libc/utils/HdrGen/IncludeFileCommand.cpp

   1 //===-- Implementation of IncludeFileCommand ------------------------------===//
   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 #include "IncludeFileCommand.h"
  10
  11 #include "llvm/Support/MemoryBuffer.h"
  12 #include "llvm/Support/SourceMgr.h"
  13
  14 #include <cstdlib>
  15
  16 namespace llvm_libc {
  17
  18 const char IncludeFileCommand::Name[] = "include_file";
  19
  20 void IncludeFileCommand::run(llvm::raw_ostream &OS, const ArgVector &Args,
  21                              llvm::StringRef StdHeader,
  22                              llvm::RecordKeeper &Records,
  23                              const Command::ErrorReporter &Reporter) const {
  24   if (Args.size() != 1) {
  25     Reporter.printFatalError(
  26         "%%include_file command takes exactly 1 argument.");
  27   }
  28
  29   llvm::StringRef IncludeFile = Args[0];
  30   auto Buffer = llvm::MemoryBuffer::getFileAsStream(IncludeFile);
  31   if (!Buffer)
  32     Reporter.printFatalError(llvm::StringRef("Unable to open ") + IncludeFile);
  33
  34   llvm::StringRef Content = Buffer.get()->getBuffer();
  35
  36   // If the included file has %%begin() command listed, then we want to write
  37   // only the content after the begin command.
  38   // TODO: The way the content is split below does not allow space within the
  39   // the parentheses and, before and after the command. This probably is too
  40   // strict and should be relaxed.
  41   auto P = Content.split("\n%%begin()\n");
  42   if (P.second.empty()) {
  43     // There was no %%begin in the content.
  44     OS << P.first;
  45   } else {
  46     OS << P.second;
  47   }
  48 }
  49
  50 } // namespace llvm_libc