::from_felt(process.get_stack_item(0));
132        let result = match self.event_handlers.handle_event(event_id, process) {
133            Ok(Some(mutations)) => Ok(mutations),
134            Ok(None) => {
135                #[derive(Debug, thiserror::Error)]
136                #[error("no event handler registered")]
137                struct UnhandledEvent;
138
139                Err(UnhandledEvent.into())
140            }
141            Err(err) => Err(err),
142        };
143        std::future::ready(result)
144    }
145
146    fn on_trace(&mut self, process: &ProcessorState<'_>, trace_id: u32) -> Result<(), TraceError> {
147        let event = TraceEvent::from(trace_id);
148        let clk = process.clock();
149        if let Some(handlers) = self.tracing_callbacks.get_mut(&trace_id) {
150            for handler in handlers.iter_mut() {
151                handler(clk, event);
152            }
153        }
154        Ok(())
155    }
156
157    fn resolve_event(&self, event_id: EventId) -> Option<&EventName> {
158        self.event_handlers.resolve_event(event_id)
159    }
160}
miden_debug_engine/exec/host.rs

miden_debug_engine/exec/
host.rs
