Updated to Clang 3.5a.

Change-Id: I8127eb568f674c2e72635b639a3295381fe8af82
diff --git a/tools/libclang/BuildSystem.cpp b/tools/libclang/BuildSystem.cpp
new file mode 100644
index 0000000..89c6e91
--- /dev/null
+++ b/tools/libclang/BuildSystem.cpp
@@ -0,0 +1,279 @@
+//===- BuildSystem.cpp - Utilities for use by build systems ---------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements various utilities for use by build systems.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang-c/BuildSystem.h"
+#include "CXString.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/TimeValue.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace clang;
+using namespace llvm::sys;
+
+unsigned long long clang_getBuildSessionTimestamp(void) {
+  return llvm::sys::TimeValue::now().toEpochTime();
+}
+
+struct CXVirtualFileOverlayImpl {
+  std::vector<std::pair<std::string, std::string> > Mappings;
+  Optional<bool> IsCaseSensitive;
+};
+
+CXVirtualFileOverlay clang_VirtualFileOverlay_create(unsigned) {
+  return new CXVirtualFileOverlayImpl();
+}
+
+enum CXErrorCode
+clang_VirtualFileOverlay_addFileMapping(CXVirtualFileOverlay VFO,
+                                        const char *virtualPath,
+                                        const char *realPath) {
+  if (!VFO || !virtualPath || !realPath)
+    return CXError_InvalidArguments;
+  if (!path::is_absolute(virtualPath))
+    return CXError_InvalidArguments;
+  if (!path::is_absolute(realPath))
+    return CXError_InvalidArguments;
+
+  for (path::const_iterator
+         PI = path::begin(virtualPath),
+         PE = path::end(virtualPath); PI != PE; ++PI) {
+    StringRef Comp = *PI;
+    if (Comp == "." || Comp == "..")
+      return CXError_InvalidArguments;
+  }
+
+  VFO->Mappings.push_back(std::make_pair(virtualPath, realPath));
+  return CXError_Success;
+}
+
+enum CXErrorCode
+clang_VirtualFileOverlay_setCaseSensitivity(CXVirtualFileOverlay VFO,
+                                            int caseSensitive) {
+  if (!VFO)
+    return CXError_InvalidArguments;
+
+  VFO->IsCaseSensitive = caseSensitive;
+  return CXError_Success;
+}
+
+namespace {
+struct EntryTy {
+  std::string VPath;
+  std::string RPath;
+
+  friend bool operator < (const EntryTy &LHS, const EntryTy &RHS) {
+    return LHS.VPath < RHS.VPath;
+  }
+};
+
+class JSONVFSPrinter {
+  llvm::raw_ostream &OS;
+  CXVirtualFileOverlay VFO;
+
+public:
+  JSONVFSPrinter(llvm::raw_ostream &OS, CXVirtualFileOverlay VFO)
+    : OS(OS), VFO(VFO) {}
+
+  /// Entries must be sorted.
+  void print(ArrayRef<EntryTy> Entries) {
+    OS << "{\n"
+          "  'version': 0,\n";
+    if (VFO->IsCaseSensitive.hasValue()) {
+      OS << "  'case-sensitive': '";
+      if (VFO->IsCaseSensitive.getValue())
+        OS << "true";
+      else
+        OS << "false";
+      OS << "',\n";
+    }
+    OS << "  'roots': [\n";
+    printDirNodes(Entries, "", 4);
+    OS << "  ]\n"
+          "}\n";
+  }
+
+private:
+  ArrayRef<EntryTy> printDirNodes(ArrayRef<EntryTy> Entries,
+                                  StringRef ParentPath,
+                                  unsigned Indent) {
+    while (!Entries.empty()) {
+      const EntryTy &Entry = Entries.front();
+      OS.indent(Indent) << "{\n";
+      Indent += 2;
+      OS.indent(Indent) << "'type': 'directory',\n";
+      OS.indent(Indent) << "'name': \"";
+      StringRef DirName = containedPart(ParentPath,
+                                        path::parent_path(Entry.VPath));
+      OS.write_escaped(DirName) << "\",\n";
+      OS.indent(Indent) << "'contents': [\n";
+      Entries = printContents(Entries, Indent + 2);
+      OS.indent(Indent) << "]\n";
+      Indent -= 2;
+      OS.indent(Indent) << '}';
+      if (Entries.empty()) {
+        OS << '\n';
+        break;
+      }
+      StringRef NextVPath = Entries.front().VPath;
+      if (!containedIn(ParentPath, NextVPath)) {
+        OS << '\n';
+        break;
+      }
+      OS << ",\n";
+    }
+    return Entries;
+  }
+
+  ArrayRef<EntryTy> printContents(ArrayRef<EntryTy> Entries,
+                                  unsigned Indent) {
+    while (!Entries.empty()) {
+      const EntryTy &Entry = Entries.front();
+      Entries = Entries.slice(1);
+      StringRef ParentPath = path::parent_path(Entry.VPath);
+      StringRef VName = path::filename(Entry.VPath);
+      OS.indent(Indent) << "{\n";
+      Indent += 2;
+      OS.indent(Indent) << "'type': 'file',\n";
+      OS.indent(Indent) << "'name': \"";
+      OS.write_escaped(VName) << "\",\n";
+      OS.indent(Indent) << "'external-contents': \"";
+      OS.write_escaped(Entry.RPath) << "\"\n";
+      Indent -= 2;
+      OS.indent(Indent) << '}';
+      if (Entries.empty()) {
+        OS << '\n';
+        break;
+      }
+      StringRef NextVPath = Entries.front().VPath;
+      if (!containedIn(ParentPath, NextVPath)) {
+        OS << '\n';
+        break;
+      }
+      OS << ",\n";
+      if (path::parent_path(NextVPath) != ParentPath) {
+        Entries = printDirNodes(Entries, ParentPath, Indent);
+      }
+    }
+    return Entries;
+  }
+
+  bool containedIn(StringRef Parent, StringRef Path) {
+    return Path.startswith(Parent);
+  }
+
+  StringRef containedPart(StringRef Parent, StringRef Path) {
+    assert(containedIn(Parent, Path));
+    if (Parent.empty())
+      return Path;
+    return Path.slice(Parent.size()+1, StringRef::npos);
+  }
+};
+}
+
+enum CXErrorCode
+clang_VirtualFileOverlay_writeToBuffer(CXVirtualFileOverlay VFO, unsigned,
+                                       char **out_buffer_ptr,
+                                       unsigned *out_buffer_size) {
+  if (!VFO || !out_buffer_ptr || !out_buffer_size)
+    return CXError_InvalidArguments;
+
+  llvm::SmallVector<EntryTy, 16> Entries;
+  for (unsigned i = 0, e = VFO->Mappings.size(); i != e; ++i) {
+    EntryTy Entry;
+    Entry.VPath = VFO->Mappings[i].first;
+    Entry.RPath = VFO->Mappings[i].second;
+    Entries.push_back(Entry);
+  }
+
+  // FIXME: We should add options to determine if the paths are case sensitive
+  // or not. The following assumes that if paths are case-insensitive the caller
+  // did not mix cases in the virtual paths it provided.
+
+  std::sort(Entries.begin(), Entries.end());
+
+  llvm::SmallString<256> Buf;
+  llvm::raw_svector_ostream OS(Buf);
+  JSONVFSPrinter Printer(OS, VFO);
+  Printer.print(Entries);
+
+  StringRef Data = OS.str();
+  *out_buffer_ptr = (char*)malloc(Data.size());
+  *out_buffer_size = Data.size();
+  memcpy(*out_buffer_ptr, Data.data(), Data.size());
+  return CXError_Success;
+}
+
+void clang_VirtualFileOverlay_dispose(CXVirtualFileOverlay VFO) {
+  delete VFO;
+}
+
+
+struct CXModuleMapDescriptorImpl {
+  std::string ModuleName;
+  std::string UmbrellaHeader;
+};
+
+CXModuleMapDescriptor clang_ModuleMapDescriptor_create(unsigned) {
+  return new CXModuleMapDescriptorImpl();
+}
+
+enum CXErrorCode
+clang_ModuleMapDescriptor_setFrameworkModuleName(CXModuleMapDescriptor MMD,
+                                                 const char *name) {
+  if (!MMD || !name)
+    return CXError_InvalidArguments;
+
+  MMD->ModuleName = name;
+  return CXError_Success;
+}
+
+enum CXErrorCode
+clang_ModuleMapDescriptor_setUmbrellaHeader(CXModuleMapDescriptor MMD,
+                                            const char *name) {
+  if (!MMD || !name)
+    return CXError_InvalidArguments;
+
+  MMD->UmbrellaHeader = name;
+  return CXError_Success;
+}
+
+enum CXErrorCode
+clang_ModuleMapDescriptor_writeToBuffer(CXModuleMapDescriptor MMD, unsigned,
+                                       char **out_buffer_ptr,
+                                       unsigned *out_buffer_size) {
+  if (!MMD || !out_buffer_ptr || !out_buffer_size)
+    return CXError_InvalidArguments;
+
+  llvm::SmallString<256> Buf;
+  llvm::raw_svector_ostream OS(Buf);
+  OS << "framework module " << MMD->ModuleName << " {\n";
+  OS << "  umbrella header \"";
+  OS.write_escaped(MMD->UmbrellaHeader) << "\"\n";
+  OS << '\n';
+  OS << "  export *\n";
+  OS << "  module * { export * }\n";
+  OS << "}\n";
+
+  StringRef Data = OS.str();
+  *out_buffer_ptr = (char*)malloc(Data.size());
+  *out_buffer_size = Data.size();
+  memcpy(*out_buffer_ptr, Data.data(), Data.size());
+  return CXError_Success;
+}
+
+void clang_ModuleMapDescriptor_dispose(CXModuleMapDescriptor MMD) {
+  delete MMD;
+}