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//{{{  Banner                                   

//============================================================================

//

//     parse.cxx

//

//     Miscellaneous parsing routines

//

//============================================================================

//####COPYRIGHTBEGIN####

//                                                                          

// ----------------------------------------------------------------------------

// Copyright (C) 2002 Bart Veer

// Copyright (C) 1999, 2000 Red Hat, Inc.

//

// This file is part of the eCos host tools.

//

// This program is free software; you can redistribute it and/or modify it 

// under the terms of the GNU General Public License as published by the Free 

// Software Foundation; either version 2 of the License, or (at your option) 

// any later version.

// 

// This program is distributed in the hope that it will be useful, but WITHOUT 

// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 

// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for 

// more details.

// 

// You should have received a copy of the GNU General Public License along with

// this program; if not, write to the Free Software Foundation, Inc., 

// 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

//

// ----------------------------------------------------------------------------

//                                                                          

//####COPYRIGHTEND####

//============================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):   bartv

// Contact(s):  bartv

// Date:        1999/02/23

// Version:     0.02

//

//####DESCRIPTIONEND####

//============================================================================

//}}}

//{{{  #include's                               

// ----------------------------------------------------------------------------

#include "cdlconfig.h"

// Get the infrastructure types, assertions, tracing and similar

// facilities.

#include <cyg/infra/cyg_ass.h>

#include <cyg/infra/cyg_trac.h>

// <cdlcore.hxx> defines everything implemented in this module.

// It implicitly supplies <string>, <vector> and <map> because

// the class definitions rely on these headers.

#include <cdlcore.hxx>

//}}}

//{{{  Description                              

// ----------------------------------------------------------------------------

// All CDL data is read via a Tcl interpreter, so the parsing is done by

// procedures that appear as Tcl commands. This has obvious advantages in

// terms of expressive power, but does result in a little bit of confusion

// when producing diagnostics.

//

// Errors should not bypass the Tcl interpreter, to ensure that that

// stays in a consistent state. In particular it is not possible to let

// arbitrary C++ exceptions to go straight through the Tcl interpreter,

// this is likely to result in a corrupted interpreter.

// 

// Also, it is not a good idea to abort parsing as soon as anything

// goes wrong. Instead there should be an error handling callback associated

// with the interpreter, which can be used to report errors. This

// callback may choose to raise an exception.

//

// Consider the case of parsing a property (which accounts for most of

// the code in this module). A property does not exist in isolation,

// only within the context of a suitable CDL entity such as an option.

// If parsing succeeds and a property object is created then it must

// be added to the current CDL entity.

//

// Therefore a typical parse routine looks like this:

//

//  1) get the current CDL node from the interpreter

//  2) do basic parsing of the data. Any errors should be reported

//     via the callback.

//  3) create a suitable CdlProperty object

//  4) add the property to the current entity

//

// std::bad_alloc and CdlStringException exceptions can be thrown, they

// will be intercepted by the CdlInterpreter class.

//}}}

//{{{  Statics                                  

// ----------------------------------------------------------------------------

// The string "property " is needed in various places. Provide it as a static

// to cut down the number of times the string constructor has to run.

static std::string property_string = "property ";

//}}}

//{{{  Generic parsing-related utilities        

//{{{  argv manipulation                        

// ----------------------------------------------------------------------------

// Some of the properties have aliases in the CDL data, so argv[0] has to be

// used to work out what is actually being parsed. However the Tcl interpreter

// may prefix the command name with :: to indicate the global namespace.

std::string

CdlParse::get_tcl_cmd_name(std::string name)

{

    std::string result;

    if ((name[0] == ':') && (name[1] == ':')) {

        result = std::string(name, 2, name.size() - 2);

    } else {

        result = name;

    }

    return result;

}

// Given a list of arguments, concatenate them together into a C++ string.

// This makes expression parsing easier. The final argument should be an

// index into the array, typically the result of a call to skip_argv_options().

std::string

CdlParse::concatenate_argv(int argc, const char* argv[], int index)

{

    CYG_REPORT_FUNCNAME("CdlParse::concatenate_argv");

    std::string result = "";

    for ( int i = index ; i < argc; i++) {

        if (i > index) {

            result += ' ';

        }

        result += std::string(argv[i]);

    }

    CYG_REPORT_RETURN();

    return result;

}

// ----------------------------------------------------------------------------

// Option parsing.

//

// Some properties accept modifiers in their argument list. For example,

// by default a "compile" property is just a list of source files that

// should be compiled and added to the current library. It is possible

// to specify an alternative library via a modifier:

//

//    ...

//    compile -library=libextras.a dummy.cxx

//    ...

//

// The rules applied for such options are intended to follow common Tcl

// practice:

//

// 1) any initial arguments beginning with a - are assumed to be

//    options.

//

// 2) the first argument which does not begin with a - stops option

//    processing.

//

// 3) option processing can also be terminated with a -- argument.

//    This may occasionally be required, e.g. to have -ve constants

//    in an expression.

//

// 4) the parsing code does not distinguish between single and double

//    hyphens. If there happens to be a second - in an option then this

//    is just ignored.

//

// 5) it is not necessary to supply the whole option name, as long as

//    what is provided is unambiguous. For example -lib=libextras.a is

//    acceptable (for now anyway, conceivably it would break in future).

//    Option processing is case sensitive.

//

// 6) name/value pairs can take the form -name=value or the form

//    -name value, whichever is appropriate.

//

// The parse_options() function takes the current interpreter (so that

// it can generate diagnostics), a prefix such as `property

// "requires"' or `package CYGPKG_HAL', details of the options to be

// parsed, an argc/argv list, an index, and a reference to a vector.

// The parsed options get placed in the vector, and the index argument

// gets updated to point at the first non-option argument. It will

// report problems via report_warning().

//

// The options description consists of a pointer to an array of

// C strings (allowing static initialization). Passing a zero

// argument indicates that the property takes no options. Otherwise

// the array should be zero terminated.

//

// Each entry in the array takes the form "name:flags". The optional

// flags consist of zero or more characters indicating how the option

// should be interpreted. Valid flags are:

//

// f    - this option takes no data, it is just a boolean flag. The

//        default behaviour assumes name/value pairs.

//

// m    - this option can occur multiple times. The default behaviour

//        is that each option can only occur once.

// Utility function to get hold of an option name without the colon

// or terminating flags.

static std::string

get_option_string(char* name)

{

    std::string result = "";

    while ((*name != ':') && (*name != '\0')) {

        result += *name++;

    }

    return result;

}

int

CdlParse::parse_options(CdlInterpreter interp, std::string diag_prefix, char** options,

                                 int argc, const char* argv[], int index,

                                 std::vector<std::pair<std::string,std::string> >& result)

{

    CYG_REPORT_FUNCNAMETYPE("CdlParse::parse_options", "final index %d");

    CYG_REPORT_FUNCARG4XV(interp, options, argc, argv);

    CYG_PRECONDITION_CLASSC(interp);

    CYG_PRECONDITIONC(argc > 0);        // The property name must be present.

    // It is possible for some of the arguments to have been processed already.

    CYG_PRECONDITIONC((index > 0) && (index <= argc));

    while((index < argc) && ('-' == argv[index][0])) {

        std::string name  = "";

        std::string value = "";

        // The sequence -- should always terminate option processing.

        if (0 == strcmp(argv[index], "--")) {

            index++;

            break;

        }

        const char* arg_ptr       = argv[index];

        // Skip the initial -, and the second one as well if it is present.

        if ('-' == *++arg_ptr) {

            arg_ptr++;

        }

        // Construct the option name. This is the current argument up

        // to but not including the '=' character or EOD.

        while (('=' != *arg_ptr) && ('\0' != *arg_ptr)) {

            name += *arg_ptr++;

        }

        if ("" == name) {

            // One of "-", "-=xxx", or "--=x"

            CdlParse::report_warning(interp, diag_prefix, std::string("Invalid option string `") + argv[index] + "'.");

        }

        // Do not try to extract the value unless we are sure there

        // should be one. Instead try to match the option name. The

        // current value of name should be a unique substring of

        // one of the known option strings.

        //

        // Note that the supplied options descriptor can be NULL,

        // since most properties do not yet take any options.

        // In that case opt_index will remain at -1, and we should

        // get an "invalid option" diagnostic.

        unsigned int i;

        int opt_index = -1;

        if (0 != options) {

            for (i = 0; 0 != options[i]; i++) {

                if (0 == strncmp(name.c_str(), options[i], name.size())) {

                    if (-1 != opt_index) {

                        CdlParse::report_warning(interp, diag_prefix,

                                                 std::string("Ambiguous option name `") + name + "'.\n" +

                                                 "It can match `" + get_option_string(options[opt_index]) + "'\n" +

                                                 "or `" + get_option_string(options[i]) + "'.");

                        index++;

                        break;

                    } else {

                        opt_index = i;

                    }

                }

            }

        }

        if (-1 == opt_index) {

            CdlParse::report_warning(interp, diag_prefix, std::string("Invalid option `") + name + "'.");

            index++;

            break;

        }

        // The option has been identified successfully. Extract the flags.

        bool    flag_flag       = false;

        bool    multiple_flag   = false;

        char*   tmp = options[opt_index];

        while (('\0' != *tmp) && (':' != *tmp)) {

            tmp++;

        }

        if (':' == *tmp) {

            do {

                tmp++;

                if ('f' == *tmp) {

                    flag_flag = true;

                } else if ('m' == *tmp) {

                    multiple_flag = true;

                } else if ('\0' != *tmp) {

                    CYG_FAIL("Invalid property option");

                }

            } while ('\0' != *tmp);

        }

        // We now know the full option name. Use it for future diagnostics.

        name = get_option_string(options[opt_index]);

        // Take care of the value.

        if (flag_flag) {

            // There should not be a value. If the current argument is of the

            // form x=y then this is an error.

            if ('=' == *arg_ptr) {

                CdlParse::report_warning(interp, diag_prefix,  std::string("Option `") + name + "' does not take any data.");

            }

            // Leave index pointing at the next argument to be processed.

            index++;

        } else {

            if ('=' == *arg_ptr) {

                value = std::string(++arg_ptr);

            } else if (++index == argc) {

                CdlParse::report_warning(interp, diag_prefix,  std::string("Missing data for option `") + name + "'.");

            } else {

                value = argv[index];

            }

            index++;

        }

        // At this stage index points at the next argument to be processed, and should not

        // be updated again.

        // Unless the option can occur multiple times, make sure that it is not already

        // present in the options vector.

        if (!multiple_flag) {

            for (i = 0; i < result.size(); i++) {

                if (name == result[i].first) {

                    CdlParse::report_warning(interp, diag_prefix, std::string("Option `") + name + "' can only be used once.");

                    break;

                }

            }

        }

        // The name/value pair is valid, so add it to the result vector.

        result.push_back(std::make_pair(name, value));

    }

    CYG_REPORT_RETVAL(index);

    return index;

}

//}}}

//{{{  Diagnostic construction                  

// Construct a suitable diagnostic for a parsing error. This may occur

// when reading in a CDL script, a savefile, a database, or anything

// similar. 

//

// A diagnostic should take the following form:

//

//     <context> <linenumber> [, <node identifier>] [, <extra identifier>] : [<classification>, ] <message>

//

// The context should be set in the Tcl interpreter. Typically it

// will be a filename.

//

// In practice generating the line number is not really feasible at

// 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, const 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");