llvm/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/Path.h"
  16 #include "llvm/Support/raw_ostream.h"
  17 #include <algorithm>
  18 #include <cassert>
  19 #include <cstddef>
  20
  21 using namespace llvm;
  22
  23 const size_t MAX_LINE_LEN = 80U;
  24
  25 namespace llvm::TableGen::Emitter {
  26 ManagedStatic<cl::opt<FnT>, OptCreatorT> Action;
  27 void *OptCreatorT::call() {
  28   return new cl::opt<FnT>(cl::desc("Action to perform:"));
  29 }
  30 } // namespace llvm::TableGen::Emitter
  31
  32 static void printLine(raw_ostream &OS, const Twine &Prefix, char Fill,
  33                       StringRef Suffix) {
  34   size_t Pos = (size_t)OS.tell();
  35   assert((Prefix.str().size() + Suffix.size() <= MAX_LINE_LEN) &&
  36          "header line exceeds max limit");
  37   OS << Prefix;
  38   for (size_t i = (size_t)OS.tell() - Pos, e = MAX_LINE_LEN - Suffix.size();
  39          i < e; ++i)
  40     OS << Fill;
  41   OS << Suffix << '\n';
  42 }
  43
  44 void llvm::emitSourceFileHeader(StringRef Desc, raw_ostream &OS,
  45                                 const RecordKeeper &Record) {
  46   printLine(OS, "/*===- TableGen'erated file ", '-', "*- C++ -*-===*\\");
  47   StringRef Prefix("|* ");
  48   StringRef Suffix(" *|");
  49   printLine(OS, Prefix, ' ', Suffix);
  50   size_t PSLen = Prefix.size() + Suffix.size();
  51   assert(PSLen < MAX_LINE_LEN);
  52   size_t Pos = 0U;
  53   do {
  54     size_t Length = std::min(Desc.size() - Pos, MAX_LINE_LEN - PSLen);
  55     printLine(OS, Prefix + Desc.substr(Pos, Length), ' ', Suffix);
  56     Pos += Length;
  57   } while (Pos < Desc.size());
  58   printLine(OS, Prefix, ' ', Suffix);
  59   printLine(OS, Prefix + "Automatically generated file, do not edit!", ' ',
  60             Suffix);
  61
  62   // Print the filename of source file
  63   if (!Record.getInputFilename().empty())
  64     printLine(
  65         OS, Prefix + "From: " + sys::path::filename(Record.getInputFilename()),
  66         ' ', Suffix);
  67   printLine(OS, Prefix, ' ', Suffix);
  68   printLine(OS, "\\*===", '-', "===*/");
  69   OS << '\n';
  70 }