flang/lib/Parser/type-parser-implementation.h

   1 //===-- lib/Parser/type-parser-implementation.h -----------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // Macros for implementing per-type parsers
  10
  11 #ifndef FORTRAN_PARSER_TYPE_PARSER_IMPLEMENTATION_H_
  12 #define FORTRAN_PARSER_TYPE_PARSER_IMPLEMENTATION_H_
  13
  14 #include "type-parsers.h"
  15
  16 #undef TYPE_PARSER
  17 #undef TYPE_CONTEXT_PARSER
  18
  19 // The result type of a parser combinator expression is determined
  20 // here via "decltype(attempt(pexpr))" to work around a g++ bug that
  21 // causes it to crash on "decltype(pexpr)" when pexpr's top-level
  22 // operator is an overridden || of parsing alternatives.
  23 #define TYPE_PARSER(pexpr) \
  24   template <> \
  25   auto Parser<typename decltype(attempt(pexpr))::resultType>::Parse( \
  26       ParseState &state) \
  27       ->std::optional<resultType> { \
  28     static constexpr auto parser{(pexpr)}; \
  29     return parser.Parse(state); \
  30   }
  31
  32 #define TYPE_CONTEXT_PARSER(contextText, pexpr) \
  33   TYPE_PARSER(CONTEXT_PARSER((contextText), (pexpr)))
  34
  35 #endif