From f4871ead55f59a7dfee56ea97c32b5df4209d9ce Mon Sep 17 00:00:00 2001
From: Sam McCall <sam.mccall@gmail.com>
Date: Fri, 10 Jan 2020 16:27:12 +0100
Subject: [PATCH] [clangd] Support pseudo-obj expr, opaque values, and property
 references in findExplicitReferences()

Reviewers: ilya-biryukov, dgoldman

Subscribers: MaskRay, jkorous, arphaman, jfb, kadircet, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D72508
---
 clang-tools-extra/clangd/FindTarget.cpp       | 24 +++++++++++++-
 .../clangd/unittests/FindTargetTests.cpp      | 33 ++++++++++++++++++-
 2 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/clang-tools-extra/clangd/FindTarget.cpp b/clang-tools-extra/clangd/FindTarget.cpp
index ca0584cbec78..352674ebc4c7 100644
--- a/clang-tools-extra/clangd/FindTarget.cpp
+++ b/clang-tools-extra/clangd/FindTarget.cpp
@@ -619,7 +619,7 @@ llvm::SmallVector<ReferenceLoc, 2> refInDecl(const Decl *D) {
 
 llvm::SmallVector<ReferenceLoc, 2> refInExpr(const Expr *E) {
   struct Visitor : ConstStmtVisitor<Visitor> {
-    // FIXME: handle more complicated cases, e.g. ObjC, designated initializers.
+    // FIXME: handle more complicated cases: more ObjC, designated initializers.
     llvm::SmallVector<ReferenceLoc, 2> Refs;
 
     void VisitConceptSpecializationExpr(const ConceptSpecializationExpr *E) {
@@ -660,6 +660,14 @@ llvm::SmallVector<ReferenceLoc, 2> refInExpr(const Expr *E) {
                                   /*IsDecl=*/false,
                                   {E->getPack()}});
     }
+
+    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), {})});
+    }
   };
 
   Visitor V;
@@ -780,6 +788,20 @@ public:
     return true;
   }
 
+  bool TraverseOpaqueValueExpr(OpaqueValueExpr *OVE) {
+    visitNode(DynTypedNode::create(*OVE));
+    // Not clear why the source expression is skipped by default...
+    // FIXME: can we just make RecursiveASTVisitor do this?
+    return RecursiveASTVisitor::TraverseStmt(OVE->getSourceExpr());
+  }
+
+  bool TraversePseudoObjectExpr(PseudoObjectExpr *POE) {
+    visitNode(DynTypedNode::create(*POE));
+    // Traverse only the syntactic form to find the *written* references.
+    // (The semantic form also contains lots of duplication)
+    return RecursiveASTVisitor::TraverseStmt(POE->getSyntacticForm());
+  }
+
   // We re-define Traverse*, since there's no corresponding Visit*.
   // TemplateArgumentLoc is the only way to get locations for references to
   // template template parameters.
diff --git a/clang-tools-extra/clangd/unittests/FindTargetTests.cpp b/clang-tools-extra/clangd/unittests/FindTargetTests.cpp
index f2659a96172b..3960ef18e0d6 100644
--- a/clang-tools-extra/clangd/unittests/FindTargetTests.cpp
+++ b/clang-tools-extra/clangd/unittests/FindTargetTests.cpp
@@ -590,6 +590,7 @@ protected:
     // parsing.
     TU.ExtraArgs.push_back("-fno-delayed-template-parsing");
     TU.ExtraArgs.push_back("-std=c++2a");
+    TU.ExtraArgs.push_back("-xobjective-c++");
 
     auto AST = TU.build();
     auto *TestDecl = &findDecl(AST, "foo");
@@ -1124,7 +1125,37 @@ TEST_F(FindExplicitReferencesTest, All) {
            "3: targets = {foo::bar}, decl\n"
            "4: targets = {T}\n"
            "5: targets = {t}, decl\n"
-           "6: targets = {t}\n"}};
+           "6: targets = {t}\n"},
+       // Objective-C: properties
+       {
+           R"cpp(
+            @interface I {}
+            @property(retain) I* x;
+            @property(retain) I* y;
+            @end
+            I *f;
+            void foo() {
+              $0^f.$1^x.$2^y = 0;
+            }
+          )cpp",
+           "0: targets = {f}\n"
+           "1: targets = {I::x}\n"
+           "2: targets = {I::y}\n"},
+       // Objective-C: implicit properties
+       {
+           R"cpp(
+            @interface I {}
+            -(I*)x;
+            -(void)setY:(I*)y;
+            @end
+            I *f;
+            void foo() {
+              $0^f.$1^x.$2^y = 0;
+            }
+          )cpp",
+           "0: targets = {f}\n"
+           "1: targets = {I::x}\n"
+           "2: targets = {I::setY:}\n"}};
 
   for (const auto &C : Cases) {
     llvm::StringRef ExpectedCode = C.first;