We can't handle '&ptr->array' like Exprs.

Author: bwendling

clang/lib/CodeGen/CGBuiltin.cpp

@@ -1068,10 +1068,17 @@ namespace {
 struct StructFieldAccess
     : public ConstStmtVisitor<StructFieldAccess, const MemberExpr *> {
   const ArraySubscriptExpr *ASE = nullptr;
+  bool AddrOfSeen = false;
 
-  const MemberExpr *VisitMemberExpr(const MemberExpr *E) { return E; }
+  const MemberExpr *VisitMemberExpr(const MemberExpr *E) {
+    if (AddrOfSeen && E->getType()->isArrayType())
+      // Avoid forms like '&ptr->array'.
+      return nullptr;
+    return E;
+  }
 
   const MemberExpr *VisitArraySubscriptExpr(const ArraySubscriptExpr *E) {
+    AddrOfSeen = false; // '&ptr->array[idx]' is okay.
     ASE = E;
     return Visit(E->getBase());
   }
@@ -1082,9 +1089,11 @@ struct StructFieldAccess
     return Visit(E->getSubExpr());
   }
   const MemberExpr *VisitUnaryAddrOf(const clang::UnaryOperator *E) {
+    AddrOfSeen = true;
     return Visit(E->getSubExpr());
   }
   const MemberExpr *VisitUnaryDeref(const clang::UnaryOperator *E) {
+    AddrOfSeen = false;
     return Visit(E->getSubExpr());
   }
 };

clang/test/CodeGen/attr-counted-by.c

@@ -2058,3 +2058,28 @@ void test32(struct annotated_with_array *ptr, int idx1, int idx2) {
 size_t test32_bdos(struct annotated_with_array *ptr, int index) {
   return __bdos(&ptr->flags[index]);
 }
+
+// SANITIZE-WITH-ATTR-LABEL: define dso_local i64 @test33(
+// SANITIZE-WITH-ATTR-SAME: ptr noundef [[PTR:%.*]]) local_unnamed_addr #[[ATTR0]] {
+// SANITIZE-WITH-ATTR-NEXT:  entry:
+// SANITIZE-WITH-ATTR-NEXT:    ret i64 -1
+//
+// NO-SANITIZE-WITH-ATTR-LABEL: define dso_local i64 @test33(
+// NO-SANITIZE-WITH-ATTR-SAME: ptr noundef readnone [[PTR:%.*]]) local_unnamed_addr #[[ATTR3]] {
+// NO-SANITIZE-WITH-ATTR-NEXT:  entry:
+// NO-SANITIZE-WITH-ATTR-NEXT:    ret i64 -1
+//
+// SANITIZE-WITHOUT-ATTR-LABEL: define dso_local i64 @test33(
+// SANITIZE-WITHOUT-ATTR-SAME: ptr noundef [[PTR:%.*]]) local_unnamed_addr #[[ATTR0]] {
+// SANITIZE-WITHOUT-ATTR-NEXT:  entry:
+// SANITIZE-WITHOUT-ATTR-NEXT:    ret i64 -1
+//
+// NO-SANITIZE-WITHOUT-ATTR-LABEL: define dso_local i64 @test33(
+// NO-SANITIZE-WITHOUT-ATTR-SAME: ptr noundef readnone [[PTR:%.*]]) local_unnamed_addr #[[ATTR1]] {
+// NO-SANITIZE-WITHOUT-ATTR-NEXT:  entry:
+// NO-SANITIZE-WITHOUT-ATTR-NEXT:    ret i64 -1
+//
+size_t test33(struct annotated *ptr) {
+  // Don't handle '&ptr->array' like normal.
+  return __bdos(&*&*&*&ptr->array);
+}