[clang][Sema] Fix uninitialized `SourceLocation` for types with multiple attributes and macros.

Some `TypeLoc`s are considered "sugar" and we go past them in
`GetTypeSourceInfoForDeclarator`. The problem is that we peel off only
the same kind of `TypeLoc` at the time which makes it impossible to
handle mixed sequences like
`AttributedTypeLoc - MacroQualifiedTypeLoc - AttributedTypeLoc - PointerTypeLoc`

In this situation, as shown in the added test, we don't get to
`PointerTypeLoc` and don't set its starLoc leaving it uninitialized.

Address FIXME and peel off "sugar" `TypeLoc`s regardless of their order.

rdar://102149264

Differential Revision: https://reviews.llvm.org/D141424

1 files changed, 41 insertions, 0 deletions

diff --git a/clang/unittests/AST/SourceLocationTest.cpp b/clang/unittests/AST/SourceLocationTest.cpp
index 43b7149bd118..ca9e9a216197 100644
--- a/clang/unittests/AST/SourceLocationTest.cpp
+++ b/clang/unittests/AST/SourceLocationTest.cpp
@@ -438,6 +438,47 @@ TEST(UnaryTransformTypeLoc, ParensRange) {
       loc(unaryTransformType())));
 }
 
+TEST(PointerTypeLoc, StarLoc) {
+  llvm::Annotations Example(R"c(
+    int $star^*var;
+  )c");
+
+  auto AST = tooling::buildASTFromCode(Example.code());
+  SourceManager &SM = AST->getSourceManager();
+  auto &Ctx = AST->getASTContext();
+
+  auto *VD = selectFirst<VarDecl>("vd", match(varDecl(hasName("var")).bind("vd"), Ctx));
+  ASSERT_NE(VD, nullptr);
+
+  auto TL =
+      VD->getTypeSourceInfo()->getTypeLoc().castAs<PointerTypeLoc>();
+  ASSERT_EQ(SM.getFileOffset(TL.getStarLoc()), Example.point("star"));
+}
+
+TEST(PointerTypeLoc, StarLocBehindSugar) {
+  llvm::Annotations Example(R"c(
+    #define NODEREF __attribute__((noderef))
+    char $1st^* NODEREF _Nonnull $2nd^* var;
+  )c");
+
+  auto AST = tooling::buildASTFromCode(Example.code());
+  SourceManager &SM = AST->getSourceManager();
+  auto &Ctx = AST->getASTContext();
+
+  auto *VD = selectFirst<VarDecl>("vd", match(varDecl(hasName("var")).bind("vd"), Ctx));
+  ASSERT_NE(VD, nullptr);
+
+  auto TL = VD->getTypeSourceInfo()->getTypeLoc().castAs<PointerTypeLoc>();
+  EXPECT_EQ(SM.getFileOffset(TL.getStarLoc()), Example.point("2nd"));
+
+  // Cast intermediate TypeLoc to make sure the structure matches expectations.
+  auto InnerPtrTL = TL.getPointeeLoc().castAs<AttributedTypeLoc>()
+    .getNextTypeLoc().castAs<MacroQualifiedTypeLoc>()
+    .getNextTypeLoc().castAs<AttributedTypeLoc>()
+    .getNextTypeLoc().castAs<PointerTypeLoc>();
+  EXPECT_EQ(SM.getFileOffset(InnerPtrTL.getStarLoc()), Example.point("1st"));
+}
+
 TEST(CXXFunctionalCastExpr, SourceRange) {
   RangeVerifier<CXXFunctionalCastExpr> Verifier;
   Verifier.expectRange(2, 10, 2, 14);