lib/TableGen/TableGenBackend.cpp

   1 //===- TableGenBackend.cpp - Utilities for TableGen Backends ----*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file provides useful services for TableGen backends...
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/TableGen/TableGenBackend.h"
  15 #include "llvm/ADT/Twine.h"
  16 #include "llvm/Support/raw_ostream.h"
  17
  18 using namespace llvm;
  19
  20 const size_t MAX_LINE_LEN = 80U;
  21
  22 static void printLine(raw_ostream &OS, const Twine &Prefix, char Fill,
  23                       StringRef Suffix) {
  24   size_t Pos = (size_t)OS.tell();
  25   assert((Prefix.str().size() + Suffix.size() <= MAX_LINE_LEN) &&
  26          "header line exceeds max limit");
  27   OS << Prefix;
  28   for (size_t i = (size_t)OS.tell() - Pos, e = MAX_LINE_LEN - Suffix.size();
  29          i < e; ++i)
  30     OS << Fill;
  31   OS << Suffix << '\n';
  32 }
  33
  34 void llvm::emitSourceFileHeader(StringRef Desc, raw_ostream &OS) {
  35   printLine(OS, "/*===- TableGen'erated file ", '-', "*- C++ -*-===*\\");
  36   StringRef Prefix("|* ");
  37   StringRef Suffix(" *|");
  38   printLine(OS, Prefix, ' ', Suffix);
  39   size_t PSLen = Prefix.size() + Suffix.size();
  40   assert(PSLen < MAX_LINE_LEN);
  41   size_t Pos = 0U;
  42   do {
  43     size_t Length = std::min(Desc.size() - Pos, MAX_LINE_LEN - PSLen);
  44     printLine(OS, Prefix + Desc.substr(Pos, Length), ' ', Suffix);
  45     Pos += Length;
  46   } while (Pos < Desc.size());
  47   printLine(OS, Prefix, ' ', Suffix);
  48   printLine(OS, Prefix + "Automatically generated file, do not edit!", ' ',
  49     Suffix);
  50   printLine(OS, Prefix, ' ', Suffix);
  51   printLine(OS, "\\*===", '-', "===*/");
  52   OS << '\n';
  53 }