supporting memory references

Author: omarArm

src/gdb/GDBDebugSessionBase.ts

@@ -2679,10 +2679,35 @@ export abstract class GDBDebugSessionBase extends LoggingDebugSession {
                               varobjName: varobj.varname,
                           })
                         : 0;
+                let memoryReferenceResult:
+                    | MIGDBDataEvaluateExpressionResponse
+                    | undefined;
+                let hasMemoryReference = false;
+                if (this.supportsMemoryReferences) {
+                    try {
+                        memoryReferenceResult =
+                            await mi.sendDataEvaluateExpression(
+                                gdb,
+                                `&(${varobj.expression})`
+                            );
+                        // Depending on the GDBServer being used, sometimes the result of evaluating an address of a symbol returns "<address> <symbol name>"
+                        if (memoryReferenceResult.value?.includes(' ')) {
+                            memoryReferenceResult.value =
+                                memoryReferenceResult.value.split(' ')[0];
+                        }
+                        hasMemoryReference = true;
+                    } catch {
+                        hasMemoryReference = false;
+                    }
+                }
                 response.body = {
                     result,
                     type: varobj.type,
                     variablesReference,
+                    memoryReference:
+                        hasMemoryReference && memoryReferenceResult
+                            ? memoryReferenceResult.value
+                            : undefined,
                 };
             }
 

src/integration-tests/debugClient.ts

@@ -141,6 +141,8 @@ export class CdtDebugClient extends DebugClient {
         if (!args) {
             args = {
                 supportsRunInTerminalRequest: true,
+                supportsMemoryEvent: true,
+                supportsMemoryReferences: true,
                 adapterID: this['_debugType'],
                 linesStartAt1: true,
                 columnsStartAt1: true,

src/integration-tests/evaluate.spec.ts

@@ -531,6 +531,26 @@ describe('evaluate request global variables', function () {
         });
         expect(evalRes.body.result).to.equal('25');
     });
+
+    it('response for variables should include memory reference if the expression has an lvalue', async function () {
+        // Read a global variable using evaluateRequest
+        const watchRes = await dc.evaluateRequest({
+            context: 'watch',
+            expression: 'global_int',
+            frameId: scope.frame.id,
+        });
+        expect(watchRes.body.memoryReference).to.not.be.undefined;
+    });
+
+    it('should not include memory reference if the expression does not have an lvalue', async function () {
+        const watchRes = await dc.evaluateRequest({
+            context: 'watch',
+            expression: 'global_int + 1',
+            frameId: scope.frame.id,
+        });
+
+        expect(watchRes.body.memoryReference).to.be.undefined;
+    });
 });
 
 describe('evaluate request - watch local variable across lexical scope transition', function () {