1 files changed, 52 insertions, 0 deletions
diff --git a/llvm/lib/TableGen/TableGenBackend.cpp b/llvm/lib/TableGen/TableGenBackend.cpp
new file mode 100644
index 000000000000..e11b28e8cff9
--- /dev/null
+++ b/llvm/lib/TableGen/TableGenBackend.cpp
@@ -0,0 +1,52 @@
+//===- TableGenBackend.cpp - Utilities for TableGen Backends ----*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file provides useful services for TableGen backends...
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/TableGen/TableGenBackend.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+const size_t MAX_LINE_LEN = 80U;
+
+static void printLine(raw_ostream &OS, const Twine &Prefix, char Fill,
+                      StringRef Suffix) {
+  size_t Pos = (size_t)OS.tell();
+  assert((Prefix.str().size() + Suffix.size() <= MAX_LINE_LEN) &&
+         "header line exceeds max limit");
+  OS << Prefix;
+  for (size_t i = (size_t)OS.tell() - Pos, e = MAX_LINE_LEN - Suffix.size();
+         i < e; ++i)
+    OS << Fill;
+  OS << Suffix << '\n';
+}
+
+void llvm::emitSourceFileHeader(StringRef Desc, raw_ostream &OS) {
+  printLine(OS, "/*===- TableGen'erated file ", '-', "*- C++ -*-===*\\");
+  StringRef Prefix("|* ");
+  StringRef Suffix(" *|");
+  printLine(OS, Prefix, ' ', Suffix);
+  size_t PSLen = Prefix.size() + Suffix.size();
+  assert(PSLen < MAX_LINE_LEN);
+  size_t Pos = 0U;
+  do {
+    size_t Length = std::min(Desc.size() - Pos, MAX_LINE_LEN - PSLen);
+    printLine(OS, Prefix + Desc.substr(Pos, Length), ' ', Suffix);
+    Pos += Length;
+  } while (Pos < Desc.size());
+  printLine(OS, Prefix, ' ', Suffix);
+  printLine(OS, Prefix + "Automatically generated file, do not edit!", ' ',
+    Suffix);
+  printLine(OS, Prefix, ' ', Suffix);
+  printLine(OS, "\\*===", '-', "===*/");
+  OS << '\n';
+}