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      1 //===--- ModuleDependencyCollector.cpp - Collect module dependencies ------===//
      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 // Collect the dependencies of a set of modules.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #include "clang/Frontend/Utils.h"
     15 #include "clang/Serialization/ASTReader.h"
     16 #include "llvm/ADT/StringSet.h"
     17 #include "llvm/ADT/iterator_range.h"
     18 #include "llvm/Support/FileSystem.h"
     19 #include "llvm/Support/Path.h"
     20 #include "llvm/Support/raw_ostream.h"
     21 
     22 using namespace clang;
     23 
     24 namespace {
     25 /// Private implementation for ModuleDependencyCollector
     26 class ModuleDependencyListener : public ASTReaderListener {
     27   ModuleDependencyCollector &Collector;
     28 
     29   std::error_code copyToRoot(StringRef Src);
     30 public:
     31   ModuleDependencyListener(ModuleDependencyCollector &Collector)
     32       : Collector(Collector) {}
     33   bool needsInputFileVisitation() override { return true; }
     34   bool needsSystemInputFileVisitation() override { return true; }
     35   bool visitInputFile(StringRef Filename, bool IsSystem,
     36                       bool IsOverridden) override;
     37 };
     38 }
     39 
     40 void ModuleDependencyCollector::attachToASTReader(ASTReader &R) {
     41   R.addListener(llvm::make_unique<ModuleDependencyListener>(*this));
     42 }
     43 
     44 void ModuleDependencyCollector::writeFileMap() {
     45   if (Seen.empty())
     46     return;
     47 
     48   SmallString<256> Dest = getDest();
     49   llvm::sys::path::append(Dest, "vfs.yaml");
     50 
     51   std::error_code EC;
     52   llvm::raw_fd_ostream OS(Dest, EC, llvm::sys::fs::F_Text);
     53   if (EC) {
     54     setHasErrors();
     55     return;
     56   }
     57   VFSWriter.write(OS);
     58 }
     59 
     60 std::error_code ModuleDependencyListener::copyToRoot(StringRef Src) {
     61   using namespace llvm::sys;
     62 
     63   // We need an absolute path to append to the root.
     64   SmallString<256> AbsoluteSrc = Src;
     65   fs::make_absolute(AbsoluteSrc);
     66   // Canonicalize to a native path to avoid mixed separator styles.
     67   path::native(AbsoluteSrc);
     68   // TODO: We probably need to handle .. as well as . in order to have valid
     69   // input to the YAMLVFSWriter.
     70   FileManager::removeDotPaths(AbsoluteSrc);
     71 
     72   // Build the destination path.
     73   SmallString<256> Dest = Collector.getDest();
     74   path::append(Dest, path::relative_path(AbsoluteSrc));
     75 
     76   // Copy the file into place.
     77   if (std::error_code EC = fs::create_directories(path::parent_path(Dest),
     78                                                    /*IgnoreExisting=*/true))
     79     return EC;
     80   if (std::error_code EC = fs::copy_file(AbsoluteSrc, Dest))
     81     return EC;
     82   // Use the absolute path under the root for the file mapping.
     83   Collector.addFileMapping(AbsoluteSrc, Dest);
     84   return std::error_code();
     85 }
     86 
     87 bool ModuleDependencyListener::visitInputFile(StringRef Filename, bool IsSystem,
     88                                               bool IsOverridden) {
     89   if (Collector.insertSeen(Filename))
     90     if (copyToRoot(Filename))
     91       Collector.setHasErrors();
     92   return true;
     93 }
     94