[clangd][ObjC] Highlight Objc Ivar refs

[dgoldman]

Summary

Treat them just like we do for properties - as a property semantic
token although ideally we could differentiate the two.

[dgoldman]

Fix test broken on non-macOS

[dgoldman]

Another attempt...

[kadircet]

Thanks! Can you also add a test to FindExplicitReferencesTest.All ? as that's where the underlying change lies.

To disambiguate properties and ivars, what if we used modifiers? I suppose we can mark properties with abstract modifier, but i am not an obj-c person so it might be better for you to vet such an idea.

[dgoldman]

Add another test case

[dgoldman]

In D101785#2741535, @kadircet wrote:

Thanks! Can you also add a test to FindExplicitReferencesTest.All ? as that's where the underlying change lies.

To disambiguate properties and ivars, what if we used modifiers? I suppose we can mark properties with abstract modifier, but i am not an obj-c person so it might be better for you to vet such an idea.

Done. I don't think a modifier would make sense though - they're not really abstract. I think it would be better if there was a Field token type, like the Field symbol kind.

[kadircet]

thanks!

clang-tools-extra/clangd/FindTarget.cpp

void VisitObjCPropertyRefExpr(const ObjCPropertyRefExpr *E) {
       }
       Refs.push_back(ReferenceLoc{
           NestedNameSpecifierLoc(), E->getLocation(),
           /*IsDecl=*/false,
           // Select the getter, setter, or @property depending on the call.
           explicitReferenceTargets(DynTypedNode::create(*E), {}, Resolver)});
     }
 
+    void VisitObjCIvarRefExpr(const ObjCIvarRefExpr *OIRE) {
+      Refs.push_back(ReferenceLoc{NestedNameSpecifierLoc(),
+                                  OIRE->getLocation(),
+                                  /*IsDecl=*/false,
+                                  {OIRE->getDecl()}});
+    }
+
     void VisitObjCMessageExpr(const ObjCMessageExpr *E) {
       // The name may have several tokens, we can only report the first.
       Refs.push_back(ReferenceLoc{NestedNameSpecifierLoc(),
                                   E->getSelectorStartLoc(),
                                   /*IsDecl=*/false,
                                   {E->getMethodDecl()}});
     }
 

clang-tools-extra/clangd/unittests/FindTargetTests.cpp

#endif
            "0: targets = {T}, decl\n"
            "1: targets = {Drawable}\n"
            "2: targets = {T}\n"
            "3: targets = {foo::bar}, decl\n"
            "4: targets = {T}\n"
            "5: targets = {t}, decl\n"
            "6: targets = {t}\n"
            "7: targets = {}\n"},
+       // Objective-C: instance variables
+       {
+           R"cpp(
+            @interface I {
+            @public
+              I *_z;
+            }
+            @end
+            I *f;
+            void foo() {
+              $0^f->$1^_z = 0;
+            }
+          )cpp",
+           "0: targets = {f}\n"
+           "1: targets = {I::_z}\n"},
        // Objective-C: properties
        {
            R"cpp(
             @interface I {}
             @property(retain) I* x;
             @property(retain) I* y;
             @end
             I *f;

clang-tools-extra/clangd/unittests/SemanticHighlightingTests.cpp

)cpp",
         // ObjC: Categories
         @interface $Class_decl[[Foo]]
         @end
         @interface $Class[[Foo]]($Namespace_decl[[Bar]])
         @end
         @implementation $Class[[Foo]]($Namespace_decl[[Bar]])
         @end
       )cpp",
+      R"cpp(
+        // ObjC: Properties and Ivars.
+        @interface $Class_decl[[Foo]] {
+          int $Field_decl[[_someProperty]];
+        }
+        @property(nonatomic, assign) int $Field_decl[[someProperty]];
+        @end
+        @implementation $Class_decl[[Foo]]
+        @synthesize someProperty = _someProperty;
+        - (int)$Method_decl[[doSomething]] {
+          self.$Field[[someProperty]] = self.$Field[[someProperty]] + 1;
+          self->$Field[[_someProperty]] = $Field[[_someProperty]] + 1;
+        }
+        @end
+      )cpp",
       // Member imported from dependent base
       R"cpp(
         template <typename> struct $Class_decl[[Base]] {
           int $Field_decl[[member]];
         };
         template <typename $TemplateParameter_decl[[T]]>
         struct $Class_decl[[Derived]] : $Class[[Base]]<$TemplateParameter[[T]]> {
           using $Class[[Base]]<$TemplateParameter[[T]]>::$Field_dependentName[[member]];