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
printLine(raw_ostream & OS,const Twine & Prefix,char Fill,StringRef Suffix)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
emitSourceFileHeader(StringRef Desc,raw_ostream & OS)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 }
53