Merge pull request #353 from YosysHQ/generic-frontend

New hierarchy-capable generic frontend framework and json11 based JSON frontend

1 files changed, 203 insertions, 0 deletions

diff --git a/frontend/json_frontend.cc b/frontend/json_frontend.cc
new file mode 100644
index 00000000..d2e6248e
--- /dev/null
+++ b/frontend/json_frontend.cc
@@ -0,0 +1,203 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2019  David Shah <dave@ds0.me>
+ *
+ *  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 "json_frontend.h"
+#include "frontend_base.h"
+#include "json11.hpp"
+#include "log.h"
+#include "nextpnr.h"
+
+#include <streambuf>
+
+NEXTPNR_NAMESPACE_BEGIN
+
+using namespace json11;
+
+struct JsonFrontendImpl
+{
+    // See specification in frontend_base.h
+    JsonFrontendImpl(Json &root) : root(root){};
+    Json &root;
+    typedef const Json &ModuleDataType;
+    typedef const Json &ModulePortDataType;
+    typedef const Json &CellDataType;
+    typedef const Json &NetnameDataType;
+    typedef const Json::array &BitVectorDataType;
+
+    template <typename TFunc> void foreach_module(TFunc Func) const
+    {
+        for (const auto &mod : root.object_items())
+            Func(mod.first, mod.second);
+    }
+
+    template <typename TFunc> void foreach_port(const ModuleDataType &mod, TFunc Func) const
+    {
+        const auto &ports = mod["ports"];
+        if (ports.is_null())
+            return;
+        for (const auto &port : ports.object_items())
+            Func(port.first, port.second);
+    }
+
+    template <typename TFunc> void foreach_cell(const ModuleDataType &mod, TFunc Func) const
+    {
+        const auto &cells = mod["cells"];
+        if (cells.is_null())
+            return;
+        for (const auto &cell : cells.object_items())
+            Func(cell.first, cell.second);
+    }
+
+    template <typename TFunc> void foreach_netname(const ModuleDataType &mod, TFunc Func) const
+    {
+        const auto &netnames = mod["netnames"];
+        if (netnames.is_null())
+            return;
+        for (const auto &netname : netnames.object_items())
+            Func(netname.first, netname.second);
+    }
+
+    PortType lookup_portdir(const std::string &dir) const
+    {
+        if (dir == "input")
+            return PORT_IN;
+        else if (dir == "inout")
+            return PORT_INOUT;
+        else if (dir == "output")
+            return PORT_OUT;
+        else
+            NPNR_ASSERT_FALSE("invalid json port direction");
+    }
+
+    PortType get_port_dir(const ModulePortDataType &port) const
+    {
+        return lookup_portdir(port["direction"].string_value());
+    }
+
+    int get_array_offset(const Json &obj) const
+    {
+        auto offset = obj["offset"];
+        return offset.is_null() ? 0 : offset.int_value();
+    }
+
+    bool is_array_upto(const Json &obj) const
+    {
+        auto upto = obj["upto"];
+        return upto.is_null() ? false : bool(upto.int_value());
+    }
+
+    const BitVectorDataType &get_port_bits(const ModulePortDataType &port) const { return port["bits"].array_items(); }
+
+    const std::string &get_cell_type(const CellDataType &cell) const { return cell["type"].string_value(); }
+
+    Property parse_property(const Json &val) const
+    {
+        if (val.is_number())
+            return Property(val.int_value(), 32);
+        else
+            return Property::from_string(val.string_value());
+    }
+
+    template <typename TFunc> void foreach_attr(const Json &obj, TFunc Func) const
+    {
+        const auto &attrs = obj["attributes"];
+        if (attrs.is_null())
+            return;
+        for (const auto &attr : attrs.object_items()) {
+            Func(attr.first, parse_property(attr.second));
+        }
+    }
+
+    template <typename TFunc> void foreach_param(const Json &obj, TFunc Func) const
+    {
+        const auto &params = obj["parameters"];
+        if (params.is_null())
+            return;
+        for (const auto &param : params.object_items()) {
+            Func(param.first, parse_property(param.second));
+        }
+    }
+
+    template <typename TFunc> void foreach_setting(const Json &obj, TFunc Func) const
+    {
+        const auto &settings = obj["settings"];
+        if (settings.is_null())
+            return;
+        for (const auto &setting : settings.object_items()) {
+            Func(setting.first, parse_property(setting.second));
+        }
+    }
+
+    template <typename TFunc> void foreach_port_dir(const CellDataType &cell, TFunc Func) const
+    {
+        for (const auto &pdir : cell["port_directions"].object_items())
+            Func(pdir.first, lookup_portdir(pdir.second.string_value()));
+    }
+
+    template <typename TFunc> void foreach_port_conn(const CellDataType &cell, TFunc Func) const
+    {
+        for (const auto &pconn : cell["connections"].object_items())
+            Func(pconn.first, pconn.second.array_items());
+    }
+
+    const BitVectorDataType &get_net_bits(const NetnameDataType &net) const { return net["bits"].array_items(); }
+
+    int get_vector_length(const BitVectorDataType &bits) const { return int(bits.size()); }
+
+    bool is_vector_bit_constant(const BitVectorDataType &bits, int i) const
+    {
+        NPNR_ASSERT(i < int(bits.size()));
+        return bits[i].is_string();
+    }
+
+    char get_vector_bit_constval(const BitVectorDataType &bits, int i) const
+    {
+        auto s = bits.at(i).string_value();
+        NPNR_ASSERT(s.size() == 1);
+        return s.at(0);
+    }
+
+    int get_vector_bit_signal(const BitVectorDataType &bits, int i) const
+    {
+        NPNR_ASSERT(bits.at(i).is_number());
+        return bits.at(i).int_value();
+    }
+};
+
+bool parse_json(std::istream &in, const std::string &filename, Context *ctx)
+{
+    Json root;
+    {
+        if (!in)
+            log_error("Failed to open JSON file '%s'.\n", filename.c_str());
+        std::string json_str((std::istreambuf_iterator<char>(in)), std::istreambuf_iterator<char>());
+        std::string error;
+        root = Json::parse(json_str, error, JsonParse::COMMENTS);
+        if (root.is_null())
+            log_error("Failed to parse JSON file '%s': %s.\n", filename.c_str(), error.c_str());
+        root = root["modules"];
+        if (root.is_null())
+            log_error("JSON file '%s' doesn't look like a netlist (doesn't contain \"modules\" key)\n",
+                      filename.c_str());
+    }
+    GenericFrontend<JsonFrontendImpl>(ctx, JsonFrontendImpl(root))();
+    return true;
+}
+
+NEXTPNR_NAMESPACE_END