Enhance debugging support by adding type information to evaluation results and updating visualization backend to handle additional type parameters

.gitignore

@@ -1,6 +1,7 @@
 # Logs
 logs
 *.log
+target
 npm-debug.log*
 yarn-debug.log*
 yarn-error.log*
@@ -87,4 +88,4 @@ __pycache__/
 *.py[cod]
 *$py.class
 
-*.vsix
+*.vsix

demos/lists/python/.vscode/launch.json

@@ -0,0 +1,16 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+    
+        {
+            "name": "Python Debugger: Current File",
+            "type": "debugpy",
+            "request": "launch",
+            "program": "${file}",
+            "console": "integratedTerminal"
+        }
+    ]
+}

demos/lists/rust/.vscode/launch.json

@@ -0,0 +1,21 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "type": "cppdbg",
+            "request": "launch",
+            "name": "Debug list_example",
+            "program": "${workspaceFolder}/target/debug/list_example",
+            "args": [],
+            "cwd": "${workspaceFolder}",
+            "preLaunchTask": "cargo build",
+            "MIMode": "gdb",
+            "miDebuggerPath": "/usr/bin/rust-gdb",
+            "stopAtEntry": false,
+            "externalConsole": false
+        }
+    ]
+}

demos/lists/rust/.vscode/tasks.json

@@ -0,0 +1,17 @@
+{
+    "version": "2.0.0",
+    "tasks": [
+        {
+            "type": "cargo",
+            "command": "build",
+            "problemMatcher": [
+                "$rustc"
+            ],
+            "group": {
+                "kind": "build",
+                "isDefault": true
+            },
+            "label": "cargo build"
+        }
+    ]
+}

demos/lists/rust/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "list_example"
+version = "0.1.0"

extension/src/VisualizationBackend/NodeTableGraphVisualizationSupport.ts

@@ -206,7 +206,9 @@ export class NodeTableGraphVisualizationBackend extends VisualizationBackendBase
 					primary.result,
 					nodes,
 					edges,
-					visited
+					visited,
+					undefined,
+					primary.type
 				);
 			} else {
 				nodes.set("root", {
@@ -321,7 +323,9 @@ export class NodeTableGraphVisualizationBackend extends VisualizationBackendBase
 					v.value,
 					nodes,
 					edges,
-					visited
+					visited,
+					undefined,
+					v.type
 				);
 				roots.push({ name: v.name, value: id, kind: "local", type: v.type });
 			} else {
@@ -430,10 +434,15 @@ export class NodeTableGraphVisualizationBackend extends VisualizationBackendBase
 	}
 
 	// Recursively walks a DAP variablesReference into `nodes`/`edges`,
-	// returning the id (a real address when one is present in the variable's
-	// own printed value, else a synthesized id) of the node it produced --
-	// mirrors the old scripts' hex(ptr_int)/id(obj)-derived node ids, giving
-	// the same cross-reference cycle dedup via `visited`. Routes to either a
+	// returning the id of the node it produced -- a real address when one
+	// is present in the variable's own printed value, else the DAP
+	// variablesReference itself (verified against a real debugpy session,
+	// including through a genuine self-referential cycle, to be stably
+	// reused for the same underlying object -- not just an arbitrary
+	// per-call counter, which would neither dedup re-visits of the same
+	// addressless object nor terminate a true cycle). Mirrors the old
+	// scripts' hex(ptr_int)/id(obj)-derived node ids, giving the same
+	// cross-reference cycle dedup via `visited`. Routes to either a
 	// regular struct node or an array-table node depending on shape, so an
 	// array of structs gets the compact table rendering everywhere it
 	// appears -- as the primary root, a struct's own field, a local, or a
@@ -444,9 +453,10 @@ export class NodeTableGraphVisualizationBackend extends VisualizationBackendBase
 		nodes: Map<string, GraphNodeData>,
 		edges: GraphEdge[],
 		visited: Set<string>,
-		prefetchedChildren?: DapVariable[]
+		prefetchedChildren?: DapVariable[],
+		ownType?: string
 	): Promise<string> {
-		const id = this.extractAddress(ownValue) || `synthetic:${nodes.size}`;
+		const id = this.extractAddress(ownValue) || `vref:${variablesReference}`;
 		if (visited.has(id)) {
 			return id;
 		}
@@ -458,7 +468,7 @@ export class NodeTableGraphVisualizationBackend extends VisualizationBackendBase
 		if (this.looksLikeArrayOfStructs(children)) {
 			await this.buildArrayTableNode(id, children, nodes, edges, visited);
 		} else {
-			await this.buildStructFields(id, children, nodes, edges, visited);
+			await this.buildStructFields(id, children, nodes, edges, visited, ownType);
 		}
 		return id;
 	}
@@ -468,13 +478,14 @@ export class NodeTableGraphVisualizationBackend extends VisualizationBackendBase
 		children: DapVariable[],
 		nodes: Map<string, GraphNodeData>,
 		edges: GraphEdge[],
-		visited: Set<string>
+		visited: Set<string>,
+		ownType?: string
 	) {
 		const fields: NodeField[] = [];
 		for (const child of children) {
-			await this.addField(child, fields, edges, nodes, visited, id, 0);
+			await this.addField(child, fields, edges, nodes, visited, id, 0, ownType);
 		}
-		nodes.set(id, { id, fields });
+		nodes.set(id, { id, fields, type: ownType });
 	}
 
 	// Builds a single node holding every element's members as columns
@@ -519,7 +530,9 @@ export class NodeTableGraphVisualizationBackend extends VisualizationBackendBase
 								m.value,
 								nodes,
 								edges,
-								visited
+								visited,
+								undefined,
+								m.type
 							);
 							edges.push({
 								from: id,
@@ -566,26 +579,50 @@ export class NodeTableGraphVisualizationBackend extends VisualizationBackendBase
 		nodes: Map<string, GraphNodeData>,
 		visited: Set<string>,
 		ownerId: string,
-		depth: number
+		depth: number,
+		ownerType?: string
 	) {
 		const addr = this.extractAddress(child.value);
-		if (addr && this.looksLikePointer(child)) {
-			fields.push({
-				name: child.name,
-				value: addr,
-				isPointer: true,
-				typeHint: child.type,
-			});
+		// A field whose *static type* matches the type of the struct that
+		// directly contains it (not necessarily the original top-level
+		// owner -- see the recursive call below, which passes child.type
+		// as the new ownerType) can only be sound if it's some kind of
+		// reference/handle rather than a true by-value member: a value type
+		// genuinely containing itself would have infinite size. This is
+		// what catches Python's (and similarly Java/C#'s) recursive
+		// dataclasses/objects, which never print an address in their repr
+		// (looksLikePointer's <object at 0x...> check only fires for
+		// classes that haven't overridden __repr__ -- dataclasses always
+		// do) and so would otherwise fall through to the inline-flatten
+		// path below and get capped/mangled at INLINE_FLATTEN_MAX_DEPTH
+		// instead of forming a proper linked node graph.
+		const isSelfReferential = !!ownerType && !!child.type && child.type === ownerType;
+		if ((addr && this.looksLikePointer(child)) || isSelfReferential) {
+			let targetId: string | undefined;
 			if (child.variablesReference > 0) {
-				const targetId = await this.walkNodeOrArrayTable(
+				targetId = await this.walkNodeOrArrayTable(
 					child.variablesReference,
 					child.value,
 					nodes,
 					edges,
-					visited
+					visited,
+					undefined,
+					child.type
 				);
 				edges.push({ from: ownerId, to: targetId, label: child.name });
 			}
+			fields.push({
+				name: child.name,
+				// Real pointers show their address; a self-referential
+				// field with no address of its own shows the id of the
+				// node it resolves to instead (still a stable, clickable
+				// cross-reference) -- child.value as a last-resort fallback
+				// covers a null/childless self-typed field (unusual, but
+				// keeps this from rendering an empty value).
+				value: addr || targetId || child.value,
+				isPointer: true,
+				typeHint: child.type,
+			});
 			return;
 		}
 
@@ -626,7 +663,8 @@ export class NodeTableGraphVisualizationBackend extends VisualizationBackendBase
 						nodes,
 						visited,
 						ownerId,
-						depth + 1
+						depth + 1,
+						child.type
 					);
 				}
 				return;

extension/src/proxies/DebugSessionProxy.ts

@@ -85,7 +85,7 @@ export class DebugSessionProxy {
 		expression: string;
 		frameId: number | undefined;
 		context: "watch" | "repl" | "copy";
-	}): Promise<{ result: string; variablesReference: number }> {
+	}): Promise<{ result: string; variablesReference: number; type?: string }> {
 		const reply = await this.session.customRequest("evaluate", {
 			expression: args.expression,
 			frameId: args.frameId,
@@ -94,6 +94,7 @@ export class DebugSessionProxy {
 		return {
 			result: reply.result,
 			variablesReference: reply.variablesReference,
+			type: reply.type,
 		};
 	}
 }