src/llvm/tools/clang/lib/Frontend/HeaderIncludeGen.cpp

   1 //===--- HeaderIncludes.cpp - Generate Header Includes --------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "clang/Frontend/Utils.h"
  11 #include "clang/Basic/SourceManager.h"
  12 #include "clang/Frontend/FrontendDiagnostic.h"
  13 #include "clang/Lex/Preprocessor.h"
  14 #include "llvm/ADT/SmallString.h"
  15 #include "llvm/Support/raw_ostream.h"
  16 using namespace clang;
  17
  18 namespace {
  19 class HeaderIncludesCallback : public PPCallbacks {
  20   SourceManager &SM;
  21   raw_ostream *OutputFile;
  22   unsigned CurrentIncludeDepth;
  23   bool HasProcessedPredefines;
  24   bool OwnsOutputFile;
  25   bool ShowAllHeaders;
  26   bool ShowDepth;
  27
  28 public:
  29   HeaderIncludesCallback(const Preprocessor *PP, bool ShowAllHeaders_,
  30                          raw_ostream *OutputFile_, bool OwnsOutputFile_,
  31                          bool ShowDepth_)
  32     : SM(PP->getSourceManager()), OutputFile(OutputFile_),
  33       CurrentIncludeDepth(0), HasProcessedPredefines(false),
  34       OwnsOutputFile(OwnsOutputFile_), ShowAllHeaders(ShowAllHeaders_),
  35       ShowDepth(ShowDepth_) {}
  36
  37   ~HeaderIncludesCallback() {
  38     if (OwnsOutputFile)
  39       delete OutputFile;
  40   }
  41
  42   virtual void FileChanged(SourceLocation Loc, FileChangeReason Reason,
  43                            SrcMgr::CharacteristicKind FileType,
  44                            FileID PrevFID);
  45 };
  46 }
  47
  48 void clang::AttachHeaderIncludeGen(Preprocessor &PP, bool ShowAllHeaders,
  49                                    StringRef OutputPath, bool ShowDepth) {
  50   raw_ostream *OutputFile = &llvm::errs();
  51   bool OwnsOutputFile = false;
  52
  53   // Open the output file, if used.
  54   if (!OutputPath.empty()) {
  55     std::string Error;
  56     llvm::raw_fd_ostream *OS = new llvm::raw_fd_ostream(
  57       OutputPath.str().c_str(), Error, llvm::raw_fd_ostream::F_Append);
  58     if (!Error.empty()) {
  59       PP.getDiagnostics().Report(
  60         clang::diag::warn_fe_cc_print_header_failure) << Error;
  61       delete OS;
  62     } else {
  63       OS->SetUnbuffered();
  64       OS->SetUseAtomicWrites(true);
  65       OutputFile = OS;
  66       OwnsOutputFile = true;
  67     }
  68   }
  69
  70   PP.addPPCallbacks(new HeaderIncludesCallback(&PP, ShowAllHeaders,
  71                                                OutputFile, OwnsOutputFile,
  72                                                ShowDepth));
  73 }
  74
  75 void HeaderIncludesCallback::FileChanged(SourceLocation Loc,
  76                                          FileChangeReason Reason,
  77                                        SrcMgr::CharacteristicKind NewFileType,
  78                                        FileID PrevFID) {
  79   // Unless we are exiting a #include, make sure to skip ahead to the line the
  80   // #include directive was at.
  81   PresumedLoc UserLoc = SM.getPresumedLoc(Loc);
  82   if (UserLoc.isInvalid())
  83     return;
  84
  85   // Adjust the current include depth.
  86   if (Reason == PPCallbacks::EnterFile) {
  87     ++CurrentIncludeDepth;
  88   } else if (Reason == PPCallbacks::ExitFile) {
  89     if (CurrentIncludeDepth)
  90       --CurrentIncludeDepth;
  91
  92     // We track when we are done with the predefines by watching for the first
  93     // place where we drop back to a nesting depth of 1.
  94     if (CurrentIncludeDepth == 1 && !HasProcessedPredefines)
  95       HasProcessedPredefines = true;
  96
  97     return;
  98   } else
  99     return;
 100
 101   // Show the header if we are (a) past the predefines, or (b) showing all
 102   // headers and in the predefines at a depth past the initial file and command
 103   // line buffers.
 104   bool ShowHeader = (HasProcessedPredefines ||
 105                      (ShowAllHeaders && CurrentIncludeDepth > 2));
 106
 107   // Dump the header include information we are past the predefines buffer or
 108   // are showing all headers.
 109   if (ShowHeader && Reason == PPCallbacks::EnterFile) {
 110     // Write to a temporary string to avoid unnecessary flushing on errs().
 111     SmallString<512> Filename(UserLoc.getFilename());
 112     Lexer::Stringify(Filename);
 113
 114     SmallString<256> Msg;
 115     if (ShowDepth) {
 116       // The main source file is at depth 1, so skip one dot.
 117       for (unsigned i = 1; i != CurrentIncludeDepth; ++i)
 118         Msg += '.';
 119       Msg += ' ';
 120     }
 121     Msg += Filename;
 122     Msg += '\n';
 123
 124     OutputFile->write(Msg.data(), Msg.size());
 125   }
 126 }