1 files changed, 126 insertions, 0 deletions
diff --git a/clang/lib/Frontend/HeaderIncludeGen.cpp b/clang/lib/Frontend/HeaderIncludeGen.cpp
new file mode 100644
index 0000000..79920df
--- /dev/null
+++ b/clang/lib/Frontend/HeaderIncludeGen.cpp
@@ -0,0 +1,126 @@
+//===--- HeaderIncludes.cpp - Generate Header Includes --------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/Utils.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Lex/Preprocessor.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace clang;
+
+namespace {
+class HeaderIncludesCallback : public PPCallbacks {
+  SourceManager &SM;
+  raw_ostream *OutputFile;
+  unsigned CurrentIncludeDepth;
+  bool HasProcessedPredefines;
+  bool OwnsOutputFile;
+  bool ShowAllHeaders;
+  bool ShowDepth;
+
+public:
+  HeaderIncludesCallback(const Preprocessor *PP, bool ShowAllHeaders_,
+                         raw_ostream *OutputFile_, bool OwnsOutputFile_,
+                         bool ShowDepth_)
+    : SM(PP->getSourceManager()), OutputFile(OutputFile_),
+      CurrentIncludeDepth(0), HasProcessedPredefines(false),
+      OwnsOutputFile(OwnsOutputFile_), ShowAllHeaders(ShowAllHeaders_),
+      ShowDepth(ShowDepth_) {}
+
+  ~HeaderIncludesCallback() {
+    if (OwnsOutputFile)
+      delete OutputFile;
+  }
+
+  virtual void FileChanged(SourceLocation Loc, FileChangeReason Reason,
+                           SrcMgr::CharacteristicKind FileType,
+                           FileID PrevFID);
+};
+}
+
+void clang::AttachHeaderIncludeGen(Preprocessor &PP, bool ShowAllHeaders,
+                                   StringRef OutputPath, bool ShowDepth) {
+  raw_ostream *OutputFile = &llvm::errs();
+  bool OwnsOutputFile = false;
+
+  // Open the output file, if used.
+  if (!OutputPath.empty()) {
+    std::string Error;
+    llvm::raw_fd_ostream *OS = new llvm::raw_fd_ostream(
+      OutputPath.str().c_str(), Error, llvm::raw_fd_ostream::F_Append);
+    if (!Error.empty()) {
+      PP.getDiagnostics().Report(
+        clang::diag::warn_fe_cc_print_header_failure) << Error;
+      delete OS;
+    } else {
+      OS->SetUnbuffered();
+      OS->SetUseAtomicWrites(true);
+      OutputFile = OS;
+      OwnsOutputFile = true;
+    }
+  }
+
+  PP.addPPCallbacks(new HeaderIncludesCallback(&PP, ShowAllHeaders,
+                                               OutputFile, OwnsOutputFile,
+                                               ShowDepth));
+}
+
+void HeaderIncludesCallback::FileChanged(SourceLocation Loc,
+                                         FileChangeReason Reason,
+                                       SrcMgr::CharacteristicKind NewFileType,
+                                       FileID PrevFID) {
+  // Unless we are exiting a #include, make sure to skip ahead to the line the
+  // #include directive was at.
+  PresumedLoc UserLoc = SM.getPresumedLoc(Loc);
+  if (UserLoc.isInvalid())
+    return;
+
+  // Adjust the current include depth.
+  if (Reason == PPCallbacks::EnterFile) {
+    ++CurrentIncludeDepth;
+  } else if (Reason == PPCallbacks::ExitFile) {
+    if (CurrentIncludeDepth)
+      --CurrentIncludeDepth;
+
+    // We track when we are done with the predefines by watching for the first
+    // place where we drop back to a nesting depth of 1.
+    if (CurrentIncludeDepth == 1 && !HasProcessedPredefines)
+      HasProcessedPredefines = true;
+
+    return;
+  } else
+    return;
+
+  // Show the header if we are (a) past the predefines, or (b) showing all
+  // headers and in the predefines at a depth past the initial file and command
+  // line buffers.
+  bool ShowHeader = (HasProcessedPredefines ||
+                     (ShowAllHeaders && CurrentIncludeDepth > 2));
+
+  // Dump the header include information we are past the predefines buffer or
+  // are showing all headers.
+  if (ShowHeader && Reason == PPCallbacks::EnterFile) {
+    // Write to a temporary string to avoid unnecessary flushing on errs().
+    SmallString<512> Filename(UserLoc.getFilename());
+    Lexer::Stringify(Filename);
+
+    SmallString<256> Msg;
+    if (ShowDepth) {
+      // The main source file is at depth 1, so skip one dot.
+      for (unsigned i = 1; i != CurrentIncludeDepth; ++i)
+        Msg += '.';
+      Msg += ' ';
+    }
+    Msg += Filename;
+    Msg += '\n';
+
+    OutputFile->write(Msg.data(), Msg.size());
+  }
+}