source: src/MakeLibCfa.cc @ bfc7811

//
// 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.
//
// MakeLibCfa.cc --
//
// Author           : Richard C. Bilson
// Created On       : Sat May 16 10:33:33 2015
// Last Modified By : Rob Schluntz
// Last Modified On : Fri Apr 22 13:54:15 2016
// Update Count     : 40
//

#include "MakeLibCfa.h"

#include <cassert>                  // for assert
#include <string>                   // for operator==, string

#include "CodeGen/OperatorTable.h"  // for OperatorInfo, operatorLookup, Ope...
#include "Common/PassVisitor.h"     // for PassVisitor
#include "Common/SemanticError.h"   // for SemanticError
#include "Common/UniqueName.h"      // for UniqueName
#include "Parser/LinkageSpec.h"     // for Spec, Intrinsic, C
#include "SynTree/Declaration.h"    // for FunctionDecl, ObjectDecl, Declara...
#include "SynTree/Expression.h"     // for NameExpr, UntypedExpr, VariableExpr
#include "SynTree/Initializer.h"    // for SingleInit
#include "SynTree/Label.h"          // for Label
#include "SynTree/Statement.h"      // for CompoundStmt, ReturnStmt
#include "SynTree/Type.h"           // for FunctionType
#include "SynTree/Visitor.h"        // for acceptAll, Visitor

namespace LibCfa {
        namespace {
                struct MakeLibCfa {
                  public:
                        void postvisit( FunctionDecl* funcDecl );

                        std::list< Declaration* > newDecls;
                };
        }

        void makeLibCfa( std::list< Declaration* > &prelude ) {
                PassVisitor<MakeLibCfa> maker;
                acceptAll( prelude, maker );
                prelude.splice( prelude.end(), maker.pass.newDecls );
        }

        namespace {
                struct TypeFinder       {
                        void postvisit( TypeInstType * inst ) {
                                // if a type variable is seen, assume all zero_t/one_t in the parameter list
                                //  can be replaced with the equivalent 'general' pointer.
                                if ( type ) return;
                                if ( inst->isFtype ) {
                                        type = new PointerType( Type::Qualifiers(), new FunctionType( Type::Qualifiers(), false ) );
                                } else {
                                        type = new PointerType( Type::Qualifiers(), new VoidType( Type::Qualifiers() ) );
                                }
                        }
                        Type * type = nullptr;
                };

                struct ZeroOneReplacer {
                        ZeroOneReplacer( Type * t ) : type( t ) {}
                        Type * type = nullptr;

                        Type * common( Type * t ) {
                                if ( ! type ) return t;
                                return type->clone();
                        }

                        Type * postmutate( OneType * t ) { return common( t ); }
                        Type * postmutate( ZeroType * t ) { return common( t ); }
                };

                void fixZeroOneType( FunctionDecl * origFuncDecl ) {
                        // find appropriate type to replace zero_t/one_t with
                        PassVisitor<TypeFinder> finder;
                        origFuncDecl->type->accept( finder );
                        // replace zero_t/one_t in function type
                        PassVisitor<ZeroOneReplacer> replacer( finder.pass.type );
                        origFuncDecl->type->acceptMutator( replacer );
                }

                void MakeLibCfa::postvisit( FunctionDecl* origFuncDecl ) {
                        // don't change non-intrinsic functions
                        if ( origFuncDecl->get_linkage() != LinkageSpec::Intrinsic ) return;
                        // replace zero_t/one_t with void */void (*)(void)
                        fixZeroOneType( origFuncDecl );
                        // skip functions already defined
                        if ( origFuncDecl->get_statements() ) return;

                        FunctionDecl *funcDecl = origFuncDecl->clone();
                        CodeGen::OperatorInfo opInfo;
                        bool lookResult = CodeGen::operatorLookup( funcDecl->get_name(), opInfo );
                        assert( lookResult );
                        assert( ! funcDecl->get_statements() );
                        // build a recursive call - this is okay, as the call will actually be codegen'd using operator syntax
                        UntypedExpr *newExpr = new UntypedExpr( new NameExpr( funcDecl->get_name() ) );
                        UniqueName paramNamer( "_p" );
                        std::list< DeclarationWithType* >::iterator param = funcDecl->get_functionType()->get_parameters().begin();
                        assert( param != funcDecl->get_functionType()->get_parameters().end() );

                        for ( ; param != funcDecl->get_functionType()->get_parameters().end(); ++param ) {
                                // name each unnamed parameter
                                if ( (*param)->get_name() == "" ) {
                                        (*param)->set_name( paramNamer.newName() );
                                        (*param)->set_linkage( LinkageSpec::C );
                                }
                                // add parameter to the expression
                                newExpr->get_args().push_back( new VariableExpr( *param ) );
                        } // for

                        funcDecl->set_statements( new CompoundStmt() );
                        newDecls.push_back( funcDecl );

                        Statement * stmt = nullptr;
                        switch ( opInfo.type ) {
                          case CodeGen::OT_INDEX:
                          case CodeGen::OT_CALL:
                          case CodeGen::OT_PREFIX:
                          case CodeGen::OT_POSTFIX:
                          case CodeGen::OT_INFIX:
                          case CodeGen::OT_PREFIXASSIGN:
                          case CodeGen::OT_POSTFIXASSIGN:
                          case CodeGen::OT_INFIXASSIGN:
                                        // return the recursive call
                                        stmt = new ReturnStmt( newExpr );
                                        break;
                          case CodeGen::OT_CTOR:
                          case CodeGen::OT_DTOR:
                                        // execute the recursive call
                                        stmt = new ExprStmt( newExpr );
                                        break;
                          case CodeGen::OT_CONSTANT:
                          case CodeGen::OT_LABELADDRESS:
                                // there are no intrinsic definitions of 0/1 or label addresses as functions
                                assert( false );
                        } // switch
                        funcDecl->get_statements()->push_back( stmt );
                }
        } // namespace
} // namespace LibCfa