Add parenthesized expression to SyntaxTree

[eduucaldas]

Ordering nit

[eduucaldas]

nitpick comment

clang/include/clang/Tooling/Syntax/Nodes.h

enum class NodeKind : uint16_t {
   Leaf,
   TranslationUnit,
 
   // Expressions.
   UnknownExpression,
   PrefixUnaryOperatorExpression,
   PostfixUnaryOperatorExpression,
   BinaryOperatorExpression,
+  ParenExpression,
   IntegerLiteralExpression,
   CharacterLiteralExpression,
   FloatingLiteralExpression,
   StringLiteralExpression,
   BoolLiteralExpression,
   CxxNullPtrExpression,
   IdExpression,
 
enum class NodeRole : uint8_t {
   TemplateDeclaration_declaration,
   ExplicitTemplateInstantiation_declaration,
   ArraySubscript_sizeExpression,
   TrailingReturnType_declarator,
   ParametersAndQualifiers_parameter,
   ParametersAndQualifiers_trailingReturn,
   IdExpression_id,
   IdExpression_qualifier,
-  NestedNameSpecifier_specifier
+  NestedNameSpecifier_specifier,
+  ParenExpression_subExpression
 };
 /// For debugging purposes.
 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, NodeRole R);
 
 class SimpleDeclarator;
 
 /// A root node for a translation unit. Parent is always null.
 class TranslationUnit final : public Tree {

 class UnknownExpression final : public Expression {
 public:
   UnknownExpression() : Expression(NodeKind::UnknownExpression) {}
   static bool classof(const Node *N) {
     return N->kind() == NodeKind::UnknownExpression;
   }
 };
 
+/// Models a parenthesized expression `(E)`. C++ [expr.prim.paren]
+/// e.g. `(3 + 2)` in `a = 1 + (3 + 2);`
+class ParenExpression final : public Expression {
+public:
+  ParenExpression() : Expression(NodeKind::ParenExpression) {}
+  static bool classof(const Node *N) {
+    return N->kind() == NodeKind::ParenExpression;
+  }
+  syntax::Leaf *openParen();
+  syntax::Expression *subExpression();
+  syntax::Leaf *closeParen();
+};
+
 /// Expression for integer literals. C++ [lex.icon]
 class IntegerLiteralExpression final : public Expression {
 public:
   IntegerLiteralExpression() : Expression(NodeKind::IntegerLiteralExpression) {}
   static bool classof(const Node *N) {
     return N->kind() == NodeKind::IntegerLiteralExpression;
   }
   syntax::Leaf *literalToken();

clang/lib/Tooling/Syntax/BuildTree.cpp

bool WalkUpFromDeclRefExpr(DeclRefExpr *S) {
     }
     Builder.markChild(unqualifiedId, syntax::NodeRole::IdExpression_id);
 
     Builder.foldNode(Builder.getExprRange(S),
                      new (allocator()) syntax::IdExpression, S);
     return true;
   }
 
+  bool WalkUpFromParenExpr(ParenExpr *S) {
+    Builder.markChildToken(S->getLParen(), syntax::NodeRole::OpenParen);
+    Builder.markExprChild(S->getSubExpr(),
+                          syntax::NodeRole::ParenExpression_subExpression);
+    Builder.markChildToken(S->getRParen(), syntax::NodeRole::CloseParen);
+    Builder.foldNode(Builder.getExprRange(S),
+                     new (allocator()) syntax::ParenExpression, S);
+    return true;
+  }
+
   bool WalkUpFromIntegerLiteral(IntegerLiteral *S) {
     Builder.markChildToken(S->getLocation(), syntax::NodeRole::LiteralToken);
     Builder.foldNode(Builder.getExprRange(S),
                      new (allocator()) syntax::IntegerLiteralExpression, S);
     return true;
   }
 
   bool WalkUpFromCharacterLiteral(CharacterLiteral *S) {

clang/lib/Tooling/Syntax/Nodes.cpp

 llvm::raw_ostream &syntax::operator<<(llvm::raw_ostream &OS, NodeKind K) {
   switch (K) {
   case NodeKind::Leaf:
     return OS << "Leaf";
   case NodeKind::TranslationUnit:
     return OS << "TranslationUnit";
   case NodeKind::UnknownExpression:
     return OS << "UnknownExpression";
+  case NodeKind::ParenExpression:
+    return OS << "ParenExpression";
   case NodeKind::IntegerLiteralExpression:
     return OS << "IntegerLiteralExpression";
   case NodeKind::CharacterLiteralExpression:
     return OS << "CharacterLiteralExpression";
   case NodeKind::FloatingLiteralExpression:
     return OS << "FloatingLiteralExpression";
   case NodeKind::StringLiteralExpression:
     return OS << "StringLiteralExpression";
llvm::raw_ostream &syntax::operator<<(llvm::raw_ostream &OS, NodeRole R) {
   case syntax::NodeRole::ParametersAndQualifiers_trailingReturn:
     return OS << "ParametersAndQualifiers_trailingReturn";
   case syntax::NodeRole::IdExpression_id:
     return OS << "IdExpression_id";
   case syntax::NodeRole::IdExpression_qualifier:
     return OS << "IdExpression_qualifier";
   case syntax::NodeRole::NestedNameSpecifier_specifier:
     return OS << "NestedNameSpecifier_specifier";
+  case syntax::NodeRole::ParenExpression_subExpression:
+    return OS << "ParenExpression_subExpression";
   }
   llvm_unreachable("invalid role");
 }
 
 std::vector<syntax::NameSpecifier *> syntax::NestedNameSpecifier::specifiers() {
   std::vector<syntax::NameSpecifier *> Children;
   for (auto *C = firstChild(); C; C = C->nextSibling()) {
     assert(C->role() == syntax::NodeRole::NestedNameSpecifier_specifier);
     Children.push_back(llvm::cast<syntax::NameSpecifier>(C));
   }
   return Children;
 }
 
 syntax::NestedNameSpecifier *syntax::IdExpression::qualifier() {
   return llvm::cast_or_null<syntax::NestedNameSpecifier>(
       findChild(syntax::NodeRole::IdExpression_qualifier));
 }
 
 syntax::UnqualifiedId *syntax::IdExpression::unqualifiedId() {
   return llvm::cast_or_null<syntax::UnqualifiedId>(
       findChild(syntax::NodeRole::IdExpression_id));
 }
 
+syntax::Leaf *syntax::ParenExpression::openParen() {
+  return llvm::cast_or_null<syntax::Leaf>(
+      findChild(syntax::NodeRole::OpenParen));
+}
+
+syntax::Expression *syntax::ParenExpression::subExpression() {
+  return llvm::cast_or_null<syntax::Expression>(
+      findChild(syntax::NodeRole::ParenExpression_subExpression));
+}
+
+syntax::Leaf *syntax::ParenExpression::closeParen() {
+  return llvm::cast_or_null<syntax::Leaf>(
+      findChild(syntax::NodeRole::CloseParen));
+}
+
 syntax::Leaf *syntax::IntegerLiteralExpression::literalToken() {
   return llvm::cast_or_null<syntax::Leaf>(
       findChild(syntax::NodeRole::LiteralToken));
 }
 
 syntax::Leaf *syntax::CharacterLiteralExpression::literalToken() {
   return llvm::cast_or_null<syntax::Leaf>(
       findChild(syntax::NodeRole::LiteralToken));

clang/unittests/Tooling/Syntax/TreeTest.cpp

`-CompoundStatement
     | | |   `-f
     | | |-(
     | | `-)
     | `-;
     `-}
 )txt"));
 }
 
+TEST_P(SyntaxTreeTest, ParenExpr) {
+  EXPECT_TRUE(treeDumpEqual(
+      R"cpp(
+void test() {
+  (1);
+  ((1));
+  (1 + (2));
+}
+)cpp",
+      R"txt(
+*: TranslationUnit
+`-SimpleDeclaration
+  |-void
+  |-SimpleDeclarator
+  | |-test
+  | `-ParametersAndQualifiers
+  |   |-(
+  |   `-)
+  `-CompoundStatement
+    |-{
+    |-ExpressionStatement
+    | |-ParenExpression
+    | | |-(
+    | | |-IntegerLiteralExpression
+    | | | `-1
+    | | `-)
+    | `-;
+    |-ExpressionStatement
+    | |-ParenExpression
+    | | |-(
+    | | |-ParenExpression
+    | | | |-(
+    | | | |-IntegerLiteralExpression
+    | | | | `-1
+    | | | `-)
+    | | `-)
+    | `-;
+    |-ExpressionStatement
+    | |-ParenExpression
+    | | |-(
+    | | |-BinaryOperatorExpression
+    | | | |-IntegerLiteralExpression
+    | | | | `-1
+    | | | |-+
+    | | | `-ParenExpression
+    | | |   |-(
+    | | |   |-IntegerLiteralExpression
+    | | |   | `-2
+    | | |   `-)
+    | | `-)
+    | `-;
+    `-}
+)txt"));
+}
+
 TEST_P(SyntaxTreeTest, IntegerLiteral) {
   EXPECT_TRUE(treeDumpEqual(
       R"cpp(
 void test() {
   12;
   12u;
   12l;
   12ul;
`-SimpleDeclaration
   |   | |-int
   |   | `-SimpleDeclarator
   |   |   `-b
   |   `-)
   `-CompoundStatement
     |-{
     |-ExpressionStatement
     | |-BinaryOperatorExpression
-    | | |-UnknownExpression
+    | | |-ParenExpression
     | | | |-(
     | | | |-BinaryOperatorExpression
     | | | | |-IntegerLiteralExpression
     | | | | | `-1
     | | | | |-+
     | | | | `-IntegerLiteralExpression
     | | | |   `-2
     | | | `-)
     | | |-*
-    | | `-UnknownExpression
+    | | `-ParenExpression
     | |   |-(
     | |   |-BinaryOperatorExpression
     | |   | |-IntegerLiteralExpression
     | |   | | `-4
     | |   | |-/
     | |   | `-IntegerLiteralExpression
     | |   |   `-2
     | |   `-)