parse.cxx

eCos1.31版

//{{{  Banner                                   

//============================================================================
//
//     parse.cxx
//
//     Miscellaneous parsing routines
//
//============================================================================
//####COPYRIGHTBEGIN####
//                                                                          
// ----------------------------------------------------------------------------
// 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.
const char*
CdlParse::get_tcl_cmd_name(const char* name)
{
    if ((name[0] == ':') && (name[1] == ':')) {
        return &(name[2]);
    } else {
        return name;
    }
}

// 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, 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, 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;
        }

        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 + ", 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 + ", ambiguous option name " + name +
                                                 ", it can match " + get_option_string(options[opt_index]) +
                                                 " or " + get_option_string(options[i]));
                        index++;
                        break;
                    } else {
                        opt_index = i;
                    }
                }
            }
        }
        if (-1 == opt_index) {
            CdlParse::report_warning(interp, diag_prefix + ", 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 + ", 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 + ", missing data for option " + name);