[lldb-dap] Improving 'variables' hover requests.

lldb/test/API/tools/lldb-dap/disconnect/TestDAP_disconnect.py

@@ -2,7 +2,6 @@
 Test lldb-dap disconnect request
 """
 
-
 import dap_server
 from lldbsuite.test.decorators import *
 from lldbsuite.test.lldbtest import *
@@ -71,7 +70,9 @@ def test_attach(self):
         lldbutil.wait_for_file_on_target(self, sync_file_path)
 
         self.attach(pid=self.process.pid, disconnectAutomatically=False)
-        response = self.dap_server.request_evaluate("wait_for_attach = false;")
+        response = self.dap_server.request_evaluate(
+            "`expr -- wait_for_attach = false;", context="repl"
+        )
         self.assertTrue(response["success"])
 
         # verify we haven't produced the side effect file yet

lldb/test/API/tools/lldb-dap/locations/TestDAP_locations.py

@@ -76,6 +76,6 @@ def test_locations(self):
         self.assertEqual(val_loc_func_ref["body"]["line"], 3)
 
         # `evaluate` responses for function pointers also have locations associated
-        eval_res = self.dap_server.request_evaluate("greet")
-        self.assertTrue(eval_res["success"])
+        eval_res = self.dap_server.request_evaluate("greet", context="repl")
+        self.assertTrue(eval_res["success"], f"evaluate failed: {eval_res}")
         self.assertIn("valueLocationReference", eval_res["body"].keys())

lldb/test/API/tools/lldb-dap/memory/TestDAP_memory.py

@@ -92,7 +92,7 @@ def test_readMemory(self):
         )
         self.continue_to_next_stop()
 
-        ptr_deref = self.dap_server.request_evaluate("*rawptr")["body"]
+        ptr_deref = self.dap_server.request_evaluate("*rawptr", context="repl")["body"]
         memref = ptr_deref["memoryReference"]
 
         # We can read the complete string

lldb/test/API/tools/lldb-dap/variables/TestDAP_variables.py

@@ -738,7 +738,7 @@ def test_indexedVariables_with_raw_child_for_synthetics(self):
         self.do_test_indexedVariables(enableSyntheticChildDebugging=True)
 
     @skipIfWindows
-    @skipIfAsan # FIXME this fails with a non-asan issue on green dragon.
+    @skipIfAsan  # FIXME this fails with a non-asan issue on green dragon.
     def test_registers(self):
         """
         Test that registers whose byte size is the size of a pointer on

lldb/tools/lldb-dap/Handler/EvaluateRequestHandler.cpp

@@ -181,7 +181,17 @@ void EvaluateRequestHandler::operator()(
         expression = dap.last_nonempty_var_expression;
       else
         dap.last_nonempty_var_expression = expression;
+    } else if (context == "hover") {
+      // If we're in the hover context trim leading pointer/reference characters
+      // to ensure we return the actual value of the expression.
+      // This can come up if you hover over a pointer or reference declaration
+      // like 'MyType *foo;' or `void fn(std::string &arg)`, which results in
+      // the hover request sending '*foo' or `&arg`. Trim these characters to
+      // get to the actual variable, which should have the proper type encoded
+      // by the compiler.
+      expression = llvm::StringRef(expression).ltrim("*&").str();
     }
+
     // Always try to get the answer from the local variables if possible. If
     // this fails, then if the context is not "hover", actually evaluate an
     // expression using the expression parser.