Document the predefined __ICARUS__ macro

[iverilog.git] / main.cc

const char COPYRIGHT[] =
          "Copyright (c) 1998-2005 Stephen Williams (steve@icarus.com)";

/*
 *    This source code is free software; you can redistribute it
 *    and/or modify it in source code form 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
 */
#ifdef HAVE_CVS_IDENT
#ident "$Id: main.cc,v 1.95 2007/04/19 02:52:53 steve Exp $"
#endif

# include "config.h"

const char NOTICE[] =
"  This program is free software; you can redistribute it and/or modify\n"
"  it under the terms of the GNU General Public License as published by\n"
"  the Free Software Foundation; either version 2 of the License, or\n"
"  (at your option) any later version.\n"
"\n"
"  This program is distributed in the hope that it will be useful,\n"
"  but WITHOUT ANY WARRANTY; without even the implied warranty of\n"
"  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\n"
"  GNU General Public License for more details.\n"
"\n"
"  You should have received a copy of the GNU General Public License\n"
"  along with this program; if not, write to the Free Software\n"
"  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA\n"
;

# include  <stdio.h>
# include  <iostream>
# include  <fstream>
# include  <queue>
# include  <list>
# include  <map>
# include  <unistd.h>
# include  <stdlib.h>
#if defined(HAVE_TIMES)
# include  <sys/times.h>
#endif
#if defined(HAVE_GETOPT_H)
# include  <getopt.h>
#endif
# include  "pform.h"
# include  "parse_api.h"
# include  "netlist.h"
# include  "target.h"
# include  "compiler.h"

#if defined(__MINGW32__) && !defined(HAVE_GETOPT_H)
extern "C" int getopt(int argc, char*argv[], const char*fmt);
extern "C" int optind;
extern "C" const char*optarg;
#endif

#if defined(__CYGWIN32__) && !defined(HAVE_GETOPT_H)
extern "C" int getopt(int argc, char*argv[], const char*fmt);
extern "C" int optind;
extern "C" const char*optarg;
#endif

/* Count errors detected in flag processing. */
unsigned flag_errors = 0;

const char VERSION[] = "$Name:  $";

const char*basedir = ".";

const char*target = "null";

/*
 * These are the language support control flags. These support which
 * language features (the generation) to support. The generation_flag
 * is a major moce, and the gn_* flags control specifc sub-features.
 */
generation_t generation_flag = GN_DEFAULT;
bool gn_cadence_types_flag = true;
bool gn_specify_blocks_flag = true;

map<string,const char*> flags;
char*vpi_module_list = 0;

map<perm_string,unsigned> missing_modules;
map<string,bool> library_file_map;

list<const char*> library_suff;

list<perm_string> roots;

char*ivlpp_string = 0;

char* depfile_name = NULL;
FILE *depend_file = NULL;

/*
 * These are the warning enable flags.
 */
bool warn_implicit  = false;
bool warn_timescale = false;
bool warn_portbinding = false;

bool error_implicit = false;

/*
 * Debug message class flags.
 */
bool debug_scopes = false;
bool debug_eval_tree = false;
bool debug_elaborate = false;
bool debug_synth2 = false;
/*
 * Verbose messages enabled.
 */
bool verbose_flag = false;

unsigned integer_width = 32;

/*
 * Keep a heap of identifier strings that I encounter. This is a more
 * efficient way to allocate those strings.
 */
StringHeapLex lex_strings;

/*
 * In library searches, Windows file names are never case sensitive.
 */
#if defined(__MINGW32__)
const bool CASE_SENSITIVE = false;
#else
const bool CASE_SENSITIVE = true;
#endif

extern void cprop(Design*des);
extern void synth(Design*des);
extern void synth2(Design*des);
extern void syn_rules(Design*des);
extern void nodangle(Design*des);
#ifdef WITH_T_XNF
extern void xnfio(Design*des);
#endif

typedef void (*net_func)(Design*);
static struct net_func_map {
      const char*name;
      void (*func)(Design*);
} func_table[] = {
      { "cprop",   &cprop },
      { "nodangle",&nodangle },
      { "synth",   &synth },
      { "synth2",  &synth2 },
      { "syn-rules",   &syn_rules },
#ifdef WITH_T_XNF
      { "xnfio",   &xnfio },
#endif
      { 0, 0 }
};

queue<net_func> net_func_queue;

net_func name_to_net_func(const string&name)
{
      for (unsigned idx = 0 ;  func_table[idx].name ;  idx += 1)
            if (name == func_table[idx].name)
                  return func_table[idx].func;

      return 0;
}

const char *net_func_to_name(const net_func func)
{
      for (unsigned idx = 0 ;  func_table[idx].name ;  idx += 1)
            if (func == func_table[idx].func)
                  return func_table[idx].name;

      return "This cannot happen";
}

static void process_generation_flag(const char*gen)
{
      if (strcmp(gen,"1") == 0) {
            generation_flag = GN_VER1995;

      } else if (strcmp(gen,"2") == 0) {
            generation_flag = GN_VER2001;

      } else if (strcmp(gen,"2x") == 0) {
            generation_flag = GN_VER2001X;

      } else if (strcmp(gen,"xtypes") == 0) {
            gn_cadence_types_flag = true;

      } else if (strcmp(gen,"no-xtypes") == 0) {
            gn_cadence_types_flag = false;

      } else if (strcmp(gen,"specify") == 0) {
            gn_specify_blocks_flag = true;
 
      } else if (strcmp(gen,"no-specify") == 0) {
            gn_specify_blocks_flag = false;
 
      } else {
      }
}

static void parm_to_flagmap(const string&flag)
{
      string key;
      const char*value;
      unsigned off = flag.find('=');
      if (off > flag.size()) {
            key = flag;
            value = "";

      } else {
            key = flag.substr(0, off);
            value = strdup(flag.substr(off+1).c_str());
      }

      flags[key] = value;
}

/*
 * Read the contents of a config file. This file is a temporary
 * configuration file made by the compiler driver to carry the bulky
 * flags generated from the user. This reduces the size of the command
 * line needed to invoke ivl.
 *
 * Each line of the iconfig file has the format:
 *
 *      <keyword>:<value>
 *
 * The <value> is all the text after the ':' and up to but not
 * including the end of the line. Thus, white spaces and ':'
 * characters may appear here.
 *
 * The valid keys are:
 *
 *    -y:<dir>
 *    -yl:<dir>
 *    -Y:<string>
 *
 *    -T:<min/typ/max>
 *        Select which expression to use.
 *
 *    -t:<target>
 *        Usually, "-t:dll"
 *
 *    basedir:<path>
 *        Location to look for installed sub-components
 *
 *    debug:<name>
 *        Activate a class of debug messages.
 *
 *    depfile:<path>
 *        Give the path to an output dependency file.
 *
 *    flag:<name>=<string>
 *        Generic compiler flag strings.
 *
 *    functor:<name>
 *        Append a named functor to the processing path.
 *
 *    generation:<1|2|2x|xtypes|no-xtypes|specify|no-specify>
 *        This is the generation flag
 *
 *    ivlpp:<preprocessor command>
 *        This specifies the ivlpp command line used to process
 *        library modules as I read them in.
 *
 *    iwidth:<bits>
 *        This specifies the width of integer variables. (that is,
 *        variables declared using the "integer" keyword.)
 *
 *    library_file:<path>
 *        This marks that a source file with the given path is a
 *        library. Any modules in that file are marked as library
 *        modules.
 *
 *    module:<name>
 *        Load a VPI module.
 *
 *    out:<path>
 *        Path to the output file.
 *
 *    sys_func:<path>
 *        Path to a system functions descriptor table
 *
 *    root:<name>
 *        Specify a root module. There may be multiple of this.
 *
 *    warnings:<string>
 *        Warning flag letters.
 */
static void read_iconfig_file(const char*ipath)
{
      char buf[8*1024];

      FILE*ifile = fopen(ipath, "r");
      if (ifile == 0) {
            cerr << "ERROR: Unable to read config file: " << ipath << endl;
            return;
      }

      while (fgets(buf, sizeof buf, ifile) != 0) {
            if (buf[0] == '#')
                  continue;
            char*cp = strchr(buf, ':');
            if (cp == 0)
                  continue;

            *cp++ = 0;
            char*ep = cp + strlen(cp);
            while (ep > cp) {
                  ep -= 1;
                  switch (*ep) {
                      case '\r':
                      case '\n':
                      case ' ':
                      case '\t':
                        *ep = 0;
                        break;
                      default:
                        ep = cp;
                  }
            }

            if (strcmp(buf, "basedir") == 0) {
                  basedir = strdup(cp);

            } else if (strcmp(buf, "debug") == 0) {
                  if (strcmp(cp, "scope") == 0) {
                        debug_scopes = true;
                        cerr << "debug: Enable scope debug" << endl;
                  } else if (strcmp(cp,"eval_tree") == 0) {
                        debug_eval_tree = true;
                        cerr << "debug: Enable eval_tree debug" << endl;
                  } else if (strcmp(cp,"elaborate") == 0) {
                        debug_elaborate = true;
                        cerr << "debug: Enable elaborate debug" << endl;
                  } else if (strcmp(cp,"synth2") == 0) {
                        debug_synth2 = true;
                        cerr << "debug: Enable synth2 debug" << endl;
                  } else {
                  }

            } else if (strcmp(buf, "depfile") == 0) {
                  depfile_name = strdup(cp);

            } else if (strcmp(buf, "flag") == 0) {
                  string parm = cp;
                  parm_to_flagmap(parm);

            } else if (strcmp(buf,"functor") == 0) {
                net_func tmp = name_to_net_func(cp);
                if (tmp == 0) {
                      cerr << "No such design transform function ``"
                           << cp << "''." << endl;
                      flag_errors += 1;
                      break;
                }
                net_func_queue.push(tmp);

            } else if (strcmp(buf, "generation") == 0) {
                  process_generation_flag(cp);

            } else if (strcmp(buf, "ivlpp") == 0) {
                  ivlpp_string = strdup(cp);

            } else if (strcmp(buf, "iwidth") == 0) {
                  integer_width = strtoul(cp,0,10);

            } else if (strcmp(buf, "library_file") == 0) {
                  const char* path = strdup(cp);
                  library_file_map[path] = true;

            } else if (strcmp(buf,"module") == 0) {
                  if (vpi_module_list == 0) {
                        vpi_module_list = strdup(cp);

                  } else {
                        char*tmp = (char*)realloc(vpi_module_list,
                                                  strlen(vpi_module_list)
                                                  + strlen(cp)
                                                  + 2);
                        strcat(tmp, ",");
                        strcat(tmp, cp);
                        vpi_module_list = tmp;
                  }
                  flags["VPI_MODULE_LIST"] = vpi_module_list;

            } else if (strcmp(buf, "out") == 0) {
                  flags["-o"] = strdup(cp);

            } else if (strcmp(buf, "sys_func") == 0) {
                  load_sys_func_table(cp);

            } else if (strcmp(buf, "root") == 0) {
                  roots.push_back(lex_strings.make(cp));

            } else if (strcmp(buf,"warnings") == 0) {
                    /* Scan the warnings enable string for warning flags. */
                  for ( ;  *cp ;  cp += 1) switch (*cp) {
                      case 'i':
                        warn_implicit = true;
                        break;
                      case 'p':
                        warn_portbinding = true;
                        break;
                      case 't':
                        warn_timescale = true;
                        break;
                      default:
                        break;
                  }

            } else if (strcmp(buf, "-y") == 0) {
                  build_library_index(cp, CASE_SENSITIVE);

            } else if (strcmp(buf, "-yl") == 0) {
                  build_library_index(cp, false);

            } else if (strcmp(buf, "-Y") == 0) {
                  library_suff.push_back(strdup(cp));

            } else if (strcmp(buf,"-t") == 0) {
                  target = strdup(cp);

            } else if (strcmp(buf,"-T") == 0) {
                  if (strcmp(cp,"min") == 0) {
                        min_typ_max_flag = MIN;
                        min_typ_max_warn = 0;
                  } else if (strcmp(cp,"typ") == 0) {
                        min_typ_max_flag = TYP;
                        min_typ_max_warn = 0;
                  } else if (strcmp(cp,"max") == 0) {
                        min_typ_max_flag = MAX;
                        min_typ_max_warn = 0;
                  } else {
                        cerr << "Invalid argument (" << optarg << ") to -T flag."
                             << endl;
                        flag_errors += 1;
                  }

            }
      }
}

extern Design* elaborate(list <perm_string> root);

#if defined(HAVE_TIMES)
static double cycles_diff(struct tms *a, struct tms *b)
{
      clock_t aa = a->tms_utime
            +      a->tms_stime
            +      a->tms_cutime
            +      a->tms_cstime;

      clock_t bb = b->tms_utime
            +      b->tms_stime
            +      b->tms_cutime
            +      b->tms_cstime;

      return (aa-bb)/(double)sysconf(_SC_CLK_TCK);
}
#else // ! defined(HAVE_TIMES)
// Provide dummies
struct tms { int x; };
inline static void times(struct tms *) { }
inline static double cycles_diff(struct tms *a, struct tms *b) { return 0; }
#endif // ! defined(HAVE_TIMES)

int main(int argc, char*argv[])
{
      bool help_flag = false;
      bool times_flag = false;

      const char* net_path = 0;
      const char* pf_path = 0;
      int opt;

      struct tms cycles[5];

      library_suff.push_back(".v");

      vpi_module_list = strdup("system");
      flags["VPI_MODULE_LIST"] = vpi_module_list;
      flags["-o"] = "a.out";
      min_typ_max_flag = TYP;
      min_typ_max_warn = 10;

      while ((opt = getopt(argc, argv, "C:f:hN:P:p:Vv")) != EOF) switch (opt) {

          case 'C':
            read_iconfig_file(optarg);
            break;

          case 'f':
            parm_to_flagmap(optarg);
            break;
          case 'h':
            help_flag = true;
            break;
          case 'N':
            net_path = optarg;
            break;
          case 'P':
            pf_path = optarg;
            break;
          case 'p':
            parm_to_flagmap(optarg);
            break;
          case 'v':
            verbose_flag = true;
#          if defined(HAVE_TIMES)
            times_flag = true;
#          endif
            break;
          case 'V':
            cout << "Icarus Verilog version " << VERSION << endl;
            cout << COPYRIGHT << endl;
            cout << endl << NOTICE << endl;
            return 0;
          default:
            flag_errors += 1;
            break;
      }

      if (flag_errors)
            return flag_errors;

      if (help_flag) {
            cout << "Icarus Verilog version " << VERSION << endl <<
"usage: ivl <options> <file>\n"
"options:\n"
"\t-C <name>        Config file from driver.\n"
"\t-h               Print usage information, and exit.\n"
"\t-N <file>        Dump the elaborated netlist to <file>.\n"
"\t-P <file>        Write the parsed input to <file>.\n"
"\t-p <assign>      Set a parameter value.\n"
"\t-v               Print progress indications"
#if defined(HAVE_TIMES)
                                           " and execution times"
#endif
                                           ".\n"
"\t-V               Print version and copyright information, and exit.\n"

                  ;
            return 0;
      }

      if (optind == argc) {
            cerr << "No input files." << endl;
            return 1;
      }

      if( depfile_name ) {
              depend_file = fopen(depfile_name, "a");
              if(! depend_file) {
                      perror(depfile_name);
              }
      }


      if (verbose_flag) {
            if (times_flag)
                  times(cycles+0);

            cout << "Using language generation: ";
            switch (generation_flag) {
                case GN_VER1995:
                  cout << "IEEE1364-1995";
                  break;
                case GN_VER2001:
                  cout << "IEEE1364-2001";
                  break;
                case GN_VER2001X:
                  cout << "IEEE1364-2001+Extensions";
                  break;
            }

            if (gn_specify_blocks_flag)
                  cout << ",specify";
            else
                  cout << ",no-specify";

            if (gn_cadence_types_flag)
                  cout << ",xtypes";
            else
                  cout << ",no-xtypes";

            cout << endl << "PARSING INPUT" << endl;
      }

        /* Parse the input. Make the pform. */
      int rc = pform_parse(argv[optind]);

      if (pf_path) {
            ofstream out (pf_path);
            out << "PFORM DUMP MODULES:" << endl;
            for (map<perm_string,Module*>::iterator mod = pform_modules.begin()
                       ; mod != pform_modules.end()
                       ; mod ++ ) {
                  pform_dump(out, (*mod).second);
            }
            out << "PFORM DUMP PRIMITIVES:" << endl;
            for (map<perm_string,PUdp*>::iterator idx = pform_primitives.begin()
                       ; idx != pform_primitives.end()
                       ; idx ++ ) {
                  (*idx).second->dump(out);
            }
      }

      if (rc) {
            return rc;
      }


        /* If the user did not give specific module(s) to start with,
           then look for modules that are not instantiated anywhere.  */

      if (roots.empty()) {
            map<perm_string,bool> mentioned_p;
            map<perm_string,Module*>::iterator mod;
            if (verbose_flag)
                  cout << "LOCATING TOP-LEVEL MODULES" << endl << "  ";
            for (mod = pform_modules.begin()
                       ; mod != pform_modules.end()
                       ; mod++) {
                  list<PGate*> gates = (*mod).second->get_gates();
                  list<PGate*>::const_iterator gate;
                  for (gate = gates.begin(); gate != gates.end(); gate++) {
                        PGModule *mod = dynamic_cast<PGModule*>(*gate);
                        if (mod) {
                              // Note that this module has been instantiated
                              mentioned_p[mod->get_type()] = true;
                        }
                  }
            }

            for (mod = pform_modules.begin()
                       ; mod != pform_modules.end()
                       ; mod++) {

                    /* Don't choose library modules. */
                  if ((*mod).second->library_flag)
                        continue;

                    /* Don't choose modules instantiated in other
                       modules. */
                  if (mentioned_p[(*mod).second->mod_name()])
                        continue;

                    /* What's left might as well be chosen as a root. */
                  if (verbose_flag)
                        cout << " " << (*mod).second->mod_name();
                  roots.push_back((*mod).second->mod_name());
            }
            if (verbose_flag)
                  cout << endl;
      }

        /* If there is *still* no guess for the root module, then give
           up completely, and complain. */

      if (roots.empty()) {
            cerr << "No top level modules, and no -s option." << endl;
            return 1;
      }


      if (verbose_flag) {
            if (times_flag) {
                  times(cycles+1);
                  cerr<<" ... done, "
                      <<cycles_diff(cycles+1, cycles+0)<<" seconds."<<endl;
            }
            cout << "ELABORATING DESIGN" << endl;
      }

        /* On with the process of elaborating the module. */
      Design*des = elaborate(roots);

      if ((des == 0) || (des->errors > 0)) {
            if (des != 0) {
                  cerr << des->errors
                       << " error(s) during elaboration." << endl;
                  if (net_path) {
                        ofstream out (net_path);
                        des->dump(out);
                  }
            } else {
                  cerr << "Elaboration failed" << endl;
            }

            goto errors_summary;
      }

      des->set_flags(flags);

        /* Done iwth all the pform data. Delete the modules. */
      for (map<perm_string,Module*>::iterator idx = pform_modules.begin()
                 ; idx != pform_modules.end() ; idx ++) {

            delete (*idx).second;
            (*idx).second = 0;
      }

      if (verbose_flag) {
            if (times_flag) {
                  times(cycles+2);
                  cerr<<" ... done, "
                      <<cycles_diff(cycles+2, cycles+1)<<" seconds."<<endl;
            }
            cout << "RUNNING FUNCTORS" << endl;
      }

      while (!net_func_queue.empty()) {
            net_func func = net_func_queue.front();
            net_func_queue.pop();
            if (verbose_flag)
                  cerr<<" -F "<<net_func_to_name(func)<< " ..." <<endl;
            func(des);
      }

      if (net_path) {
            if (verbose_flag)
                  cerr<<" dumping netlist to " <<net_path<< "..." <<endl;

            ofstream out (net_path);
            des->dump(out);
      }

      if (des->errors) {
            cerr << des->errors
                 << " error(s) in post-elaboration processing." <<
                  endl;
            return des->errors;
      }

      if (verbose_flag) {
            if (times_flag) {
                  times(cycles+3);
                  cerr<<" ... done, "
                      <<cycles_diff(cycles+3, cycles+2)<<" seconds."<<endl;
            }
      }

      if (verbose_flag) {
            cout << "CODE GENERATION -t "<<target<< endl;
      }

      int emit_rc;
      emit_rc = emit(des, target);
      if (emit_rc > 0) {
            cerr << "error: Code generation had "
                 << emit_rc << " errors."
                 << endl;
            return 1;
      }
      if (emit_rc < 0) {
            cerr << "error: Code generator failure: " << emit_rc << endl;
            return -1;
      }

      if (verbose_flag) {
            if (times_flag) {
                  times(cycles+4);
                  cerr<<" ... done, "
                      <<cycles_diff(cycles+4, cycles+3)<<" seconds."<<endl;
            } else {
                  cout << "DONE." << endl;
            }
      }

      if (verbose_flag) {
            cout << "STATISTICS" << endl;
            cout << "lex_string:"
                 << " add_count=" << lex_strings.add_count()
                 << " hit_count=" << lex_strings.add_hit_count()
                 << endl;
      }

      return 0;

 errors_summary:
      if (missing_modules.size() > 0) {
            cerr << "*** These modules were missing:" << endl;

            map<perm_string,unsigned>::const_iterator idx;
            for (idx = missing_modules.begin()
                       ; idx != missing_modules.end()
                       ; idx ++)
                  cerr << "        " << (*idx).first
                       << " referenced " << (*idx).second
                       << " times."<< endl;

            cerr << "***" << endl;
      }

      return des? des->errors : 1;
}

/*
 * $Log: main.cc,v $
 * Revision 1.95  2007/04/19 02:52:53  steve
 *  Add support for -v flag in command file.
 *
 * Revision 1.94  2007/03/07 04:24:59  steve
 *  Make integer width controllable.
 *
 * Revision 1.93  2006/09/28 04:35:18  steve
 *  Support selective control of specify and xtypes features.
 *
 * Revision 1.92  2005/07/14 23:38:43  steve
 *  Display as version 0.9.devel
 *
 * Revision 1.91  2005/07/07 16:22:49  steve
 *  Generalize signals to carry types.
 *
 * Revision 1.90  2005/06/28 04:25:55  steve
 *  Remove reference to SystemVerilog.
 *
 * Revision 1.89  2005/04/24 23:44:02  steve
 *  Update DFF support to new data flow.
 *
 * Revision 1.88  2005/01/22 01:06:55  steve
 *  Change case compare from logic to an LPM node.
 *
 * Revision 1.87  2004/12/11 02:31:26  steve
 *  Rework of internals to carry vectors through nexus instead
 *  of single bits. Make the ivl, tgt-vvp and vvp initial changes
 *  down this path.
 *
 * Revision 1.86  2004/10/04 01:10:53  steve
 *  Clean up spurious trailing white space.
 *
 * Revision 1.85  2004/09/25 01:58:44  steve
 *  Add a debug_elaborate flag
 *
 * Revision 1.84  2004/09/10 23:51:42  steve
 *  Fix the evaluation of constant ternary expressions.
 *
 * Revision 1.83  2004/09/05 17:44:42  steve
 *  Add support for module instance arrays.
 *
 * Revision 1.82  2004/03/10 04:51:24  steve
 *  Add support for system function table files.
 *
 * Revision 1.81  2004/02/18 17:11:56  steve
 *  Use perm_strings for named langiage items.
 *
 * Revision 1.80  2004/02/15 00:19:29  steve
 *  Report elaboration errors without crashing.
 *
 * Revision 1.79  2003/11/26 01:37:14  steve
 *  Properly initialize vpi_module_list with system.
 *
 * Revision 1.78  2003/11/13 05:55:33  steve
 *  Move the DLL= flag to target config files.
 *
 * Revision 1.77  2003/11/13 04:09:49  steve
 *  Pass flags through the temporary config file.
 *
 * Revision 1.76  2003/11/13 03:10:38  steve
 *  ivl -F and -t flags are onpassed throught the -C file.
 *
 * Revision 1.75  2003/11/10 20:59:03  steve
 *  Design::get_flag returns const char* instead of string.
 *
 * Revision 1.74  2003/11/01 04:22:30  steve
 *  Accept functors in the config file.
 *
 * Revision 1.73  2003/10/26 22:43:42  steve
 *  Improve -V messages,
 *
 * Revision 1.72  2003/09/26 02:17:14  steve
 *  Delete pform when done with it.
 *
 * Revision 1.71  2003/09/25 00:25:14  steve
 *  Summary list of missing modules.
 *
 * Revision 1.70  2003/09/23 05:57:36  steve
 *  Pass -m flag from driver via iconfig file.
 *
 * Revision 1.69  2003/09/22 01:12:08  steve
 *  Pass more ivl arguments through the iconfig file.
 *
 * Revision 1.68  2003/06/20 00:53:19  steve
 *  Module attributes from the parser
 *  through to elaborated form.
 *
 * Revision 1.67  2003/04/24 05:25:27  steve
 *  Dump design even on errors.
 *
 * Revision 1.66  2003/03/01 06:25:30  steve
 *  Add the lex_strings string handler, and put
 *  scope names and system task/function names
 *  into this table. Also, permallocate event
 *  names from the beginning.
 */