Check member access expressions more rigorously.

Closes issue #21.
bloomberg · Apr 3, 2024 · de7203a · tambry · Apr 8, 2024 · katzdm
1 parent 20df57e
commit de7203a
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Showing 3 changed files with 38 additions and 13 deletions.
diff --git a/clang/lib/CodeGen/CGExprAgg.cpp b/clang/lib/CodeGen/CGExprAgg.cpp
@@ -242,6 +242,10 @@ class AggExprEmitter : public StmtVisitor<AggExprEmitter> {
   void VisitPackIndexingExpr(PackIndexingExpr *E) {
     Visit(E->getSelectedExpr());
   }
+
+  void VisitCXXExprSpliceExpr(CXXExprSpliceExpr *E) {
+    Visit(E->getOperand());
+  }
 };
 }  // end anonymous namespace.
 

diff --git a/clang/lib/Sema/SemaExprMember.cpp b/clang/lib/Sema/SemaExprMember.cpp
@@ -989,6 +989,15 @@ static bool IsInFnTryBlockHandler(const Scope *S) {
   return false;
 }
 
+static bool isRecordType(QualType T) {
+  return T->isRecordType();
+}
+static bool isPointerToRecordType(QualType T) {
+  if (const PointerType *PT = T->getAs<PointerType>())
+    return PT->getPointeeType()->isRecordType();
+  return false;
+}
+
 ExprResult
 Sema::BuildMemberReferenceExpr(Expr *BaseExpr, QualType BaseExprType,
                                SourceLocation OpLoc, bool IsArrow,
@@ -1231,9 +1240,30 @@ Sema::BuildMemberReferenceExpr(Scope *S, Expr *Base, SourceLocation OpLoc,
   // Disable access control for the duration of the splice expression
   AccessControlScopeGuard guard {*this, true};
 
+  bool IsRHSDependent = (RHS->isValueDependent() || RHS->isTypeDependent());
   bool IsArrow = (OpKind == tok::arrow);
-  if (RHS->isValueDependent() || RHS->isTypeDependent())
+  if (Base) {
+    const PointerType *PT = Base->getType()->getAs<PointerType>();
+    bool IsPtr = (PT != nullptr);
+    bool IsRecord = isRecordType(PT ? PT->getPointeeType() : Base->getType());
+    if (IsRecord && IsArrow != IsPtr) {
+      std::string Suggestion = IsPtr ? "." : "->";
+      Diag(OpLoc, diag::err_typecheck_member_reference_suggestion)
+        << Base->getType() << int(IsArrow) << Base->getSourceRange()
+        << FixItHint::CreateReplacement(OpLoc, Suggestion);
+      return ExprError();
+    } else if (!IsRecord && !IsRHSDependent) {
+        Base->getType()->dump();
+        Diag(OpLoc, diag::err_typecheck_member_reference_struct_union)
+          << Base->getType() << Base->getSourceRange()
+          << RHS->getSourceRange();
+      return ExprError();
+    }
+  }
+
+  if (IsRHSDependent) {
     return BuildDependentMemberSpliceExpr(Base, OpLoc, IsArrow, RHS);
+  }
 
   CXXScopeSpec SS;
   ValueDecl *VD = nullptr;
@@ -1321,15 +1351,6 @@ static bool ShouldTryAgainWithRedefinitionType(Sema &S, ExprResult &base) {
   return true;
 }
 
-static bool isRecordType(QualType T) {
-  return T->isRecordType();
-}
-static bool isPointerToRecordType(QualType T) {
-  if (const PointerType *PT = T->getAs<PointerType>())
-    return PT->getPointeeType()->isRecordType();
-  return false;
-}
-
 /// Perform conversions on the LHS of a member access expression.
 ExprResult
 Sema::PerformMemberExprBaseConversion(Expr *Base, bool IsArrow) {

diff --git a/clang/lib/Sema/SemaReflect.cpp b/clang/lib/Sema/SemaReflect.cpp
@@ -642,15 +642,15 @@ ExprResult Sema::BuildReflectionSpliceExpr(SourceLocation LSplice,
     }
     case ReflectionValue::RK_const_value: {
       Operand = RV.getAsConstValueExpr();
-      Operand = CXXExprSpliceExpr::Create(Context, VK_PRValue, LSplice, Operand,
-                                          RSplice);
-      if (!isConstantEvaluatedContext()) {
+      if (!isConstantEvaluatedContext() && !isa<ConstantExpr>(Operand)) {
         Operand = ConstantExpr::Create(Context, Operand,
                                        ConstantResultStorageKind::APValue,
                                        true);
         ExprEvalContexts.back().ImmediateInvocationCandidates.emplace_back(
               cast<ConstantExpr>(Operand), 0);
       }
+      Operand = CXXExprSpliceExpr::Create(Context, VK_PRValue, LSplice, Operand,
+                                          RSplice);
       break;
     }
     case ReflectionValue::RK_template: {