[AST] Add more source information for DecltypeTypeLoc.

Adds the paren source location, and removes the hack in clangd.

Differential Revision: https://reviews.llvm.org/D116793

clang-tools-extra/clangd/Selection.cpp

@@ -60,21 +60,6 @@ void recordMetrics(const SelectionTree &S, const LangOptions &Lang) {
 
 // Return the range covering a node and all its children.
 SourceRange getSourceRange(const DynTypedNode &N) {
-  // DeclTypeTypeLoc::getSourceRange() is incomplete, which would lead to
-  // failing to descend into the child expression.
-  // decltype(2+2);
-  // ~~~~~~~~~~~~~ <-- correct range
-  // ~~~~~~~~      <-- range reported by getSourceRange()
-  // ~~~~~~~~~~~~  <-- range with this hack(i.e, missing closing paren)
-  // FIXME: Alter DecltypeTypeLoc to contain parentheses locations and get
-  // rid of this patch.
-  if (const auto *TL = N.get<TypeLoc>()) {
-    if (auto DT = TL->getAs<DecltypeTypeLoc>()) {
-      SourceRange S = DT.getSourceRange();
-      S.setEnd(DT.getUnderlyingExpr()->getEndLoc());
-      return S;
-    }
-  }
   // MemberExprs to implicitly access anonymous fields should not claim any
   // tokens for themselves. Given:
   //   struct A { struct { int b; }; };

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

@@ -390,7 +390,7 @@ TEST(SelectionTest, CommonAncestor) {
         decltype([[^a]] + a) b;
         )cpp",
           "DeclRefExpr"},
-      {"[[decltype]]^(1) b;", "DecltypeTypeLoc"}, // Not the VarDecl.
+      {"[[decltype^(1)]] b;", "DecltypeTypeLoc"}, // Not the VarDecl.
 
       // Objective-C nullability attributes.
       {

clang/include/clang/AST/TypeLoc.h

@@ -1994,12 +1994,35 @@ class TypeOfTypeLoc
   void initializeLocal(ASTContext &Context, SourceLocation Loc);
 };
 
-// FIXME: location of the 'decltype' and parens.
-class DecltypeTypeLoc : public InheritingConcreteTypeLoc<TypeSpecTypeLoc,
-                                                         DecltypeTypeLoc,
-                                                         DecltypeType> {
+// decltype(expression) abc;
+// ~~~~~~~~                  DecltypeLoc
+//                    ~      RParenLoc
+// FIXME: add LParenLoc, it is tricky to support due to the limitation of
+// annotated-decltype token.
+struct DecltypeTypeLocInfo {
+  SourceLocation DecltypeLoc;
+  SourceLocation RParenLoc;
+};
+class DecltypeTypeLoc
+    : public ConcreteTypeLoc<UnqualTypeLoc, DecltypeTypeLoc, DecltypeType,
+                             DecltypeTypeLocInfo> {
 public:
   Expr *getUnderlyingExpr() const { return getTypePtr()->getUnderlyingExpr(); }
+
+  SourceLocation getDecltypeLoc() const { return getLocalData()->DecltypeLoc; }
+  void setDecltypeLoc(SourceLocation Loc) { getLocalData()->DecltypeLoc = Loc; }
+
+  SourceLocation getRParenLoc() const { return getLocalData()->RParenLoc; }
+  void setRParenLoc(SourceLocation Loc) { getLocalData()->RParenLoc = Loc; }
+
+  SourceRange getLocalSourceRange() const {
+    return SourceRange(getDecltypeLoc(), getRParenLoc());
+  }
+
+  void initializeLocal(ASTContext &Context, SourceLocation Loc) {
+    setDecltypeLoc(Loc);
+    setRParenLoc(Loc);
+  }
 };
 
 struct UnaryTransformTypeLocInfo {

clang/lib/Parse/ParseDeclCXX.cpp

@@ -1007,6 +1007,9 @@ SourceLocation Parser::ParseDecltypeSpecifier(DeclSpec &DS) {
   if (Tok.is(tok::annot_decltype)) {
     Result = getExprAnnotation(Tok);
     EndLoc = Tok.getAnnotationEndLoc();
+    // Unfortunately, we don't know the LParen source location as the annotated
+    // token doesn't have it.
+    DS.setTypeofParensRange(SourceRange(SourceLocation(), EndLoc));
     ConsumeAnnotationToken();
     if (Result.isInvalid()) {
       DS.SetTypeSpecError();
@@ -1071,6 +1074,7 @@ SourceLocation Parser::ParseDecltypeSpecifier(DeclSpec &DS) {
 
     // Match the ')'
     T.consumeClose();
+    DS.setTypeofParensRange(T.getRange());
     if (T.getCloseLocation().isInvalid()) {
       DS.SetTypeSpecError();
       // FIXME: this should return the location of the last token

clang/lib/Sema/SemaCXXScopeSpec.cpp

@@ -881,7 +881,8 @@ bool Sema::ActOnCXXNestedNameSpecifierDecltype(CXXScopeSpec &SS,
 
   TypeLocBuilder TLB;
   DecltypeTypeLoc DecltypeTL = TLB.push<DecltypeTypeLoc>(T);
-  DecltypeTL.setNameLoc(DS.getTypeSpecTypeLoc());
+  DecltypeTL.setDecltypeLoc(DS.getTypeSpecTypeLoc());
+  DecltypeTL.setRParenLoc(DS.getTypeofParensRange().getEnd());
   SS.Extend(Context, SourceLocation(), TLB.getTypeLocInContext(Context, T),
             ColonColonLoc);
   return false;

clang/lib/Sema/SemaExprCXX.cpp

@@ -7767,7 +7767,8 @@ ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base,
 
   TypeLocBuilder TLB;
   DecltypeTypeLoc DecltypeTL = TLB.push<DecltypeTypeLoc>(T);
-  DecltypeTL.setNameLoc(DS.getTypeSpecTypeLoc());
+  DecltypeTL.setDecltypeLoc(DS.getTypeSpecTypeLoc());
+  DecltypeTL.setRParenLoc(DS.getTypeofParensRange().getEnd());
   TypeSourceInfo *DestructedTypeInfo = TLB.getTypeSourceInfo(Context, T);
   PseudoDestructorTypeStorage Destructed(DestructedTypeInfo);
 

clang/lib/Sema/SemaType.cpp

@@ -5973,6 +5973,11 @@ namespace {
       Sema::GetTypeFromParser(DS.getRepAsType(), &TInfo);
       TL.setUnderlyingTInfo(TInfo);
     }
+    void VisitDecltypeTypeLoc(DecltypeTypeLoc TL) {
+      assert(DS.getTypeSpecType() == DeclSpec::TST_decltype);
+      TL.setDecltypeLoc(DS.getTypeSpecTypeLoc());
+      TL.setRParenLoc(DS.getTypeofParensRange().getEnd());
+    }
     void VisitUnaryTransformTypeLoc(UnaryTransformTypeLoc TL) {
       // FIXME: This holds only because we only have one unary transform.
       assert(DS.getTypeSpecType() == DeclSpec::TST_underlyingType);

clang/lib/Sema/TreeTransform.h

@@ -6228,15 +6228,15 @@ QualType TreeTransform<Derived>::TransformDecltypeType(TypeLocBuilder &TLB,
   QualType Result = TL.getType();
   if (getDerived().AlwaysRebuild() ||
       E.get() != T->getUnderlyingExpr()) {
-    Result = getDerived().RebuildDecltypeType(E.get(), TL.getNameLoc());
+    Result = getDerived().RebuildDecltypeType(E.get(), TL.getDecltypeLoc());
     if (Result.isNull())
       return QualType();
   }
   else E.get();
 
   DecltypeTypeLoc NewTL = TLB.push<DecltypeTypeLoc>(Result);
-  NewTL.setNameLoc(TL.getNameLoc());
-
+  NewTL.setDecltypeLoc(TL.getDecltypeLoc());
+  NewTL.setRParenLoc(TL.getRParenLoc());
   return Result;
 }
 

clang/lib/Serialization/ASTReader.cpp

@@ -6628,7 +6628,8 @@ void TypeLocReader::VisitTypeOfTypeLoc(TypeOfTypeLoc TL) {
 }
 
 void TypeLocReader::VisitDecltypeTypeLoc(DecltypeTypeLoc TL) {
-  TL.setNameLoc(readSourceLocation());
+  TL.setDecltypeLoc(readSourceLocation());
+  TL.setRParenLoc(readSourceLocation());
 }
 
 void TypeLocReader::VisitUnaryTransformTypeLoc(UnaryTransformTypeLoc TL) {

clang/lib/Serialization/ASTWriter.cpp

@@ -427,7 +427,8 @@ void TypeLocWriter::VisitTypeOfTypeLoc(TypeOfTypeLoc TL) {
 }
 
 void TypeLocWriter::VisitDecltypeTypeLoc(DecltypeTypeLoc TL) {
-  Record.AddSourceLocation(TL.getNameLoc());
+  Record.AddSourceLocation(TL.getDecltypeLoc());
+  Record.AddSourceLocation(TL.getRParenLoc());
 }
 
 void TypeLocWriter::VisitUnaryTransformTypeLoc(UnaryTransformTypeLoc TL) {

clang/unittests/AST/SourceLocationTest.cpp

@@ -215,6 +215,33 @@ TEST(TypeLoc, LongRange) {
   EXPECT_TRUE(Verifier.match("long a;", typeLoc()));
 }
 
+TEST(TypeLoc, DecltypeTypeLocRange) {
+  llvm::Annotations Code(R"(
+    $full1[[decltype(1)]] a;
+    struct A {struct B{};} var;
+    $full2[[decltype(var)]]::B c;
+  )");
+  auto AST = tooling::buildASTFromCodeWithArgs(Code.code(), /*Args=*/{});
+  ASTContext &Ctx = AST->getASTContext();
+  const auto &SM = Ctx.getSourceManager();
+
+  auto MatchedLocs = clang::ast_matchers::match(
+      typeLoc(loc(decltypeType())).bind("target"), Ctx);
+  ASSERT_EQ(MatchedLocs.size(), 2u);
+  auto verify = [&](SourceRange ActualRange,
+                    const llvm::Annotations::Range &Expected) {
+    auto ActualCharRange =
+        Lexer::getAsCharRange(ActualRange, SM, Ctx.getLangOpts());
+    EXPECT_EQ(SM.getFileOffset(ActualCharRange.getBegin()), Expected.Begin);
+    EXPECT_EQ(SM.getFileOffset(ActualCharRange.getEnd()), Expected.End);
+  };
+  const auto *Target1 = MatchedLocs[0].getNodeAs<DecltypeTypeLoc>("target");
+  verify(Target1->getSourceRange(), Code.range("full1"));
+
+  const auto *Target2 = MatchedLocs[1].getNodeAs<DecltypeTypeLoc>("target");
+  verify(Target2->getSourceRange(), Code.range("full2"));
+}
+
 TEST(TypeLoc, LongDoubleRange) {
   RangeVerifier<TypeLoc> Verifier;
   Verifier.expectRange(1, 1, 1, 6);
@@ -559,7 +586,7 @@ TEST(FriendDecl, FriendDecltypeLocation) {
 
 TEST(FriendDecl, FriendDecltypeRange) {
   RangeVerifier<FriendDecl> Verifier;
-  Verifier.expectRange(4, 1, 4, 8);
+  Verifier.expectRange(4, 1, 4, 22);
   EXPECT_TRUE(Verifier.match("struct A;\n"
                              "A foo();\n"
                              "struct A {\n"