lib/TableGen/TableGenBackend.cpp

   1 //===- TableGenBackend.cpp - Utilities for TableGen Backends ----*- 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 // This file provides useful services for TableGen backends...
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/TableGen/TableGenBackend.h"
  14 #include "llvm/ADT/Twine.h"
  15 #include "llvm/Support/raw_ostream.h"
  16
  17 using namespace llvm;
  18
  19 const size_t MAX_LINE_LEN = 80U;
  20
  21 static void printLine(raw_ostream &OS, const Twine &Prefix, char Fill,
  22                       StringRef Suffix) {
  23   size_t Pos = (size_t)OS.tell();
  24   assert((Prefix.str().size() + Suffix.size() <= MAX_LINE_LEN) &&
  25          "header line exceeds max limit");
  26   OS << Prefix;
  27   for (size_t i = (size_t)OS.tell() - Pos, e = MAX_LINE_LEN - Suffix.size();
  28          i < e; ++i)
  29     OS << Fill;
  30   OS << Suffix << '\n';
  31 }
  32
  33 void llvm::emitSourceFileHeader(StringRef Desc, raw_ostream &OS) {
  34   printLine(OS, "/*===- TableGen'erated file ", '-', "*- C++ -*-===*\\");
  35   StringRef Prefix("|* ");
  36   StringRef Suffix(" *|");
  37   printLine(OS, Prefix, ' ', Suffix);
  38   size_t PSLen = Prefix.size() + Suffix.size();
  39   assert(PSLen < MAX_LINE_LEN);
  40   size_t Pos = 0U;
  41   do {
  42     size_t Length = std::min(Desc.size() - Pos, MAX_LINE_LEN - PSLen);
  43     printLine(OS, Prefix + Desc.substr(Pos, Length), ' ', Suffix);
  44     Pos += Length;
  45   } while (Pos < Desc.size());
  46   printLine(OS, Prefix, ' ', Suffix);
  47   printLine(OS, Prefix + "Automatically generated file, do not edit!", ' ',
  48     Suffix);
  49   printLine(OS, Prefix, ' ', Suffix);
  50   printLine(OS, "\\*===", '-', "===*/");
  51   OS << '\n';
  52 }