Changes in src/Tuples/TupleExpansion.cc [c6b4432:9939dc3]

File:

• src/Tuples/TupleExpansion.cc (modified) (2 diffs)

src/Tuples/TupleExpansion.cc

@@ -23 +23 @@
 #include "AST/Node.hpp"
 #include "AST/Type.hpp"
+#include "Common/PassVisitor.h"   // for PassVisitor, WithDeclsToAdd, WithGu...
 #include "Common/ScopedMap.h"     // for ScopedMap
 #include "Common/utility.h"       // for CodeLocation
 #include "InitTweak/InitTweak.h"  // for getFunction
+#include "SynTree/LinkageSpec.h"  // for Spec, C, Intrinsic
+#include "SynTree/Constant.h"     // for Constant
+#include "SynTree/Declaration.h"  // for StructDecl, DeclarationWithType
+#include "SynTree/Expression.h"   // for UntypedMemberExpr, Expression, Uniq...
+#include "SynTree/Label.h"        // for operator==, Label
+#include "SynTree/Mutator.h"      // for Mutator
+#include "SynTree/Type.h"         // for Type, Type::Qualifiers, TupleType
+#include "SynTree/Visitor.h"      // for Visitor
 #include "Tuples.h"
 
+class CompoundStmt;
+class TypeSubstitution;
+
 namespace Tuples {
-
+        namespace {
+                struct MemberTupleExpander final : public WithShortCircuiting, public WithVisitorRef<MemberTupleExpander> {
+                        void premutate( UntypedMemberExpr * ) { visit_children = false; }
+                        Expression * postmutate( UntypedMemberExpr * memberExpr );
+                };
+
+                struct UniqueExprExpander final : public WithDeclsToAdd {
+                        Expression * postmutate( UniqueExpr * unqExpr );
+
+                        std::map< int, Expression * > decls; // not vector, because order added may not be increasing order
+
+                        ~UniqueExprExpander() {
+                                for ( std::pair<const int, Expression *> & p : decls ) {
+                                        delete p.second;
+                                }
+                        }
+                };
+
+                struct TupleAssignExpander {
+                        Expression * postmutate( TupleAssignExpr * tupleExpr );
+                };
+
+                struct TupleTypeReplacer : public WithDeclsToAdd, public WithGuards, public WithConstTypeSubstitution {
+                        Type * postmutate( TupleType * tupleType );
+
+                        void premutate( CompoundStmt * ) {
+                                GuardScope( typeMap );
+                        }
+                  private:
+                        ScopedMap< int, StructDecl * > typeMap;
+                };
+
+                struct TupleIndexExpander {
+                        Expression * postmutate( TupleIndexExpr * tupleExpr );
+                };
+
+                struct TupleExprExpander final {
+                        Expression * postmutate( TupleExpr * tupleExpr );
+                };
+        }
+
+        void expandMemberTuples( std::list< Declaration * > & translationUnit ) {
+                PassVisitor<MemberTupleExpander> expander;
+                mutateAll( translationUnit, expander );
+        }
+
+        void expandUniqueExpr( std::list< Declaration * > & translationUnit ) {
+                PassVisitor<UniqueExprExpander> unqExpander;
+                mutateAll( translationUnit, unqExpander );
+        }
+
+        void expandTuples( std::list< Declaration * > & translationUnit ) {
+                PassVisitor<TupleAssignExpander> assnExpander;
+                mutateAll( translationUnit, assnExpander );
+
+                PassVisitor<TupleTypeReplacer> replacer;
+                mutateAll( translationUnit, replacer );
+
+                PassVisitor<TupleIndexExpander> idxExpander;
+                mutateAll( translationUnit, idxExpander );
+
+                PassVisitor<TupleExprExpander> exprExpander;
+                mutateAll( translationUnit, exprExpander );
+        }
+
+        namespace {
+                /// given a expression representing the member and an expression representing the aggregate,
+                /// reconstructs a flattened UntypedMemberExpr with the right precedence
+                Expression * reconstructMemberExpr( Expression * member, Expression * aggr, CodeLocation & loc ) {
+                        if ( UntypedMemberExpr * memberExpr = dynamic_cast< UntypedMemberExpr * >( member ) ) {
+                                // construct a new UntypedMemberExpr with the correct structure , and recursively
+                                // expand that member expression.
+                                PassVisitor<MemberTupleExpander> expander;
+                                UntypedMemberExpr * inner = new UntypedMemberExpr( memberExpr->aggregate, aggr->clone() );
+                                UntypedMemberExpr * newMemberExpr = new UntypedMemberExpr( memberExpr->member, inner );
+                                inner->location = newMemberExpr->location = loc;
+                                memberExpr->member = nullptr;
+                                memberExpr->aggregate = nullptr;
+                                delete memberExpr;
+                                return newMemberExpr->acceptMutator( expander );
+                        } else {
+                                // not a member expression, so there is nothing to do but attach and return
+                                UntypedMemberExpr * newMemberExpr = new UntypedMemberExpr( member, aggr->clone() );
+                                newMemberExpr->location = loc;
+                                return newMemberExpr;
+                        }
+                }
+        }
+
+        Expression * MemberTupleExpander::postmutate( UntypedMemberExpr * memberExpr ) {
+                if ( UntypedTupleExpr * tupleExpr = dynamic_cast< UntypedTupleExpr * > ( memberExpr->member ) ) {
+                        Expression * aggr = memberExpr->aggregate->clone()->acceptMutator( *visitor );
+                        // aggregate expressions which might be impure must be wrapped in unique expressions
+                        if ( Tuples::maybeImpureIgnoreUnique( memberExpr->aggregate ) ) aggr = new UniqueExpr( aggr );
+                        for ( Expression *& expr : tupleExpr->exprs ) {
+                                expr = reconstructMemberExpr( expr, aggr, memberExpr->location );
+                                expr->location = memberExpr->location;
+                        }
+                        delete aggr;
+                        tupleExpr->location = memberExpr->location;
+                        return tupleExpr;
+                } else {
+                        // there may be a tuple expr buried in the aggregate
+                        // xxx - this is a memory leak
+                        UntypedMemberExpr * newMemberExpr = new UntypedMemberExpr( memberExpr->member->clone(), memberExpr->aggregate->acceptMutator( *visitor ) );
+                        newMemberExpr->location = memberExpr->location;
+                        return newMemberExpr;
+                }
+        }
+
+        Expression * UniqueExprExpander::postmutate( UniqueExpr * unqExpr ) {
+                const int id = unqExpr->get_id();
+
+                // on first time visiting a unique expr with a particular ID, generate the expression that replaces all UniqueExprs with that ID,
+                // and lookup on subsequent hits. This ensures that all unique exprs with the same ID reference the same variable.
+                if ( ! decls.count( id ) ) {
+                        Expression * assignUnq;
+                        Expression * var = unqExpr->get_var();
+                        if ( unqExpr->get_object() ) {
+                                // an object was generated to represent this unique expression -- it should be added to the list of declarations now
+                                declsToAddBefore.push_back( unqExpr->get_object() );
+                                unqExpr->set_object( nullptr );
+                                // steal the expr from the unqExpr
+                                assignUnq = UntypedExpr::createAssign( unqExpr->get_var()->clone(), unqExpr->get_expr() );
+                                unqExpr->set_expr( nullptr );
+                        } else {
+                                // steal the already generated assignment to var from the unqExpr - this has been generated by FixInit
+                                Expression * expr = unqExpr->get_expr();
+                                CommaExpr * commaExpr = strict_dynamic_cast< CommaExpr * >( expr );
+                                assignUnq = commaExpr->get_arg1();
+                                commaExpr->set_arg1( nullptr );
+                        }
+                        ObjectDecl * finished = new ObjectDecl( toString( "_unq", id, "_finished_" ), Type::StorageClasses(), LinkageSpec::Cforall, nullptr, new BasicType( Type::Qualifiers(), BasicType::Bool ),
+                                                                                                        new SingleInit( new ConstantExpr( Constant::from_int( 0 ) ) ) );
+                        declsToAddBefore.push_back( finished );
+                        // (finished ? _unq_expr_N : (_unq_expr_N = <unqExpr->get_expr()>, finished = 1, _unq_expr_N))
+                        // This pattern ensures that each unique expression is evaluated once, regardless of evaluation order of the generated C code.
+                        Expression * assignFinished = UntypedExpr::createAssign( new VariableExpr(finished), new ConstantExpr( Constant::from_int( 1 ) ) );
+                        ConditionalExpr * condExpr = new ConditionalExpr( new VariableExpr( finished ), var->clone(),
+                                new CommaExpr( new CommaExpr( assignUnq, assignFinished ), var->clone() ) );
+                        condExpr->set_result( var->get_result()->clone() );
+                        condExpr->set_env( maybeClone( unqExpr->get_env() ) );
+                        decls[id] = condExpr;
+                }
+                delete unqExpr;
+                return decls[id]->clone();
+        }
+
+        Expression * TupleAssignExpander::postmutate( TupleAssignExpr * assnExpr ) {
+                StmtExpr * ret = assnExpr->get_stmtExpr();
+                assnExpr->set_stmtExpr( nullptr );
+                // move env to StmtExpr
+                ret->set_env( assnExpr->get_env() );
+                assnExpr->set_env( nullptr );
+                delete assnExpr;
+                return ret;
+        }
+
+        Type * TupleTypeReplacer::postmutate( TupleType * tupleType ) {
+                unsigned tupleSize = tupleType->size();
+                if ( ! typeMap.count( tupleSize ) ) {
+                        // generate struct type to replace tuple type based on the number of components in the tuple
+                        StructDecl * decl = new StructDecl( toString( "_tuple", tupleSize, "_" ) );
+                        decl->location = tupleType->location;
+                        decl->set_body( true );
+                        for ( size_t i = 0; i < tupleSize; ++i ) {
+                                TypeDecl * tyParam = new TypeDecl( toString( "tuple_param_", tupleSize, "_", i ), Type::StorageClasses(), nullptr, TypeDecl::Dtype, true );
+                                decl->get_members().push_back( new ObjectDecl( toString("field_", i ), Type::StorageClasses(), LinkageSpec::C, nullptr, new TypeInstType( Type::Qualifiers(), tyParam->get_name(), tyParam ), nullptr ) );
+                                decl->get_parameters().push_back( tyParam );
+                        }
+                        if ( tupleSize == 0 ) {
+                                // empty structs are not standard C. Add a dummy field to empty tuples to silence warnings when a compound literal Tuple0 is created.
+                                decl->get_members().push_back( new ObjectDecl( "dummy", Type::StorageClasses(), LinkageSpec::C, nullptr, new BasicType( Type::Qualifiers(), BasicType::SignedInt ), nullptr ) );
+                        }
+                        typeMap[tupleSize] = decl;
+                        declsToAddBefore.push_back( decl );
+                }
+                Type::Qualifiers qualifiers = tupleType->get_qualifiers();
+
+                StructDecl * decl = typeMap[tupleSize];
+                StructInstType * newType = new StructInstType( qualifiers, decl );
+                for ( auto p : group_iterate( tupleType->get_types(), decl->get_parameters() ) ) {
+                        Type * t = std::get<0>(p);
+                        newType->get_parameters().push_back( new TypeExpr( t->clone() ) );
+                }
+                delete tupleType;
+                return newType;
+        }
+
+        Expression * TupleIndexExpander::postmutate( TupleIndexExpr * tupleExpr ) {
+                Expression * tuple = tupleExpr->tuple;
+                assert( tuple );
+                tupleExpr->tuple = nullptr;
+                unsigned int idx = tupleExpr->index;
+                TypeSubstitution * env = tupleExpr->env;
+                tupleExpr->env = nullptr;
+                delete tupleExpr;
+
+                if ( TupleExpr * tupleExpr = dynamic_cast< TupleExpr * > ( tuple ) ) {
+                        if ( ! maybeImpureIgnoreUnique( tupleExpr ) ) {
+                                // optimization: definitely pure tuple expr => can reduce to the only relevant component.
+                                assert( tupleExpr->exprs.size() > idx );
+                                Expression *& expr = *std::next(tupleExpr->exprs.begin(), idx);
+                                Expression * ret = expr;
+                                ret->env = env;
+                                expr = nullptr; // remove from list so it can safely be deleted
+                                delete tupleExpr;
+                                return ret;
+                        }
+                }
+
+                StructInstType * type = strict_dynamic_cast< StructInstType * >( tuple->result );
+                StructDecl * structDecl = type->baseStruct;
+                assert( structDecl->members.size() > idx );
+                Declaration * member = *std::next(structDecl->members.begin(), idx);
+                MemberExpr * memExpr = new MemberExpr( strict_dynamic_cast< DeclarationWithType * >( member ), tuple );
+                memExpr->env = env;
+                return memExpr;
+        }
+
+        Expression * replaceTupleExpr( Type * result, const std::list< Expression * > & exprs, TypeSubstitution * env ) {
+                if ( result->isVoid() ) {
+                        // void result - don't need to produce a value for cascading - just output a chain of comma exprs
+                        assert( ! exprs.empty() );
+                        std::list< Expression * >::const_iterator iter = exprs.begin();
+                        Expression * expr = new CastExpr( *iter++ );
+                        for ( ; iter != exprs.end(); ++iter ) {
+                                expr = new CommaExpr( expr, new CastExpr( *iter ) );
+                        }
+                        expr->set_env( env );
+                        return expr;
+                } else {
+                        // typed tuple expression - produce a compound literal which performs each of the expressions
+                        // as a distinct part of its initializer - the produced compound literal may be used as part of
+                        // another expression
+                        std::list< Initializer * > inits;
+                        for ( Expression * expr : exprs ) {
+                                inits.push_back( new SingleInit( expr ) );
+                        }
+                        Expression * expr = new CompoundLiteralExpr( result, new ListInit( inits ) );
+                        expr->set_env( env );
+                        return expr;
+                }
+        }
+
+        Expression * TupleExprExpander::postmutate( TupleExpr * tupleExpr ) {
+                Type * result = tupleExpr->get_result();
+                std::list< Expression * > exprs = tupleExpr->get_exprs();
+                assert( result );
+                TypeSubstitution * env = tupleExpr->get_env();
+
+                // remove data from shell and delete it
+                tupleExpr->set_result( nullptr );
+                tupleExpr->get_exprs().clear();
+                tupleExpr->set_env( nullptr );
+                delete tupleExpr;
+
+                return replaceTupleExpr( result, exprs, env );
+        }
+
+        Type * makeTupleType( const std::list< Expression * > & exprs ) {
+                // produce the TupleType which aggregates the types of the exprs
+                std::list< Type * > types;
+                Type::Qualifiers qualifiers( Type::Const | Type::Volatile | Type::Restrict | Type::Atomic | Type::Mutex );
+                for ( Expression * expr : exprs ) {
+                        assert( expr->get_result() );
+                        if ( expr->get_result()->isVoid() ) {
+                                // if the type of any expr is void, the type of the entire tuple is void
+                                return new VoidType( Type::Qualifiers() );
+                        }
+                        Type * type = expr->get_result()->clone();
+                        types.push_back( type );
+                        // the qualifiers on the tuple type are the qualifiers that exist on all component types
+                        qualifiers &= type->get_qualifiers();
+                } // for
+                if ( exprs.empty() ) qualifiers = Type::Qualifiers();
+                return new TupleType( qualifiers, types );
+        }
         const ast::Type * makeTupleType( const std::vector<ast::ptr<ast::Expr>> & exprs ) {
                 // produce the TupleType which aggregates the types of the exprs
@@ -52 +341 @@
         }
 
+        TypeInstType * isTtype( Type * type ) {
+                if ( TypeInstType * inst = dynamic_cast< TypeInstType * >( type ) ) {
+                        if ( inst->get_baseType() && inst->get_baseType()->get_kind() == TypeDecl::Ttype ) {
+                                return inst;
+                        }
+                }
+                return nullptr;
+        }
+
+        const TypeInstType * isTtype( const Type * type ) {
+                if ( const TypeInstType * inst = dynamic_cast< const TypeInstType * >( type ) ) {
+                        if ( inst->baseType && inst->baseType->kind == TypeDecl::Ttype ) {
+                                return inst;
+                        }
+                }
+                return nullptr;
+        }
+
         const ast::TypeInstType * isTtype( const ast::Type * type ) {
                 if ( const ast::TypeInstType * inst = dynamic_cast< const ast::TypeInstType * >( type ) ) {