path: root/lib/Lex/HeaderSearch.cpp

//===--- HeaderSearch.cpp - Resolve Header File Locations ---===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file implements the DirectoryLookup and HeaderSearch interfaces.
//
//===----------------------------------------------------------------------===//

#include "clang/Lex/HeaderSearch.h"
#include "clang/Lex/HeaderMap.h"
#include "clang/Lex/Lexer.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/FileManager.h"
#include "clang/Basic/IdentifierTable.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Path.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/Capacity.h"
#include <cstdio>
using namespace clang;

const IdentifierInfo *
HeaderFileInfo::getControllingMacro(ExternalIdentifierLookup *External) {
  if (ControllingMacro)
    return ControllingMacro;

  if (!ControllingMacroID || !External)
    return 0;

  ControllingMacro = External->GetIdentifier(ControllingMacroID);
  return ControllingMacro;
}

ExternalHeaderFileInfoSource::~ExternalHeaderFileInfoSource() {}

HeaderSearch::HeaderSearch(FileManager &FM, DiagnosticsEngine &Diags,
                           const LangOptions &LangOpts)
  : FileMgr(FM), Diags(Diags), FrameworkMap(64), 
    ModMap(FileMgr, *Diags.getClient(), LangOpts) 
{
  AngledDirIdx = 0;
  SystemDirIdx = 0;
  NoCurDirSearch = false;

  ExternalLookup = 0;
  ExternalSource = 0;
  NumIncluded = 0;
  NumMultiIncludeFileOptzn = 0;
  NumFrameworkLookups = NumSubFrameworkLookups = 0;
}

HeaderSearch::~HeaderSearch() {
  // Delete headermaps.
  for (unsigned i = 0, e = HeaderMaps.size(); i != e; ++i)
    delete HeaderMaps[i].second;
}

void HeaderSearch::PrintStats() {
  fprintf(stderr, "\n*** HeaderSearch Stats:\n");
  fprintf(stderr, "%d files tracked.\n", (int)FileInfo.size());
  unsigned NumOnceOnlyFiles = 0, MaxNumIncludes = 0, NumSingleIncludedFiles = 0;
  for (unsigned i = 0, e = FileInfo.size(); i != e; ++i) {
    NumOnceOnlyFiles += FileInfo[i].isImport;
    if (MaxNumIncludes < FileInfo[i].NumIncludes)
      MaxNumIncludes = FileInfo[i].NumIncludes;
    NumSingleIncludedFiles += FileInfo[i].NumIncludes == 1;
  }
  fprintf(stderr, "  %d #import/#pragma once files.\n", NumOnceOnlyFiles);
  fprintf(stderr, "  %d included exactly once.\n", NumSingleIncludedFiles);
  fprintf(stderr, "  %d max times a file is included.\n", MaxNumIncludes);

  fprintf(stderr, "  %d #include/#include_next/#import.\n", NumIncluded);
  fprintf(stderr, "    %d #includes skipped due to"
          " the multi-include optimization.\n", NumMultiIncludeFileOptzn);

  fprintf(stderr, "%d framework lookups.\n", NumFrameworkLookups);
  fprintf(stderr, "%d subframework lookups.\n", NumSubFrameworkLookups);
}

/// CreateHeaderMap - This method returns a HeaderMap for the specified
/// FileEntry, uniquing them through the the 'HeaderMaps' datastructure.
const HeaderMap *HeaderSearch::CreateHeaderMap(const FileEntry *FE) {
  // We expect the number of headermaps to be small, and almost always empty.
  // If it ever grows, use of a linear search should be re-evaluated.
  if (!HeaderMaps.empty()) {
    for (unsigned i = 0, e = HeaderMaps.size(); i != e; ++i)
      // Pointer equality comparison of FileEntries works because they are
      // already uniqued by inode.
      if (HeaderMaps[i].first == FE)
        return HeaderMaps[i].second;
  }

  if (const HeaderMap *HM = HeaderMap::Create(FE, FileMgr)) {
    HeaderMaps.push_back(std::make_pair(FE, HM));
    return HM;
  }

  return 0;
}

const FileEntry *HeaderSearch::lookupModule(StringRef ModuleName,
                                            Module *&Module,
                                            std::string *ModuleFileName) {
  Module = 0;
  
  // If we don't have a module cache path, we can't do anything.
  if (ModuleCachePath.empty()) {
    if (ModuleFileName)
      ModuleFileName->clear();
    return 0;
  }
  
  // Try to find the module path.
  llvm::SmallString<256> FileName(ModuleCachePath);
  llvm::sys::path::append(FileName, ModuleName + ".pcm");
  if (ModuleFileName)
    *ModuleFileName = FileName.str();
      
  // Look in the module map to determine if there is a module by this name.
  Module = ModMap.findModule(ModuleName);
  if (!Module) {
    // Look through the various header search paths to load any avaiable module 
    // maps, searching for a module map that describes this module.
    for (unsigned