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 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 } 54