1 files changed, 231 insertions, 0 deletions
diff --git a/clang/lib/Frontend/DependencyFile.cpp b/clang/lib/Frontend/DependencyFile.cpp
new file mode 100644
index 0000000..21f5daa
--- /dev/null
+++ b/clang/lib/Frontend/DependencyFile.cpp
@@ -0,0 +1,231 @@
+//===--- DependencyFile.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 dependency files.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/Utils.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Frontend/DependencyOutputOptions.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Lex/DirectoryLookup.h"
+#include "clang/Lex/LexDiagnostic.h"
+#include "clang/Lex/PPCallbacks.h"
+#include "clang/Lex/Preprocessor.h"
+#include "llvm/ADT/StringSet.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace clang;
+
+namespace {
+class DependencyFileCallback : public PPCallbacks {
+  std::vector<std::string> Files;
+  llvm::StringSet<> FilesSet;
+  const Preprocessor *PP;
+  std::string OutputFile;
+  std::vector<std::string> Targets;
+  bool IncludeSystemHeaders;
+  bool PhonyTarget;
+  bool AddMissingHeaderDeps;
+  bool SeenMissingHeader;
+private:
+  bool FileMatchesDepCriteria(const char *Filename,
+                              SrcMgr::CharacteristicKind FileType);
+  void AddFilename(StringRef Filename);
+  void OutputDependencyFile();
+
+public:
+  DependencyFileCallback(const Preprocessor *_PP,
+                         const DependencyOutputOptions &Opts)
+    : PP(_PP), OutputFile(Opts.OutputFile), Targets(Opts.Targets),
+      IncludeSystemHeaders(Opts.IncludeSystemHeaders),
+      PhonyTarget(Opts.UsePhonyTargets),
+      AddMissingHeaderDeps(Opts.AddMissingHeaderDeps),
+      SeenMissingHeader(false) {}
+
+  virtual void FileChanged(SourceLocation Loc, FileChangeReason Reason,
+                           SrcMgr::CharacteristicKind FileType,
+                           FileID PrevFID);
+  virtual void InclusionDirective(SourceLocation HashLoc,
+                                  const Token &IncludeTok,
+                                  StringRef FileName,
+                                  bool IsAngled,
+                                  const FileEntry *File,
+                                  SourceLocation EndLoc,
+                                  StringRef SearchPath,
+                                  StringRef RelativePath);
+
+  virtual void EndOfMainFile() {
+    OutputDependencyFile();
+  }
+};
+}
+
+void clang::AttachDependencyFileGen(Preprocessor &PP,
+                                    const DependencyOutputOptions &Opts) {
+  if (Opts.Targets.empty()) {
+    PP.getDiagnostics().Report(diag::err_fe_dependency_file_requires_MT);
+    return;
+  }
+
+  // Disable the "file not found" diagnostic if the -MG option was given.
+  if (Opts.AddMissingHeaderDeps)
+    PP.SetSuppressIncludeNotFoundError(true);
+
+  PP.addPPCallbacks(new DependencyFileCallback(&PP, Opts));
+}
+
+/// FileMatchesDepCriteria - Determine whether the given Filename should be
+/// considered as a dependency.
+bool DependencyFileCallback::FileMatchesDepCriteria(const char *Filename,
+                                          SrcMgr::CharacteristicKind FileType) {
+  if (strcmp("<built-in>", Filename) == 0)
+    return false;
+
+  if (IncludeSystemHeaders)
+    return true;
+
+  return FileType == SrcMgr::C_User;
+}
+
+void DependencyFileCallback::FileChanged(SourceLocation Loc,
+                                         FileChangeReason Reason,
+                                         SrcMgr::CharacteristicKind FileType,
+                                         FileID PrevFID) {
+  if (Reason != PPCallbacks::EnterFile)
+    return;
+
+  // Dependency generation really does want to go all the way to the
+  // file entry for a source location to find out what is depended on.
+  // We do not want #line markers to affect dependency generation!
+  SourceManager &SM = PP->getSourceManager();
+
+  const FileEntry *FE =
+    SM.getFileEntryForID(SM.getFileID(SM.getExpansionLoc(Loc)));
+  if (FE == 0) return;
+
+  StringRef Filename = FE->getName();
+  if (!FileMatchesDepCriteria(Filename.data(), FileType))
+    return;
+
+  // Remove leading "./" (or ".//" or "././" etc.)
+  while (Filename.size() > 2 && Filename[0] == '.' &&
+         llvm::sys::path::is_separator(Filename[1])) {
+    Filename = Filename.substr(1);
+    while (llvm::sys::path::is_separator(Filename[0]))
+      Filename = Filename.substr(1);
+  }
+    
+  AddFilename(Filename);
+}
+
+void DependencyFileCallback::InclusionDirective(SourceLocation HashLoc,
+                                                const Token &IncludeTok,
+                                                StringRef FileName,
+                                                bool IsAngled,
+                                                const FileEntry *File,
+                                                SourceLocation EndLoc,
+                                                StringRef SearchPath,
+                                                StringRef RelativePath) {
+  if (!File) {
+    if (AddMissingHeaderDeps)
+      AddFilename(FileName);
+    else
+      SeenMissingHeader = true;
+  }
+}
+
+void DependencyFileCallback::AddFilename(StringRef Filename) {
+  if (FilesSet.insert(Filename))
+    Files.push_back(Filename);
+}
+
+/// PrintFilename - GCC escapes spaces, but apparently not ' or " or other
+/// scary characters.
+static void PrintFilename(raw_ostream &OS, StringRef Filename) {
+  for (unsigned i = 0, e = Filename.size(); i != e; ++i) {
+    if (Filename[i] == ' ')
+      OS << '\\';
+    OS << Filename[i];
+  }
+}
+
+void DependencyFileCallback::OutputDependencyFile() {
+  if (SeenMissingHeader) {
+    llvm::sys::Path(OutputFile).eraseFromDisk();
+    return;
+  }
+
+  std::string Err;
+  llvm::raw_fd_ostream OS(OutputFile.c_str(), Err);
+  if (!Err.empty()) {
+    PP->getDiagnostics().Report(diag::err_fe_error_opening)
+      << OutputFile << Err;
+    return;
+  }
+
+  // Write out the dependency targets, trying to avoid overly long
+  // lines when possible. We try our best to emit exactly the same
+  // dependency file as GCC (4.2), assuming the included files are the
+  // same.
+  const unsigned MaxColumns = 75;
+  unsigned Columns = 0;
+
+  for (std::vector<std::string>::iterator
+         I = Targets.begin(), E = Targets.end(); I != E; ++I) {
+    unsigned N = I->length();
+    if (Columns == 0) {
+      Columns += N;
+    } else if (Columns + N + 2 > MaxColumns) {
+      Columns = N + 2;
+      OS << " \\\n  ";
+    } else {
+      Columns += N + 1;
+      OS << ' ';
+    }
+    // Targets already quoted as needed.
+    OS << *I;
+  }
+
+  OS << ':';
+  Columns += 1;
+
+  // Now add each dependency in the order it was seen, but avoiding
+  // duplicates.
+  for (std::vector<std::string>::iterator I = Files.begin(),
+         E = Files.end(); I != E; ++I) {
+    // Start a new line if this would exceed the column limit. Make
+    // sure to leave space for a trailing " \" in case we need to
+    // break the line on the next iteration.
+    unsigned N = I->length();
+    if (Columns + (N + 1) + 2 > MaxColumns) {
+      OS << " \\\n ";
+      Columns = 2;
+    }
+    OS << ' ';
+    PrintFilename(OS, *I);
+    Columns += N + 1;
+  }
+  OS << '\n';
+
+  // Create phony targets if requested.
+  if (PhonyTarget && !Files.empty()) {
+    // Skip the first entry, this is always the input file itself.
+    for (std::vector<std::string>::iterator I = Files.begin() + 1,
+           E = Files.end(); I != E; ++I) {
+      OS << '\n';
+      PrintFilename(OS, *I);
+      OS << ":\n";
+    }
+  }
+}
+