[clangd] Fix targetDecl() on certain usage of ObjC properties.

[sammccall]

Summary

In particular there's a common chain:

OpaqueValueExpr->PseudoObjectExpr->ObjCPropertyRefExpr->ObjCPropertyDecl

and we weren't handling the first two edges

[ilya-biryukov]

Could you also add a test (and possibly support this in the visitors) for findExplicitReferences?

[merge_guards_bot]

Unit tests: pass. 61742 tests passed, 0 failed and 780 were skipped.

clang-tidy: fail. Please fix clang-tidy findings.

clang-format: fail. Please format your changes with clang-format by running git-clang-format HEAD^ or applying this patch.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

[sammccall]

In D72494#1813719, @ilya-biryukov wrote:

Could you also add a test (and possibly support this in the visitors) for findExplicitReferences?

I've written tests, but it doesn't work and it's not obvious to me yet how to make it work, so I'll do this in a separate patch.
(We're close to the release cut... as far as major features, this patch fixes go to def and hover. Extending to findExplicitRefs will fix rename. Xrefs works already via libindex)

[sammccall]

In D72494#1813875, @sammccall wrote:

In D72494#1813719, @ilya-biryukov wrote:

Could you also add a test (and possibly support this in the visitors) for findExplicitReferences?

I've written tests, but it doesn't work and it's not obvious to me yet how to make it work, so I'll do this in a separate patch.

By which I mean, adding the same delegation to the RAV there doesn't work, and I'm not confident that jiggling it around until the test passes is correct here, so I want to understand the traversal behavior a bit better first (RAV has several special cases around OVE/POE)

[kadircet]

LGTM, thanks!

[dgoldman]

LGMT, thanks for fixing

clang-tools-extra/clangd/FindTarget.cpp

struct Visitor : public ConstStmtVisitor<Visitor> {
           Outer.add(OPRE->getExplicitProperty(), Flags);
         else {
           if (OPRE->isMessagingGetter())
             Outer.add(OPRE->getImplicitPropertyGetter(), Flags);
           if (OPRE->isMessagingSetter())
             Outer.add(OPRE->getImplicitPropertySetter(), Flags);
         }
       }
       void VisitObjCProtocolExpr(const ObjCProtocolExpr *OPE) {
         Outer.add(OPE->getProtocol(), Flags);
       }
+      void VisitOpaqueValueExpr(const OpaqueValueExpr *OVE) {
+        Outer.add(OVE->getSourceExpr(), Flags);
+      }
+      void VisitPseudoObjectExpr(const PseudoObjectExpr *POE) {
+        Outer.add(POE->getSyntacticForm(), Flags);
+      }
     };
     Visitor(*this, Flags).Visit(S);
   }
 
   void add(QualType T, RelSet Flags) {
     if (T.isNull())
       return;
     debug(T, Flags);

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

Code = R"cpp(
     @end
     void test(Foo *f) {
       [[f.x]] = 42;
     }
   )cpp";
   EXPECT_DECLS("ObjCPropertyRefExpr", "- (void)setX:(int)x");
 
   Code = R"cpp(
-    @interface Foo {}
-    @property int x;
+    @interface I {}
+    @property(retain) I* x;
+    @property(retain) I* y;
     @end
-    void test(Foo *f) {
-      [[f.x]] = 42;
+    void test(I *f) {
+      [[f.x]].y = 0;
     }
   )cpp";
-  EXPECT_DECLS("ObjCPropertyRefExpr",
-               "@property(atomic, assign, unsafe_unretained, readwrite) int x");
+  EXPECT_DECLS("OpaqueValueExpr",
+               "@property(atomic, retain, readwrite) I *x");
 
   Code = R"cpp(
     @protocol Foo
     @end
     id test() {
       return [[@protocol(Foo)]];
     }
   )cpp";