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#include <cassert>
17
18using namespace llvm;
19
20const size_t MAX_LINE_LEN = 80U;
21
22static 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
34void 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}
54