Merge pull request #1879 from jjj11x/jjj11x/package_decl

[yosys.git] / passes / cmds / show.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/register.h"
#include "kernel/celltypes.h"
#include "kernel/log.h"
#include <string.h>

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

#ifdef __APPLE__
#  include <unistd.h>
#endif

#ifdef YOSYS_ENABLE_READLINE
#  include <readline/readline.h>
#endif

#ifdef YOSYS_ENABLE_EDITLINE
#  include <editline/readline.h>
#endif

USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN

#undef CLUSTER_CELLS_AND_PORTBOXES

struct ShowWorker
{
        CellTypes ct;

        vector<shared_str> dot_escape_store;
        std::map<RTLIL::IdString, int> dot_id2num_store;
        std::map<RTLIL::IdString, int> autonames;
        int single_idx_count;

        struct net_conn { std::set<std::string> in, out; int bits; std::string color; };
        std::map<std::string, net_conn> net_conn_map;

        FILE *f;
        RTLIL::Design *design;
        RTLIL::Module *module;
        uint32_t currentColor;
        bool genWidthLabels;
        bool genSignedLabels;
        bool stretchIO;
        bool enumerateIds;
        bool abbreviateIds;
        bool notitle;
        int page_counter;

        const std::vector<std::pair<std::string, RTLIL::Selection>> &color_selections;
        const std::vector<std::pair<std::string, RTLIL::Selection>> &label_selections;

        std::map<RTLIL::Const, int> colorattr_cache;
        RTLIL::IdString colorattr;


        static uint32_t xorshift32(uint32_t x) {
                x ^= x << 13;
                x ^= x >> 17;
                x ^= x << 5;
                return x;
        }

        std::string nextColor()
        {
                if (currentColor == 0)
                        return "color=\"black\"";
                return stringf("colorscheme=\"dark28\", color=\"%d\", fontcolor=\"%d\"", currentColor%8+1, currentColor%8+1);
        }

        std::string nextColor(std::string presetColor)
        {
                if (presetColor.empty())
                        return nextColor();
                return presetColor;
        }

        std::string nextColor(RTLIL::SigSpec sig, std::string defaultColor)
        {
                sig.sort_and_unify();
                for (auto &c : sig.chunks()) {
                        if (c.wire != nullptr)
                                for (auto &s : color_selections)
                                        if (s.second.selected_members.count(module->name) > 0 && s.second.selected_members.at(module->name).count(c.wire->name) > 0)
                                                return stringf("color=\"%s\"", s.first.c_str());
                }
                return defaultColor;
        }

        std::string nextColor(const RTLIL::SigSig &conn, std::string defaultColor)
        {
                return nextColor(conn.first, nextColor(conn.second, defaultColor));
        }

        std::string nextColor(const RTLIL::SigSpec &sig)
        {
                return nextColor(sig, nextColor());
        }

        std::string nextColor(const RTLIL::SigSig &conn)
        {
                return nextColor(conn, nextColor());
        }

        std::string widthLabel(int bits)
        {
                if (bits <= 1)
                        return "label=\"\"";
                if (!genWidthLabels)
                        return "style=\"setlinewidth(3)\", label=\"\"";
                return stringf("style=\"setlinewidth(3)\", label=\"<%d>\"", bits);
        }

        const char *findColor(std::string member_name)
        {
                for (auto &s : color_selections)
                        if (s.second.selected_member(module->name, member_name)) {
                                dot_escape_store.push_back(stringf(", color=\"%s\"", s.first.c_str()));
                                return dot_escape_store.back().c_str();
                        }

                RTLIL::Const colorattr_value;
                RTLIL::Cell *cell = module->cell(member_name);
                RTLIL::Wire *wire = module->wire(member_name);

                if (cell && cell->attributes.count(colorattr))
                        colorattr_value = cell->attributes.at(colorattr);
                else if (wire && wire->attributes.count(colorattr))
                        colorattr_value = wire->attributes.at(colorattr);
                else
                        return "";

                if (colorattr_cache.count(colorattr_value) == 0) {
                        int next_id = GetSize(colorattr_cache);
                        colorattr_cache[colorattr_value] = (next_id % 8) + 1;
                }

                dot_escape_store.push_back(stringf(", colorscheme=\"dark28\", color=\"%d\", fontcolor=\"%d\"", colorattr_cache.at(colorattr_value), colorattr_cache.at(colorattr_value)));
                return dot_escape_store.back().c_str();
        }

        const char *findLabel(std::string member_name)
        {
                for (auto &s : label_selections)
                        if (s.second.selected_member(module->name, member_name))
                                return escape(s.first);
                return escape(member_name, true);
        }

        const char *escape(std::string id, bool is_name = false)
        {
                if (id.size() == 0)
                        return "";

                if (id[0] == '$' && is_name) {
                        if (enumerateIds) {
                                if (autonames.count(id) == 0) {
                                        autonames[id] = autonames.size() + 1;
                                        log("Generated short name for internal identifier: _%d_ -> %s\n", autonames[id], id.c_str());
                                }
                                id = stringf("_%d_", autonames[id]);
                        } else if (abbreviateIds) {
                                const char *p = id.c_str();
                                const char *q = strrchr(p, '$');
                                id = std::string(q);
                        }
                }

                if (id[0] == '\\')
                        id = id.substr(1);

                std::string str;
                for (char ch : id) {
                        if (ch == '\\' || ch == '"')
                                str += "\\";
                        str += ch;
                }

                dot_escape_store.push_back(str);
                return dot_escape_store.back().c_str();
        }

        int id2num(RTLIL::IdString id)
        {
                if (dot_id2num_store.count(id) > 0)
                        return dot_id2num_store[id];
                return dot_id2num_store[id] = dot_id2num_store.size() + 1;
        }

        std::string gen_signode_simple(RTLIL::SigSpec sig, bool range_check = true)
        {
                if (GetSize(sig) == 0) {
                        fprintf(f, "v%d [ label=\"\" ];\n", single_idx_count);
                        return stringf("v%d", single_idx_count++);
                }

                if (sig.is_chunk()) {
                        const RTLIL::SigChunk &c = sig.as_chunk();
                        if (c.wire != nullptr && design->selected_member(module->name, c.wire->name)) {
                                if (!range_check || c.wire->width == c.width)
                                                return stringf("n%d", id2num(c.wire->name));
                        } else {
                                fprintf(f, "v%d [ label=\"%s\" ];\n", single_idx_count, findLabel(log_signal(c)));
                                return stringf("v%d", single_idx_count++);
                        }
                }

                return std::string();
        }

        std::string gen_portbox(std::string port, RTLIL::SigSpec sig, bool driver, std::string *node = nullptr)
        {
                std::string code;
                std::string net = gen_signode_simple(sig);
                if (net.empty())
                {
                        std::string label_string;
                        int pos = sig.size()-1;
                        int idx = single_idx_count++;
                        for (int rep, i = int(sig.chunks().size())-1; i >= 0; i -= rep) {
                                const RTLIL::SigChunk &c = sig.chunks().at(i);
                                if (!driver && c.wire == nullptr) {
                                        RTLIL::State s1 = c.data.front();
                                        for (auto s2 : c.data)
                                                if (s1 != s2)
                                                        goto not_const_stream;
                                        net.clear();
                                } else {
                        not_const_stream:
                                        net = gen_signode_simple(c, false);
                                        log_assert(!net.empty());
                                }
                                for (rep = 1; i-rep >= 0 && c == sig.chunks().at(i-rep); rep++) {}
                                std::string repinfo = rep > 1 ? stringf("%dx ", rep) : "";
                                if (driver) {
                                        log_assert(!net.empty());
                                        label_string += stringf("<s%d> %d:%d - %s%d:%d |", i, pos, pos-c.width+1, repinfo.c_str(), c.offset+c.width-1, c.offset);
                                        net_conn_map[net].in.insert(stringf("x%d:s%d", idx, i));
                                        net_conn_map[net].bits = rep*c.width;
                                        net_conn_map[net].color = nextColor(c, net_conn_map[net].color);
                                } else
                                if (net.empty()) {
                                        log_assert(rep == 1);
                                        label_string += stringf("%c -&gt; %d:%d |",
                                                        c.data.front() == State::S0 ? '0' :
                                                        c.data.front() == State::S1 ? '1' :
                                                        c.data.front() == State::Sx ? 'X' :
                                                        c.data.front() == State::Sz ? 'Z' : '?',
                                                        pos, pos-rep*c.width+1);
                                } else {
                                        label_string += stringf("<s%d> %s%d:%d - %d:%d |", i, repinfo.c_str(), c.offset+c.width-1, c.offset, pos, pos-rep*c.width+1);
                                        net_conn_map[net].out.insert(stringf("x%d:s%d", idx, i));
                                        net_conn_map[net].bits = rep*c.width;
                                        net_conn_map[net].color = nextColor(c, net_conn_map[net].color);
                                }
                                pos -= rep * c.width;
                        }
                        if (label_string[label_string.size()-1] == '|')
                                label_string = label_string.substr(0, label_string.size()-1);
                        code += stringf("x%d [ shape=record, style=rounded, label=\"%s\" ];\n", idx, label_string.c_str());
                        if (!port.empty()) {
                                currentColor = xorshift32(currentColor);
                                if (driver)
                                        code += stringf("%s:e -> x%d:w [arrowhead=odiamond, arrowtail=odiamond, dir=both, %s, %s];\n", port.c_str(), idx, nextColor(sig).c_str(), widthLabel(sig.size()).c_str());
                                else
                                        code += stringf("x%d:e -> %s:w [arrowhead=odiamond, arrowtail=odiamond, dir=both, %s, %s];\n", idx, port.c_str(), nextColor(sig).c_str(), widthLabel(sig.size()).c_str());
                        }
                        if (node != nullptr)
                                *node = stringf("x%d", idx);
                }
                else
                {
                        if (!port.empty()) {
                                if (driver)
                                        net_conn_map[net].in.insert(port);
                                else
                                        net_conn_map[net].out.insert(port);
                                net_conn_map[net].bits = sig.size();
                                net_conn_map[net].color = nextColor(sig, net_conn_map[net].color);
                        }
                        if (node != nullptr)
                                *node = net;
                }
                return code;
        }

        void collect_proc_signals(std::vector<RTLIL::SigSpec> &obj, std::set<RTLIL::SigSpec> &signals)
        {
                for (auto &it : obj)
                        if (!it.is_fully_const())
                                signals.insert(it);
        }

        void collect_proc_signals(std::vector<RTLIL::SigSig> &obj, std::set<RTLIL::SigSpec> &input_signals, std::set<RTLIL::SigSpec> &output_signals)
        {
                for (auto &it : obj) {
                        output_signals.insert(it.first);
                        if (!it.second.is_fully_const())
                                input_signals.insert(it.second);
                }
        }

        void collect_proc_signals(RTLIL::CaseRule *obj, std::set<RTLIL::SigSpec> &input_signals, std::set<RTLIL::SigSpec> &output_signals)
        {
                collect_proc_signals(obj->compare, input_signals);
                collect_proc_signals(obj->actions, input_signals, output_signals);
                for (auto it : obj->switches)
                        collect_proc_signals(it, input_signals, output_signals);
        }

        void collect_proc_signals(RTLIL::SwitchRule *obj, std::set<RTLIL::SigSpec> &input_signals, std::set<RTLIL::SigSpec> &output_signals)
        {
                input_signals.insert(obj->signal);
                for (auto it : obj->cases)
                        collect_proc_signals(it, input_signals, output_signals);
        }

        void collect_proc_signals(RTLIL::SyncRule *obj, std::set<RTLIL::SigSpec> &input_signals, std::set<RTLIL::SigSpec> &output_signals)
        {
                input_signals.insert(obj->signal);
                collect_proc_signals(obj->actions, input_signals, output_signals);
        }

        void collect_proc_signals(RTLIL::Process *obj, std::set<RTLIL::SigSpec> &input_signals, std::set<RTLIL::SigSpec> &output_signals)
        {
                collect_proc_signals(&obj->root_case, input_signals, output_signals);
                for (auto it : obj->syncs)
                        collect_proc_signals(it, input_signals, output_signals);
        }

        void handle_module()
        {
                single_idx_count = 0;
                dot_escape_store.clear();
                dot_id2num_store.clear();
                net_conn_map.clear();

                fprintf(f, "digraph \"%s\" {\n", escape(module->name.str()));
                if (!notitle)
                        fprintf(f, "label=\"%s\";\n", escape(module->name.str()));
                fprintf(f, "rankdir=\"LR\";\n");
                fprintf(f, "remincross=true;\n");

                std::set<std::string> all_sources, all_sinks;

                std::map<std::string, std::string> wires_on_demand;
                for (auto wire : module->selected_wires()) {
                        const char *shape = "diamond";
                        if (wire->port_input || wire->port_output)
                                shape = "octagon";
                        if (wire->name[0] == '\\') {
                                fprintf(f, "n%d [ shape=%s, label=\"%s\", %s, fontcolor=\"black\" ];\n",
                                                id2num(wire->name), shape, findLabel(wire->name.str()),
                                                nextColor(RTLIL::SigSpec(wire), "color=\"black\"").c_str());
                                if (wire->port_input)
                                        all_sources.insert(stringf("n%d", id2num(wire->name)));
                                else if (wire->port_output)
                                        all_sinks.insert(stringf("n%d", id2num(wire->name)));
                        } else {
                                wires_on_demand[stringf("n%d", id2num(wire->name))] = wire->name.str();
                        }
                }

                if (stretchIO)
                {
                        fprintf(f, "{ rank=\"source\";");
                        for (auto n : all_sources)
                                fprintf(f, " %s;", n.c_str());
                        fprintf(f, "}\n");

                        fprintf(f, "{ rank=\"sink\";");
                        for (auto n : all_sinks)
                                fprintf(f, " %s;", n.c_str());
                        fprintf(f, "}\n");
                }

                for (auto cell : module->selected_cells())
                {
                        std::vector<RTLIL::IdString> in_ports, out_ports;

                        for (auto &conn : cell->connections()) {
                                if (!ct.cell_output(cell->type, conn.first))
                                        in_ports.push_back(conn.first);
                                else
                                        out_ports.push_back(conn.first);
                        }

                        std::sort(in_ports.begin(), in_ports.end(), RTLIL::sort_by_id_str());
                        std::sort(out_ports.begin(), out_ports.end(), RTLIL::sort_by_id_str());

                        std::string label_string = "{{";

                        for (auto &p : in_ports)
                                label_string += stringf("<p%d> %s%s|", id2num(p), escape(p.str()),
                                                genSignedLabels && cell->hasParam(p.str() + "_SIGNED") &&
                                                cell->getParam(p.str() + "_SIGNED").as_bool() ? "*" : "");
                        if (label_string[label_string.size()-1] == '|')
                                label_string = label_string.substr(0, label_string.size()-1);

                        label_string += stringf("}|%s\\n%s|{", findLabel(cell->name.str()), escape(cell->type.str()));

                        for (auto &p : out_ports)
                                label_string += stringf("<p%d> %s|", id2num(p), escape(p.str()));
                        if (label_string[label_string.size()-1] == '|')
                                label_string = label_string.substr(0, label_string.size()-1);

                        label_string += "}}";

                        std::string code;
                        for (auto &conn : cell->connections()) {
                                code += gen_portbox(stringf("c%d:p%d", id2num(cell->name), id2num(conn.first)),
                                                conn.second, ct.cell_output(cell->type, conn.first));
                        }

#ifdef CLUSTER_CELLS_AND_PORTBOXES
                        if (!code.empty())
                                fprintf(f, "subgraph cluster_c%d {\nc%d [ shape=record, label=\"%s\"%s ];\n%s}\n",
                                                id2num(cell->name), id2num(cell->name), label_string.c_str(), findColor(cell->name), code.c_str());
                        else
#endif
                                fprintf(f, "c%d [ shape=record, label=\"%s\"%s ];\n%s",
                                                id2num(cell->name), label_string.c_str(), findColor(cell->name.str()), code.c_str());
                }

                for (auto &it : module->processes)
                {
                        RTLIL::Process *proc = it.second;

                        if (!design->selected_member(module->name, proc->name))
                                continue;

                        std::set<RTLIL::SigSpec> input_signals, output_signals;
                        collect_proc_signals(proc, input_signals, output_signals);

                        int pidx = single_idx_count++;
                        input_signals.erase(RTLIL::SigSpec());
                        output_signals.erase(RTLIL::SigSpec());

                        for (auto &sig : input_signals) {
                                std::string code, node;
                                code += gen_portbox("", sig, false, &node);
                                fprintf(f, "%s", code.c_str());
                                net_conn_map[node].out.insert(stringf("p%d", pidx));
                                net_conn_map[node].bits = sig.size();
                                net_conn_map[node].color = nextColor(sig, net_conn_map[node].color);
                        }

                        for (auto &sig : output_signals) {
                                std::string code, node;
                                code += gen_portbox("", sig, true, &node);
                                fprintf(f, "%s", code.c_str());
                                net_conn_map[node].in.insert(stringf("p%d", pidx));
                                net_conn_map[node].bits = sig.size();
                                net_conn_map[node].color = nextColor(sig, net_conn_map[node].color);
                        }

                        std::string proc_src = RTLIL::unescape_id(proc->name);
                        if (proc->attributes.count(ID::src) > 0)
                                proc_src = proc->attributes.at(ID::src).decode_string();
                        fprintf(f, "p%d [shape=box, style=rounded, label=\"PROC %s\\n%s\"];\n", pidx, findLabel(proc->name.str()), proc_src.c_str());
                }

                for (auto &conn : module->connections())
                {
                        bool found_lhs_wire = false;
                        for (auto &c : conn.first.chunks()) {
                                if (c.wire == nullptr || design->selected_member(module->name, c.wire->name))
                                        found_lhs_wire = true;
                        }
                        bool found_rhs_wire = false;
                        for (auto &c : conn.second.chunks()) {
                                if (c.wire == nullptr || design->selected_member(module->name, c.wire->name))
                                        found_rhs_wire = true;
                        }
                        if (!found_lhs_wire || !found_rhs_wire)
                                continue;

                        std::string code, left_node, right_node;
                        code += gen_portbox("", conn.second, false, &left_node);
                        code += gen_portbox("", conn.first, true, &right_node);
                        fprintf(f, "%s", code.c_str());

                        if (left_node[0] == 'x' && right_node[0] == 'x') {
                                currentColor = xorshift32(currentColor);
                                fprintf(f, "%s:e -> %s:w [arrowhead=odiamond, arrowtail=odiamond, dir=both, %s, %s];\n", left_node.c_str(), right_node.c_str(), nextColor(conn).c_str(), widthLabel(conn.first.size()).c_str());
                        } else {
                                net_conn_map[right_node].bits = conn.first.size();
                                net_conn_map[right_node].color = nextColor(conn, net_conn_map[right_node].color);
                                net_conn_map[left_node].bits = conn.first.size();
                                net_conn_map[left_node].color = nextColor(conn, net_conn_map[left_node].color);
                                if (left_node[0] == 'x') {
                                        net_conn_map[right_node].in.insert(left_node);
                                } else if (right_node[0] == 'x') {
                                        net_conn_map[left_node].out.insert(right_node);
                                } else {
                                        net_conn_map[right_node].in.insert(stringf("x%d:e", single_idx_count));
                                        net_conn_map[left_node].out.insert(stringf("x%d:w", single_idx_count));
                                        fprintf(f, "x%d [shape=box, style=rounded, label=\"BUF\"];\n", single_idx_count++);
                                }
                        }
                }

                for (auto &it : net_conn_map)
                {
                        currentColor = xorshift32(currentColor);
                        if (wires_on_demand.count(it.first) > 0) {
                                if (it.second.in.size() == 1 && it.second.out.size() > 1 && it.second.in.begin()->compare(0, 1, "p") == 0)
                                        it.second.out.erase(*it.second.in.begin());
                                if (it.second.in.size() == 1 && it.second.out.size() == 1) {
                                        std::string from = *it.second.in.begin(), to = *it.second.out.begin();
                                        if (from != to || from.compare(0, 1, "p") != 0)
                                                fprintf(f, "%s:e -> %s:w [%s, %s];\n", from.c_str(), to.c_str(), nextColor(it.second.color).c_str(), widthLabel(it.second.bits).c_str());
                                        continue;
                                }
                                if (it.second.in.size() == 0 || it.second.out.size() == 0)
                                        fprintf(f, "%s [ shape=diamond, label=\"%s\" ];\n", it.first.c_str(), findLabel(wires_on_demand[it.first]));
                                else
                                        fprintf(f, "%s [ shape=point ];\n", it.first.c_str());
                        }
                        for (auto &it2 : it.second.in)
                                fprintf(f, "%s:e -> %s:w [%s, %s];\n", it2.c_str(), it.first.c_str(), nextColor(it.second.color).c_str(), widthLabel(it.second.bits).c_str());
                        for (auto &it2 : it.second.out)
                                fprintf(f, "%s:e -> %s:w [%s, %s];\n", it.first.c_str(), it2.c_str(), nextColor(it.second.color).c_str(), widthLabel(it.second.bits).c_str());
                }

                fprintf(f, "}\n");
        }

        ShowWorker(FILE *f, RTLIL::Design *design, std::vector<RTLIL::Design*> &libs, uint32_t colorSeed, bool genWidthLabels,
                        bool genSignedLabels, bool stretchIO, bool enumerateIds, bool abbreviateIds, bool notitle,
                        const std::vector<std::pair<std::string, RTLIL::Selection>> &color_selections,
                        const std::vector<std::pair<std::string, RTLIL::Selection>> &label_selections, RTLIL::IdString colorattr) :
                        f(f), design(design), currentColor(colorSeed), genWidthLabels(genWidthLabels),
                        genSignedLabels(genSignedLabels), stretchIO(stretchIO), enumerateIds(enumerateIds), abbreviateIds(abbreviateIds),
                        notitle(notitle), color_selections(color_selections), label_selections(label_selections), colorattr(colorattr)
        {
                ct.setup_internals();
                ct.setup_internals_mem();
                ct.setup_stdcells();
                ct.setup_stdcells_mem();
                ct.setup_design(design);

                for (auto lib : libs)
                        ct.setup_design(lib);

                design->optimize();
                page_counter = 0;
                for (auto mod : design->selected_modules())
                {
                        module = mod;
                        if (design->selected_whole_module(module->name)) {
                                if (module->get_blackbox_attribute()) {
                                        // log("Skipping blackbox module %s.\n", log_id(module->name));
                                        continue;
                                } else
                                if (module->cells().size() == 0 && module->connections().empty() && module->processes.empty()) {
                                        log("Skipping empty module %s.\n", log_id(module->name));
                                        continue;
                                } else
                                        log("Dumping module %s to page %d.\n", log_id(module->name), ++page_counter);
                        } else
                                log("Dumping selected parts of module %s to page %d.\n", log_id(module->name), ++page_counter);
                        handle_module();
                }
        }
};

struct ShowPass : public Pass {
        ShowPass() : Pass("show", "generate schematics using graphviz") { }
        void help() YS_OVERRIDE
        {
                //   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
                log("\n");
                log("    show [options] [selection]\n");
                log("\n");
                log("Create a graphviz DOT file for the selected part of the design and compile it\n");
                log("to a graphics file (usually SVG or PostScript).\n");
                log("\n");
                log("    -viewer <viewer>\n");
                log("        Run the specified command with the graphics file as parameter.\n");
                log("        On Windows, this pauses yosys until the viewer exits.\n");
                log("\n");
                log("    -format <format>\n");
                log("        Generate a graphics file in the specified format. Use 'dot' to just\n");
                log("        generate a .dot file, or other <format> strings such as 'svg' or 'ps'\n");
                log("        to generate files in other formats (this calls the 'dot' command).\n");
                log("\n");
                log("    -lib <verilog_or_ilang_file>\n");
                log("        Use the specified library file for determining whether cell ports are\n");
                log("        inputs or outputs. This option can be used multiple times to specify\n");
                log("        more than one library.\n");
                log("\n");
                log("        note: in most cases it is better to load the library before calling\n");
                log("        show with 'read_verilog -lib <filename>'. it is also possible to\n");
                log("        load liberty files with 'read_liberty -lib <filename>'.\n");
                log("\n");
                log("    -prefix <prefix>\n");
                log("        generate <prefix>.* instead of ~/.yosys_show.*\n");
                log("\n");
                log("    -color <color> <object>\n");
                log("        assign the specified color to the specified object. The object can be\n");
                log("        a single selection wildcard expressions or a saved set of objects in\n");
                log("        the @<name> syntax (see \"help select\" for details).\n");
                log("\n");
                log("    -label <text> <object>\n");
                log("        assign the specified label text to the specified object. The object can\n");
                log("        be a single selection wildcard expressions or a saved set of objects in\n");
                log("        the @<name> syntax (see \"help select\" for details).\n");
                log("\n");
                log("    -colors <seed>\n");
                log("        Randomly assign colors to the wires. The integer argument is the seed\n");
                log("        for the random number generator. Change the seed value if the colored\n");
                log("        graph still is ambiguous. A seed of zero deactivates the coloring.\n");
                log("\n");
                log("    -colorattr <attribute_name>\n");
                log("        Use the specified attribute to assign colors. A unique color is\n");
                log("        assigned to each unique value of this attribute.\n");
                log("\n");
                log("    -width\n");
                log("        annotate buses with a label indicating the width of the bus.\n");
                log("\n");
                log("    -signed\n");
                log("        mark ports (A, B) that are declared as signed (using the [AB]_SIGNED\n");
                log("        cell parameter) with an asterisk next to the port name.\n");
                log("\n");
                log("    -stretch\n");
                log("        stretch the graph so all inputs are on the left side and all outputs\n");
                log("        (including inout ports) are on the right side.\n");
                log("\n");
                log("    -pause\n");
                log("        wait for the use to press enter to before returning\n");
                log("\n");
                log("    -enum\n");
                log("        enumerate objects with internal ($-prefixed) names\n");
                log("\n");
                log("    -long\n");
                log("        do not abbreviate objects with internal ($-prefixed) names\n");
                log("\n");
                log("    -notitle\n");
                log("        do not add the module name as graph title to the dot file\n");
                log("\n");
                log("    -nobg\n");
                log("        don't run viewer in the background, IE wait for the viewer tool to\n");
                log("        exit before returning\n");
                log("\n");
                log("When no <format> is specified, 'dot' is used. When no <format> and <viewer> is\n");
                log("specified, 'xdot' is used to display the schematic (POSIX systems only).\n");
                log("\n");
                log("The generated output files are '~/.yosys_show.dot' and '~/.yosys_show.<format>',\n");
                log("unless another prefix is specified using -prefix <prefix>.\n");
                log("\n");
                log("Yosys on Windows and YosysJS use different defaults: The output is written\n");
                log("to 'show.dot' in the current directory and new viewer is launched each time\n");
                log("the 'show' command is executed.\n");
                log("\n");
        }
        void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
        {
                log_header(design, "Generating Graphviz representation of design.\n");
                log_push();

                std::vector<std::pair<std::string, RTLIL::Selection>> color_selections;
                std::vector<std::pair<std::string, RTLIL::Selection>> label_selections;

#if defined(EMSCRIPTEN) || defined(_WIN32)
                std::string format = "dot";
                std::string prefix = "show";
#else
                std::string format;
                std::string prefix = stringf("%s/.yosys_show", getenv("HOME") ? getenv("HOME") : ".");
#endif
                std::string viewer_exe;
                std::vector<std::string> libfiles;
                std::vector<RTLIL::Design*> libs;
                uint32_t colorSeed = 0;
                bool flag_width = false;
                bool flag_signed = false;
                bool flag_stretch = false;
                bool flag_pause = false;
                bool flag_enum = false;
                bool flag_abbreviate = true;
                bool flag_notitle = false;
                bool custom_prefix = false;
                std::string background = "&";
                RTLIL::IdString colorattr;

                size_t argidx;
                for (argidx = 1; argidx < args.size(); argidx++)
                {
                        std::string arg = args[argidx];
                        if (arg == "-viewer" && argidx+1 < args.size()) {
                                viewer_exe = args[++argidx];
                                continue;
                        }
                        if (arg == "-lib" && argidx+1 < args.size()) {
                                libfiles.push_back(args[++argidx]);
                                continue;
                        }
                        if (arg == "-prefix" && argidx+1 < args.size()) {
                                prefix = args[++argidx];
                                custom_prefix = true;
                                continue;
                        }
                        if (arg == "-color" && argidx+2 < args.size()) {
                                std::pair<std::string, RTLIL::Selection> data;
                                data.first = args[++argidx], argidx++;
                                handle_extra_select_args(this, args, argidx, argidx+1, design);
                                data.second = design->selection_stack.back();
                                design->selection_stack.pop_back();
                                color_selections.push_back(data);
                                continue;
                        }
                        if (arg == "-label" && argidx+2 < args.size()) {
                                std::pair<std::string, RTLIL::Selection> data;
                                data.first = args[++argidx], argidx++;
                                handle_extra_select_args(this, args, argidx, argidx+1, design);
                                data.second = design->selection_stack.back();
                                design->selection_stack.pop_back();
                                label_selections.push_back(data);
                                continue;
                        }
                        if (arg == "-colors" && argidx+1 < args.size()) {
                                colorSeed = atoi(args[++argidx].c_str());
                                for (int i = 0; i < 100; i++)
                                        colorSeed = ShowWorker::xorshift32(colorSeed);
                                continue;
                        }
                        if (arg == "-colorattr" && argidx+1 < args.size()) {
                                colorattr = RTLIL::escape_id(args[++argidx]);
                                continue;
                        }
                        if (arg == "-format" && argidx+1 < args.size()) {
                                format = args[++argidx];
                                continue;
                        }
                        if (arg == "-width") {
                                flag_width= true;
                                continue;
                        }
                        if (arg == "-signed") {
                                flag_signed= true;
                                continue;
                        }
                        if (arg == "-stretch") {
                                flag_stretch= true;
                                continue;
                        }
                        if (arg == "-pause") {
                                flag_pause= true;
                                continue;
                        }
                        if (arg == "-enum") {
                                flag_enum = true;
                                flag_abbreviate = false;
                                continue;
                        }
                        if (arg == "-long") {
                                flag_enum = false;
                                flag_abbreviate = false;
                                continue;
                        }
                        if (arg == "-notitle") {
                                flag_notitle = true;
                                continue;
                        }
                        if (arg == "-nobg") {
                                background= "";
                                continue;
                        }
                        break;
                }
                extra_args(args, argidx, design);

                if (format != "ps" && format != "dot") {
                        int modcount = 0;
                        for (auto module : design->selected_modules()) {
                                if (module->get_blackbox_attribute())
                                        continue;
                                if (module->cells().size() == 0 && module->connections().empty())
                                        continue;
                                modcount++;
                        }
                        if (modcount > 1)
                                log_cmd_error("For formats different than 'ps' or 'dot' only one module must be selected.\n");
                }

                for (auto filename : libfiles) {
                        std::ifstream f;
                        f.open(filename.c_str());
                        yosys_input_files.insert(filename);
                        if (f.fail())
                                log_error("Can't open lib file `%s'.\n", filename.c_str());
                        RTLIL::Design *lib = new RTLIL::Design;
                        Frontend::frontend_call(lib, &f, filename, (filename.size() > 3 && filename.compare(filename.size()-3, std::string::npos, ".il") == 0 ? "ilang" : "verilog"));
                        libs.push_back(lib);
                }

                if (libs.size() > 0)
                        log_header(design, "Continuing show pass.\n");

                std::string dot_file = stringf("%s.dot", prefix.c_str());
                std::string out_file = stringf("%s.%s", prefix.c_str(), format.empty() ? "svg" : format.c_str());

                log("Writing dot description to `%s'.\n", dot_file.c_str());
                FILE *f = fopen(dot_file.c_str(), "w");
                if (custom_prefix)
                        yosys_output_files.insert(dot_file);
                if (f == nullptr) {
                        for (auto lib : libs)
                                delete lib;
                        log_cmd_error("Can't open dot file `%s' for writing.\n", dot_file.c_str());
                }
                ShowWorker worker(f, design, libs, colorSeed, flag_width, flag_signed, flag_stretch, flag_enum, flag_abbreviate, flag_notitle, color_selections, label_selections, colorattr);
                fclose(f);

                for (auto lib : libs)
                        delete lib;

                if (worker.page_counter == 0)
                        log_cmd_error("Nothing there to show.\n");

                if (format != "dot" && !format.empty()) {
                        #ifdef _WIN32
                                // system()/cmd.exe does not understand single quotes on Windows.
                                #define DOT_CMD "dot -T%s \"%s\" > \"%s.new\" && move \"%s.new\" \"%s\""
                        #else
                                #define DOT_CMD "dot -T%s '%s' > '%s.new' && mv '%s.new' '%s'"
                        #endif
                        std::string cmd = stringf(DOT_CMD, format.c_str(), dot_file.c_str(), out_file.c_str(), out_file.c_str(), out_file.c_str());
                        #undef DOT_CMD
                        log("Exec: %s\n", cmd.c_str());
                        if (run_command(cmd) != 0)
                                log_cmd_error("Shell command failed!\n");
                }

                if (!viewer_exe.empty()) {
                        #ifdef _WIN32
                                // system()/cmd.exe does not understand single quotes nor
                                // background tasks on Windows. So we have to pause yosys
                                // until the viewer exits.
                                std::string cmd = stringf("%s \"%s\"", viewer_exe.c_str(), out_file.c_str());
                        #else
                                std::string cmd = stringf("%s '%s' %s", viewer_exe.c_str(), out_file.c_str(), background.c_str());
                        #endif
                        log("Exec: %s\n", cmd.c_str());
                        if (run_command(cmd) != 0)
                                log_cmd_error("Shell command failed!\n");
                } else
                if (format.empty()) {
                        #ifdef __APPLE__
                        std::string cmd = stringf("ps -fu %d | grep -q '[ ]%s' || xdot '%s' %s", getuid(), dot_file.c_str(), dot_file.c_str(), background.c_str());
                        #else
                        std::string cmd = stringf("{ test -f '%s.pid' && fuser -s '%s.pid' 2> /dev/null; } || ( echo $$ >&3; exec xdot '%s'; ) 3> '%s.pid' %s", dot_file.c_str(), dot_file.c_str(), dot_file.c_str(), dot_file.c_str(), background.c_str());
                        #endif
                        log("Exec: %s\n", cmd.c_str());
                        if (run_command(cmd) != 0)
                                log_cmd_error("Shell command failed!\n");
                }

                if (flag_pause) {
                #ifdef YOSYS_ENABLE_READLINE
                        char *input = nullptr;
                        while ((input = readline("Press ENTER to continue (or type 'shell' to open a shell)> ")) != nullptr) {
                                if (input[strspn(input, " \t\r\n")] == 0)
                                        break;
                                char *p = input + strspn(input, " \t\r\n");
                                if (!strcmp(p, "shell")) {
                                        Pass::call(design, "shell");
                                        break;
                                }
                        }
                #else
                        log_cmd_error("This version of yosys is built without readline support => 'show -pause' is not available.\n");
                #endif
                }

                log_pop();
        }
} ShowPass;

PRIVATE_NAMESPACE_END