[lldb-vscode] Add presentation hints for scopes

[werat]

Summary

Scopes can have an optional hint for how to present this scope in the UI:
https://microsoft.github.io/debug-adapter-protocol/specification#Types_Scope

The IDEs can use the hint to present the data accordingly. For example,
Visual Studio has a separate Registers window, which is populated with the
data from the scope with presentationHint: "registers".

[wallace]

could you share a screenshot of how this looks like?

And thanks for doing this!!

[werat]

In D113400#3117500, @wallace wrote:

could you share a screenshot of how this looks like?

Sure! Here are the screenshots of before/after in Visual Studio 2022.

Before everything is in one place (in Locals Window):

After, Registers Window (marked in red -- changed since previous step):

After, Locals Window (locals are displayed directly, without "Locals" expand block):

---

There are no visible changes in Visual Studio Code.

[wallace]

Cool. I hope that vscode catches up.

Do you have push permissions or should I land this for you?

Il Mar 9 Nov 2021, 2:16 AM Andy Yankovsky via Phabricator <
[e-mail]> ha scritto:

werat added a comment.

In D113400#3117500 https://reviews.llvm.org/D113400#3117500, @wallace
wrote:

could you share a screenshot of how this looks like?

Sure! Here are the screenshots of before/after in Visual Studio 2022.

Before everything is in one place (in Locals Window):
F20179455: visual-studio-before.png https://reviews.llvm.org/F20179455
After, Registers Window (marked in red -- changed since previous step):
F20179456: registers-after.png https://reviews.llvm.org/F20179456
After, Locals Window (locals are displayed directly, without "Locals"
expand block):
F20179454: locals-after.png https://reviews.llvm.org/F20179454

---

There are no visible changes in Visual Studio Code.

Repository:

rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION

https://reviews.llvm.org/D113400/new/

https://reviews.llvm.org/D113400

[werat]

Thanks! I have push permission, will land it myself in a bit

[clayborg]

nice!

lldb/test/API/tools/lldb-vscode/variables/TestVSCode_variables.py

def test_scopes_and_evaluate_expansion(self):
         )
         self.continue_to_breakpoints(breakpoint_ids)
 
         var_ref = permanent_expr_varref_dict[expandable_expression["name"]]
         response = self.vscode.request_variables(var_ref)
         self.verify_variables(
             expandable_expression["children"], response["body"]["variables"]
         )
+
+        # Test that frame scopes have corresponding presentation hints.
+        frame_id = self.vscode.get_stackFrame()["id"]
+        scopes = self.vscode.request_scopes(frame_id)["body"]["scopes"]
+
+        scope_names = [scope["name"] for scope in scopes]
+        self.assertIn("Locals", scope_names)
+        self.assertIn("Registers", scope_names)
+
+        for scope in scopes:
+            if scope["name"] == "Locals":
+                self.assertEquals(scope.get("presentationHint"), "locals")
+            if scope["name"] == "Registers":
+                self.assertEquals(scope.get("presentationHint"), "registers")

lldb/tools/lldb-vscode/JSONUtils.cpp

 //   "type": "object",
 //   "description": "A Scope is a named container for variables. Optionally
 //                   a scope can map to a source or a range within a source.",
 //   "properties": {
 //     "name": {
 //       "type": "string",
 //       "description": "Name of the scope such as 'Arguments', 'Locals'."
 //     },
+//     "presentationHint": {
+//       "type": "string",
+//       "description": "An optional hint for how to present this scope in the
+//                       UI. If this attribute is missing, the scope is shown
+//                       with a generic UI.",
+//       "_enum": [ "arguments", "locals", "registers" ],
+//     },
 //     "variablesReference": {
 //       "type": "integer",
 //       "description": "The variables of this scope can be retrieved by
 //                       passing the value of variablesReference to the
 //                       VariablesRequest."
 //     },
 //     "namedVariables": {
 //       "type": "integer",

 //   },
 //   "required": [ "name", "variablesReference", "expensive" ]
 // }
 llvm::json::Value CreateScope(const llvm::StringRef name,
                               int64_t variablesReference,
                               int64_t namedVariables, bool expensive) {
   llvm::json::Object object;
   EmplaceSafeString(object, "name", name.str());
+
+  // TODO: Support "arguments" scope. At the moment lldb-vscode includes the
+  // arguments into the "locals" scope.
+  if (variablesReference == VARREF_LOCALS) {
+    object.try_emplace("presentationHint", "locals");
+  } else if (variablesReference == VARREF_REGS) {
+    object.try_emplace("presentationHint", "registers");
+  }
+
   object.try_emplace("variablesReference", variablesReference);
   object.try_emplace("expensive", expensive);
   object.try_emplace("namedVariables", namedVariables);
   return llvm::json::Value(std::move(object));
 }
 
 // "Breakpoint": {
 //   "type": "object",