Add automatic verific import in hierarchy command

[yosys.git] / passes / hierarchy / hierarchy.cc

/*
 *  yosys -- Yosys Open SYnthesis Suite
 *
 *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
 *
 *  Permission to use, copy, modify, and/or distribute this software for any
 *  purpose with or without fee is hereby granted, provided that the above
 *  copyright notice and this permission notice appear in all copies.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 */

#include "kernel/yosys.h"
#include "frontends/verific/verific.h"
#include <stdlib.h>
#include <stdio.h>
#include <set>

#ifndef _WIN32
#  include <unistd.h>
#endif


USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN

struct generate_port_decl_t {
        bool input, output;
        string portname;
        int index;
};

void generate(RTLIL::Design *design, const std::vector<std::string> &celltypes, const std::vector<generate_port_decl_t> &portdecls)
{
        std::set<RTLIL::IdString> found_celltypes;

        for (auto i1 : design->modules_)
        for (auto i2 : i1.second->cells_)
        {
                RTLIL::Cell *cell = i2.second;
                if (design->has(cell->type))
                        continue;
                if (cell->type.substr(0, 1) == "$" && cell->type.substr(0, 3) != "$__")
                        continue;
                for (auto &pattern : celltypes)
                        if (patmatch(pattern.c_str(), RTLIL::unescape_id(cell->type).c_str()))
                                found_celltypes.insert(cell->type);
        }

        for (auto &celltype : found_celltypes)
        {
                std::set<RTLIL::IdString> portnames;
                std::set<RTLIL::IdString> parameters;
                std::map<RTLIL::IdString, int> portwidths;
                log("Generate module for cell type %s:\n", celltype.c_str());

                for (auto i1 : design->modules_)
                for (auto i2 : i1.second->cells_)
                        if (i2.second->type == celltype) {
                                for (auto &conn : i2.second->connections()) {
                                        if (conn.first[0] != '$')
                                                portnames.insert(conn.first);
                                        portwidths[conn.first] = max(portwidths[conn.first], conn.second.size());
                                }
                                for (auto &para : i2.second->parameters)
                                        parameters.insert(para.first);
                        }

                for (auto &decl : portdecls)
                        if (decl.index > 0)
                                portnames.insert(decl.portname);

                std::set<int> indices;
                for (int i = 0; i < int(portnames.size()); i++)
                        indices.insert(i+1);

                std::vector<generate_port_decl_t> ports(portnames.size());

                for (auto &decl : portdecls)
                        if (decl.index > 0) {
                                portwidths[decl.portname] = max(portwidths[decl.portname], 1);
                                portwidths[decl.portname] = max(portwidths[decl.portname], portwidths[stringf("$%d", decl.index)]);
                                log("  port %d: %s [%d:0] %s\n", decl.index, decl.input ? decl.output ? "inout" : "input" : "output", portwidths[decl.portname]-1, RTLIL::id2cstr(decl.portname));
                                if (indices.count(decl.index) > ports.size())
                                        log_error("Port index (%d) exceeds number of found ports (%d).\n", decl.index, int(ports.size()));
                                if (indices.count(decl.index) == 0)
                                        log_error("Conflict on port index %d.\n", decl.index);
                                indices.erase(decl.index);
                                portnames.erase(decl.portname);
                                ports[decl.index-1] = decl;
                        }

                while (portnames.size() > 0) {
                        RTLIL::IdString portname = *portnames.begin();
                        for (auto &decl : portdecls)
                                if (decl.index == 0 && patmatch(decl.portname.c_str(), RTLIL::unescape_id(portname).c_str())) {
                                        generate_port_decl_t d = decl;
                                        d.portname = portname.str();
                                        d.index = *indices.begin();
                                        log_assert(!indices.empty());
                                        indices.erase(d.index);
                                        ports[d.index-1] = d;
                                        portwidths[d.portname] = max(portwidths[d.portname], 1);
                                        log("  port %d: %s [%d:0] %s\n", d.index, d.input ? d.output ? "inout" : "input" : "output", portwidths[d.portname]-1, RTLIL::id2cstr(d.portname));
                                        goto found_matching_decl;
                                }
                        log_error("Can't match port %s.\n", RTLIL::id2cstr(portname));
                found_matching_decl:;
                        portnames.erase(portname);
                }

                log_assert(indices.empty());

                RTLIL::Module *mod = new RTLIL::Module;
                mod->name = celltype;
                mod->attributes["\\blackbox"] = RTLIL::Const(1);
                design->add(mod);

                for (auto &decl : ports) {
                        RTLIL::Wire *wire = mod->addWire(decl.portname, portwidths.at(decl.portname));
                        wire->port_id = decl.index;
                        wire->port_input = decl.input;
                        wire->port_output = decl.output;
                }

                mod->fixup_ports();

                for (auto &para : parameters)
                        log("  ignoring parameter %s.\n", RTLIL::id2cstr(para));

                log("  module %s created.\n", RTLIL::id2cstr(mod->name));
        }
}

bool expand_module(RTLIL::Design *design, RTLIL::Module *module, bool flag_check, bool flag_simcheck, std::vector<std::string> &libdirs)
{
        bool did_something = false;
        std::map<RTLIL::Cell*, std::pair<int, int>> array_cells;
        std::string filename;

        for (auto &cell_it : module->cells_)
        {
                RTLIL::Cell *cell = cell_it.second;

                if (cell->type.substr(0, 7) == "$array:") {
                        int pos_idx = cell->type.str().find_first_of(':');
                        int pos_num = cell->type.str().find_first_of(':', pos_idx + 1);
                        int pos_type = cell->type.str().find_first_of(':', pos_num + 1);
                        int idx = atoi(cell->type.str().substr(pos_idx + 1, pos_num).c_str());
                        int num = atoi(cell->type.str().substr(pos_num + 1, pos_type).c_str());
                        array_cells[cell] = std::pair<int, int>(idx, num);
                        cell->type = cell->type.str().substr(pos_type + 1);
                }

                if (design->modules_.count(cell->type) == 0)
                {
                        if (design->modules_.count("$abstract" + cell->type.str()))
                        {
                                cell->type = design->modules_.at("$abstract" + cell->type.str())->derive(design, cell->parameters);
                                cell->parameters.clear();
                                did_something = true;
                                continue;
                        }

                        if (cell->type[0] == '$')
                                continue;

                        for (auto &dir : libdirs)
                        {
                                static const vector<pair<string, string>> extensions_list =
                                {
                                        {".v", "verilog"},
                                        {".sv", "verilog -sv"},
                                        {".il", "ilang"}
                                };

                                for (auto &ext : extensions_list)
                                {
                                        filename = dir + "/" + RTLIL::unescape_id(cell->type) + ext.first;
                                        if (check_file_exists(filename)) {
                                                Frontend::frontend_call(design, NULL, filename, ext.second);
                                                goto loaded_module;
                                        }
                                }
                        }

                        if ((flag_check || flag_simcheck) && cell->type[0] != '$')
                                log_error("Module `%s' referenced in module `%s' in cell `%s' is not part of the design.\n",
                                                cell->type.c_str(), module->name.c_str(), cell->name.c_str());
                        continue;

                loaded_module:
                        if (design->modules_.count(cell->type) == 0)
                                log_error("File `%s' from libdir does not declare module `%s'.\n", filename.c_str(), cell->type.c_str());
                        did_something = true;
                } else
                if (flag_check || flag_simcheck)
                {
                        RTLIL::Module *mod = design->module(cell->type);
                        for (auto &conn : cell->connections())
                                if (conn.first[0] == '$' && '0' <= conn.first[1] && conn.first[1] <= '9') {
                                        int id = atoi(conn.first.c_str()+1);
                                        if (id <= 0 || id > GetSize(mod->ports))
                                                log_error("Module `%s' referenced in module `%s' in cell `%s' has only %d ports, requested port %d.\n",
                                                                log_id(cell->type), log_id(module), log_id(cell), GetSize(mod->ports), id);
                                } else if (mod->wire(conn.first) == nullptr || mod->wire(conn.first)->port_id == 0)
                                        log_error("Module `%s' referenced in module `%s' in cell `%s' does not have a port named '%s'.\n",
                                                        log_id(cell->type), log_id(module), log_id(cell), log_id(conn.first));
                        for (auto &param : cell->parameters)
                                if (mod->avail_parameters.count(param.first) == 0 && param.first[0] != '$' && strchr(param.first.c_str(), '.') == NULL)
                                        log_error("Module `%s' referenced in module `%s' in cell `%s' does not have a parameter named '%s'.\n",
                                                        log_id(cell->type), log_id(module), log_id(cell), log_id(param.first));
                }

                if (design->modules_.at(cell->type)->get_bool_attribute("\\blackbox")) {
                        if (flag_simcheck)
                                log_error("Module `%s' referenced in module `%s' in cell `%s' is a blackbox module.\n",
                                                cell->type.c_str(), module->name.c_str(), cell->name.c_str());
                        continue;
                }

                if (cell->parameters.size() == 0)
                        continue;

                RTLIL::Module *mod = design->modules_[cell->type];
                cell->type = mod->derive(design, cell->parameters);
                cell->parameters.clear();
                did_something = true;
        }

        for (auto &it : array_cells)
        {
                RTLIL::Cell *cell = it.first;
                int idx = it.second.first, num = it.second.second;

                if (design->modules_.count(cell->type) == 0)
                        log_error("Array cell `%s.%s' of unknown type `%s'.\n", RTLIL::id2cstr(module->name), RTLIL::id2cstr(cell->name), RTLIL::id2cstr(cell->type));

                RTLIL::Module *mod = design->modules_[cell->type];

                for (auto &conn : cell->connections_) {
                        int conn_size = conn.second.size();
                        RTLIL::IdString portname = conn.first;
                        if (portname.substr(0, 1) == "$") {
                                int port_id = atoi(portname.substr(1).c_str());
                                for (auto &wire_it : mod->wires_)
                                        if (wire_it.second->port_id == port_id) {
                                                portname = wire_it.first;
                                                break;
                                        }
                        }
                        if (mod->wires_.count(portname) == 0)
                                log_error("Array cell `%s.%s' connects to unknown port `%s'.\n", RTLIL::id2cstr(module->name), RTLIL::id2cstr(cell->name), RTLIL::id2cstr(conn.first));
                        int port_size = mod->wires_.at(portname)->width;
                        if (conn_size == port_size || conn_size == 0)
                                continue;
                        if (conn_size != port_size*num)
                                log_error("Array cell `%s.%s' has invalid port vs. signal size for port `%s'.\n", RTLIL::id2cstr(module->name), RTLIL::id2cstr(cell->name), RTLIL::id2cstr(conn.first));
                        conn.second = conn.second.extract(port_size*idx, port_size);
                }
        }

        return did_something;
}

void hierarchy_worker(RTLIL::Design *design, std::set<RTLIL::Module*, IdString::compare_ptr_by_name<Module>> &used, RTLIL::Module *mod, int indent)
{
        if (used.count(mod) > 0)
                return;

        if (indent == 0)
                log("Top module:  %s\n", mod->name.c_str());
        else if (!mod->get_bool_attribute("\\blackbox"))
                log("Used module: %*s%s\n", indent, "", mod->name.c_str());
        used.insert(mod);

        for (auto cell : mod->cells()) {
                std::string celltype = cell->type.str();
                if (celltype.substr(0, 7) == "$array:") {
                        int pos_idx = celltype.find_first_of(':');
                        int pos_num = celltype.find_first_of(':', pos_idx + 1);
                        int pos_type = celltype.find_first_of(':', pos_num + 1);
                        celltype = celltype.substr(pos_type + 1);
                }
                if (design->module(celltype))
                        hierarchy_worker(design, used, design->module(celltype), indent+4);
        }
}

void hierarchy_clean(RTLIL::Design *design, RTLIL::Module *top, bool purge_lib)
{
        std::set<RTLIL::Module*, IdString::compare_ptr_by_name<Module>> used;
        hierarchy_worker(design, used, top, 0);

        std::vector<RTLIL::Module*> del_modules;
        for (auto &it : design->modules_)
                if (used.count(it.second) == 0)
                        del_modules.push_back(it.second);

        int del_counter = 0;
        for (auto mod : del_modules) {
                if (!purge_lib && mod->get_bool_attribute("\\blackbox"))
                        continue;
                log("Removing unused module `%s'.\n", mod->name.c_str());
                design->modules_.erase(mod->name);
                del_counter++;
                delete mod;
        }

        log("Removed %d unused modules.\n", del_counter);
}

bool set_keep_assert(std::map<RTLIL::Module*, bool> &cache, RTLIL::Module *mod)
{
        if (cache.count(mod) == 0)
                for (auto c : mod->cells()) {
                        RTLIL::Module *m = mod->design->module(c->type);
                        if ((m != nullptr && set_keep_assert(cache, m)) || c->type.in("$assert", "$assume", "$live", "$fair", "$cover"))
                                return cache[mod] = true;
                }
        return cache[mod];
}

int find_top_mod_score(Design *design, Module *module, dict<Module*, int> &db)
{
        if (db.count(module) == 0) {
                int score = 0;
                db[module] = 0;
                for (auto cell : module->cells())
                        if (design->module(cell->type))
                                score = max(score, find_top_mod_score(design, design->module(cell->type), db) + 1);
                db[module] = score;
        }
        return db.at(module);
}

struct HierarchyPass : public Pass {
        HierarchyPass() : Pass("hierarchy", "check, expand and clean up design hierarchy") { }
        virtual void help()
        {
                //   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
                log("\n");
                log("    hierarchy [-check] [-top <module>]\n");
                log("    hierarchy -generate <cell-types> <port-decls>\n");
                log("\n");
                log("In parametric designs, a module might exists in several variations with\n");
                log("different parameter values. This pass looks at all modules in the current\n");
                log("design an re-runs the language frontends for the parametric modules as\n");
                log("needed.\n");
                log("\n");
                log("    -check\n");
                log("        also check the design hierarchy. this generates an error when\n");
                log("        an unknown module is used as cell type.\n");
                log("\n");
                log("    -simcheck\n");
                log("        like -check, but also thow an error if blackbox modules are\n");
                log("        instantiated, and throw an error if the design has no top module\n");
                log("\n");
                log("    -purge_lib\n");
                log("        by default the hierarchy command will not remove library (blackbox)\n");
                log("        modules. use this option to also remove unused blackbox modules.\n");
                log("\n");
                log("    -libdir <directory>\n");
                log("        search for files named <module_name>.v in the specified directory\n");
                log("        for unknown modules and automatically run read_verilog for each\n");
                log("        unknown module.\n");
                log("\n");
                log("    -keep_positionals\n");
                log("        per default this pass also converts positional arguments in cells\n");
                log("        to arguments using port names. this option disables this behavior.\n");
                log("\n");
                log("    -keep_portwidths\n");
                log("        per default this pass adjusts the port width on cells that are\n");
                log("        module instances when the width does not match the module port. this\n");
                log("        option disables this behavior.\n");
                log("\n");
                log("    -nokeep_asserts\n");
                log("        per default this pass sets the \"keep\" attribute on all modules\n");
                log("        that directly or indirectly contain one or more $assert cells. this\n");
                log("        option disables this behavior.\n");
                log("\n");
                log("    -top <module>\n");
                log("        use the specified top module to built a design hierarchy. modules\n");
                log("        outside this tree (unused modules) are removed.\n");
                log("\n");
                log("        when the -top option is used, the 'top' attribute will be set on the\n");
                log("        specified top module. otherwise a module with the 'top' attribute set\n");
                log("        will implicitly be used as top module, if such a module exists.\n");
                log("\n");
                log("    -auto-top\n");
                log("        automatically determine the top of the design hierarchy and mark it.\n");
                log("\n");
                log("In -generate mode this pass generates blackbox modules for the given cell\n");
                log("types (wildcards supported). For this the design is searched for cells that\n");
                log("match the given types and then the given port declarations are used to\n");
                log("determine the direction of the ports. The syntax for a port declaration is:\n");
                log("\n");
                log("    {i|o|io}[@<num>]:<portname>\n");
                log("\n");
                log("Input ports are specified with the 'i' prefix, output ports with the 'o'\n");
                log("prefix and inout ports with the 'io' prefix. The optional <num> specifies\n");
                log("the position of the port in the parameter list (needed when instantiated\n");
                log("using positional arguments). When <num> is not specified, the <portname> can\n");
                log("also contain wildcard characters.\n");
                log("\n");
                log("This pass ignores the current selection and always operates on all modules\n");
                log("in the current design.\n");
                log("\n");
        }
        virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
        {
                log_header(design, "Executing HIERARCHY pass (managing design hierarchy).\n");

                bool flag_check = false;
                bool flag_simcheck = false;
                bool purge_lib = false;
                RTLIL::Module *top_mod = NULL;
                std::string load_top_mod;
                std::vector<std::string> libdirs;

                bool auto_top_mode = false;
                bool generate_mode = false;
                bool keep_positionals = false;
                bool keep_portwidths = false;
                bool nokeep_asserts = false;
                std::vector<std::string> generate_cells;
                std::vector<generate_port_decl_t> generate_ports;

                size_t argidx;
                for (argidx = 1; argidx < args.size(); argidx++)
                {
                        if (args[argidx] == "-generate" && !flag_check && !flag_simcheck && !top_mod) {
                                generate_mode = true;
                                log("Entering generate mode.\n");
                                while (++argidx < args.size()) {
                                        const char *p = args[argidx].c_str();
                                        generate_port_decl_t decl;
                                        if (p[0] == 'i' && p[1] == 'o')
                                                decl.input = true, decl.output = true, p += 2;
                                        else if (*p == 'i')
                                                decl.input = true, decl.output = false, p++;
                                        else if (*p == 'o')
                                                decl.input = false, decl.output = true, p++;
                                        else
                                                goto is_celltype;
                                        if (*p == '@') {
                                                char *endptr;
                                                decl.index = strtol(++p, &endptr, 10);
                                                if (decl.index < 1)
                                                        goto is_celltype;
                                                p = endptr;
                                        } else
                                                decl.index = 0;
                                        if (*(p++) != ':')
                                                goto is_celltype;
                                        if (*p == 0)
                                                goto is_celltype;
                                        decl.portname = p;
                                        log("Port declaration: %s", decl.input ? decl.output ? "inout" : "input" : "output");
                                        if (decl.index >= 1)
                                                log(" [at position %d]", decl.index);
                                        log(" %s\n", decl.portname.c_str());
                                        generate_ports.push_back(decl);
                                        continue;
                                is_celltype:
                                        log("Celltype: %s\n", args[argidx].c_str());
                                        generate_cells.push_back(RTLIL::unescape_id(args[argidx]));
                                }
                                continue;
                        }
                        if (args[argidx] == "-check") {
                                flag_check = true;
                                continue;
                        }
                        if (args[argidx] == "-simcheck") {
                                flag_simcheck = true;
                                continue;
                        }
                        if (args[argidx] == "-purge_lib") {
                                purge_lib = true;
                                continue;
                        }
                        if (args[argidx] == "-keep_positionals") {
                                keep_positionals = true;
                                continue;
                        }
                        if (args[argidx] == "-keep_portwidths") {
                                keep_portwidths = true;
                                continue;
                        }
                        if (args[argidx] == "-nokeep_asserts") {
                                nokeep_asserts = true;
                                continue;
                        }
                        if (args[argidx] == "-libdir" && argidx+1 < args.size()) {
                                libdirs.push_back(args[++argidx]);
                                continue;
                        }
                        if (args[argidx] == "-top") {
                                if (++argidx >= args.size())
                                        log_cmd_error("Option -top requires an additional argument!\n");
                                top_mod = design->modules_.count(RTLIL::escape_id(args[argidx])) ? design->modules_.at(RTLIL::escape_id(args[argidx])) : NULL;
                                if (top_mod == NULL && design->modules_.count("$abstract" + RTLIL::escape_id(args[argidx]))) {
                                        dict<RTLIL::IdString, RTLIL::Const> empty_parameters;
                                        design->modules_.at("$abstract" + RTLIL::escape_id(args[argidx]))->derive(design, empty_parameters);
                                        top_mod = design->modules_.count(RTLIL::escape_id(args[argidx])) ? design->modules_.at(RTLIL::escape_id(args[argidx])) : NULL;
                                }
                                if (top_mod == NULL)
                                        load_top_mod = args[argidx];
                                continue;
                        }
                        if (args[argidx] == "-auto-top") {
                                auto_top_mode = true;
                                continue;
                        }
                        break;
                }
                extra_args(args, argidx, design, false);

                if (!load_top_mod.empty()) {
#ifdef YOSYS_ENABLE_VERIFIC
                        if (verific_import_pending) {
                                verific_import(design, load_top_mod);
                                top_mod = design->module(RTLIL::escape_id(load_top_mod));
                        }
#endif
                        if (top_mod == NULL)
                                log_cmd_error("Module `%s' not found!\n", load_top_mod.c_str());
                } else {
#ifdef YOSYS_ENABLE_VERIFIC
                        if (verific_import_pending)
                                verific_import(design);
#endif
                }

                if (generate_mode) {
                        generate(design, generate_cells, generate_ports);
                        return;
                }

                log_push();

                if (top_mod == nullptr)
                        for (auto &mod_it : design->modules_)
                                if (mod_it.second->get_bool_attribute("\\top"))
                                        top_mod = mod_it.second;

                if (top_mod == nullptr && auto_top_mode) {
                        log_header(design, "Finding top of design hierarchy..\n");
                        dict<Module*, int> db;
                        for (Module *mod : design->selected_modules()) {
                                int score = find_top_mod_score(design, mod, db);
                                log("root of %3d design levels: %-20s\n", score, log_id(mod));
                                if (!top_mod || score > db[top_mod])
                                        top_mod = mod;
                        }
                        if (top_mod != nullptr)
                                log("Automatically selected %s as design top module.\n", log_id(top_mod));
                }

                if (flag_simcheck && top_mod == nullptr)
                        log_error("Design has no top module.\n");

                bool did_something = true;
                while (did_something)
                {
                        did_something = false;

                        std::set<RTLIL::Module*, IdString::compare_ptr_by_name<Module>> used_modules;
                        if (top_mod != NULL) {
                                log_header(design, "Analyzing design hierarchy..\n");
                                hierarchy_worker(design, used_modules, top_mod, 0);
                        } else {
                                for (auto mod : design->modules())
                                        used_modules.insert(mod);
                        }

                        for (auto module : used_modules) {
                                if (expand_module(design, module, flag_check, flag_simcheck, libdirs))
                                        did_something = true;
                        }
                }

                if (top_mod != NULL) {
                        log_header(design, "Analyzing design hierarchy..\n");
                        hierarchy_clean(design, top_mod, purge_lib);
                }

                if (top_mod != NULL) {
                        for (auto &mod_it : design->modules_)
                                if (mod_it.second == top_mod)
                                        mod_it.second->attributes["\\top"] = RTLIL::Const(1);
                                else
                                        mod_it.second->attributes.erase("\\top");
                }

                if (!nokeep_asserts) {
                        std::map<RTLIL::Module*, bool> cache;
                        for (auto mod : design->modules())
                                if (set_keep_assert(cache, mod)) {
                                        log("Module %s directly or indirectly contains $assert cells -> setting \"keep\" attribute.\n", log_id(mod));
                                        mod->set_bool_attribute("\\keep");
                                }
                }

                if (!keep_positionals)
                {
                        std::set<RTLIL::Module*> pos_mods;
                        std::map<std::pair<RTLIL::Module*,int>, RTLIL::IdString> pos_map;
                        std::vector<std::pair<RTLIL::Module*,RTLIL::Cell*>> pos_work;

                        for (auto &mod_it : design->modules_)
                        for (auto &cell_it : mod_it.second->cells_) {
                                RTLIL::Cell *cell = cell_it.second;
                                if (design->modules_.count(cell->type) == 0)
                                        continue;
                                for (auto &conn : cell->connections())
                                        if (conn.first[0] == '$' && '0' <= conn.first[1] && conn.first[1] <= '9') {
                                                pos_mods.insert(design->modules_.at(cell->type));
                                                pos_work.push_back(std::pair<RTLIL::Module*,RTLIL::Cell*>(mod_it.second, cell));
                                                break;
                                        }
                        }

                        for (auto module : pos_mods)
                        for (auto &wire_it : module->wires_) {
                                RTLIL::Wire *wire = wire_it.second;
                                if (wire->port_id > 0)
                                        pos_map[std::pair<RTLIL::Module*,int>(module, wire->port_id)] = wire->name;
                        }

                        for (auto &work : pos_work) {
                                RTLIL::Module *module = work.first;
                                RTLIL::Cell *cell = work.second;
                                log("Mapping positional arguments of cell %s.%s (%s).\n",
                                                RTLIL::id2cstr(module->name), RTLIL::id2cstr(cell->name), RTLIL::id2cstr(cell->type));
                                dict<RTLIL::IdString, RTLIL::SigSpec> new_connections;
                                for (auto &conn : cell->connections())
                                        if (conn.first[0] == '$' && '0' <= conn.first[1] && conn.first[1] <= '9') {
                                                int id = atoi(conn.first.c_str()+1);
                                                std::pair<RTLIL::Module*,int> key(design->modules_.at(cell->type), id);
                                                if (pos_map.count(key) == 0) {
                                                        log("  Failed to map positional argument %d of cell %s.%s (%s).\n",
                                                                        id, RTLIL::id2cstr(module->name), RTLIL::id2cstr(cell->name), RTLIL::id2cstr(cell->type));
                                                        new_connections[conn.first] = conn.second;
                                                } else
                                                        new_connections[pos_map.at(key)] = conn.second;
                                        } else
                                                new_connections[conn.first] = conn.second;
                                cell->connections_ = new_connections;
                        }
                }

                std::set<Module*> blackbox_derivatives;
                std::vector<Module*> design_modules = design->modules();

                for (auto module : design_modules)
                for (auto cell : module->cells())
                {
                        Module *m = design->module(cell->type);

                        if (m == nullptr)
                                continue;

                        if (m->get_bool_attribute("\\blackbox") && !cell->parameters.empty()) {
                                IdString new_m_name = m->derive(design, cell->parameters, true);
                                if (new_m_name.empty())
                                        continue;
                                if (new_m_name != m->name) {
                                        m = design->module(new_m_name);
                                        blackbox_derivatives.insert(m);
                                }
                        }

                        for (auto &conn : cell->connections())
                        {
                                Wire *w = m->wire(conn.first);

                                if (w == nullptr || w->port_id == 0)
                                        continue;

                                if (GetSize(conn.second) == 0)
                                        continue;

                                SigSpec sig = conn.second;

                                if (!keep_portwidths && GetSize(w) != GetSize(conn.second))
                                {
                                        if (GetSize(w) < GetSize(conn.second))
                                        {
                                                int n = GetSize(conn.second) - GetSize(w);
                                                if (!w->port_input && w->port_output)
                                                        module->connect(sig.extract(GetSize(w), n), Const(0, n));
                                                sig.remove(GetSize(w), n);
                                        }
                                        else
                                        {
                                                int n = GetSize(w) - GetSize(conn.second);
                                                if (w->port_input && !w->port_output)
                                                        sig.append(Const(0, n));
                                                else
                                                        sig.append(module->addWire(NEW_ID, n));
                                        }

                                        if (!conn.second.is_fully_const() || !w->port_input || w->port_output)
                                                log_warning("Resizing cell port %s.%s.%s from %d bits to %d bits.\n", log_id(module), log_id(cell),
                                                                log_id(conn.first), GetSize(conn.second), GetSize(sig));
                                        cell->setPort(conn.first, sig);
                                }

                                if (w->port_output && !w->port_input && sig.has_const())
                                        log_error("Output port %s.%s.%s (%s) is connected to constants: %s\n",
                                                        log_id(module), log_id(cell), log_id(conn.first), log_id(cell->type), log_signal(sig));
                        }
                }

                for (auto module : blackbox_derivatives)
                        design->remove(module);

                log_pop();
        }
} HierarchyPass;

PRIVATE_NAMESPACE_END