Changeset f27331c for src/AST/Expr.cpp

Timestamp:

Nov 30, 2021, 2:34:25 PM (18 months ago)

Author:

Andrew Beach <ajbeach@…>

Branches:

ADT, enum, forall-pointer-decay, master, pthread-emulation, qualifiedEnum

Children:

56f519b

Parents:

2cf3b87

Message:

Factored the AddressExpr? constructor body into a helper that makes it clear what it does.

File:

• src/AST/Expr.cpp (modified) (2 diffs)

src/AST/Expr.cpp

@@ -9 +9 @@
 // Author           : Aaron B. Moss
 // Created On       : Wed May 15 17:00:00 2019
-// Last Modified By : Peter A. Buhr
-// Created On       : Thr Jun 13 13:38:00 2019
-// Update Count     : 6
+// Last Modified By : Andrew Beach
+// Created On       : Tue Nov 30 14:23:00 2021
+// Update Count     : 7
 //
 
@@ -141 +141 @@
         /// The type of the address of a type.
         /// Caller is responsible for managing returned memory
-        Type * addrType( const Type * type ) {
-                if ( const ReferenceType * refType = dynamic_cast< const ReferenceType * >( type ) ) {
-                        return new ReferenceType{ addrType( refType->base ), refType->qualifiers };
+        Type * addrType( const ptr<Type> & type ) {
+                if ( auto refType = type.as< ReferenceType >() ) {
+                        return new ReferenceType( addrType( refType->base ), refType->qualifiers );
                 } else {
-                        return new PointerType{ type };
+                        return new PointerType( type );
                 }
         }
-}
-
-AddressExpr::AddressExpr( const CodeLocation & loc, const Expr * a ) : Expr( loc ), arg( a ) {
-        if ( arg->result ) {
-                if ( arg->get_lvalue() ) {
-                        // lvalue, retains all levels of reference, and gains a pointer inside the references
-                        Type * res = addrType( arg->result );
-                        result = res;
+
+        /// The type of the address of an expression.
+        /// Caller is responsible for managing returned memory
+        Type * addrExprType( const CodeLocation & loc, const Expr * arg ) {
+                assert( arg );
+                // If the expression's type is unknown, the address type is unknown.
+                if ( nullptr == arg->result ) {
+                        return nullptr;
+                // An lvalue is transformed directly.
+                } else if ( arg->get_lvalue() ) {
+                        return addrType( arg->result );
+                // Strip a layer of reference to "create" an lvalue expression.
+                } else if ( auto refType = arg->result.as< ReferenceType >() ) {
+                        return addrType( refType->base );
                 } else {
-                        // taking address of non-lvalue, must be a reference, loses one layer of reference
-                        if ( const ReferenceType * refType =
-                                        dynamic_cast< const ReferenceType * >( arg->result.get() ) ) {
-                                Type * res = addrType( refType->base );
-                                result = res;
-                        } else {
-                                SemanticError( loc, arg->result.get(),
-                                        "Attempt to take address of non-lvalue expression: " );
-                        }
+                        SemanticError( loc, arg->result.get(),
+                                "Attempt to take address of non-lvalue expression: " );
                 }
         }
 }
+
+AddressExpr::AddressExpr( const CodeLocation & loc, const Expr * a ) :
+        Expr( loc, addrExprType( loc, a ) ), arg( a )
+{}
 
 // --- LabelAddressExpr