source: src/CodeGen/FixMain.cc @ 0c577f7

//
// 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.
//
// FixMain.cc --
//
// Author           : Thierry Delisle
// Created On       : Thr Jan 12 14:11:09 2017
// Last Modified By :
// Last Modified On :
// Update Count     : 0
//


#include "FixMain.h"

#include <cassert>                 // for assert, assertf
#include <fstream>                 // for operator<<, basic_ostream::operator<<
#include <list>                    // for list
#include <string>                  // for operator<<

#include "AST/Decl.hpp"
#include "AST/Type.hpp"
#include "Common/PassVisitor.h"
#include "Common/SemanticError.h"  // for SemanticError
#include "CodeGen/GenType.h"       // for GenType
#include "SynTree/Declaration.h"   // for FunctionDecl, operator<<
#include "SynTree/Type.h"          // for FunctionType
#include "SymTab/Mangler.h"

namespace CodeGen {
        bool FixMain::replace_main = false;
        std::unique_ptr<FunctionDecl> FixMain::main_signature = nullptr;

        template<typename container>
        std::string genTypeAt(const container& p, size_t idx) {
                return genType((*std::next(p.begin(), idx))->get_type(), "");
        }

        void FixMain::registerMain(FunctionDecl* functionDecl)
        {
                if(main_signature) {
                        SemanticError(functionDecl, "Multiple definition of main routine\n");
                }
                main_signature.reset( functionDecl->clone() );
        }

        void FixMain::fix(std::ostream &os, const char* bootloader_filename) {
                if( main_signature ) {
                        os << "static inline int invoke_main(int argc, char* argv[], char* envp[]) { (void)argc; (void)argv; (void)envp; return ";
                        main_signature->mangleName = SymTab::Mangler::mangle(main_signature.get());

                        os << main_signature->get_scopedMangleName() << "(";
                        const auto& params = main_signature->get_functionType()->get_parameters();
                        switch(params.size()) {
                                case 3: os << "(" << genTypeAt(params, 0) << ")argc, (" << genTypeAt(params, 1) << ")argv, (" << genTypeAt(params, 2) << ")envp"; break;
                                case 2: os << "(" << genTypeAt(params, 0) << ")argc, (" << genTypeAt(params, 1) << ")argv"; break;
                                case 0: break;
                                default : assert(false);
                        }
                        os << "); }\n";

                        std::ifstream bootloader(bootloader_filename, std::ios::in);
                        assertf( bootloader.is_open(), "cannot open bootloader.c\n" );
                        os << bootloader.rdbuf();
                }
        }

namespace {

ObjectDecl * signedIntObj() {
        return new ObjectDecl(
                "", Type::StorageClasses(), LinkageSpec::Cforall, 0,
                new BasicType( Type::Qualifiers(), BasicType::SignedInt ), nullptr );
}

ObjectDecl * charStarObj() {
        return new ObjectDecl(
                "", Type::StorageClasses(), LinkageSpec::Cforall, 0,
                new PointerType( Type::Qualifiers(),
                        new PointerType( Type::Qualifiers(),
                                new BasicType( Type::Qualifiers(), BasicType::Char ) ) ),
                nullptr );
}

std::string create_mangled_main_function_name( FunctionType * function_type ) {
        std::unique_ptr<FunctionDecl> decl( new FunctionDecl(
                "main", Type::StorageClasses(), LinkageSpec::Cforall,
                function_type, nullptr ) );
        return SymTab::Mangler::mangle( decl.get() );
}

std::string mangled_0_argument_main() {
        FunctionType* main_type = new FunctionType( Type::Qualifiers(), true );
        main_type->get_returnVals().push_back( signedIntObj() );
        return create_mangled_main_function_name( main_type );
}

std::string mangled_2_argument_main() {
        FunctionType* main_type = new FunctionType( Type::Qualifiers(), false );
        main_type->get_returnVals().push_back( signedIntObj() );
        main_type->get_parameters().push_back( signedIntObj() );
        main_type->get_parameters().push_back( charStarObj() );
        return create_mangled_main_function_name( main_type );
}

bool is_main( const std::string & mangled_name ) {
        // This breaks if you move it out of the function.
        static const std::string mangled_mains[] = {
                mangled_0_argument_main(),
                mangled_2_argument_main(),
                //mangled_3_argument_main(),
        };

        for ( auto main_name : mangled_mains ) {
                if ( main_name == mangled_name ) return true;
        }
        return false;
}

struct FindMainCore {
        void previsit( FunctionDecl * decl ) {
                if ( FixMain::isMain( decl ) ) {
                        FixMain::registerMain( decl );
                }
        }
};

} // namespace

bool FixMain::isMain( FunctionDecl * decl ) {
        if ( std::string("main") != decl->name ) {
                return false;
        }
        return is_main( SymTab::Mangler::mangle( decl, true, true ) );
}

bool FixMain::isMain( const ast::FunctionDecl * decl ) {
        if ( std::string("main") != decl->name ) {
                return false;
        }
        return is_main( Mangle::mangle( decl, Mangle::Type ) );
}

void FixMain::findMain( std::list< Declaration * > & translationUnit ) {
        PassVisitor< FindMainCore > mainFinder;
        acceptAll( translationUnit, mainFinder );
}

};