parse.cxx

移植到WLIT项目的redboot源代码

// present, the Tcl interpreter does not keep track of sufficient
// information. At least, not in the public data structures, there is
// a termOffset field in the internal data structures which might
// be used to do the right thing. I do not want to start relying
// on Tcl internals just yet, or add support to the Tcl core for
// keeping track of line numbers.
//
// For many data files there will the concept of a current node,
// e.g. an option whose properties or savefile information are
// being processed. The CdlInterpreter class keeps track of the
// current node, so if it is defined then the node's class and
// name can be part of the message. This happens automatically,
// no effort is required on the part of calling code.
//
// There may also be additional information, for example
// identifying the specific property where the error was detected.
// This is handled by an extra argument.
//
// The classification is likely to be something like "warning",
// "error", or "internal error". It is controlled by the calling
// code, but typically it is provided by calling via report_warning()
// etc.
//
// The message should identify the actual error. It should be
// a proper sentence, i.e. begin with a capital error and end with
// a full stop, unless the last word is an identifier or filename
// or something similarly special in which case the trailing
// dot will be discarded. The message should not end with a
// newline character, and the result string will not end with one
// either. That is left to higher level code.

std::string
CdlParse::construct_diagnostic(CdlInterpreter interp, std::string classification, std::string sub_id, std::string message)
{
    CYG_REPORT_FUNCNAME("CdlParse::construct_diagnostic");
    CYG_PRECONDITION_CLASSC(interp);

    std::string context      = interp->get_context();
    CdlNode     current_node = interp->get_node();

    std::string result;
    if ("" == context) {
        result = "<unknown context>";
    } else {
        result = context;
    }
    if (0 != current_node) {
        result += ", " + current_node->get_class_name() + " " + current_node->get_name();
    }
    if ("" != sub_id) {
        result += ", " + sub_id;
    }
    result += ": " + classification;
    
    // Now it is time to start worrying about layout, indenting
    // subsequent lines, and so on.
    int index        = result.length();
    int message_len  = message.length();
    int message_index;
    bool indent_needed = false;

    // Find out how many characters there are in the message up to the first newline
    for (message_index = 0; (message_index < message_len) && ('\n' != message[message_index]); message_index++) {
        ;
    }

    // Should the message start on the next line, suitably indented?
    // This depends in part on whether or not there was a classification.
    if ("" == classification) {
        // The current result ends with a colon and a space.
        if ((index + message_index) <= 72) {
            // The first line of the message can still fit. No need to do anything.
        } else {
            // Start indenting immediately, do not add anything else to the current line.
            indent_needed = true;
        }
    } else {
        // We may want a comma and a space after the classification
        if ((index + 2 + message_index) <= 72) {
            result += ", ";
        } else {
            indent_needed = true;
        }
    }

    // Now we can process the message one character at a time, adding
    // newlines and indentation just in time.
    for (message_index = 0; message_index < message_len; message_index++) {
        if (indent_needed) {
            result += "\n    ";
            indent_needed = false;
        }

        if ('\n' == message[message_index]) {
            indent_needed = true;
        } else {
            result += message[message_index];
        }
    }

    CYG_REPORT_RETURN();
    return result;
}

//}}}
//{{{  Error count tracking                     

// Keep track of the number of errors that have occurred while doing some
// parsing. This functionality is not provided directly by the CdlInterpreter
// class, instead it is implemented using assoc data.

static const char       error_count_key[]       = "CdlErrorCount";

static void
error_count_delproc(ClientData data, Tcl_Interp* interp)
{
    CYG_REPORT_FUNCNAME("CdlParse::error_count_delproc");
    int* newed_ptr = static_cast<int*>(data);
    delete newed_ptr;
    CYG_REPORT_RETURN();
}

void
CdlParse::clear_error_count(CdlInterpreter interp)
{
    CYG_REPORT_FUNCNAME("CdlParse::clear_error_count");
    CYG_REPORT_FUNCARG1("interp %p", interp);
    CYG_PRECONDITION_CLASSC(interp);

    int*        newed_ptr = static_cast<int*>(interp->get_assoc_data(error_count_key));
    if (0 != newed_ptr) {
        *newed_ptr = 0;
    }

    CYG_REPORT_RETURN();
}

void
CdlParse::incr_error_count(CdlInterpreter interp, int how_much)
{
    CYG_REPORT_FUNCNAME("CdlParse::incr_error_counter");
    CYG_REPORT_FUNCARG2("interp %p, how_much %d", interp, how_much);
    CYG_PRECONDITION_CLASSC(interp);
    CYG_PRECONDITION(how_much > 0, "previous errors cannot be undone");
    
    int* newed_ptr = static_cast<int*>(interp->get_assoc_data(error_count_key));
    if (0 == newed_ptr) {
        newed_ptr = new int(how_much);
        interp->set_assoc_data(error_count_key, static_cast<void*>(newed_ptr), &error_count_delproc);
    } else {
        CYG_ASSERT((*newed_ptr + how_much) > *newed_ptr, "number of parsing errors should not overflow");
        *newed_ptr += how_much;
    }

    CYG_REPORT_RETURN();
}

int
CdlParse::get_error_count(CdlInterpreter interp)
{
    CYG_REPORT_FUNCNAMETYPE("CdlParse::get_error_count", "count %d");
    CYG_REPORT_FUNCARG1("interp %p", interp);
    CYG_PRECONDITION_CLASSC(interp);

    int result = 0;
    int* newed_ptr = static_cast<int*>(interp->get_assoc_data(error_count_key));
    if (0 != newed_ptr) {
        result = *newed_ptr;
    }

    CYG_REPORT_RETVAL(result);
    return result;
}

//}}}
//{{{  Error and warning reporting              

// Report errors and warnings. These will be called during parsing
// operations, both of CDL and similar data scripts and for savefiles.
// The parsing involves running a Tcl interpreter extended with the
// appropriate set of commands. Typically the call graph will look
// something like this:
//
//     libcdl C++ code such as load_package()
//     libcdl CdlInterpreter::eval()
//     Tcl interpreter
//     libcdl parsing code
//     report_error()
//     
// If the Tcl script is invalid then parsing errors may get reported
// at the higher level code as well.
//
// There are two classes of diagnostic: errors and warnings.
// Additional levels may be added in future, but there does not seem
// to be an urgent need for them. Client code should provide callback
// functions so that the messages can be displayed to the user, and
// these callbacks will be registered with the current CdlInterpreter.
//
// If no error callback is defined then a ParseException will be
// raised instead, and the rest of the current script will not be
// processed. Alternatively the error callback itself can raise a
// ParseException. Care is taken to ensure that the exception does not
// go straight through the Tcl interpreter, since that would prevent
// the Tcl code from cleaning up appropriately. If no exception is
// raised then the library keeps track of the number of errors, and
// this information is accessible once the script has been fully
// processed. This allows multiple errors to be reported in a single
// run.
//
// If no warning callback is provided then warnings are ignored.

void
CdlParse::report_error(CdlInterpreter interp, std::string sub_id, std::string message)
{
    CYG_REPORT_FUNCNAME("CdlParse::report_error");
    CYG_REPORT_FUNCARG1("interp %p", interp);
    CYG_PRECONDITION_CLASSC(interp);

    incr_error_count(interp);

    std::string full_message = construct_diagnostic(interp, "error", sub_id, message);

    // Now, either invoke the callback if it is provided, or throw the exception.
    CdlDiagnosticFnPtr fn = interp->get_error_fn_ptr();
    if (0 == fn) {
        throw CdlParseException(full_message);
    } else {
        (*fn)(full_message);
    }
    
    CYG_REPORT_RETURN();
}

void
CdlParse::report_warning(CdlInterpreter interp, std::string sub_id, std::string message)
{
    CYG_REPORT_FUNCNAME("CdlParse::report_warning");
    CYG_REPORT_FUNCARG1("interp %p", interp);
    CYG_PRECONDITION_CLASSC(interp);

    // If there is no warning callback, do nothing. This is really a
    // bug in the calling application.
    CdlDiagnosticFnPtr fn = interp->get_warning_fn_ptr();
    if (0 != fn) {
        std::string full_message = construct_diagnostic(interp, "warning", sub_id, message);
        (*fn)(full_message);
    }

    CYG_REPORT_RETURN();
}

//}}}
//{{{  The "unknown" command                    

// ----------------------------------------------------------------------------
// This routine should be installed in interpreters that get used for
// parsing CDL scripts. It gets invoked when the CDL script contains
// an unrecognised command, e.g. because of a typo, and makes sure that
// the usual diagnostics process is observed.
//
// This routine should be uninstalled after the parsing is complete,
// to avoid e.g. a ParseException when it is not expected.
int
CdlParse::unknown_command(CdlInterpreter interp, int argc, char** argv)
{
    CYG_REPORT_FUNCNAME("CdlParse::unknown_command");
    CYG_REPORT_FUNCARG3XV(interp, argc, argv);
    CYG_PRECONDITIONC(2 <= argc);
    CYG_PRECONDITION_CLASSC(interp);

    report_error(interp, "", std::string("Unknown command `") + argv[1] + "'.");
    CYG_UNUSED_PARAM(int, argc);
    
    return TCL_OK;
}

//}}}

//}}}
//{{{  Property-related parser utilities        

// ----------------------------------------------------------------------------
// Utilities related to parsing properties, rather than more general parsing.

// A variant of report_parse_error() which also adds the property prefix.
void
CdlParse::report_property_parse_error(CdlInterpreter interp, std::string argv0, std::string msg)
{
    CYG_REPORT_FUNCNAME("CdlPase::report_property_parse_error");

    incr_error_count(interp);
    
    std::string diag = construct_diagnostic(interp, "error",
                                            std::string("property ") + CdlParse::get_tcl_cmd_name(argv0),
                                            msg);

    // Now, either invoke the callback if it is provided, or throw the exception.
    CdlDiagnosticFnPtr fn = interp->get_error_fn_ptr();
    if (0 == fn) {
        throw CdlParseException(diag);
    } else {
        (*fn)(diag);
    }
    
    CYG_REPORT_RETURN();
}

void
CdlParse::report_property_parse_error(CdlInterpreter interp, CdlProperty prop, std::string msg)
{
    CYG_REPORT_FUNCNAME("CdlParse::report_property_parse_error");
    report_property_parse_error(interp, (prop->get_argv())[0], msg);
    CYG_REPORT_RETURN();
}

// Repeat for warnings
void
CdlParse::report_property_parse_warning(CdlInterpreter interp, std::string argv0, std::string msg)
{
    CYG_REPORT_FUNCNAME("CdlPase::report_property_parse_warning");

    CdlDiagnosticFnPtr fn = interp->get_error_fn_ptr();
    if (0 != fn) {
        std::string diag = construct_diagnostic(interp, "error",
                                                std::string("property ") + CdlParse::get_tcl_cmd_name(argv0),
                                                msg);
        (*fn)(diag);
    }
    
    CYG_REPORT_RETURN();
}

void
CdlParse::report_property_parse_warning(CdlInterpreter interp, CdlProperty prop, std::string msg)
{
    CYG_REPORT_FUNCNAME("CdlParse::report_property_parse_warning");
    report_property_parse_warning(interp, (prop->get_argv())[0], msg);
    CYG_REPORT_RETURN();
}

//}}}
//{{{  Generic property parsers                 

// ----------------------------------------------------------------------------
// Generic parsers
//
// These routines provide some more generic property parsing routines. argv[0]
// generally provides sufficient information to allow for sensible error messages.
// The command-specific parsers have to provide a property name. In addition it is
// possible to provide a function to handle per-command options, and another
// function that performs a final sanity check before the property gets added
// to the current entity.

//{{{  parse_minimal_property()         

// ----------------------------------------------------------------------------
// A minimal property takes no arguments.

int
CdlParse::parse_minimal_property(CdlInterpreter interp, int argc, char** argv, std::string name,
                                 char** options_desc, void (*final_parser)(CdlInterpreter, CdlProperty_Minimal))
{
    CYG_REPORT_FUNCNAME("parse_minimal_property");
    CYG_PRECONDITION_CLASSC(interp);
    
    CdlProperty_Minimal new_property = 0;
    try {
        std::vector<std::pair<std::string,std::string> > options;
        int data_index = CdlParse::parse_options(interp, property_string + argv[0], options_desc, argc, argv, 1, options);
        
        if (data_index < argc) {
            CdlParse::report_property_parse_error(interp, argv[0], std::string("Unexpected data `") + argv[data_index] + "'.");