// // Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo // // The contents of this file are covered under the licence agreement in the // file "LICENCE" distributed with Cforall. // // Unify.cc -- // // Author : Richard C. Bilson // Created On : Sun May 17 12:27:10 2015 // Last Modified By : Peter A. Buhr // Last Modified On : Fri Dec 13 23:43:05 2019 // Update Count : 46 // #include "Unify.h" #include // for assertf, assert #include // for back_insert_iterator, back_inserter #include // for _Rb_tree_const_iterator, _Rb_tree_i... #include // for unique_ptr #include // for set #include // for string, operator==, operator!=, bas... #include // for pair, move #include #include "AST/Copy.hpp" #include "AST/Decl.hpp" #include "AST/Node.hpp" #include "AST/Pass.hpp" #include "AST/Print.hpp" #include "AST/Type.hpp" #include "AST/TypeEnvironment.hpp" #include "Common/PassVisitor.h" // for PassVisitor #include "FindOpenVars.h" // for findOpenVars #include "SynTree/LinkageSpec.h" // for C #include "SynTree/Constant.h" // for Constant #include "SynTree/Declaration.h" // for TypeDecl, TypeDecl::Data, Declarati... #include "SynTree/Expression.h" // for TypeExpr, Expression, ConstantExpr #include "SynTree/Mutator.h" // for Mutator #include "SynTree/Type.h" // for Type, TypeInstType, FunctionType #include "SynTree/Visitor.h" // for Visitor #include "Tuples/Tuples.h" // for isTtype #include "TypeEnvironment.h" // for EqvClass, AssertionSet, OpenVarSet #include "typeops.h" // for flatten, occurs, commonType namespace ast { class SymbolTable; } namespace SymTab { class Indexer; } // namespace SymTab // #define DEBUG namespace ResolvExpr { struct Unify_old : public WithShortCircuiting { Unify_old( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer ); bool get_result() const { return result; } void previsit( BaseSyntaxNode * ) { visit_children = false; } void postvisit( VoidType * voidType ); void postvisit( BasicType * basicType ); void postvisit( PointerType * pointerType ); void postvisit( ArrayType * arrayType ); void postvisit( ReferenceType * refType ); void postvisit( FunctionType * functionType ); void postvisit( StructInstType * aggregateUseType ); void postvisit( UnionInstType * aggregateUseType ); void postvisit( EnumInstType * aggregateUseType ); void postvisit( TraitInstType * aggregateUseType ); void postvisit( TypeInstType * aggregateUseType ); void postvisit( TupleType * tupleType ); void postvisit( VarArgsType * varArgsType ); void postvisit( ZeroType * zeroType ); void postvisit( OneType * oneType ); private: template< typename RefType > void handleRefType( RefType *inst, Type *other ); template< typename RefType > void handleGenericRefType( RefType *inst, Type *other ); bool result; Type *type2; // inherited TypeEnvironment &env; AssertionSet &needAssertions; AssertionSet &haveAssertions; const OpenVarSet &openVars; WidenMode widen; const SymTab::Indexer &indexer; }; /// Attempts an inexact unification of type1 and type2. /// Returns false if no such unification; if the types can be unified, sets common (unless they unify exactly and have identical type qualifiers) bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer, Type *&common ); bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer ); bool unifyExact( const ast::Type * type1, const ast::Type * type2, ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open, WidenMode widen, const ast::SymbolTable & symtab ); bool typesCompatible( const Type * first, const Type * second, const SymTab::Indexer & indexer, const TypeEnvironment & env ) { TypeEnvironment newEnv; OpenVarSet openVars, closedVars; // added closedVars AssertionSet needAssertions, haveAssertions; Type * newFirst = first->clone(), * newSecond = second->clone(); env.apply( newFirst ); env.apply( newSecond ); // do we need to do this? Seems like we do, types should be able to be compatible if they // have free variables that can unify findOpenVars( newFirst, openVars, closedVars, needAssertions, haveAssertions, false ); findOpenVars( newSecond, openVars, closedVars, needAssertions, haveAssertions, true ); bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ); delete newFirst; delete newSecond; return result; } bool typesCompatible( const ast::Type * first, const ast::Type * second, const ast::SymbolTable & symtab, const ast::TypeEnvironment & env ) { ast::TypeEnvironment newEnv; ast::OpenVarSet open, closed; ast::AssertionSet need, have; ast::ptr newFirst{ first }, newSecond{ second }; env.apply( newFirst ); env.apply( newSecond ); findOpenVars( newFirst, open, closed, need, have, FirstClosed ); findOpenVars( newSecond, open, closed, need, have, FirstOpen ); return unifyExact(newFirst, newSecond, newEnv, need, have, open, noWiden(), symtab ); } bool typesCompatibleIgnoreQualifiers( const Type * first, const Type * second, const SymTab::Indexer &indexer, const TypeEnvironment &env ) { TypeEnvironment newEnv; OpenVarSet openVars; AssertionSet needAssertions, haveAssertions; Type *newFirst = first->clone(), *newSecond = second->clone(); env.apply( newFirst ); env.apply( newSecond ); newFirst->get_qualifiers() = Type::Qualifiers(); newSecond->get_qualifiers() = Type::Qualifiers(); bool result = unifyExact( newFirst, newSecond, newEnv, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ); delete newFirst; delete newSecond; return result; } bool typesCompatibleIgnoreQualifiers( const ast::Type * first, const ast::Type * second, const ast::SymbolTable & symtab, const ast::TypeEnvironment & env ) { ast::TypeEnvironment newEnv; ast::OpenVarSet open; ast::AssertionSet need, have; ast::Type * newFirst = shallowCopy( first ); ast::Type * newSecond = shallowCopy( second ); newFirst ->qualifiers = {}; newSecond->qualifiers = {}; ast::ptr< ast::Type > t1_(newFirst ); ast::ptr< ast::Type > t2_(newSecond); ast::ptr< ast::Type > subFirst = env.apply(newFirst).node; ast::ptr< ast::Type > subSecond = env.apply(newSecond).node; return unifyExact( subFirst, subSecond, newEnv, need, have, open, noWiden(), symtab ); } bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) { OpenVarSet closedVars; findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false ); findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true ); Type *commonType = 0; if ( unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType ) ) { if ( commonType ) { delete commonType; } // if return true; } else { return false; } // if } bool unify( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer, Type *&commonType ) { OpenVarSet closedVars; findOpenVars( type1, openVars, closedVars, needAssertions, haveAssertions, false ); findOpenVars( type2, openVars, closedVars, needAssertions, haveAssertions, true ); return unifyInexact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( true, true ), indexer, commonType ); } bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer ) { #ifdef DEBUG TypeEnvironment debugEnv( env ); #endif if ( type1->get_qualifiers() != type2->get_qualifiers() ) { return false; } bool result; TypeInstType *var1 = dynamic_cast< TypeInstType* >( type1 ); TypeInstType *var2 = dynamic_cast< TypeInstType* >( type2 ); OpenVarSet::const_iterator entry1, entry2; if ( var1 ) { entry1 = openVars.find( var1->get_name() ); } // if if ( var2 ) { entry2 = openVars.find( var2->get_name() ); } // if bool isopen1 = var1 && ( entry1 != openVars.end() ); bool isopen2 = var2 && ( entry2 != openVars.end() ); if ( isopen1 && isopen2 ) { if ( entry1->second.kind != entry2->second.kind ) { result = false; } else { result = env.bindVarToVar( var1, var2, TypeDecl::Data{ entry1->second, entry2->second }, needAssertions, haveAssertions, openVars, widen, indexer ); } } else if ( isopen1 ) { result = env.bindVar( var1, type2, entry1->second, needAssertions, haveAssertions, openVars, widen, indexer ); } else if ( isopen2 ) { // TODO: swap widen values in call, since type positions are flipped? result = env.bindVar( var2, type1, entry2->second, needAssertions, haveAssertions, openVars, widen, indexer ); } else { PassVisitor comparator( type2, env, needAssertions, haveAssertions, openVars, widen, indexer ); type1->accept( comparator ); result = comparator.pass.get_result(); } // if #ifdef DEBUG std::cerr << "============ unifyExact" << std::endl; std::cerr << "type1 is "; type1->print( std::cerr ); std::cerr << std::endl << "type2 is "; type2->print( std::cerr ); std::cerr << std::endl << "openVars are "; printOpenVarSet( openVars, std::cerr, 8 ); std::cerr << std::endl << "input env is " << std::endl; debugEnv.print( std::cerr, 8 ); std::cerr << std::endl << "result env is " << std::endl; env.print( std::cerr, 8 ); std::cerr << "result is " << result << std::endl; #endif return result; } bool unifyExact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, OpenVarSet &openVars, const SymTab::Indexer &indexer ) { return unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ); } bool unifyInexact( Type *type1, Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer, Type *&common ) { Type::Qualifiers tq1 = type1->get_qualifiers(), tq2 = type2->get_qualifiers(); type1->get_qualifiers() = Type::Qualifiers(); type2->get_qualifiers() = Type::Qualifiers(); bool result; #ifdef DEBUG std::cerr << "unifyInexact type 1 is "; type1->print( std::cerr ); std::cerr << " type 2 is "; type2->print( std::cerr ); std::cerr << std::endl; #endif if ( ! unifyExact( type1, type2, env, needAssertions, haveAssertions, openVars, widen, indexer ) ) { #ifdef DEBUG std::cerr << "unifyInexact: no exact unification found" << std::endl; #endif if ( ( common = commonType( type1, type2, widen.first, widen.second, indexer, env, openVars ) ) ) { common->tq = tq1.unify( tq2 ); #ifdef DEBUG std::cerr << "unifyInexact: common type is "; common->print( std::cerr ); std::cerr << std::endl; #endif result = true; } else { #ifdef DEBUG std::cerr << "unifyInexact: no common type found" << std::endl; #endif result = false; } // if } else { if ( tq1 != tq2 ) { if ( ( tq1 > tq2 || widen.first ) && ( tq2 > tq1 || widen.second ) ) { common = type1->clone(); common->tq = tq1.unify( tq2 ); result = true; } else { result = false; } // if } else { common = type1->clone(); common->tq = tq1.unify( tq2 ); result = true; } // if } // if type1->get_qualifiers() = tq1; type2->get_qualifiers() = tq2; return result; } Unify_old::Unify_old( Type *type2, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer ) : result( false ), type2( type2 ), env( env ), needAssertions( needAssertions ), haveAssertions( haveAssertions ), openVars( openVars ), widen( widen ), indexer( indexer ) { } void Unify_old::postvisit( __attribute__((unused)) VoidType *voidType) { result = dynamic_cast< VoidType* >( type2 ); } void Unify_old::postvisit(BasicType *basicType) { if ( BasicType *otherBasic = dynamic_cast< BasicType* >( type2 ) ) { result = basicType->get_kind() == otherBasic->get_kind(); } // if } void markAssertionSet( AssertionSet &assertions, DeclarationWithType *assert ) { AssertionSet::iterator i = assertions.find( assert ); if ( i != assertions.end() ) { i->second.isUsed = true; } // if } void markAssertions( AssertionSet &assertion1, AssertionSet &assertion2, Type *type ) { for ( std::list< TypeDecl* >::const_iterator tyvar = type->get_forall().begin(); tyvar != type->get_forall().end(); ++tyvar ) { for ( std::list< DeclarationWithType* >::const_iterator assert = (*tyvar)->get_assertions().begin(); assert != (*tyvar)->get_assertions().end(); ++assert ) { markAssertionSet( assertion1, *assert ); markAssertionSet( assertion2, *assert ); } // for } // for } void Unify_old::postvisit(PointerType *pointerType) { if ( PointerType *otherPointer = dynamic_cast< PointerType* >( type2 ) ) { result = unifyExact( pointerType->get_base(), otherPointer->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ); markAssertions( haveAssertions, needAssertions, pointerType ); markAssertions( haveAssertions, needAssertions, otherPointer ); } // if } void Unify_old::postvisit(ReferenceType *refType) { if ( ReferenceType *otherRef = dynamic_cast< ReferenceType* >( type2 ) ) { result = unifyExact( refType->get_base(), otherRef->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ); markAssertions( haveAssertions, needAssertions, refType ); markAssertions( haveAssertions, needAssertions, otherRef ); } // if } void Unify_old::postvisit(ArrayType *arrayType) { ArrayType *otherArray = dynamic_cast< ArrayType* >( type2 ); // to unify, array types must both be VLA or both not VLA // and must both have a dimension expression or not have a dimension if ( otherArray && arrayType->get_isVarLen() == otherArray->get_isVarLen() ) { if ( ! arrayType->get_isVarLen() && ! otherArray->get_isVarLen() && arrayType->get_dimension() != 0 && otherArray->get_dimension() != 0 ) { ConstantExpr * ce1 = dynamic_cast< ConstantExpr * >( arrayType->get_dimension() ); ConstantExpr * ce2 = dynamic_cast< ConstantExpr * >( otherArray->get_dimension() ); // see C11 Reference Manual 6.7.6.2.6 // two array types with size specifiers that are integer constant expressions are // compatible if both size specifiers have the same constant value if ( ce1 && ce2 ) { Constant * c1 = ce1->get_constant(); Constant * c2 = ce2->get_constant(); if ( c1->get_value() != c2->get_value() ) { // does not unify if the dimension is different return; } } } result = unifyExact( arrayType->get_base(), otherArray->get_base(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ); } // if } template< typename Iterator, typename Func > std::unique_ptr combineTypes( Iterator begin, Iterator end, Func & toType ) { std::list< Type * > types; for ( ; begin != end; ++begin ) { // it's guaranteed that a ttype variable will be bound to a flat tuple, so ensure that this results in a flat tuple flatten( toType( *begin ), back_inserter( types ) ); } return std::unique_ptr( new TupleType( Type::Qualifiers(), types ) ); } template< typename Iterator1, typename Iterator2 > bool unifyTypeList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) { auto get_type = [](DeclarationWithType * dwt){ return dwt->get_type(); }; for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) { Type * t1 = (*list1Begin)->get_type(); Type * t2 = (*list2Begin)->get_type(); bool isTtype1 = Tuples::isTtype( t1 ); bool isTtype2 = Tuples::isTtype( t2 ); // xxx - assumes ttype must be last parameter // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases. if ( isTtype1 && ! isTtype2 ) { // combine all of the things in list2, then unify return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ); } else if ( isTtype2 && ! isTtype1 ) { // combine all of the things in list1, then unify return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ); } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) { return false; } // if } // for // may get to the end of one argument list before the end of the other. This is only okay when the other is a ttype if ( list1Begin != list1End ) { // try unifying empty tuple type with ttype Type * t1 = (*list1Begin)->get_type(); if ( Tuples::isTtype( t1 ) ) { return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ); } else return false; } else if ( list2Begin != list2End ) { // try unifying empty tuple type with ttype Type * t2 = (*list2Begin)->get_type(); if ( Tuples::isTtype( t2 ) ) { return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ); } else return false; } else { return true; } // if } /// Finds ttypes and replaces them with their expansion, if known. /// This needs to be done so that satisfying ttype assertions is easier. /// If this isn't done then argument lists can have wildly different /// size and structure, when they should be compatible. struct TtypeExpander_old : public WithShortCircuiting { TypeEnvironment & tenv; TtypeExpander_old( TypeEnvironment & tenv ) : tenv( tenv ) {} void premutate( TypeInstType * ) { visit_children = false; } Type * postmutate( TypeInstType * typeInst ) { if ( const EqvClass *eqvClass = tenv.lookup( typeInst->get_name() ) ) { // expand ttype parameter into its actual type if ( eqvClass->data.kind == TypeDecl::Ttype && eqvClass->type ) { delete typeInst; return eqvClass->type->clone(); } } return typeInst; } }; /// flattens a list of declarations, so that each tuple type has a single declaration. /// makes use of TtypeExpander to ensure ttypes are flat as well. void flattenList( std::list< DeclarationWithType * > src, std::list< DeclarationWithType * > & dst, TypeEnvironment & env ) { dst.clear(); for ( DeclarationWithType * dcl : src ) { PassVisitor expander( env ); dcl->acceptMutator( expander ); std::list< Type * > types; flatten( dcl->get_type(), back_inserter( types ) ); for ( Type * t : types ) { // outermost const, volatile, _Atomic qualifiers in parameters should not play a role in the unification of function types, since they do not determine whether a function is callable. // Note: MUST consider at least mutex qualifier, since functions can be overloaded on outermost mutex and a mutex function has different requirements than a non-mutex function. t->get_qualifiers() -= Type::Qualifiers(Type::Const | Type::Volatile | Type::Atomic); dst.push_back( new ObjectDecl( "", Type::StorageClasses(), LinkageSpec::C, nullptr, t, nullptr ) ); } delete dcl; } } void Unify_old::postvisit(FunctionType *functionType) { FunctionType *otherFunction = dynamic_cast< FunctionType* >( type2 ); if ( otherFunction && functionType->get_isVarArgs() == otherFunction->get_isVarArgs() ) { // flatten the parameter lists for both functions so that tuple structure // doesn't affect unification. Must be a clone so that the types don't change. std::unique_ptr flatFunc( functionType->clone() ); std::unique_ptr flatOther( otherFunction->clone() ); flattenList( flatFunc->get_parameters(), flatFunc->get_parameters(), env ); flattenList( flatOther->get_parameters(), flatOther->get_parameters(), env ); // sizes don't have to match if ttypes are involved; need to be more precise wrt where the ttype is to prevent errors if ( (flatFunc->parameters.size() == flatOther->parameters.size() && flatFunc->returnVals.size() == flatOther->returnVals.size()) || flatFunc->isTtype() || flatOther->isTtype() ) { if ( unifyTypeList( flatFunc->parameters.begin(), flatFunc->parameters.end(), flatOther->parameters.begin(), flatOther->parameters.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) { if ( unifyTypeList( flatFunc->returnVals.begin(), flatFunc->returnVals.end(), flatOther->returnVals.begin(), flatOther->returnVals.end(), env, needAssertions, haveAssertions, openVars, indexer ) ) { // the original types must be used in mark assertions, since pointer comparisons are used markAssertions( haveAssertions, needAssertions, functionType ); markAssertions( haveAssertions, needAssertions, otherFunction ); result = true; } // if } // if } // if } // if } template< typename RefType > void Unify_old::handleRefType( RefType *inst, Type *other ) { // check that other type is compatible and named the same RefType *otherStruct = dynamic_cast< RefType* >( other ); result = otherStruct && inst->name == otherStruct->name; } template< typename RefType > void Unify_old::handleGenericRefType( RefType *inst, Type *other ) { // Check that other type is compatible and named the same handleRefType( inst, other ); if ( ! result ) return; // Check that parameters of types unify, if any std::list< Expression* > params = inst->parameters; std::list< Expression* > otherParams = ((RefType*)other)->parameters; std::list< Expression* >::const_iterator it = params.begin(), jt = otherParams.begin(); for ( ; it != params.end() && jt != otherParams.end(); ++it, ++jt ) { TypeExpr *param = dynamic_cast< TypeExpr* >(*it); assertf(param, "Aggregate parameters should be type expressions"); TypeExpr *otherParam = dynamic_cast< TypeExpr* >(*jt); assertf(otherParam, "Aggregate parameters should be type expressions"); Type* paramTy = param->get_type(); Type* otherParamTy = otherParam->get_type(); bool tupleParam = Tuples::isTtype( paramTy ); bool otherTupleParam = Tuples::isTtype( otherParamTy ); if ( tupleParam && otherTupleParam ) { ++it; ++jt; // skip ttype parameters for break } else if ( tupleParam ) { // bundle other parameters into tuple to match std::list< Type * > binderTypes; do { binderTypes.push_back( otherParam->get_type()->clone() ); ++jt; if ( jt == otherParams.end() ) break; otherParam = dynamic_cast< TypeExpr* >(*jt); assertf(otherParam, "Aggregate parameters should be type expressions"); } while (true); otherParamTy = new TupleType{ paramTy->get_qualifiers(), binderTypes }; ++it; // skip ttype parameter for break } else if ( otherTupleParam ) { // bundle parameters into tuple to match other std::list< Type * > binderTypes; do { binderTypes.push_back( param->get_type()->clone() ); ++it; if ( it == params.end() ) break; param = dynamic_cast< TypeExpr* >(*it); assertf(param, "Aggregate parameters should be type expressions"); } while (true); paramTy = new TupleType{ otherParamTy->get_qualifiers(), binderTypes }; ++jt; // skip ttype parameter for break } if ( ! unifyExact( paramTy, otherParamTy, env, needAssertions, haveAssertions, openVars, WidenMode(false, false), indexer ) ) { result = false; return; } // ttype parameter should be last if ( tupleParam || otherTupleParam ) break; } result = ( it == params.end() && jt == otherParams.end() ); } void Unify_old::postvisit(StructInstType *structInst) { handleGenericRefType( structInst, type2 ); } void Unify_old::postvisit(UnionInstType *unionInst) { handleGenericRefType( unionInst, type2 ); } void Unify_old::postvisit(EnumInstType *enumInst) { handleRefType( enumInst, type2 ); } void Unify_old::postvisit(TraitInstType *contextInst) { handleRefType( contextInst, type2 ); } void Unify_old::postvisit(TypeInstType *typeInst) { assert( openVars.find( typeInst->get_name() ) == openVars.end() ); TypeInstType *otherInst = dynamic_cast< TypeInstType* >( type2 ); if ( otherInst && typeInst->get_name() == otherInst->get_name() ) { result = true; /// } else { /// NamedTypeDecl *nt = indexer.lookupType( typeInst->get_name() ); /// if ( nt ) { /// TypeDecl *type = dynamic_cast< TypeDecl* >( nt ); /// assert( type ); /// if ( type->get_base() ) { /// result = unifyExact( type->get_base(), typeInst, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ); /// } /// } } // if } template< typename Iterator1, typename Iterator2 > bool unifyList( Iterator1 list1Begin, Iterator1 list1End, Iterator2 list2Begin, Iterator2 list2End, TypeEnvironment &env, AssertionSet &needAssertions, AssertionSet &haveAssertions, const OpenVarSet &openVars, const SymTab::Indexer &indexer ) { auto get_type = [](Type * t) { return t; }; for ( ; list1Begin != list1End && list2Begin != list2End; ++list1Begin, ++list2Begin ) { Type * t1 = *list1Begin; Type * t2 = *list2Begin; bool isTtype1 = Tuples::isTtype( t1 ); bool isTtype2 = Tuples::isTtype( t2 ); // xxx - assumes ttype must be last parameter // xxx - there may be a nice way to refactor this, but be careful because the argument positioning might matter in some cases. if ( isTtype1 && ! isTtype2 ) { // combine all of the things in list2, then unify return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ); } else if ( isTtype2 && ! isTtype1 ) { // combine all of the things in list1, then unify return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ); } else if ( ! unifyExact( t1, t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ) ) { return false; } // if } // for if ( list1Begin != list1End ) { // try unifying empty tuple type with ttype Type * t1 = *list1Begin; if ( Tuples::isTtype( t1 ) ) { return unifyExact( t1, combineTypes( list2Begin, list2End, get_type ).get(), env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ); } else return false; } else if ( list2Begin != list2End ) { // try unifying empty tuple type with ttype Type * t2 = *list2Begin; if ( Tuples::isTtype( t2 ) ) { return unifyExact( combineTypes( list1Begin, list1End, get_type ).get(), t2, env, needAssertions, haveAssertions, openVars, WidenMode( false, false ), indexer ); } else return false; } else { return true; } // if } void Unify_old::postvisit(TupleType *tupleType) { if ( TupleType *otherTuple = dynamic_cast< TupleType* >( type2 ) ) { std::unique_ptr flat1( tupleType->clone() ); std::unique_ptr flat2( otherTuple->clone() ); std::list types1, types2; PassVisitor expander( env ); flat1->acceptMutator( expander ); flat2->acceptMutator( expander ); flatten( flat1.get(), back_inserter( types1 ) ); flatten( flat2.get(), back_inserter( types2 ) ); result = unifyList( types1.begin(), types1.end(), types2.begin(), types2.end(), env, needAssertions, haveAssertions, openVars, indexer ); } // if } void Unify_old::postvisit( __attribute__((unused)) VarArgsType *varArgsType ) { result = dynamic_cast< VarArgsType* >( type2 ); } void Unify_old::postvisit( __attribute__((unused)) ZeroType *zeroType ) { result = dynamic_cast< ZeroType* >( type2 ); } void Unify_old::postvisit( __attribute__((unused)) OneType *oneType ) { result = dynamic_cast< OneType* >( type2 ); } Type * extractResultType( FunctionType * function ) { if ( function->get_returnVals().size() == 0 ) { return new VoidType( Type::Qualifiers() ); } else if ( function->get_returnVals().size() == 1 ) { return function->get_returnVals().front()->get_type()->clone(); } else { std::list< Type * > types; for ( DeclarationWithType * decl : function->get_returnVals() ) { types.push_back( decl->get_type()->clone() ); } // for return new TupleType( Type::Qualifiers(), types ); } } class Unify_new final : public ast::WithShortCircuiting { const ast::Type * type2; ast::TypeEnvironment & tenv; ast::AssertionSet & need; ast::AssertionSet & have; const ast::OpenVarSet & open; WidenMode widen; const ast::SymbolTable & symtab; public: static size_t traceId; bool result; Unify_new( const ast::Type * type2, ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open, WidenMode widen, const ast::SymbolTable & symtab ) : type2(type2), tenv(env), need(need), have(have), open(open), widen(widen), symtab(symtab), result(false) {} void previsit( const ast::Node * ) { visit_children = false; } void postvisit( const ast::VoidType * ) { result = dynamic_cast< const ast::VoidType * >( type2 ); } void postvisit( const ast::BasicType * basic ) { if ( auto basic2 = dynamic_cast< const ast::BasicType * >( type2 ) ) { result = basic->kind == basic2->kind; } } void postvisit( const ast::PointerType * pointer ) { if ( auto pointer2 = dynamic_cast< const ast::PointerType * >( type2 ) ) { result = unifyExact( pointer->base, pointer2->base, tenv, need, have, open, noWiden(), symtab ); } } void postvisit( const ast::ArrayType * array ) { auto array2 = dynamic_cast< const ast::ArrayType * >( type2 ); if ( ! array2 ) return; // to unify, array types must both be VLA or both not VLA and both must have a // dimension expression or not have a dimension if ( array->isVarLen != array2->isVarLen ) return; if ( ! array->isVarLen && ! array2->isVarLen && array->dimension && array2->dimension ) { auto ce1 = array->dimension.as< ast::ConstantExpr >(); auto ce2 = array2->dimension.as< ast::ConstantExpr >(); // see C11 Reference Manual 6.7.6.2.6 // two array types with size specifiers that are integer constant expressions are // compatible if both size specifiers have the same constant value if ( ce1 && ce2 && ce1->intValue() != ce2->intValue() ) return; } result = unifyExact( array->base, array2->base, tenv, need, have, open, noWiden(), symtab ); } void postvisit( const ast::ReferenceType * ref ) { if ( auto ref2 = dynamic_cast< const ast::ReferenceType * >( type2 ) ) { result = unifyExact( ref->base, ref2->base, tenv, need, have, open, noWiden(), symtab ); } } private: /// Replaces ttype variables with their bound types. /// If this isn't done when satifying ttype assertions, then argument lists can have /// different size and structure when they should be compatible. struct TtypeExpander_new : public ast::WithShortCircuiting, public ast::PureVisitor { ast::TypeEnvironment & tenv; TtypeExpander_new( ast::TypeEnvironment & env ) : tenv( env ) {} const ast::Type * postvisit( const ast::TypeInstType * typeInst ) { if ( const ast::EqvClass * clz = tenv.lookup( typeInst->name ) ) { // expand ttype parameter into its actual type if ( clz->data.kind == ast::TypeDecl::Ttype && clz->bound ) { return clz->bound; } } return typeInst; } }; /// returns flattened version of `src` static std::vector< ast::ptr< ast::Type > > flattenList( const std::vector< ast::ptr< ast::Type > > & src, ast::TypeEnvironment & env ) { std::vector< ast::ptr< ast::Type > > dst; dst.reserve( src.size() ); for ( const auto & d : src ) { ast::Pass expander{ env }; // TtypeExpander pass is impure (may mutate nodes in place) // need to make nodes shared to prevent accidental mutation ast::ptr dc = d->accept(expander); auto types = flatten( dc ); for ( ast::ptr< ast::Type > & t : types ) { // outermost const, volatile, _Atomic qualifiers in parameters should not play // a role in the unification of function types, since they do not determine // whether a function is callable. // NOTE: **must** consider at least mutex qualifier, since functions can be // overloaded on outermost mutex and a mutex function has different // requirements than a non-mutex function remove_qualifiers( t, ast::CV::Const | ast::CV::Volatile | ast::CV::Atomic ); dst.emplace_back( t ); } } return dst; } /// Creates a tuple type based on a list of DeclWithType template< typename Iter > static ast::ptr< ast::Type > tupleFromTypes( Iter crnt, Iter end ) { std::vector< ast::ptr< ast::Type > > types; while ( crnt != end ) { // it is guaranteed that a ttype variable will be bound to a flat tuple, so ensure // that this results in a flat tuple flatten( *crnt, types ); ++crnt; } return { new ast::TupleType{ std::move(types) } }; } template< typename Iter > static bool unifyTypeList( Iter crnt1, Iter end1, Iter crnt2, Iter end2, ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open, const ast::SymbolTable & symtab ) { while ( crnt1 != end1 && crnt2 != end2 ) { const ast::Type * t1 = *crnt1; const ast::Type * t2 = *crnt2; bool isTuple1 = Tuples::isTtype( t1 ); bool isTuple2 = Tuples::isTtype( t2 ); // assumes here that ttype *must* be last parameter if ( isTuple1 && ! isTuple2 ) { // combine remainder of list2, then unify return unifyExact( t1, tupleFromTypes( crnt2, end2 ), env, need, have, open, noWiden(), symtab ); } else if ( ! isTuple1 && isTuple2 ) { // combine remainder of list1, then unify return unifyExact( tupleFromTypes( crnt1, end1 ), t2, env, need, have, open, noWiden(), symtab ); } if ( ! unifyExact( t1, t2, env, need, have, open, noWiden(), symtab ) ) return false; ++crnt1; ++crnt2; } // May get to the end of one argument list before the other. This is only okay if the // other is a ttype if ( crnt1 != end1 ) { // try unifying empty tuple with ttype const ast::Type * t1 = *crnt1; if ( ! Tuples::isTtype( t1 ) ) return false; return unifyExact( t1, tupleFromTypes( crnt2, end2 ), env, need, have, open, noWiden(), symtab ); } else if ( crnt2 != end2 ) { // try unifying empty tuple with ttype const ast::Type * t2 = *crnt2; if ( ! Tuples::isTtype( t2 ) ) return false; return unifyExact( tupleFromTypes( crnt1, end1 ), t2, env, need, have, open, noWiden(), symtab ); } return true; } static bool unifyTypeList( const std::vector< ast::ptr< ast::Type > > & list1, const std::vector< ast::ptr< ast::Type > > & list2, ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open, const ast::SymbolTable & symtab ) { return unifyTypeList( list1.begin(), list1.end(), list2.begin(), list2.end(), env, need, have, open, symtab ); } static void markAssertionSet( ast::AssertionSet & assns, const ast::DeclWithType * assn ) { auto i = assns.find( assn ); if ( i != assns.end() ) { i->second.isUsed = true; } } /// mark all assertions in `type` used in both `assn1` and `assn2` static void markAssertions( ast::AssertionSet & assn1, ast::AssertionSet & assn2, const ast::ParameterizedType * type ) { for ( const auto & tyvar : type->forall ) { for ( const ast::DeclWithType * assert : tyvar->assertions ) { markAssertionSet( assn1, assert ); markAssertionSet( assn2, assert ); } } } public: void postvisit( const ast::FunctionType * func ) { auto func2 = dynamic_cast< const ast::FunctionType * >( type2 ); if ( ! func2 ) return; if ( func->isVarArgs != func2->isVarArgs ) return; // Flatten the parameter lists for both functions so that tuple structure does not // affect unification. Does not actually mutate function parameters. auto params = flattenList( func->params, tenv ); auto params2 = flattenList( func2->params, tenv ); // sizes don't have to match if ttypes are involved; need to be more precise w.r.t. // where the ttype is to prevent errors if ( ( params.size() != params2.size() || func->returns.size() != func2->returns.size() ) && ! func->isTtype() && ! func2->isTtype() ) return; if ( ! unifyTypeList( params, params2, tenv, need, have, open, symtab ) ) return; if ( ! unifyTypeList( func->returns, func2->returns, tenv, need, have, open, symtab ) ) return; markAssertions( have, need, func ); markAssertions( have, need, func2 ); result = true; } private: // Returns: other, cast as XInstType // Assigns this->result: whether types are compatible (up to generic parameters) template< typename XInstType > const XInstType * handleRefType( const XInstType * inst, const ast::Type * other ) { // check that the other type is compatible and named the same auto otherInst = dynamic_cast< const XInstType * >( other ); this->result = otherInst && inst->name == otherInst->name; return otherInst; } /// Creates a tuple type based on a list of TypeExpr template< typename Iter > static const ast::Type * tupleFromExprs( const ast::TypeExpr * param, Iter & crnt, Iter end, ast::CV::Qualifiers qs ) { std::vector< ast::ptr< ast::Type > > types; do { types.emplace_back( param->type ); ++crnt; if ( crnt == end ) break; param = strict_dynamic_cast< const ast::TypeExpr * >( crnt->get() ); } while(true); return new ast::TupleType{ std::move(types), qs }; } template< typename XInstType > void handleGenericRefType( const XInstType * inst, const ast::Type * other ) { // check that other type is compatible and named the same const XInstType * otherInst = handleRefType( inst, other ); if ( ! this->result ) return; // check that parameters of types unify, if any const std::vector< ast::ptr< ast::Expr > > & params = inst->params; const std::vector< ast::ptr< ast::Expr > > & params2 = otherInst->params; auto it = params.begin(); auto jt = params2.begin(); for ( ; it != params.end() && jt != params2.end(); ++it, ++jt ) { auto param = strict_dynamic_cast< const ast::TypeExpr * >( it->get() ); auto param2 = strict_dynamic_cast< const ast::TypeExpr * >( jt->get() ); ast::ptr< ast::Type > pty = param->type; ast::ptr< ast::Type > pty2 = param2->type; bool isTuple = Tuples::isTtype( pty ); bool isTuple2 = Tuples::isTtype( pty2 ); if ( isTuple && isTuple2 ) { ++it; ++jt; // skip ttype parameters before break } else if ( isTuple ) { // bundle remaining params into tuple pty2 = tupleFromExprs( param2, jt, params2.end(), pty->qualifiers ); ++it; // skip ttype parameter for break } else if ( isTuple2 ) { // bundle remaining params into tuple pty = tupleFromExprs( param, it, params.end(), pty2->qualifiers ); ++jt; // skip ttype parameter for break } if ( ! unifyExact( pty, pty2, tenv, need, have, open, noWiden(), symtab ) ) { result = false; return; } // ttype parameter should be last if ( isTuple || isTuple2 ) break; } result = it == params.end() && jt == params2.end(); } public: void postvisit( const ast::StructInstType * aggrType ) { handleGenericRefType( aggrType, type2 ); } void postvisit( const ast::UnionInstType * aggrType ) { handleGenericRefType( aggrType, type2 ); } void postvisit( const ast::EnumInstType * aggrType ) { handleRefType( aggrType, type2 ); } void postvisit( const ast::TraitInstType * aggrType ) { handleRefType( aggrType, type2 ); } void postvisit( const ast::TypeInstType * typeInst ) { assert( open.find( typeInst->name ) == open.end() ); handleRefType( typeInst, type2 ); } private: /// Creates a tuple type based on a list of Type static ast::ptr< ast::Type > tupleFromTypes( const std::vector< ast::ptr< ast::Type > > & tys ) { std::vector< ast::ptr< ast::Type > > out; for ( const ast::Type * ty : tys ) { // it is guaranteed that a ttype variable will be bound to a flat tuple, so ensure // that this results in a flat tuple flatten( ty, out ); } return { new ast::TupleType{ std::move(out) } }; } static bool unifyList( const std::vector< ast::ptr< ast::Type > > & list1, const std::vector< ast::ptr< ast::Type > > & list2, ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open, const ast::SymbolTable & symtab ) { auto crnt1 = list1.begin(); auto crnt2 = list2.begin(); while ( crnt1 != list1.end() && crnt2 != list2.end() ) { const ast::Type * t1 = *crnt1; const ast::Type * t2 = *crnt2; bool isTuple1 = Tuples::isTtype( t1 ); bool isTuple2 = Tuples::isTtype( t2 ); // assumes ttype must be last parameter if ( isTuple1 && ! isTuple2 ) { // combine entirety of list2, then unify return unifyExact( t1, tupleFromTypes( list2 ), env, need, have, open, noWiden(), symtab ); } else if ( ! isTuple1 && isTuple2 ) { // combine entirety of list1, then unify return unifyExact( tupleFromTypes( list1 ), t2, env, need, have, open, noWiden(), symtab ); } if ( ! unifyExact( t1, t2, env, need, have, open, noWiden(), symtab ) ) return false; ++crnt1; ++crnt2; } if ( crnt1 != list1.end() ) { // try unifying empty tuple type with ttype const ast::Type * t1 = *crnt1; if ( ! Tuples::isTtype( t1 ) ) return false; // xxx - this doesn't generate an empty tuple, contrary to comment; both ported // from Rob's code return unifyExact( t1, tupleFromTypes( list2 ), env, need, have, open, noWiden(), symtab ); } else if ( crnt2 != list2.end() ) { // try unifying empty tuple with ttype const ast::Type * t2 = *crnt2; if ( ! Tuples::isTtype( t2 ) ) return false; // xxx - this doesn't generate an empty tuple, contrary to comment; both ported // from Rob's code return unifyExact( tupleFromTypes( list1 ), t2, env, need, have, open, noWiden(), symtab ); } return true; } public: void postvisit( const ast::TupleType * tuple ) { auto tuple2 = dynamic_cast< const ast::TupleType * >( type2 ); if ( ! tuple2 ) return; ast::Pass expander{ tenv }; const ast::Type * flat = tuple->accept( expander ); const ast::Type * flat2 = tuple2->accept( expander ); auto types = flatten( flat ); auto types2 = flatten( flat2 ); result = unifyList( types, types2, tenv, need, have, open, symtab ); } void postvisit( const ast::VarArgsType * ) { result = dynamic_cast< const ast::VarArgsType * >( type2 ); } void postvisit( const ast::ZeroType * ) { result = dynamic_cast< const ast::ZeroType * >( type2 ); } void postvisit( const ast::OneType * ) { result = dynamic_cast< const ast::OneType * >( type2 ); } private: template< typename RefType > void handleRefType( RefType *inst, Type *other ); template< typename RefType > void handleGenericRefType( RefType *inst, Type *other ); }; // size_t Unify_new::traceId = Stats::Heap::new_stacktrace_id("Unify_new"); bool unify( const ast::ptr & type1, const ast::ptr & type2, ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have, ast::OpenVarSet & open, const ast::SymbolTable & symtab ) { ast::ptr common; return unify( type1, type2, env, need, have, open, symtab, common ); } bool unify( const ast::ptr & type1, const ast::ptr & type2, ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have, ast::OpenVarSet & open, const ast::SymbolTable & symtab, ast::ptr & common ) { ast::OpenVarSet closed; findOpenVars( type1, open, closed, need, have, FirstClosed ); findOpenVars( type2, open, closed, need, have, FirstOpen ); return unifyInexact( type1, type2, env, need, have, open, WidenMode{ true, true }, symtab, common ); } bool unifyExact( const ast::Type * type1, const ast::Type * type2, ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open, WidenMode widen, const ast::SymbolTable & symtab ) { if ( type1->qualifiers != type2->qualifiers ) return false; auto var1 = dynamic_cast< const ast::TypeInstType * >( type1 ); auto var2 = dynamic_cast< const ast::TypeInstType * >( type2 ); ast::OpenVarSet::const_iterator entry1 = var1 ? open.find( var1->name ) : open.end(), entry2 = var2 ? open.find( var2->name ) : open.end(); bool isopen1 = entry1 != open.end(); bool isopen2 = entry2 != open.end(); if ( isopen1 && isopen2 ) { if ( entry1->second.kind != entry2->second.kind ) return false; return env.bindVarToVar( var1, var2, ast::TypeDecl::Data{ entry1->second, entry2->second }, need, have, open, widen, symtab ); } else if ( isopen1 ) { return env.bindVar( var1, type2, entry1->second, need, have, open, widen, symtab ); } else if ( isopen2 ) { return env.bindVar( var2, type1, entry2->second, need, have, open, widen, symtab ); } else { ast::Pass comparator{ type2, env, need, have, open, widen, symtab }; type1->accept( comparator ); return comparator.core.result; } } bool unifyInexact( const ast::ptr & type1, const ast::ptr & type2, ast::TypeEnvironment & env, ast::AssertionSet & need, ast::AssertionSet & have, const ast::OpenVarSet & open, WidenMode widen, const ast::SymbolTable & symtab, ast::ptr & common ) { ast::CV::Qualifiers q1 = type1->qualifiers, q2 = type2->qualifiers; // force t1 and t2 to be cloned if their qualifiers must be stripped, so that type1 and // type2 are left unchanged; calling convention forces type{1,2}->strong_ref >= 1 ast::Type * t1 = shallowCopy(type1.get()); ast::Type * t2 = shallowCopy(type2.get()); t1->qualifiers = {}; t2->qualifiers = {}; ast::ptr< ast::Type > t1_(t1); ast::ptr< ast::Type > t2_(t2); if ( unifyExact( t1, t2, env, need, have, open, widen, symtab ) ) { // if exact unification on unqualified types, try to merge qualifiers if ( q1 == q2 || ( ( q1 > q2 || widen.first ) && ( q2 > q1 || widen.second ) ) ) { t1->qualifiers = q1 | q2; common = t1; return true; } else { return false; } } else if (( common = commonType( t1, t2, widen, symtab, env, open ) )) { // no exact unification, but common type auto c = shallowCopy(common.get()); c->qualifiers = q1 | q2; common = c; return true; } else { return false; } } ast::ptr extractResultType( const ast::FunctionType * func ) { if ( func->returns.empty() ) return new ast::VoidType{}; if ( func->returns.size() == 1 ) return func->returns[0]; std::vector> tys; for ( const auto & decl : func->returns ) { tys.emplace_back( decl ); } return new ast::TupleType{ std::move(tys) }; } } // namespace ResolvExpr // Local Variables: // // tab-width: 4 // // mode: c++ // // compile-command: "make install" // // End: //