YugabyteDB (2.13.0.0-b42, bfc6a6643e7399ac8a0e81d06a3ee6d6571b33ab)

//--------------------------------------------------------------------------------------------------

// Copyright (c) YugaByte, Inc.

//

// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except

// in compliance with the License.  You may obtain a copy of the License at

//

// http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software distributed under the License

// is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express

// or implied.  See the License for the specific language governing permissions and limitations

// under the License.

//

//--------------------------------------------------------------------------------------------------

#include <fstream>

#include <vector>

#include <glog/logging.h>

#include "yb/bfql/directory.h"

#include "yb/common/ql_type.h"

#include "yb/gutil/strings/substitute.h"

using std::endl;

using std::map;

using std::ofstream;

using std::string;

using std::to_string;

using std::vector;

namespace yb {

namespace bfql {

static const char *kFileStart =

  "// Copyright (c) YugaByte, Inc.\n\n";

static const char *kFileNamespace =

  "namespace yb {\n"

  "namespace bfql {\n"

  "\n";

static const char *kFileEnd =

  "\n"

  "} // namespace bfql\n"

  "} // namespace yb\n";

struct BFClassInfo {

  BFClassInfo(const string& cname, const string& oname, const string& ovl_oname)

      : class_name(cname), opname(oname), overloaded_opname(ovl_oname) {

  }

  string class_name;

  string opname;

  string overloaded_opname;

};

class BFCodegen {

 public:

  static const int kHasParamResult = 0;

  static const int kHasParamOnly = 1;

  static const int kHasResultOnly = 1;

  // Because SQL functions might need to support IN/OUT parameters, we won't provide const& option.

  // Each argument is either a shared_ptr, raw pointer, or reference.

  enum class BFApiParamOption {

    kSharedPtr, // Both arguments and returned-result are shared_ptr.

    kRawPtr,    // Both arguments and returned-result are raw pointers.

    kRefAndRaw, // Arguments are references (Type &arg), and returned-result is a raw pointer.

  };

  // Typeargs datatype.

  void GenerateOpcodes(string build_dir) {

    ofstream fopcode;

    fopcode.open(build_dir + "/gen_opcodes.h");

    fopcode << kFileStart

            << "#ifndef YB_UTIL_BFQL_GEN_OPCODES_H_" << endl

            << "#define YB_UTIL_BFQL_GEN_OPCODES_H_" << endl

            << endl

            << "#include <unordered_map>" << endl

            << endl

            << kFileNamespace;

    // Start an enum class with a NO_OP.

    operator_ids_.reserve(kBFDirectory.size());

    fopcode << "enum class BFOpcode : int32_t {" << endl;

    // All builtin operators should be prefix with "OP_".

    string min_opcode;

    int op_index = 0;

    for (BFDecl entry : kBFDirectory) {

      // Form the opcode and print it.

      string current_opcode = entry.bfopcode_name();

      if (current_opcode.empty()) {

        current_opcode = strings::Substitute("OPCODE_$0_$1", entry.cpp_name(), op_index);

      }

      fopcode << "  " << current_opcode << "," << endl;

      if (op_index == 0) {

        min_opcode = current_opcode;

      }

      // Find the last generated opcode that this opcode is overloading.

      string overloaded_opcode;

      if (yql2opcode_.find(entry.ql_name()) == yql2opcode_.end()) {

        overloaded_opcode = current_opcode;

      } else {

        overloaded_opcode = yql2opcode_[entry.ql_name()];

      }

      yql2opcode_[entry.ql_name()] = current_opcode;

      // Use opcode enum value to create unique operator name. This operator keeps the last

      // overloaded opcode to form a chain between overloading opcodes for the same ql_name.

      // Using this chain we can track all opcodes that are mapped to the same ql_name.

      operator_ids_.emplace_back(strings::Substitute("OPERATOR_$0_$1", entry.cpp_name(), op_index),

                                 current_opcode, overloaded_opcode);

      op_index++;

    }

    fopcode << "  OPCODE_MAX_VALUE" << endl;

    fopcode << "};" << endl;

    fopcode << "const BFOpcode BFOPCODE_NOOP = BFOpcode::" << min_opcode << ";" << endl

            << "const BFOpcode BFOPCODE_MIN_VALUE = BFOpcode::" << min_opcode << ";" << endl

            << "const BFOpcode BFOPCODE_MAX_VALUE = BFOpcode::OPCODE_MAX_VALUE" << ";" << endl

            << endl;

    fopcode << "extern const std::unordered_map<std::string, BFOpcode> kBfqlName2Opcode;" << endl;

    // Ending the file.

    fopcode << kFileEnd;

    fopcode << "#endif" << endl;

    fopcode.close();

  }

  void GenerateOpcodeTable(string build_dir) {

    ofstream fopcode;

    fopcode.open(build_dir + "/gen_opcode_table.cc");

    fopcode << kFileStart

            // Including header files.

            << "#include <iostream>" << endl

            << "#include <unordered_map>" << endl

            << "#include \"yb/bfql/gen_opcodes.h\"" << endl

            << endl

            // Use namespaces.

            << "using std::string;" << endl

            << "using std::unordered_map;" << endl

            << endl

            << kFileNamespace;

    // Generating code.

    fopcode << "// Defining table to map ql_name to opcodes." << endl;

    fopcode << "const std::unordered_map<string, BFOpcode> kBfqlName2Opcode = {" << endl;

    for (auto entry : yql2opcode_) {

      // For overload function only the opcode with max value is inserted.

      // string ql_name = entry.first;

      // string opname = strings::Substitute("BFOpcode::OPCODE_$0_$1", entry.first, entry.second);

      // string opname = entry.second;

      fopcode << "  { \"" << entry.first << "\", " << "BFOpcode::" << entry.second << " }," << endl;

    }

    fopcode << "};" << endl;

    // Ending the file.

    fopcode << kFileEnd;

    fopcode.close();

  }

  void GenerateOperators(string build_dir) {

    // Create header file, "gen_operator.h", for operator declarations.

    ofstream foper_h;

    foper_h.open(build_dir + "/gen_operator.h");

    foper_h << kFileStart

            << "#ifndef YB_UTIL_BFQL_GEN_OPERATOR_H_" << endl

            << "#define YB_UTIL_BFQL_GEN_OPERATOR_H_" << endl

            << endl

            << "#include \"yb/bfql/base_operator.h\"" << endl

            << "#include \"yb/bfql/bfunc.h\"" << endl

            << endl

            << "#include <vector>" << endl

            << endl

            // Use namespaces.

            << "using std::vector;" << endl

            << endl

            << kFileNamespace;

    int op_index = 0;

    for (BFDecl entry : kBFDirectory) {

      // Define operator class.

      GenerateDecl(entry, foper_h, operator_ids_[op_index].class_name);

      op_index++;

    }

    foper_h << endl;

    foper_h << "extern const std::vector<BFOperator::SharedPtr> kBFOperators;" << endl

            << endl;

    // Ending the header file.

    foper_h << kFileEnd

            << "#endif" << endl;

    foper_h.close();

  }

  void GenerateDecl(BFDecl entry, ofstream &foper_h, string class_name) {

    // Declare an operator with the following specification

    // class OPERATOR_xxx : public BFOperator {

    //  public:

    //   OPERATOR_xxx(...) : BFOperator(...);

    //   static Status Exec(...); -- This takes mutable parameters.

    // };

    foper_h << "class " << class_name << " : public BFOperator {" << endl

            << " public:" << endl

            << "  " << class_name << "(" << endl

            << "    BFOpcode opcode," << endl

            << "    BFOpcode overloaded_opcode," << endl

            << "    const BFDecl *op_decl)" << endl

            << "      : BFOperator(opcode, overloaded_opcode, op_decl) {" << endl

            << "  }" << endl

            << endl;

    GenerateExecFunc(entry, foper_h, BFApiParamOption::kSharedPtr);

    foper_h << endl;

    GenerateExecFunc(entry, foper_h, BFApiParamOption::kRawPtr);

    foper_h << endl;

    GenerateExecFunc(entry, foper_h, BFApiParamOption::kRefAndRaw);

    // End operator class.

    foper_h << "};" << endl

            << endl;

  }

  void GenerateExecFunc(BFDecl entry, ofstream &foper_h, BFApiParamOption param_option) {

    // Print function call. Four possible cases

    // - No parameter & no result:     func()

    //

    // - No result:                    func(params[0])

    //                              OR func(&params[0])

    //

    // - No parameter:                 func(result)

    //

    // - Has parameter & result:       func(params[0], params[1], result)

    //                              OR func(&params[0], &params[1], result)

    // When arguments are ref, character "&" is used to convert it to pointer. For argument that

    // are already pointers, no conversion is needed.

    const char *param_pointer = "params";

    switch (param_option) {

      case BFApiParamOption::kSharedPtr:

        // For shared_ptr, the parameter would be "const std::shared_ptr<>&".

        foper_h << "  template<typename PType, typename RType>" << endl

                << "  static Status Exec(const std::vector<std::shared_ptr<PType>>& params," << endl

                << "                     const std::shared_ptr<RType>& result) {" << endl

                << "    return "

                << entry.cpp_name() << "(";

        break;

      case BFApiParamOption::kRawPtr:

        // Raw pointer.

        foper_h << "  template<typename PType, typename RType>" << endl

                << "  static Status ExecRaw(const std::vector<PType*>& params," << endl

                << "                        RType *result) {" << endl

                << "    return " << entry.cpp_name() << "(";

        break;

      case BFApiParamOption::kRefAndRaw:

        // Reference of object.

        foper_h << "  template<typename PType, typename RType>" << endl

                << "  static Status ExecRefAndRaw(std::vector<PType> *params," << endl

                << "                              RType *result) {" << endl;

        if (entry.param_types().size() == 1 && entry.param_types()[0] == DataType::TYPEARGS) {

          // If the caller used the kRefAndRaw option, we'll have to convert the params vector from

          // vector<object> to vector<object*>.

          param_pointer = "local_params";

          foper_h << "    const auto count = params->size();" << endl

                  << "    std::vector<PType*> local_params(count);" << endl

                  << "    for (size_t i = 0; i < count; i++) {" << endl

                  << "      local_params[i] = &(*params)[i];" << endl

                  << "    }" << endl;

          foper_h << "    return " << entry.cpp_name() << "(";

        } else {

          param_pointer = "&(*params)";

          foper_h << "    return " << entry.cpp_name() << "(";

        }

    }

    string param_end;

    int pindex = 0;

    for (DataType param_type : entry.param_types()) {

      foper_h << param_end;

      param_end = ", ";

      if (param_type == DataType::TYPEARGS) {

        // Break from the loop as we don't allow other argument to be use to TYPE_ARGS.

        foper_h << param_pointer;

        break;

      }

      // Deref the parameters and pass them.

      foper_h << param_pointer << "[" << pindex << "]";

      pindex++;

      // SPECIAL CASE: For CAST operator, at compile time, we need two input parameter for type

      // resolution. However, at runtime, the associated function would take one parameter and

      // convert the value to proper result, so break the loop here.

      if (strcmp(entry.ql_name(), "cast") == 0 ||

          strcmp(entry.ql_name(), "cql_cast") == 0) {

        break;

      }

    }

    if (!QLType::IsUnknown(entry.return_type())) {

      foper_h << param_end << "result";

    }

    foper_h << ");" << endl;

    // End of function Exec() and operator class

    foper_h << "  }" << endl;

  }

  void GenerateOpspecTable(string build_dir) {

    // File headers, includes, namespaces, and other declarations.

    ofstream ftable;

    ftable.open(build_dir + "/gen_opspec_table.cc");

    ftable << kFileStart

           << "#include \"yb/bfql/base_operator.h\"" << endl

           << "#include \"yb/bfql/directory.h\"" << endl

           << "#include \"yb/bfql/gen_operator.h\"" << endl

           << endl

           << "#include <iostream>" << endl

           << "#include <vector>" << endl

           << "#include <functional>" << endl

           << endl

           << "using std::function;" << endl

           << "using std::make_shared;" << endl

           << "using std::vector;" << endl

           << "using std::shared_ptr;" << endl

           << kFileNamespace;

    // Generating table of operators.

    ftable << "const vector<BFOperator::SharedPtr> kBFOperators = {" << endl;

    int op_index = 0;

    for (BFDecl entry : kBFDirectory) {

      const BFClassInfo& bfclass = operator_ids_[op_index];

      ftable << "  make_shared<" << bfclass.class_name << ">("

             << "BFOpcode::" << bfclass.opname << ", "

             << "BFOpcode::" << bfclass.overloaded_opname << ", "

             << "&kBFDirectory[" << op_index << "])," << endl;

      op_index++;

    }

    ftable << "};" << endl

           << endl;

    ftable << kFileEnd;

    ftable.close();

  }

  void GenerateExecTable(string build_dir) {

    // File headers, includes, namespaces, and other declarations.

    ofstream ftable;

    ftable.open(build_dir + "/gen_bfunc_table.h");

    ftable << kFileStart

           << "#include <iostream>" << endl

           << "#include <vector>" << endl

           << "#include <functional>" << endl

           << endl

           << "#include \"yb/bfql/bfunc.h\"" << endl

           << "#include \"yb/bfql/base_operator.h\"" << endl

           << "#include \"yb/bfql/gen_operator.h\"" << endl

           << kFileNamespace;

    // Generating table of functions whose outputs are shared pointers.

    ftable << "template<typename PType, typename RType," << endl

           << "         template<typename, typename> class CType," << endl

           << "         template<typename> class AType>" << endl

           << "const vector<std::function<Status(const std::vector<std::shared_ptr<PType>>&, "

           << "const std::shared_ptr<RType>&)>>" << endl

           << "    BFExecApi<PType, RType, CType, AType>::kBFExecFuncs = {" << endl;

    for (size_t op_index = 0; op_index < operator_ids_.size(); op_index++) {

      const BFClassInfo& bfclass = operator_ids_[op_index];

      ftable << "  " << bfclass.class_name << "::" << "Exec<PType, RType>," << endl;

    }

    ftable << "};" << endl

           << endl;

    // Generating table of functions whose outputs are raw pointers.

    ftable << "template<typename PType, typename RType," << endl

           << "         template<typename, typename> class CType," << endl

           << "         template<typename> class AType>" << endl

           << "const vector<std::function<Status(const std::vector<PType*>&, RType*)>>"

           << endl

           << "    BFExecApi<PType, RType, CType, AType>::kBFExecFuncsRaw = {" << endl;

    for (size_t op_index = 0; op_index < operator_ids_.size(); op_index++) {

      const BFClassInfo& bfclass = operator_ids_[op_index];

      ftable << "  " << bfclass.class_name << "::" << "ExecRaw<PType, RType>," << endl;

    }

    ftable << "};" << endl

           << endl;

    // Generating table of functions whose outputs are raw pointers.

    ftable << "template<typename PType, typename RType," << endl

           << "         template<typename, typename> class CType," << endl

           << "         template<typename> class AType>" << endl

           << "const vector<std::function<Status(std::vector<PType>*, RType*)>>"

           << endl

           << "    BFExecApi<PType, RType, CType, AType>::kBFExecFuncsRefAndRaw = {" << endl;

    for (size_t op_index = 0; op_index < operator_ids_.size(); op_index++) {

      const BFClassInfo& bfclass = operator_ids_[op_index];

      ftable << "  " << bfclass.class_name << "::" << "ExecRefAndRaw<PType, RType>," << endl;

    }

    ftable << "};" << endl

           << endl;

    ftable << kFileEnd;

    ftable.close();

  }

 private:

  map<string, string> yql2opcode_;

  vector<BFClassInfo> operator_ids_;

};

} // namespace bfql

} // namespace yb

using yb::bfql::BFCodegen;

int main(int argc,  char** argv) {

  if (argc < 2) {

    LOG(FATAL) << "Missing directory";

  }

  BFCodegen coder;

  string outdir = argv[1];

  // Form table of opcodes.

  coder.GenerateOpcodes(outdir);

  coder.GenerateOpcodeTable(outdir);

  // Form table of operator specification. This is used to typecheck during compilation.

  coder.GenerateOperators(outdir);

  coder.GenerateOpspecTable(outdir);

  // Form table of exec function pointer. This template is used for builtin execution.

  coder.GenerateExecTable(outdir);

  return 0;

}