fix: improve debug var loc tracking

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - Implemented project assembly ([#2877](https://github.com/0xMiden/miden-vm/pull/2877)).
 - Added `FastProcessor::into_parts()` to extract advice provider, memory, and precompile transcript after step-based execution ([#2901](https://github.com/0xMiden/miden-vm/pull/2901)).
+- Added `FrameBase` variant to `DebugVarLocation` and `set_value_location` to `DebugVarInfo` for frame-pointer-relative debug variable locations ([#2955](https://github.com/0xMiden/miden-vm/pull/2955)).
 
 ## 0.22.0 (2026-03-18)
 

core/src/mast/debuginfo/asm_op_storage.rs

@@ -183,6 +183,12 @@ impl OpToAsmOpId {
         entries.first().map(|(_, id)| *id)
     }
 
+    /// Returns all `(op_idx, AsmOpId)` pairs for the given node, or an empty vec if the
+    /// node has no asm ops.
+    pub fn asm_ops_for_node(&self, node_id: MastNodeId) -> Vec<(usize, AsmOpId)> {
+        self.inner.row(node_id).map(|r| r.to_vec()).unwrap_or_default()
+    }
+
     /// Validates the CSR structure integrity.
     ///
     /// # Arguments

core/src/mast/debuginfo/debug_var_storage.rs

@@ -452,6 +452,71 @@ impl OpToDebugVarIds {
         Ok(result)
     }
 
+    /// Returns all `(op_idx, DebugVarId)` pairs for the given node, or an empty vec if the
+    /// node has no debug vars.
+    pub fn debug_vars_for_node(&self, node: MastNodeId) -> Vec<(usize, DebugVarId)> {
+        let op_range = match self.operation_range_for_node(node) {
+            Ok(range) => range,
+            Err(_) => return Vec::new(),
+        };
+
+        let mut result = Vec::new();
+        for (op_offset, op_idx) in op_range.clone().enumerate() {
+            if op_idx + 1 >= self.op_indptr_for_var_ids.len() {
+                break;
+            }
+            let var_start = self.op_indptr_for_var_ids[op_idx];
+            let var_end = self.op_indptr_for_var_ids[op_idx + 1];
+            for &var_id in &self.debug_var_ids[var_start..var_end] {
+                result.push((op_offset, var_id));
+            }
+        }
+        result
+    }
+
+    /// Creates a new [`OpToDebugVarIds`] with remapped node IDs.
+    ///
+    /// This is used when nodes are removed from a MastForest and the remaining nodes are
+    /// renumbered. The remapping maps old node IDs to new node IDs.
+    ///
+    /// Nodes that are not in the remapping are considered removed and their debug var data
+    /// is discarded.
+    pub fn remap_nodes(
+        &self,
+        remapping: &alloc::collections::BTreeMap<MastNodeId, MastNodeId>,
+    ) -> Self {
+        if self.is_empty() {
+            return Self::new();
+        }
+        if remapping.is_empty() {
+            return self.clone();
+        }
+
+        let max_new_id = remapping.values().map(|id| id.to_usize()).max().unwrap_or(0);
+        let num_new_nodes = max_new_id + 1;
+
+        let mut new_node_data: alloc::collections::BTreeMap<usize, Vec<(usize, DebugVarId)>> =
+            alloc::collections::BTreeMap::new();
+
+        for (old_id, new_id) in remapping {
+            let vars = self.debug_vars_for_node(*old_id);
+            if !vars.is_empty() {
+                new_node_data.insert(new_id.to_usize(), vars);
+            }
+        }
+
+        let mut new_storage = Self::new();
+        for idx in 0..num_new_nodes {
+            let node_id = MastNodeId::new_unchecked(idx as u32);
+            let vars = new_node_data.remove(&idx).unwrap_or_default();
+            new_storage
+                .add_debug_var_info_for_node(node_id, vars)
+                .expect("failed to remap debug var storage");
+        }
+
+        new_storage
+    }
+
     /// Clears this storage.
     pub fn clear(&mut self) {
         self.debug_var_ids.clear();

core/src/mast/debuginfo/mod.rs

@@ -272,6 +272,12 @@ impl DebugInfo {
         self.debug_vars.get(debug_var_id)
     }
 
+    /// Returns all `(op_idx, DebugVarId)` pairs for the given node, or an empty vec if the
+    /// node has no debug vars.
+    pub fn debug_vars_for_node(&self, node_id: MastNodeId) -> Vec<(usize, DebugVarId)> {
+        self.op_debug_var_storage.debug_vars_for_node(node_id)
+    }
+
     /// Returns debug variable IDs for a specific operation within a node.
     pub fn debug_vars_for_operation(
         &self,
@@ -364,6 +370,11 @@ impl DebugInfo {
         self.asm_ops.get(asm_op_id)
     }
 
+    /// Returns all `(op_idx, AsmOpId)` pairs for the given node.
+    pub fn asm_ops_for_node(&self, node_id: MastNodeId) -> Vec<(usize, AsmOpId)> {
+        self.asm_op_storage.asm_ops_for_node(node_id)
+    }
+
     // ASSEMBLY OP MUTATORS
     // --------------------------------------------------------------------------------------------
 
@@ -413,6 +424,14 @@ impl DebugInfo {
         self.asm_op_storage = self.asm_op_storage.remap_nodes(remapping);
     }
 
+    /// Remaps the debug var storage to use new node IDs after nodes have been removed/reordered.
+    ///
+    /// This should be called after nodes are removed from the MastForest to ensure the debug
+    /// var storage still references valid node IDs.
+    pub(super) fn remap_debug_var_storage(&mut self, remapping: &BTreeMap<MastNodeId, MastNodeId>) {
+        self.op_debug_var_storage = self.op_debug_var_storage.remap_nodes(remapping);
+    }
+
     // DEBUG VARIABLE MUTATORS
     // --------------------------------------------------------------------------------------------