[clangd] Improve ObjC property handling in SelectionTree.

sam-mccall · sam-mccall · commit af071f03f379 · 2020-01-28T11:07:19.000+01:00
Fixes clangd/clangd#233 Reviewers: dgoldman Subscribers: ilya-biryukov, MaskRay, jkorous, arphaman, jfb, kadircet, usaxena95, cfe-commits Tags: #clang Differential Revision: https://reviews.llvm.org/D72634
diff --git a/clang-tools-extra/clangd/Selection.cpp b/clang-tools-extra/clangd/Selection.cpp
@@ -462,6 +462,14 @@ class SelectionVisitor : public RecursiveASTVisitor<SelectionVisitor> {
              TraverseStmt(S->getRangeInit()) && TraverseStmt(S->getBody());
     });
   }
+  // OpaqueValueExpr blocks traversal, we must explicitly traverse it.
+  bool TraverseOpaqueValueExpr(OpaqueValueExpr *E) {
+    return traverseNode(E, [&] { return TraverseStmt(E->getSourceExpr()); });
+  }
+  // We only want to traverse the *syntactic form* to understand the selection.
+  bool TraversePseudoObjectExpr(PseudoObjectExpr *E) {
+    return traverseNode(E, [&] { return TraverseStmt(E->getSyntacticForm()); });
+  }
 
 private:
   using Base = RecursiveASTVisitor<SelectionVisitor>;
diff --git a/clang-tools-extra/clangd/unittests/FindTargetTests.cpp b/clang-tools-extra/clangd/unittests/FindTargetTests.cpp
@@ -536,7 +536,8 @@ TEST_F(TargetDeclTest, ObjC) {
       [[f.x]].y = 0;
     }
   )cpp";
-  EXPECT_DECLS("OpaqueValueExpr", "@property(atomic, retain, readwrite) I *x");
+  EXPECT_DECLS("ObjCPropertyRefExpr",
+               "@property(atomic, retain, readwrite) I *x");
 
   Code = R"cpp(
     @protocol Foo
diff --git a/clang-tools-extra/clangd/unittests/SelectionTests.cpp b/clang-tools-extra/clangd/unittests/SelectionTests.cpp
@@ -323,12 +323,52 @@ TEST(SelectionTest, CommonAncestor) {
             Foo x = [[^12_ud]];
           )cpp",
           "UserDefinedLiteral"},
+
       {
           R"cpp(
         int a;
         decltype([[^a]] + a) b;
         )cpp",
           "DeclRefExpr"},
+
+      // Objective-C OpaqueValueExpr/PseudoObjectExpr has weird ASTs.
+      // Need to traverse the contents of the OpaqueValueExpr to the POE,
+      // and ensure we traverse only the syntactic form of the PseudoObjectExpr.
+      {
+          R"cpp(
+            @interface I{}
+            @property(retain) I*x;
+            @property(retain) I*y;
+            @end
+            void test(I *f) { [[^f]].x.y = 0; }
+          )cpp",
+          "DeclRefExpr"},
+      {
+          R"cpp(
+            @interface I{}
+            @property(retain) I*x;
+            @property(retain) I*y;
+            @end
+            void test(I *f) { [[f.^x]].y = 0; }
+          )cpp",
+          "ObjCPropertyRefExpr"},
+      // Examples with implicit properties.
+      {
+          R"cpp(
+            @interface I{}
+            -(int)foo;
+            @end
+            int test(I *f) { return 42 + [[^f]].foo; }
+          )cpp",
+          "DeclRefExpr"},
+      {
+          R"cpp(
+            @interface I{}
+            -(int)foo;
+            @end
+            int test(I *f) { return 42 + [[f.^foo]]; }
+          )cpp",
+          "ObjCPropertyRefExpr"},
   };
   for (const Case &C : Cases) {
     Annotations Test(C.Code);
@@ -339,6 +379,7 @@ TEST(SelectionTest, CommonAncestor) {
     // FIXME: Auto-completion in a template requires disabling delayed template
     // parsing.
     TU.ExtraArgs.push_back("-fno-delayed-template-parsing");
+    TU.ExtraArgs.push_back("-xobjective-c++");
 
     auto AST = TU.build();
     auto T = makeSelectionTree(C.Code, AST);

Original file line number	Diff line number	Diff line change
`@@ -536,7 +536,8 @@ TEST_F(TargetDeclTest, ObjC) {`
`536`	`536`	`[[f.x]].y = 0;`
`537`	`537`	`}`
`538`	`538`	`)cpp";`
`539`		`- EXPECT_DECLS("OpaqueValueExpr", "@property(atomic, retain, readwrite) I *x");`
	`539`	`+ EXPECT_DECLS("ObjCPropertyRefExpr",`
	`540`	`+ "@property(atomic, retain, readwrite) I *x");`
`540`	`541`
`541`	`542`	`Code = R"cpp(`
`542`	`543`	`@protocol Foo`