llvm/flang/lib/parser/debug-parser.h

#ifndef FORTRAN_PARSER_DEBUG_PARSER_H_
#define FORTRAN_PARSER_DEBUG_PARSER_H_

// Implements the parser with syntax "(YOUR MESSAGE HERE)"_debug for use
// in temporary modifications to the grammar intended for tracing the
// flow of the parsers.  Not to be used in production.

#include "basic-parsers.h"
#include "parse-state.h"
#include <iostream>
#include <optional>
#include <string>

namespace Fortran {
namespace parser {

class DebugParser {
public:
  using resultType = Success;
  constexpr DebugParser(const DebugParser &) = default;
  constexpr DebugParser(const char *str, size_t n) : str_{str}, length_{n} {}
  std::optional<Success> Parse(ParseState *state) const {
    if (auto context = state->context()) {
      context->Emit(std::cout, *state->cooked().allSources());
    }
    state->cooked().allSources()->Identify(
        std::cout, state->GetProvenance(), "");
    std::cout << "   parser debug: " << std::string{str_, length_} << '\n';
    return {Success{}};
  }

private:
  const char *const str_;
  size_t length_;
};

constexpr DebugParser operator""_debug(const char str[], size_t n) {
  return DebugParser{str, n};
}
}  // namespace parser
}  // namespace Fortran
#endif  // FORTRAN_PARSER_DEBUG_PARSER_H_