Index: src/GenPoly/Lvalue.cc =================================================================== --- src/GenPoly/Lvalue.cc (revision 453b586b335eda3abcfceef3d1f00b177fa613c4) +++ src/GenPoly/Lvalue.cc (revision fae90d5f4e6f14db5c582aeb2a6ec9c0dbc21e73) @@ -279,5 +279,6 @@ // pointer casts in the right places. - // need to reorganize this so that depth difference is the determining factor in what code is run, rather than whether something is reference type or not. + // Note: reference depth difference is the determining factor in what code is run, rather than whether something is + // reference type or not, since conversion still needs to occur when both types are references that differ in depth. Type * destType = castExpr->result; @@ -303,5 +304,5 @@ PRINT( std::cerr << "made temp: " << temp << std::endl; ) stmtsToAddBefore.push_back( new DeclStmt( temp ) ); - for ( int i = 0; i < depth1-1; i++ ) { + for ( int i = 0; i < depth1-1; i++ ) { // xxx - maybe this should be diff-1? check how this works with reference type for srcType ObjectDecl * newTemp = ObjectDecl::newObject( tempNamer.newName(), new ReferenceType( Type::Qualifiers(), temp->type->clone() ), new SingleInit( new AddressExpr( new VariableExpr( temp ) ) ) ); PRINT( std::cerr << "made temp" << i << ": " << newTemp << std::endl; ) @@ -318,4 +319,5 @@ } + // handle conversion between different depths PRINT ( if ( depth1 || depth2 ) { @@ -369,154 +371,4 @@ return castExpr; } - - // // conversion to reference type - // if ( ReferenceType * refType = dynamic_cast< ReferenceType * >( castExpr->result ) ) { - // (void)refType; - // if ( ReferenceType * otherRef = dynamic_cast< ReferenceType * >( castExpr->arg->result ) ) { - // // nothing to do if casting from reference to reference. - // (void)otherRef; - // PRINT( std::cerr << "convert reference to reference -- nop" << std::endl; ) - // if ( isIntrinsicReference( castExpr->arg ) ) { - // Expression * callExpr = castExpr->arg; - // PRINT( - // std::cerr << "but arg is deref -- &" << std::endl; - // std::cerr << callExpr << std::endl; - // ) - // callExpr = new AddressExpr( callExpr ); // this doesn't work properly for multiple casts - // delete callExpr->result; - // callExpr->set_result( refType->clone() ); - // // move environment out to new top-level - // callExpr->env = castExpr->env; - // castExpr->arg = nullptr; - // castExpr->env = nullptr; - // delete castExpr; - // return callExpr; - // } - // int depth1 = refType->referenceDepth(); - // int depth2 = otherRef->referenceDepth(); - // int diff = depth1-depth2; - // if ( diff == 0 ) { - // // conversion between references of the same depth - // assertf( depth1 == depth2, "non-intrinsic reference with cast of reference to reference not yet supported: %d %d %s", depth1, depth2, toString( castExpr ).c_str() ); - // PRINT( std::cerr << castExpr << std::endl; ) - // return castExpr; - // } else if ( diff < 0 ) { - // // conversion from reference to reference with less depth (e.g. int && -> int &): add dereferences - // Expression * ret = castExpr->arg; - // for ( int i = 0; i < diff; ++i ) { - // ret = mkDeref( ret ); - // } - // ret->env = castExpr->env; - // delete ret->result; - // ret->result = castExpr->result; - // ret->result->set_lvalue( true ); // ensure result is lvalue - // castExpr->env = nullptr; - // castExpr->arg = nullptr; - // castExpr->result = nullptr; - // delete castExpr; - // return ret; - // } else if ( diff > 0 ) { - // // conversion from reference to reference with more depth (e.g. int & -> int &&): add address-of - // Expression * ret = castExpr->arg; - // for ( int i = 0; i < diff; ++i ) { - // ret = new AddressExpr( ret ); - // } - // ret->env = castExpr->env; - // delete ret->result; - // ret->result = castExpr->result; - // castExpr->env = nullptr; - // castExpr->arg = nullptr; - // castExpr->result = nullptr; - // delete castExpr; - // return ret; - // } - - // assertf( depth1 == depth2, "non-intrinsic reference with cast of reference to reference not yet supported: %d %d %s", depth1, depth2, toString( castExpr ).c_str() ); - // PRINT( std::cerr << castExpr << std::endl; ) - // return castExpr; - // } else if ( castExpr->arg->result->get_lvalue() ) { - // // conversion from lvalue to reference - // // xxx - keep cast, but turn into pointer cast?? - // // xxx - memory - // PRINT( - // std::cerr << "convert lvalue to reference -- &" << std::endl; - // std::cerr << castExpr->arg << std::endl; - // ) - // AddressExpr * ret = new AddressExpr( castExpr->arg ); - // if ( refType->base->get_qualifiers() != castExpr->arg->result->get_qualifiers() ) { - // // must keep cast if cast-to type is different from the actual type - // castExpr->arg = ret; - // return castExpr; - // } - // ret->env = castExpr->env; - // delete ret->result; - // ret->result = castExpr->result; - // castExpr->env = nullptr; - // castExpr->arg = nullptr; - // castExpr->result = nullptr; - // delete castExpr; - // return ret; - // } else { - // // rvalue to reference conversion -- introduce temporary - // // know that reference depth of cast argument is 0, need to introduce n temporaries for reference depth of n, e.g. - // // (int &&&)3; - // // becomes - // // int __ref_tmp_0 = 3; - // // int & __ref_tmp_1 = _&_ref_tmp_0; - // // int && __ref_tmp_2 = &__ref_tmp_1; - // // &__ref_tmp_2; - - // static UniqueName tempNamer( "__ref_tmp_" ); - // ObjectDecl * temp = ObjectDecl::newObject( tempNamer.newName(), castExpr->arg->result->clone(), new SingleInit( castExpr->arg ) ); - // stmtsToAddBefore.push_back( new DeclStmt( temp ) ); - // auto depth = castExpr->result->referenceDepth(); - // for ( int i = 0; i < depth-1; i++ ) { - // ObjectDecl * newTemp = ObjectDecl::newObject( tempNamer.newName(), new ReferenceType( Type::Qualifiers(), temp->type->clone() ), new SingleInit( new AddressExpr( new VariableExpr( temp ) ) ) ); - // stmtsToAddBefore.push_back( new DeclStmt( newTemp ) ); - // temp = newTemp; - // } - // Expression * ret = new AddressExpr( new VariableExpr( temp ) ); - // // for ( int i = 0; i < depth; ++i ) { - // // ret = mkDeref( ret ); - // // } - // ret->result = castExpr->result; - // ret->result->set_lvalue( true ); // ensure result is lvalue - // ret->env = castExpr->env; - // castExpr->arg = nullptr; - // castExpr->env = nullptr; - // castExpr->result = nullptr; - // delete castExpr; - // return ret; - // } - // } else if ( ReferenceType * refType = dynamic_cast< ReferenceType * >( castExpr->arg->result ) ) { - // (void)refType; - // // conversion from reference to rvalue - // PRINT( - // std::cerr << "convert reference to rvalue -- *" << std::endl; - // std::cerr << "was = " << castExpr << std::endl; - // ) - // Expression * ret = castExpr->arg; - // TypeSubstitution * env = castExpr->env; - // castExpr->set_env( nullptr ); - // if ( ! isIntrinsicReference( ret ) ) { - // // dereference if not already dereferenced - // ret = mkDeref( ret ); - // } - // if ( ResolvExpr::typesCompatibleIgnoreQualifiers( castExpr->result, castExpr->arg->result->stripReferences(), SymTab::Indexer() ) ) { - // // can remove cast if types are compatible, changing expression type to value type - // ret->result = castExpr->result->clone(); - // ret->result->set_lvalue( true ); // ensure result is lvalue - // castExpr->arg = nullptr; - // delete castExpr; - // } else { - // // must keep cast if types are different - // castExpr->arg = ret; - // ret = castExpr; - // } - // ret->set_env( env ); - // PRINT( std::cerr << "now: " << ret << std::endl; ) - // return ret; - // } - // return castExpr; }