config.cxx

eCos1.31版

//
//  3) create the package object, and add it to the toplevel of the current
//     configuration. It may get reparented later on. Part of the creation
//     process is to allocate a new slave interpreter, which can be updated
//     with various bits of information.
//
//  4) evaluate the toplevel script. Subsidiary component scripts will
//     get evaluated as a side effect. The various nodes will be added
//     to the hierarchy as they are created, but no property binding
//     happens yet.
//
//     Any failure up to this point should result in the entire package
//     being removed from the hierarchy and then destroyed, thus leaving
//     the configuration in its original state.
//
//  5) now property binding needs to take place. This can have lots
//     of side effects, e.g. default values may get calculated, the
//     hierarchy may change because of parent properties, etc.
//     The work is done inside CdlLoadable::bind() which will undo
//     everything on failure - although bad_alloc is the only
//     failure that should occur.
//
//  6) load operations can get cancelled, so a suitable commit/cancel
//     operation needs to allocated and added to the transaction.
//
//  7) if limbo is enabled, previous values should be extracted from
//     limbo if at all possible. In addition the package's value can
//     be set to its version.

void
CdlConfigurationBody::load_package(CdlTransaction transaction, std::string name, std::string version,
                                   CdlDiagnosticFnPtr error_fn, CdlDiagnosticFnPtr warn_fn, bool limbo)
    throw(CdlInputOutputException, CdlParseException, std::bad_alloc)
{
    CYG_REPORT_FUNCNAME("CdlConfiguration::load_package");
    CYG_REPORT_FUNCARG1XV(this);
    CYG_PRECONDITION_THISC();
    CYG_PRECONDITION_CLASSC(transaction);
    CYG_PRECONDITIONC("" != name);

    // Locate the database entry. Also check the version (filling it in if necessary).
    // Get hold of the package directory and the initial script.
    if (!database->is_known_package(name)) {
        throw CdlInputOutputException("Unknown package " + name);
    }
    const std::vector<std::string>& versions = database->get_package_versions(name);
    if ("" == version) {
        version = *(versions.begin());
    } else {
        if (std::find(versions.begin(), versions.end(), version) == versions.end()) {
            throw CdlInputOutputException("Package " + name + " does not have an installed version " + version);
        }
    }
    std::string directory       = database->get_package_directory(name);
    std::string script          = database->get_package_script(name);
    CYG_ASSERTC(("" != directory) && ("" != script));

    // Check that the directory actually exists. For this the configuration's own
    // interpreter can be used.
    CdlInterpreter interp = get_interpreter();
    CYG_ASSERT_CLASSC(interp);

    std::string tcl_cmd = "regsub -all -- {\\\\} [file join " + directory + " " + version + "] / result; return $result";
    std::string tcl_result;
    if (TCL_OK != interp->eval(tcl_cmd, tcl_result)) {
        throw CdlInputOutputException("Cannot load package " + name + ", internal error constructing pathname");
    }
    directory = tcl_result;
    
    tcl_cmd   = "file isdirectory [file join \"" + database->get_component_repository() + "\" " + directory + "]";
    if ((TCL_OK != interp->eval(tcl_cmd, tcl_result)) || ("1" != tcl_result)) {
        throw CdlInputOutputException("Cannot load package " + name + ", there is no directory " + directory);
    }
    
    // Make sure that there is no name conflict. No resources have been allocated
    // yet, so this is a good time.
    CdlNode node = lookup(name);
    if (0 != node) {
        if (0 != dynamic_cast<CdlPackage>(node)) {
            throw CdlInputOutputException("Package " + name + " is already loaded");
        } else {

            std::string msg = "Name clash for package " + name + ",there is a " +
                node->get_class_name() + " " + name + " already loaded";
            CdlLoadable owner_pkg = node->get_owner();
            if (0 != owner_pkg) {
                msg += " in package " + owner_pkg->get_name();
            }
            throw CdlInputOutputException(msg);
        }
    }
    
    // Now create the package object itself.
    CdlPackage package  = 0;
    bool       bound    = false;
    CdlConfiguration_CommitCancelLoad* load_op  = 0;
    
    try {
        package = new CdlPackageBody(name, this, directory);

        // The package should be added to the hierarchy immediately.
        // All nodes will get added to the hierarchy as they are
        // created, an operation that has to be undone during
        // failure. 
        this->add_node(package, this, package);
        
        // Load the package data. The various nodes will all end up
        // in a hierarchy below the package, but without any checks
        // for name conflicts etc and ignoring any re-parenting.
        CdlInterpreter interp = package->get_interpreter();
        CYG_ASSERT_CLASSC(interp);

        interp->add_command("unknown", &CdlParse::unknown_command);
        
        // Next figure out the script name, and make sure that it exists.
        std::string actual_script = package->find_absolute_file(script, "cdl");
        if ("" == actual_script) {
            throw CdlInputOutputException("Package " + name + ", unable to find initial script " + script);
        }
        tcl_cmd = "file isfile \"" + actual_script + "\"";
        if ((TCL_OK != interp->eval(tcl_cmd, tcl_result)) || ("1" != tcl_result)) {
            throw CdlInputOutputException("Package " + name + ", " + actual_script + " is not a CDL script");
        }

        // The script is valid. Set up the interpreter appropriately.
        CdlContainer old_container      = interp->push_container(package);
        std::string old_filename        = interp->push_filename(actual_script);
        CdlDiagnosticFnPtr old_error_fn = interp->push_error_fn_ptr(error_fn);
        CdlDiagnosticFnPtr old_warn_fn  = interp->push_warning_fn_ptr(warn_fn);
        CdlParse::clear_error_count(interp);

        static CdlInterpreterCommandEntry commands[] =
        {
            CdlInterpreterCommandEntry("cdl_package",    &CdlPackageBody::parse_package     ),
            CdlInterpreterCommandEntry("cdl_component",  &CdlComponentBody::parse_component ),
            CdlInterpreterCommandEntry("cdl_option",     &CdlOptionBody::parse_option       ),
            CdlInterpreterCommandEntry("cdl_interface",  &CdlInterfaceBody::parse_interface ),
            CdlInterpreterCommandEntry("cdl_dialog",     &CdlDialogBody::parse_dialog       ),
            CdlInterpreterCommandEntry("cdl_wizard",     &CdlWizardBody::parse_wizard       ),
            CdlInterpreterCommandEntry("",               0                                  )
        };
        std::vector<CdlInterpreterCommandEntry> new_commands;
        for (int i = 0; 0 != commands[i].command; i++) {
            new_commands.push_back(commands[i]);
        }
        std::vector<CdlInterpreterCommandEntry>* old_commands = interp->push_commands(new_commands);
        
        // The interpreter is now ready.
        if (TCL_OK != interp->eval_file(actual_script, tcl_result)) {
            throw CdlInputOutputException("Package " + name + ", error executing CDL script.\n" + tcl_result);
        }

        // Clean out the commands etc. This interpreter may get used again
        // in future, and it should not be possible to define new options
        // etc. in that invocation.
        interp->remove_command("unknown");
        interp->pop_commands(old_commands);
        interp->pop_container(old_container);
        interp->pop_filename(old_filename);
        interp->pop_error_fn_ptr(old_error_fn);
        interp->pop_warning_fn_ptr(old_warn_fn);
        
        // All the data has been read in without generating an
        // exception. However there may have been errors reported via
        // the parse_error_fn, and any errors at all should result
        // in an exception.
        int error_count = CdlParse::get_error_count(interp);
        if (error_count > 0) {
            std::string tmp;
            Cdl::integer_to_string(error_count, tmp);
            throw CdlParseException("Package " + name + ", " + tmp + " error" +
                                    ((error_count > 1) ? "s" : "") +
                                    " occurred while reading in the CDL data.");
        }

        // All the data has been read in, implying that there are no
        // fatal problems with the data. Now try to bind all
        // references to and from this loadable.
        package->bind(transaction);
        bound = true;

        // Finally, create a suitable transaction commit/cancel object
        // and add it to the transaction.
        load_op = new CdlConfiguration_CommitCancelLoad(package);
        transaction->add_commit_cancel_op(load_op);
        
    } catch (...) {

        // Something went wrong during the create or load. It is necessary
        // to delete the package. Undo all the operations above, in
        // reverse order. The add_commit_cancel_op() was the last step,
        // so need not be undone here.
        if (0 != load_op) {
            delete load_op;
        }
        
        if (0 != package) {
            // Note: no attempt is made to recover from errors here
            if (bound) {
                package->unbind(transaction);
            }
            this->remove_loadable_from_toplevel(package);
            delete package;
        } 
        throw;
    }

    // FIXME: implement limbo support
    
    // We also have a sensible value for the package as a whole.
    // Use this value for both default and user - after all the
    // user has selected the package.
    package->enable_and_set_value(transaction, version, CdlValueSource_Default);
    package->enable_and_set_value(transaction, version, CdlValueSource_User);

    CYG_REPORT_RETURN();
}

//}}}
//{{{  CdlConfiguration::unload_package()               

// ----------------------------------------------------------------------------
// Unloading a package is very simple. If requested, save all current
// values to limbo: there is no point in saving default values, these
// will get recalculated from the default_value property anyway;
// inferred values should be saved, there is no guarantee that the exact
// same value will be calculated again, and if the inferred value is no
// longer correct then the inference engine can freely update it.
//
// Next, unbind the package and remove it from the hierarchy. These
// operations are reversible if the transaction gets cancelled.
// A suitable transaction commit/cancel object is created and
// added to the transaction.
void
CdlConfigurationBody::unload_package(CdlTransaction transaction, CdlPackage package, bool limbo)
{
    CYG_REPORT_FUNCNAME("CdlConfiguration::unload_package");
    CYG_REPORT_FUNCARG4XV(this, transaction, package, limbo);
    CYG_INVARIANT_THISC(CdlConfigurationBody);
    CYG_INVARIANT_CLASSC(CdlTransactionBody, transaction);
    CYG_PRECONDITION_CLASSC(package);

    if (limbo) {
        const std::vector<CdlNode>& pkg_contents = package->get_owned();
        std::vector<CdlNode>::const_iterator node_i;

        for (node_i = pkg_contents.begin(); node_i != pkg_contents.end(); node_i++) {
            CdlValuable valuable = dynamic_cast<CdlValuable>(*node_i);
            if (0 != valuable) {
                if (valuable->has_source(CdlValueSource_Inferred) ||
                    valuable->has_source(CdlValueSource_Wizard)   ||
                    valuable->has_source(CdlValueSource_User)) {
                    
                    set_limbo_value(valuable);
                }
            }
        }
    }

    bool unbound = false;
    bool removed = false;
    CdlConfiguration_CommitCancelUnload* unload_op = 0;
    try {
        
        package->unbind(transaction);
        unbound = true;
        this->remove_loadable_from_toplevel(package);
        removed = true;
        unload_op = new CdlConfiguration_CommitCancelUnload(package);
        transaction->add_commit_cancel_op(unload_op);
        
    } catch(...) {
        if (0 != unload_op) {
            delete unload_op;
        }
        if (removed) {
            this->add_loadable_to_toplevel(package);
        }
        if (unbound) {
            package->bind(transaction);
        }
        throw;
    }
    
    CYG_REPORT_RETURN();
}

//}}}
//{{{  CdlConfiguration::change_package_version()       

// ----------------------------------------------------------------------------
// Changing a package version is just a case of unloading the old version
// and then loading in the new version. Because this all happens in the
// context of a transaction it is possible to undo the unload on
// failure, and the whole transaction can be cancelled at a higher level.

void
CdlConfigurationBody::change_package_version(CdlTransaction transaction, CdlPackage package, std::string new_version,
                                             CdlDiagnosticFnPtr error_fn, CdlDiagnosticFnPtr warn_fn, bool limbo)
    throw(CdlInputOutputException, CdlParseException, std::bad_alloc)
{
    CYG_REPORT_FUNCNAME("CdlConfiguration::change_package_version");
    CYG_REPORT_FUNCARG3XV(this, transaction, package);
    CYG_PRECONDITION_THISC();
    CYG_INVARIANT_CLASSC(CdlTransactionBody, transaction);
    CYG_PRECONDITION_CLASSC(package);
    // "" is valid for the version, it indicates the default

    // Since the package is already loaded it must be in the database,
    // but it is possible that the desired version does not exist.
    std::string name = package->get_name();
    const std::vector<std::string>& pkg_versions = database->get_package_versions(name);
    if ("" == new_version) {
        new_version = *(pkg_versions.begin());
    } else if (std::find(pkg_versions.begin(), pkg_versions.end(), new_version) == pkg_versions.end()) {
        throw CdlInputOutputException("Version " + new_version + " of package " + name + " is not installed.");
    }

    bool unloaded = false;
    try {
        this->unload_package(transaction, package, limbo);
        unloaded = true;
        this->load_package(transaction, name, new_version, error_fn, warn_fn, limbo);
    } catch(...) {
        if (unloaded) {
            // There should be a commit/cancel op for the unload package step.
            // This can be undone.
            CdlTransactionCommitCancelOp* unload_op = transaction->get_last_commit_cancel_op();
            CYG_ASSERTC(0 != unload_op);
            CYG_ASSERTC(0 != dynamic_cast<CdlConfiguration_CommitCancelUnload*>(unload_op));
            transaction->cancel_last_commit_cancel_op();
            CYG_UNUSED_PARAM(CdlTransactionCommitCancelOp*, unload_op);
        }
        throw;
    }

    CYG_REPORT_RETURN();
}

//}}}
//{{{  CdlConfiguration::set_hardware() etc.            

// ----------------------------------------------------------------------------
// Setting the hardware involves unloading the old hardware, if any, and
// then loading in the new one. Obviously this should only happen if
// the new hardware name is valid. It would be possible to optimise for
// the case where the old and new hardware are the same, subject
// to dynamic database reload support.

void
CdlConfigurationBody::set_hardware(CdlTransaction transaction, std::string target_name,