source: src/Concurrency/Keywords.cc @ fb04321

//                              -*- Mode: CPP -*-
//
// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// Keywords.cc --
//
// Author           : Thierry Delisle
// Created On       : Mon Mar 13 12:41:22 2017
// Last Modified By :
// Last Modified On :
// Update Count     : 1
//

#include "Concurrency/Keywords.h"

#include "SynTree/Declaration.h"
#include "SynTree/Expression.h"
#include "SynTree/Initializer.h"
#include "SynTree/Mutator.h"
#include "SynTree/Statement.h"
#include "SynTree/Type.h"
#include "SynTree/Visitor.h"

namespace Concurrency {

        namespace {
                const std::list<Label> noLabels;
                Type::StorageClasses noStorage;
                Type::Qualifiers noQualifiers;
        }

        //=============================================================================================
        // Visitors declaration
        //=============================================================================================

        //-----------------------------------------------------------------------------
        //Handles thread type declarations :
        // thread Mythread {                         struct MyThread {
        //      int data;                                  int data;
        //      a_struct_t more_data;                      a_struct_t more_data;
        //                                =>             thread_desc __thrd_d;
        // };                                        };
        //                                           static inline thread_desc * get_thread( MyThread * this ) { return &this->__thrd_d; }
        //                                           void main( MyThread * this );
        //
        class ThreadKeyword final : public Mutator {
          public:

                static void implement( std::list< Declaration * > & translationUnit ) {}
        };

        //-----------------------------------------------------------------------------
        //Handles coroutine type declarations :
        // coroutine MyCoroutine {                   struct MyCoroutine {
        //      int data;                                  int data;
        //      a_struct_t more_data;                      a_struct_t more_data;
        //                                =>             coroutine_desc __cor_d;
        // };                                        };
        //                                           static inline coroutine_desc * get_coroutine( MyCoroutine * this ) { return &this->__cor_d; }
        //                                           void main( MyCoroutine * this );
        //
        class CoroutineKeyword final : public Mutator {
          public:

                static void implement( std::list< Declaration * > & translationUnit ) {}
        };

        //-----------------------------------------------------------------------------
        //Handles monitor type declarations :
        // monitor MyMonitor {                       struct MyMonitor {
        //      int data;                                  int data;
        //      a_struct_t more_data;                      a_struct_t more_data;
        //                                =>             monitor_desc __mon_d;
        // };                                        };
        //                                           static inline monitor_desc * get_coroutine( MyMonitor * this ) { return &this->__cor_d; }
        //                                           void main( MyMonitor * this );
        //
        class MonitorKeyword final : public Mutator {
          public:

                static void implement( std::list< Declaration * > & translationUnit ) {}
        };

        //-----------------------------------------------------------------------------
        //Handles mutex routines definitions :
        // void foo( A * mutex a, B * mutex b,  int i ) {                  void foo( A * a, B * b,  int i ) {
        //                                                                       monitor_desc * __monitors[] = { get_monitor(a), get_monitor(b) };
        //                                                                       monitor_guard_t __guard = { __monitors, 2 };
        //    /*Some code*/                                       =>           /*Some code*/
        // }                                                               }
        //
        class MutexKeyword final : public Visitor {
          public:

                using Visitor::visit;
                virtual void visit( FunctionDecl *functionDecl ) override final;
                virtual void visit(   StructDecl *functionDecl ) override final;

                std::list<DeclarationWithType*> findMutexArgs( FunctionDecl* );
                void validate( DeclarationWithType * );
                void addStatments( CompoundStmt *, const std::list<DeclarationWithType * > &);

                static void implement( std::list< Declaration * > & translationUnit ) {
                        MutexKeyword impl;
                        acceptAll( translationUnit, impl );
                }

          private:
                StructDecl* monitor_decl = nullptr;
        };

        //=============================================================================================
        // General entry routine
        //=============================================================================================
        void applyKeywords( std::list< Declaration * > & translationUnit ) {
                ThreadKeyword   ::implement( translationUnit );
                CoroutineKeyword        ::implement( translationUnit );
                MonitorKeyword  ::implement( translationUnit );
                MutexKeyword    ::implement( translationUnit );
        }

        //=============================================================================================
        // Mutex keyword implementation
        //=============================================================================================
        void MutexKeyword::visit(FunctionDecl* decl) {
                std::list<DeclarationWithType*> mutexArgs = findMutexArgs( decl );
                if( mutexArgs.empty() ) return;

                for(auto arg : mutexArgs) {
                        validate( arg );
                }

                CompoundStmt* body = decl->get_statements();
                if( ! body ) return;

                assert(monitor_decl);
                addStatments( body, mutexArgs );
        }

        void MutexKeyword::visit(StructDecl* decl) {
                if( decl->get_name() == "monitor_desc" ) {
                        assert( !monitor_decl );
                        monitor_decl = decl;
                }
        }

        std::list<DeclarationWithType*> MutexKeyword::findMutexArgs( FunctionDecl* decl ) {
                std::list<DeclarationWithType*> mutexArgs;

                for( auto arg : decl->get_functionType()->get_parameters()) {
                        //Find mutex arguments
                        Type* ty = arg->get_type();
                        if( ! ty->get_qualifiers().isMutex ) continue;

                        //Append it to the list
                        mutexArgs.push_back( arg );
                }

                return mutexArgs;
        }

        void MutexKeyword::validate( DeclarationWithType * arg ) {
                Type* ty = arg->get_type();

                //Makes sure it's not a copy
                PointerType* pty = dynamic_cast< PointerType * >( ty );
                if( ! pty ) throw SemanticError( "Mutex argument must be of pointer/reference type ", arg );

                //Make sure the we are pointing directly to a type
                Type* base = pty->get_base();
                if(  dynamic_cast< PointerType * >( base ) ) throw SemanticError( "Mutex argument have exactly one level of indirection ", arg );

                //Make sure that typed isn't mutex
                if( ! base->get_qualifiers().isMutex ) throw SemanticError( "mutex keyword may only appear once per argument ", arg );
        }

        void MutexKeyword::addStatments( CompoundStmt * body, const std::list<DeclarationWithType * > & args ) {

                ObjectDecl * monitors = new ObjectDecl(
                        "__monitors",
                        noStorage,
                        LinkageSpec::Cforall,
                        nullptr,
                        new ArrayType(
                                noQualifiers,
                                new PointerType(
                                        noQualifiers,
                                        new StructInstType(
                                                noQualifiers,
                                                monitor_decl
                                        )
                                ),
                                new ConstantExpr( Constant::from_ulong( args.size() ) ),
                                false,
                                false
                        ),
                        new ListInit(
                                map_range < std::list<Initializer*> > ( args, [](DeclarationWithType * var ){
                                        return new SingleInit( new UntypedExpr(
                                                new NameExpr( "get_monitor" ),
                                                {  new VariableExpr( var ) }
                                        ) );
                                })
                        )
                );

                //in reverse order :
                // monitor_guard_t __guard = { __monitors, # };
                body->push_front(
                        new DeclStmt( noLabels, new ObjectDecl(
                                "__guard",
                                noStorage,
                                LinkageSpec::Cforall,
                                nullptr,
                                new StructInstType(
                                        noQualifiers,
                                        "monitor_guard_t"
                                ),
                                new ListInit(
                                        {
                                                new SingleInit( new VariableExpr( monitors ) ),
                                                new SingleInit( new ConstantExpr( Constant::from_ulong( args.size() ) ) )
                                        }
                                )
                        ))
                );

                //monitor_desc * __monitors[] = { a, b };
                body->push_front( new DeclStmt( noLabels, monitors) );
        }
};