Compute value category of member accesses

src/parser/cxx/control.cc

@@ -851,4 +851,4 @@ auto Control::instantiate(TranslationUnit* unit, Symbol* symbol,
   return instantiate(symbol);
 }
 
-}  // namespace cxx
+}  // namespace cxx

src/parser/cxx/parser.cc

@@ -2508,14 +2508,14 @@ void Parser::check_member_expression(MemberExpressionAST* ast) {
 
 auto Parser::check_member_access(MemberExpressionAST* ast) -> bool {
   const Type* objectType = ast->baseExpression->type;
-  auto cv = strip_cv(objectType);
+  auto cv1 = strip_cv(objectType);
 
   if (ast->accessOp == TokenKind::T_MINUS_GREATER) {
     auto pointerType = type_cast<PointerType>(objectType);
     if (!pointerType) return false;
 
     objectType = pointerType->elementType();
-    cv = strip_cv(objectType);
+    cv1 = strip_cv(objectType);
   }
 
   auto classType = type_cast<ClassType>(objectType);
@@ -2532,9 +2532,36 @@ auto Parser::check_member_access(MemberExpressionAST* ast) -> bool {
 
   if (symbol) {
     ast->type = symbol->type();
-  }
 
-  // TODO: value category
+    if (symbol->isEnumerator()) {
+      ast->valueCategory = ValueCategory::kPrValue;
+    } else {
+      if (is_lvalue(ast->baseExpression)) {
+        ast->valueCategory = ValueCategory::kLValue;
+      } else {
+        ast->valueCategory = ValueCategory::kXValue;
+      }
+
+      if (auto field = symbol_cast<FieldSymbol>(symbol);
+          field && !field->isStatic()) {
+        auto cv2 = strip_cv(ast->type);
+
+        auto vq = is_volatile(cv1) || is_volatile(cv2);
+        auto cq = is_const(cv1) || is_const(cv2);
+
+        CvQualifiers cv = CvQualifiers::kNone;
+        if (vq) cv = CvQualifiers::kVolatile;
+
+        if (!field->isMutable() && cq) {
+          cv = merge_cv(cv, CvQualifiers::kConst);
+        }
+
+        if (cv != CvQualifiers::kNone) {
+          ast->type = control_->getQualType(ast->type, cv);
+        }
+      }
+    }
+  }
 
   return true;
 }
@@ -6297,6 +6324,27 @@ auto Parser::strip_cv(const Type*& type) -> CvQualifiers {
   return {};
 }
 
+auto Parser::is_const(CvQualifiers cv) const -> bool {
+  return cv == CvQualifiers::kConst || cv == CvQualifiers::kConstVolatile;
+}
+
+auto Parser::is_volatile(CvQualifiers cv) const -> bool {
+  return cv == CvQualifiers::kVolatile || cv == CvQualifiers::kConstVolatile;
+}
+
+auto Parser::merge_cv(CvQualifiers cv1, CvQualifiers cv2) const
+    -> CvQualifiers {
+  CvQualifiers cv = CvQualifiers::kNone;
+  if (is_const(cv1) || is_const(cv2)) cv = CvQualifiers::kConst;
+  if (is_volatile(cv1) || is_volatile(cv2)) {
+    if (cv == CvQualifiers::kConst)
+      cv = CvQualifiers::kConstVolatile;
+    else
+      cv = CvQualifiers::kVolatile;
+  }
+  return cv;
+}
+
 auto Parser::lvalue_to_rvalue_conversion(ExpressionAST*& expr) -> bool {
   if (!is_glvalue(expr)) return false;
 
@@ -10007,6 +10055,7 @@ auto Parser::declareField(DeclaratorAST* declarator, const Decl& decl)
   applySpecifiers(fieldSymbol, decl.specs);
   fieldSymbol->setName(name);
   fieldSymbol->setType(type);
+  fieldSymbol->setMutable(decl.specs.isMutable);
   if (auto alignment = control_->memoryLayout()->alignmentOf(type)) {
     fieldSymbol->setAlignment(alignment.value());
   }

src/parser/cxx/parser.h

@@ -837,6 +837,10 @@ class Parser final {
 
   [[nodiscard]] auto strip_parentheses(ExpressionAST* ast) -> ExpressionAST*;
   [[nodiscard]] auto strip_cv(const Type*& type) -> CvQualifiers;
+  [[nodiscard]] auto merge_cv(CvQualifiers cv1, CvQualifiers cv2) const
+      -> CvQualifiers;
+  [[nodiscard]] auto is_const(CvQualifiers cv) const -> bool;
+  [[nodiscard]] auto is_volatile(CvQualifiers cv) const -> bool;
 
   // standard conversions
   [[nodiscard]] auto lvalue_to_rvalue_conversion(ExpressionAST*& expr) -> bool;

src/parser/cxx/symbols.cc

@@ -564,6 +564,10 @@ auto FieldSymbol::isInline() const -> bool { return isInline_; }
 
 void FieldSymbol::setInline(bool isInline) { isInline_ = isInline; }
 
+auto FieldSymbol::isMutable() const -> bool { return isMutable_; }
+
+void FieldSymbol::setMutable(bool isMutable) { isMutable_ = isMutable; }
+
 auto FieldSymbol::offset() const -> int { return offset_; }
 
 void FieldSymbol::setOffset(int offset) { offset_ = offset; }

src/parser/cxx/symbols.h

@@ -575,6 +575,9 @@ class FieldSymbol final : public Symbol {
   [[nodiscard]] auto isInline() const -> bool;
   void setInline(bool isInline);
 
+  [[nodiscard]] auto isMutable() const -> bool;
+  void setMutable(bool isMutable);
+
   [[nodiscard]] auto offset() const -> int;
   void setOffset(int offset);
 
@@ -590,6 +593,7 @@ class FieldSymbol final : public Symbol {
       std::uint32_t isConstexpr_ : 1;
       std::uint32_t isConstinit_ : 1;
       std::uint32_t isInline_ : 1;
+      std::uint32_t isMutable_ : 1;
     };
   };
   int offset_{};

tests/unit_tests/sema/member_access_02.cc

@@ -6,6 +6,16 @@ struct X {
   static int s_value;
 };
 
+struct W {
+  int& r;
+  const int& cr;
+
+  const int const_k = 0;
+  int k = 0;
+
+  mutable int m = 0;
+};
+
 auto main() -> int {
   X x;
   static_assert(__is_reference(decltype(x.kValue)) == false);
@@ -27,5 +37,25 @@ auto main() -> int {
   static_assert(__is_reference(decltype(px->s_value)) == false);
   static_assert(__is_same(decltype(px->s_value), int));
 
+  int i;
+  W w{i, i};
+
+  static_assert(__is_lvalue_reference(decltype(w.r)));
+  static_assert(__is_same(decltype(w.r), int&));
+
+  static_assert(__is_lvalue_reference(decltype(w.cr)));
+  static_assert(__is_same(decltype(w.cr), const int&));
+
+  static_assert(__is_same(decltype((w.const_k)), const int&));
+  static_assert(__is_same(decltype((w.k)), int&));
+
+  const W cw{i, i};
+  static_assert(__is_same(decltype(cw.const_k), const int));
+  static_assert(__is_same(decltype(cw.k), int));
+
+  static_assert(__is_same(decltype((cw.const_k)), const int&));
+  static_assert(__is_same(decltype((cw.k)), const int&));
+  static_assert(__is_same(decltype((cw.m)), int&));
+
   return 0;
 }