1 files changed, 141 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/Frontend/DependencyGraph.cpp b/contrib/llvm/tools/clang/lib/Frontend/DependencyGraph.cpp
new file mode 100644
index 000000000000..c6c9ac2ea2fa
--- /dev/null
+++ b/contrib/llvm/tools/clang/lib/Frontend/DependencyGraph.cpp
@@ -0,0 +1,141 @@
+//===--- DependencyGraph.cpp - Generate dependency file -------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This code generates a header dependency graph in DOT format, for use
+// with, e.g., GraphViz.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/Utils.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Lex/PPCallbacks.h"
+#include "clang/Lex/Preprocessor.h"
+#include "llvm/ADT/SetVector.h"
+#include "llvm/Support/GraphWriter.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace clang;
+namespace DOT = llvm::DOT;
+
+namespace {
+class DependencyGraphCallback : public PPCallbacks {
+  const Preprocessor *PP;
+  std::string OutputFile;
+  std::string SysRoot;
+  llvm::SetVector<const FileEntry *> AllFiles;
+  typedef llvm::DenseMap<const FileEntry *,
+                         SmallVector<const FileEntry *, 2> > DependencyMap;
+
+  DependencyMap Dependencies;
+
+private:
+  raw_ostream &writeNodeReference(raw_ostream &OS,
+                                  const FileEntry *Node);
+  void OutputGraphFile();
+
+public:
+  DependencyGraphCallback(const Preprocessor *_PP, StringRef OutputFile,
+                          StringRef SysRoot)
+    : PP(_PP), OutputFile(OutputFile.str()), SysRoot(SysRoot.str()) { }
+
+  void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
+                          StringRef FileName, bool IsAngled,
+                          CharSourceRange FilenameRange, const FileEntry *File,
+                          StringRef SearchPath, StringRef RelativePath,
+                          const Module *Imported,
+                          SrcMgr::CharacteristicKind FileType) override;
+
+  void EndOfMainFile() override {
+    OutputGraphFile();
+  }
+
+};
+}
+
+void clang::AttachDependencyGraphGen(Preprocessor &PP, StringRef OutputFile,
+                                     StringRef SysRoot) {
+  PP.addPPCallbacks(llvm::make_unique<DependencyGraphCallback>(&PP, OutputFile,
+                                                               SysRoot));
+}
+
+void DependencyGraphCallback::InclusionDirective(
+    SourceLocation HashLoc,
+    const Token &IncludeTok,
+    StringRef FileName,
+    bool IsAngled,
+    CharSourceRange FilenameRange,
+    const FileEntry *File,
+    StringRef SearchPath,
+    StringRef RelativePath,
+    const Module *Imported,
+    SrcMgr::CharacteristicKind FileType) {
+  if (!File)
+    return;
+
+  SourceManager &SM = PP->getSourceManager();
+  const FileEntry *FromFile
+    = SM.getFileEntryForID(SM.getFileID(SM.getExpansionLoc(HashLoc)));
+  if (!FromFile)
+    return;
+
+  Dependencies[FromFile].push_back(File);
+
+  AllFiles.insert(File);
+  AllFiles.insert(FromFile);
+}
+
+raw_ostream &
+DependencyGraphCallback::writeNodeReference(raw_ostream &OS,
+                                            const FileEntry *Node) {
+  OS << "header_" << Node->getUID();
+  return OS;
+}
+
+void DependencyGraphCallback::OutputGraphFile() {
+  std::error_code EC;
+  llvm::raw_fd_ostream OS(OutputFile, EC, llvm::sys::fs::F_Text);
+  if (EC) {
+    PP->getDiagnostics().Report(diag::err_fe_error_opening) << OutputFile
+                                                            << EC.message();
+    return;
+  }
+
+  OS << "digraph \"dependencies\" {\n";
+
+  // Write the nodes
+  for (unsigned I = 0, N = AllFiles.size(); I != N; ++I) {
+    // Write the node itself.
+    OS.indent(2);
+    writeNodeReference(OS, AllFiles[I]);
+    OS << " [ shape=\"box\", label=\"";
+    StringRef FileName = AllFiles[I]->getName();
+    if (FileName.startswith(SysRoot))
+      FileName = FileName.substr(SysRoot.size());
+
+    OS << DOT::EscapeString(FileName)
+    << "\"];\n";
+  }
+
+  // Write the edges
+  for (DependencyMap::iterator F = Dependencies.begin(),
+                            FEnd = Dependencies.end();
+       F != FEnd; ++F) {
+    for (unsigned I = 0, N = F->second.size(); I != N; ++I) {
+      OS.indent(2);
+      writeNodeReference(OS, F->first);
+      OS << " -> ";
+      writeNodeReference(OS, F->second[I]);
+      OS << ";\n";
+    }
+  }
+  OS << "}\n";
+}
+