[Sema] Fix location of star ('*') inside MemberPointerTypeLoc

Summary: Copy of https://reviews.llvm.org/D72073?id=235842, submitting with ilya-biryukov's permission.

Reviewers: gribozavr, gribozavr2

Reviewed By: gribozavr2

Subscribers: mgorny, gribozavr2, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D76061

clang/include/clang/Sema/DeclSpec.h

@@ -1518,6 +1518,8 @@ struct DeclaratorChunk {
   struct MemberPointerTypeInfo {
     /// The type qualifiers: const/volatile/restrict/__unaligned/_Atomic.
     unsigned TypeQuals : 5;
+    /// Location of the '*' token.
+    unsigned StarLoc;
     // CXXScopeSpec has a constructor, so it can't be a direct member.
     // So we need some pointer-aligned storage and a bit of trickery.
     alignas(CXXScopeSpec) char ScopeMem[sizeof(CXXScopeSpec)];
@@ -1660,11 +1662,13 @@ struct DeclaratorChunk {
 
   static DeclaratorChunk getMemberPointer(const CXXScopeSpec &SS,
                                           unsigned TypeQuals,
-                                          SourceLocation Loc) {
+                                          SourceLocation StarLoc,
+                                          SourceLocation EndLoc) {
     DeclaratorChunk I;
     I.Kind          = MemberPointer;
     I.Loc           = SS.getBeginLoc();
-    I.EndLoc        = Loc;
+    I.EndLoc = EndLoc;
+    I.Mem.StarLoc = StarLoc.getRawEncoding();
     I.Mem.TypeQuals = TypeQuals;
     new (I.Mem.ScopeMem) CXXScopeSpec(SS);
     return I;

clang/lib/Parse/ParseDecl.cpp

@@ -5643,8 +5643,8 @@ void Parser::ParseDeclaratorInternal(Declarator &D,
         return;
       }
 
-      SourceLocation Loc = ConsumeToken();
-      D.SetRangeEnd(Loc);
+      SourceLocation StarLoc = ConsumeToken();
+      D.SetRangeEnd(StarLoc);
       DeclSpec DS(AttrFactory);
       ParseTypeQualifierListOpt(DS);
       D.ExtendWithDeclSpec(DS);
@@ -5655,7 +5655,7 @@ void Parser::ParseDeclaratorInternal(Declarator &D,
       // Sema will have to catch (syntactically invalid) pointers into global
       // scope. It has to catch pointers into namespace scope anyway.
       D.AddTypeInfo(DeclaratorChunk::getMemberPointer(
-                        SS, DS.getTypeQualifiers(), DS.getEndLoc()),
+                        SS, DS.getTypeQualifiers(), StarLoc, DS.getEndLoc()),
                     std::move(DS.getAttributes()),
                     /* Don't replace range end. */ SourceLocation());
       return;

clang/lib/Sema/SemaType.cpp

@@ -5840,7 +5840,7 @@ namespace {
       }
 
       // Finally fill in MemberPointerLocInfo fields.
-      TL.setStarLoc(Chunk.Loc);
+      TL.setStarLoc(SourceLocation::getFromRawEncoding(Chunk.Mem.StarLoc));
       TL.setClassTInfo(ClsTInfo);
     }
     void VisitLValueReferenceTypeLoc(LValueReferenceTypeLoc TL) {

clang/unittests/AST/CMakeLists.txt

@@ -42,4 +42,5 @@ clang_target_link_libraries(ASTTests
   clangFrontend
   clangSerialization
   clangTooling
+  LLVMTestingSupport
   )

clang/unittests/AST/SourceLocationTest.cpp

@@ -15,11 +15,12 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "clang/AST/ASTContext.h"
 #include "MatchVerifier.h"
+#include "clang/AST/ASTContext.h"
 #include "clang/ASTMatchers/ASTMatchFinder.h"
 #include "clang/ASTMatchers/ASTMatchers.h"
 #include "clang/Tooling/Tooling.h"
+#include "llvm/Testing/Support/Annotations.h"
 #include "gtest/gtest.h"
 
 namespace clang {
@@ -842,5 +843,23 @@ TEST(FunctionDecl, ExceptionSpecifications) {
                               Language::Lang_CXX11));
 }
 
+TEST(Decl, MemberPointerStarLoc) {
+  llvm::Annotations Example(R"cpp(
+    struct X {};
+    int X::$star^* a;
+  )cpp");
+
+  auto AST = tooling::buildASTFromCode(Example.code());
+  SourceManager &SM = AST->getSourceManager();
+  auto &Ctx = AST->getASTContext();
+
+  auto *VD = selectFirst<VarDecl>("vd", match(varDecl().bind("vd"), Ctx));
+  ASSERT_TRUE(VD != nullptr);
+
+  auto TL =
+      VD->getTypeSourceInfo()->getTypeLoc().castAs<MemberPointerTypeLoc>();
+  ASSERT_EQ(SM.getFileOffset(TL.getStarLoc()), Example.point("star"));
+}
+
 } // end namespace ast_matchers
 } // end namespace clang