third_party/protobuf: Update to HEAD (83d681ee2c)

third_party/protobuf/src/google/protobuf/compiler/objectivec/objectivec_helpers.cc

Index: third_party/protobuf/src/google/protobuf/compiler/objectivec/objectivec_helpers.cc
diff --git a/third_party/protobuf/src/google/protobuf/compiler/objectivec/objectivec_helpers.cc b/third_party/protobuf/src/google/protobuf/compiler/objectivec/objectivec_helpers.cc
index 196b39dd93207e5529a8e5a0701afcb72b658c2d..c7fd96ac22c2da9b72f4985a42297b0eb878fa62 100644
--- a/third_party/protobuf/src/google/protobuf/compiler/objectivec/objectivec_helpers.cc
+++ b/third_party/protobuf/src/google/protobuf/compiler/objectivec/objectivec_helpers.cc
@@ -44,9 +44,10 @@
 
 #include <google/protobuf/stubs/hash.h>
 #include <google/protobuf/compiler/objectivec/objectivec_helpers.h>
+#include <google/protobuf/descriptor.pb.h>
 #include <google/protobuf/io/coded_stream.h>
+#include <google/protobuf/io/printer.h>
 #include <google/protobuf/io/zero_copy_stream_impl.h>
-#include <google/protobuf/descriptor.pb.h>
 #include <google/protobuf/stubs/common.h>
 #include <google/protobuf/stubs/strutil.h>
 
@@ -81,6 +82,10 @@ const char* const kUpperSegmentsList[] = {"url", "http", "https"};
 hash_set<string> kUpperSegments =
     MakeWordsMap(kUpperSegmentsList, GOOGLE_ARRAYSIZE(kUpperSegmentsList));
 
+bool ascii_isnewline(char c) {
+  return c == '\n' || c == '\r';
+}
+
 // Internal helper for name handing.
 // Do not expose this outside of helpers, stick to having functions for specific
 // cases (ClassName(), FieldName()), so there is always consistent suffix rules.
@@ -205,10 +210,14 @@ const char* const kReservedWordList[] = {
 hash_set<string> kReservedWords =
     MakeWordsMap(kReservedWordList, GOOGLE_ARRAYSIZE(kReservedWordList));
 
-string SanitizeNameForObjC(const string& input, const string& extension) {
+string SanitizeNameForObjC(const string& input,
+                           const string& extension,
+                           string* out_suffix_added) {
   if (kReservedWords.count(input) > 0) {
+    if (out_suffix_added) *out_suffix_added = extension;
     return input + extension;
   }
+  if (out_suffix_added) out_suffix_added->clear();
   return input;
 }
 
@@ -257,6 +266,34 @@ bool IsSpecialName(const string& name, const string* special_names,
   return false;
 }
 
+string GetZeroEnumNameForFlagType(const FlagType flag_type) {
+  switch(flag_type) {
+    case FLAGTYPE_DESCRIPTOR_INITIALIZATION:
+      return "GPBDescriptorInitializationFlag_None";
+    case FLAGTYPE_EXTENSION:
+      return "GPBExtensionNone";
+    case FLAGTYPE_FIELD:
+      return "GPBFieldNone";
+    default:
+      GOOGLE_LOG(FATAL) << "Can't get here.";
+      return "0";
+  }
+}
+
+string GetEnumNameForFlagType(const FlagType flag_type) {
+  switch(flag_type) {
+    case FLAGTYPE_DESCRIPTOR_INITIALIZATION:
+      return "GPBDescriptorInitializationFlags";
+    case FLAGTYPE_EXTENSION:
+      return "GPBExtensionOptions";
+    case FLAGTYPE_FIELD:
+      return "GPBFieldFlags";
+    default:
+      GOOGLE_LOG(FATAL) << "Can't get here.";
+      return string();
+  }
+}
+
 }  // namespace
 
 // Escape C++ trigraphs by escaping question marks to \?
@@ -272,6 +309,16 @@ string StripProto(const string& filename) {
   }
 }
 
+void StringPieceTrimWhitespace(StringPiece* input) {
+  while (!input->empty() && ascii_isspace(*input->data())) {
+    input->remove_prefix(1);
+  }
+  while (!input->empty() && ascii_isspace((*input)[input->length() - 1])) {
+    input->remove_suffix(1);
+  }
+}
+
+
 bool IsRetainedName(const string& name) {
   // List of prefixes from
   // http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/MemoryMgmt/Articles/mmRules.html
@@ -293,11 +340,10 @@ string BaseFileName(const FileDescriptor* file) {
   return basename;
 }
 
-string FileName(const FileDescriptor* file) {
-  string path = FilePath(file);
-  string basename;
-  PathSplit(path, NULL, &basename);
-  return basename;
+string FileClassPrefix(const FileDescriptor* file) {
+  // Default is empty string, no need to check has_objc_class_prefix.
+  string result = file->options().objc_class_prefix();
+  return result;
 }
 
 string FilePath(const FileDescriptor* file) {
@@ -317,10 +363,17 @@ string FilePath(const FileDescriptor* file) {
   return output;
 }
 
-string FileClassPrefix(const FileDescriptor* file) {
-  // Default is empty string, no need to check has_objc_class_prefix.
-  string result = file->options().objc_class_prefix();
-  return result;
+string FilePathBasename(const FileDescriptor* file) {
+  string output;
+  string basename;
+  string directory;
+  PathSplit(file->name(), &directory, &basename);
+  basename = StripProto(basename);
+
+  // CamelCase to be more ObjC friendly.
+  output = UnderscoresToCamelCase(basename, true);
+
+  return output;
 }
 
 string FileClassName(const FileDescriptor* file) {
@@ -329,7 +382,7 @@ string FileClassName(const FileDescriptor* file) {
   name += "Root";
   // There aren't really any reserved words that end in "Root", but playing
   // it safe and checking.
-  return SanitizeNameForObjC(name, "_RootClass");
+  return SanitizeNameForObjC(name, "_RootClass", NULL);
 }
 
 string ClassNameWorker(const Descriptor* descriptor) {
@@ -351,11 +404,15 @@ string ClassNameWorker(const EnumDescriptor* descriptor) {
 }
 
 string ClassName(const Descriptor* descriptor) {
+  return ClassName(descriptor, NULL);
+}
+
+string ClassName(const Descriptor* descriptor, string* out_suffix_added) {
   // 1. Message names are used as is (style calls for CamelCase, trust it).
   // 2. Check for reserved word at the very end and then suffix things.
   string prefix = FileClassPrefix(descriptor->file());
   string name = ClassNameWorker(descriptor);
-  return SanitizeNameForObjC(prefix + name, "_Class");
+  return SanitizeNameForObjC(prefix + name, "_Class", out_suffix_added);
 }
 
 string EnumName(const EnumDescriptor* descriptor) {
@@ -369,7 +426,7 @@ string EnumName(const EnumDescriptor* descriptor) {
   //    yields Fixed_Class, Fixed_Size.
   string name = FileClassPrefix(descriptor->file());
   name += ClassNameWorker(descriptor);
-  return SanitizeNameForObjC(name, "_Enum");
+  return SanitizeNameForObjC(name, "_Enum", NULL);
 }
 
 string EnumValueName(const EnumValueDescriptor* descriptor) {
@@ -384,7 +441,7 @@ string EnumValueName(const EnumValueDescriptor* descriptor) {
   const string& name = class_name + "_" + value_str;
   // There aren't really any reserved words with an underscore and a leading
   // capital letter, but playing it safe and checking.
-  return SanitizeNameForObjC(name, "_Value");
+  return SanitizeNameForObjC(name, "_Value", NULL);
 }
 
 string EnumValueShortName(const EnumValueDescriptor* descriptor) {
@@ -421,7 +478,7 @@ string UnCamelCaseEnumShortName(const string& name) {
 string ExtensionMethodName(const FieldDescriptor* descriptor) {
   const string& name = NameFromFieldDescriptor(descriptor);
   const string& result = UnderscoresToCamelCase(name, false);
-  return SanitizeNameForObjC(result, "_Extension");
+  return SanitizeNameForObjC(result, "_Extension", NULL);
 }
 
 string FieldName(const FieldDescriptor* field) {
@@ -436,7 +493,7 @@ string FieldName(const FieldDescriptor* field) {
       result += "_p";
     }
   }
-  return SanitizeNameForObjC(result, "_p");
+  return SanitizeNameForObjC(result, "_p", NULL);
 }
 
 string FieldNameCapitalized(const FieldDescriptor* field) {
@@ -796,21 +853,26 @@ bool HasNonZeroDefaultValue(const FieldDescriptor* field) {
   return false;
 }
 
-string BuildFlagsString(const vector<string>& strings) {
+string BuildFlagsString(const FlagType flag_type,
+                        const vector<string>& strings) {
   if (strings.size() == 0) {
-    return "0";
+    return GetZeroEnumNameForFlagType(flag_type);
+  } else if (strings.size() == 1) {
+    return strings[0];
   }
-  string string;
+  string string("(" + GetEnumNameForFlagType(flag_type) + ")(");
   for (size_t i = 0; i != strings.size(); ++i) {
     if (i > 0) {
       string.append(" | ");
     }
     string.append(strings[i]);
   }
+  string.append(")");
   return string;
 }
 
-string BuildCommentsString(const SourceLocation& location) {
+string BuildCommentsString(const SourceLocation& location,
+                           bool prefer_single_line) {
   const string& comments = location.leading_comments.empty()
                                ? location.trailing_comments
                                : location.leading_comments;
@@ -819,77 +881,82 @@ string BuildCommentsString(const SourceLocation& location) {
   while (!lines.empty() && lines.back().empty()) {
     lines.pop_back();
   }
-  string prefix("///");
-  string suffix("\n");
-  string final_comments;
-  for (int i = 0; i < lines.size(); i++) {
-    // HeaderDoc uses '\' and '@' for markers; escape them.
-    const string line = StringReplace(lines[i], "\\", "\\\\", true);
-    final_comments +=
-        prefix + StringReplace(line, "@", "\\@", true) + suffix;
+  // If there are no comments, just return an empty string.
+  if (lines.size() == 0) {
+    return "";
   }
-  return final_comments;
-}
-
-namespace {
-
-// Internal helper class that parses the expected package to prefix mappings
-// file.
-class Parser {
- public:
-  Parser(map<string, string>* inout_package_to_prefix_map)
-      : prefix_map_(inout_package_to_prefix_map), line_(0) {}
-
-  // Parses a check of input, returning success/failure.
-  bool ParseChunk(StringPiece chunk);
-
-  // Should be called to finish parsing (after all input has been provided via
-  // ParseChunk()).  Returns success/failure.
-  bool Finish();
-
-  int last_line() const { return line_; }
-  string error_str() const { return error_str_; }
 
- private:
-  bool ParseLoop();
+  string prefix;
+  string suffix;
+  string final_comments;
+  string epilogue;
 
-  map<string, string>* prefix_map_;
-  int line_;
-  string error_str_;
-  StringPiece p_;
-  string leftover_;
-};
+  bool add_leading_space = false;
 
-bool Parser::ParseChunk(StringPiece chunk) {
-  if (!leftover_.empty()) {
-    chunk.AppendToString(&leftover_);
-    p_ = StringPiece(leftover_);
-  } else {
-    p_ = chunk;
-  }
-  bool result = ParseLoop();
-  if (p_.empty()) {
-    leftover_.clear();
+  if (prefer_single_line && lines.size() == 1) {
+    prefix = "/** ";
+    suffix = " */\n";
   } else {
-    leftover_ = p_.ToString();
+    prefix = "* ";
+    suffix = "\n";
+    final_comments += "/**\n";
+    epilogue = " **/\n";
+    add_leading_space = true;
   }
+
+  for (int i = 0; i < lines.size(); i++) {
+    string line = StripPrefixString(lines[i], " ");
+    // HeaderDoc and appledoc use '\' and '@' for markers; escape them.
+    line = StringReplace(line, "\\", "\\\\", true);
+    line = StringReplace(line, "@", "\\@", true);
+    // Decouple / from * to not have inline comments inside comments.
+    line = StringReplace(line, "/*", "/\\*", true);
+    line = StringReplace(line, "*/", "*\\/", true);
+    line = prefix + line;
+    StripWhitespace(&line);
+    // If not a one line, need to add the first space before *, as
+    // StripWhitespace would have removed it.
+    line = (add_leading_space ? " " : "") + line;
+    final_comments += line + suffix;
+  }
+  final_comments += epilogue;
+  return final_comments;
+}
+
+// Making these a generator option for folks that don't use CocoaPods, but do
+// want to put the library in a framework is an interesting question. The
+// problem is it means changing sources shipped with the library to actually
+// use a different value; so it isn't as simple as a option.
+const char* const ProtobufLibraryFrameworkName = "Protobuf";
+
+string ProtobufFrameworkImportSymbol(const string& framework_name) {
+  // GPB_USE_[framework_name]_FRAMEWORK_IMPORTS
+  string result = string("GPB_USE_");
+  result += ToUpper(framework_name);
+  result += "_FRAMEWORK_IMPORTS";
   return result;
 }
 
-bool Parser::Finish() {
-  if (leftover_.empty()) {
+bool IsProtobufLibraryBundledProtoFile(const FileDescriptor* file) {
+  // We don't check the name prefix or proto package because some files
+  // (descriptor.proto), aren't shipped generated by the library, so this
+  // seems to be the safest way to only catch the ones shipped.
+  const string name = file->name();
+  if (name == "google/protobuf/any.proto" ||
+      name == "google/protobuf/api.proto" ||
+      name == "google/protobuf/duration.proto" ||
+      name == "google/protobuf/empty.proto" ||
+      name == "google/protobuf/field_mask.proto" ||
+      name == "google/protobuf/source_context.proto" ||
+      name == "google/protobuf/struct.proto" ||
+      name == "google/protobuf/timestamp.proto" ||
+      name == "google/protobuf/type.proto" ||
+      name == "google/protobuf/wrappers.proto") {
     return true;
   }
-  // Force a newline onto the end to finish parsing.
-  p_ = StringPiece(leftover_ + "\n");
-  if (!ParseLoop()) {
-    return false;
-  }
-  return p_.empty();  // Everything used?
+  return false;
 }
 
-static bool ascii_isnewline(char c) { return c == '\n' || c == '\r'; }
-
 bool ReadLine(StringPiece* input, StringPiece* line) {
   for (int len = 0; len < input->size(); ++len) {
     if (ascii_isnewline((*input)[len])) {
@@ -902,15 +969,6 @@ bool ReadLine(StringPiece* input, StringPiece* line) {
   return false;  // Ran out of input with no newline.
 }
 
-void TrimWhitespace(StringPiece* input) {
-  while (!input->empty() && ascii_isspace(*input->data())) {
-    input->remove_prefix(1);
-  }
-  while (!input->empty() && ascii_isspace((*input)[input->length() - 1])) {
-    input->remove_suffix(1);
-  }
-}
-
 void RemoveComment(StringPiece* input) {
   int offset = input->find('#');
   if (offset != StringPiece::npos) {
@@ -918,29 +976,35 @@ void RemoveComment(StringPiece* input) {
   }
 }
 
-bool Parser::ParseLoop() {
-  StringPiece line;
-  while (ReadLine(&p_, &line)) {
-    ++line_;
-    RemoveComment(&line);
-    TrimWhitespace(&line);
-    if (line.size() == 0) {
-      continue;  // Blank line.
-    }
-    int offset = line.find('=');
-    if (offset == StringPiece::npos) {
-      error_str_ =
-          string("Line without equal sign: '") + line.ToString() + "'.";
-      return false;
-    }
-    StringPiece package(line, 0, offset);
-    StringPiece prefix(line, offset + 1, line.length() - offset - 1);
-    TrimWhitespace(&package);
-    TrimWhitespace(&prefix);
-    // Don't really worry about error checking the package/prefix for
-    // being valid.  Assume the file is validated when it is created/edited.
-    (*prefix_map_)[package.ToString()] = prefix.ToString();
+namespace {
+
+class ExpectedPrefixesCollector : public LineConsumer {
+ public:
+  ExpectedPrefixesCollector(map<string, string>* inout_package_to_prefix_map)
+      : prefix_map_(inout_package_to_prefix_map) {}
+
+  virtual bool ConsumeLine(const StringPiece& line, string* out_error);
+
+ private:
+  map<string, string>* prefix_map_;
+};
+
+bool ExpectedPrefixesCollector::ConsumeLine(
+    const StringPiece& line, string* out_error) {
+  int offset = line.find('=');
+  if (offset == StringPiece::npos) {
+    *out_error =
+        string("Expected prefixes file line without equal sign: '") +
+        line.ToString() + "'.";
+    return false;
   }
+  StringPiece package(line, 0, offset);
+  StringPiece prefix(line, offset + 1, line.length() - offset - 1);
+  StringPieceTrimWhitespace(&package);
+  StringPieceTrimWhitespace(&prefix);
+  // Don't really worry about error checking the package/prefix for
+  // being valid.  Assume the file is validated when it is created/edited.
+  (*prefix_map_)[package.ToString()] = prefix.ToString();
   return true;
 }
 
@@ -951,60 +1015,25 @@ bool LoadExpectedPackagePrefixes(const Options &generation_options,
     return true;
   }
 
-  int fd;
-  do {
-    fd = open(generation_options.expected_prefixes_path.c_str(), O_RDONLY);
-  } while (fd < 0 && errno == EINTR);
-  if (fd < 0) {
-    *out_error =
-        string("error: Unable to open \"") +
-        generation_options.expected_prefixes_path +
-        "\", " + strerror(errno);
-    return false;
-  }
-  io::FileInputStream file_stream(fd);
-  file_stream.SetCloseOnDelete(true);
-
-  Parser parser(prefix_map);
-  const void* buf;
-  int buf_len;
-  while (file_stream.Next(&buf, &buf_len)) {
-    if (buf_len == 0) {
-      continue;
-    }
-
-    if (!parser.ParseChunk(StringPiece(static_cast<const char*>(buf), buf_len))) {
-      *out_error =
-          string("error: ") + generation_options.expected_prefixes_path +
-          " Line " + SimpleItoa(parser.last_line()) + ", " + parser.error_str();
-      return false;
-    }
-  }
-  return parser.Finish();
+  ExpectedPrefixesCollector collector(prefix_map);
+  return ParseSimpleFile(
+      generation_options.expected_prefixes_path, &collector, out_error);
 }
 
-}  // namespace
-
-bool ValidateObjCClassPrefix(const FileDescriptor* file,
-                             const Options& generation_options,
-                             string* out_error) {
+bool ValidateObjCClassPrefix(
+    const FileDescriptor* file,
+    const string& expected_prefixes_path,
+    const map<string, string>& expected_package_prefixes,
+    string* out_error) {
   const string prefix = file->options().objc_class_prefix();
   const string package = file->package();
 
   // NOTE: src/google/protobuf/compiler/plugin.cc makes use of cerr for some
   // error cases, so it seems to be ok to use as a back door for warnings.
 
-  // Load any expected package prefixes to validate against those.
-  map<string, string> expected_package_prefixes;
-  if (!LoadExpectedPackagePrefixes(generation_options,
-                                   &expected_package_prefixes,
-                                   out_error)) {
-    return false;
-  }
-
   // Check: Error - See if there was an expected prefix for the package and
   // report if it doesn't match (wrong or missing).
-  map<string, string>::iterator package_match =
+  map<string, string>::const_iterator package_match =
       expected_package_prefixes.find(package);
   if (package_match != expected_package_prefixes.end()) {
     // There was an entry, and...
@@ -1025,27 +1054,11 @@ bool ValidateObjCClassPrefix(const FileDescriptor* file,
   }
 
   // If there was no prefix option, we're done at this point.
-  if (prefix.length() == 0) {
+  if (prefix.empty()) {
     // No prefix, nothing left to check.
     return true;
   }
 
-  // Check: Error - Make sure the prefix wasn't expected for a different
-  // package (overlap is allowed, but it has to be listed as an expected
-  // overlap).
-  for (map<string, string>::iterator i = expected_package_prefixes.begin();
-       i != expected_package_prefixes.end(); ++i) {
-    if (i->second == prefix) {
-      *out_error =
-          "error: Found 'option objc_class_prefix = \"" + prefix +
-          "\";' in '" + file->name() +
-          "'; that prefix is already used for 'package " + i->first +
-          ";'. It can only be reused by listing it in the expected file (" +
-          generation_options.expected_prefixes_path + ").";
-      return false;  // Only report first usage of the prefix.
-    }
-  }
-
   // Check: Warning - Make sure the prefix is is a reasonable value according
   // to Apple's rules (the checks above implicitly whitelist anything that
   // doesn't meet these rules).
@@ -1067,6 +1080,56 @@ bool ValidateObjCClassPrefix(const FileDescriptor* file,
     cerr.flush();
   }
 
+  // Look for any other package that uses the same prefix.
+  string other_package_for_prefix;
+  for (map<string, string>::const_iterator i = expected_package_prefixes.begin();
+       i != expected_package_prefixes.end(); ++i) {
+    if (i->second == prefix) {
+      other_package_for_prefix = i->first;
+      break;
+    }
+  }
+
+  // Check: Warning - If the file does not have a package, check whether
+  // the prefix declared is being used by another package or not.
+  if (package.empty()) {
+    // The file does not have a package and ...
+    if (other_package_for_prefix.empty()) {
+      // ... no other package has declared that prefix.
+      cerr << endl
+           << "protoc:0: warning: File '" << file->name() << "' has no "
+           << "package. Consider adding a new package to the proto and adding '"
+           << "new.package = " << prefix << "' to the expected prefixes file ("
+           << expected_prefixes_path << ")." << endl;
+      cerr.flush();
+    } else {
+      // ... another package has declared the same prefix.
+      cerr << endl
+           << "protoc:0: warning: File '" << file->name() << "' has no package "
+           << "and package '" << other_package_for_prefix << "' already uses '"
+           << prefix << "' as its prefix. Consider either adding a new package "
+           << "to the proto, or reusing one of the packages already using this "
+           << "prefix in the expected prefixes file ("
+           << expected_prefixes_path << ")." << endl;
+      cerr.flush();
+    }
+    return true;
+  }
+
+  // Check: Error - Make sure the prefix wasn't expected for a different
+  // package (overlap is allowed, but it has to be listed as an expected
+  // overlap).
+  if (!other_package_for_prefix.empty()) {
+    *out_error =
+        "error: Found 'option objc_class_prefix = \"" + prefix +
+        "\";' in '" + file->name() +
+        "'; that prefix is already used for 'package " +
+        other_package_for_prefix + ";'. It can only be reused by listing " +
+        "it in the expected file (" +
+        expected_prefixes_path + ").";
+    return false;  // Only report first usage of the prefix.
+  }
+
   // Check: Warning - If the given package/prefix pair wasn't expected, issue a
   // warning issue a warning suggesting it gets added to the file.
   if (!expected_package_prefixes.empty()) {
@@ -1074,13 +1137,43 @@ bool ValidateObjCClassPrefix(const FileDescriptor* file,
          << "protoc:0: warning: Found unexpected 'option objc_class_prefix = \""
          << prefix << "\";' in '" << file->name() << "';"
          << " consider adding it to the expected prefixes file ("
-         << generation_options.expected_prefixes_path << ")." << endl;
+         << expected_prefixes_path << ")." << endl;
     cerr.flush();
   }
 
   return true;
 }
 
+}  // namespace
+
+bool ValidateObjCClassPrefixes(const vector<const FileDescriptor*>& files,
+                               const Options& generation_options,
+                               string* out_error) {
+  // Load the expected package prefixes, if available, to validate against.
+  map<string, string> expected_package_prefixes;
+  if (!LoadExpectedPackagePrefixes(generation_options,
+                                   &expected_package_prefixes,
+                                   out_error)) {
+    return false;
+  }
+
+  for (int i = 0; i < files.size(); i++) {
+    bool is_valid =
+        ValidateObjCClassPrefix(files[i],
+                                generation_options.expected_prefixes_path,
+                                expected_package_prefixes,
+                                out_error);
+    if (!is_valid) {
+      return false;
+    }
+  }
+  return true;
+}
+
+TextFormatDecodeData::TextFormatDecodeData() { }
+
+TextFormatDecodeData::~TextFormatDecodeData() { }
+
 void TextFormatDecodeData::AddString(int32 key,
                                      const string& input_for_decode,
                                      const string& desired_output) {
@@ -1289,6 +1382,289 @@ string TextFormatDecodeData::DecodeDataForString(const string& input_for_decode,
   return builder.Finish() + (char)'\0';
 }
 
+namespace {
+
+class Parser {
+ public:
+  Parser(LineConsumer* line_consumer)
+      : line_consumer_(line_consumer), line_(0) {}
+
+  // Parses a check of input, returning success/failure.
+  bool ParseChunk(StringPiece chunk);
+
+  // Should be called to finish parsing (after all input has been provided via
+  // ParseChunk()).  Returns success/failure.
+  bool Finish();
+
+  int last_line() const { return line_; }
+  string error_str() const { return error_str_; }
+
+ private:
+  bool ParseLoop();
+
+  LineConsumer* line_consumer_;
+  int line_;
+  string error_str_;
+  StringPiece p_;
+  string leftover_;
+};
+
+bool Parser::ParseChunk(StringPiece chunk) {
+  if (!leftover_.empty()) {
+    chunk.AppendToString(&leftover_);
+    p_ = StringPiece(leftover_);
+  } else {
+    p_ = chunk;
+  }
+  bool result = ParseLoop();
+  if (p_.empty()) {
+    leftover_.clear();
+  } else {
+    leftover_ = p_.ToString();
+  }
+  return result;
+}
+
+bool Parser::Finish() {
+  if (leftover_.empty()) {
+    return true;
+  }
+  // Force a newline onto the end to finish parsing.
+  leftover_ += "\n";
+  p_ = StringPiece(leftover_);
+  if (!ParseLoop()) {
+    return false;
+  }
+  return p_.empty();  // Everything used?
+}
+
+bool Parser::ParseLoop() {
+  StringPiece line;
+  while (ReadLine(&p_, &line)) {
+    ++line_;
+    RemoveComment(&line);
+    StringPieceTrimWhitespace(&line);
+    if (line.size() == 0) {
+      continue;  // Blank line.
+    }
+    if (!line_consumer_->ConsumeLine(line, &error_str_)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+}  // namespace
+
+LineConsumer::LineConsumer() {}
+
+LineConsumer::~LineConsumer() {}
+
+bool ParseSimpleFile(
+    const string& path, LineConsumer* line_consumer, string* out_error) {
+  int fd;
+  do {
+    fd = open(path.c_str(), O_RDONLY);
+  } while (fd < 0 && errno == EINTR);
+  if (fd < 0) {
+    *out_error =
+        string("error: Unable to open \"") + path + "\", " + strerror(errno);
+    return false;
+  }
+  io::FileInputStream file_stream(fd);
+  file_stream.SetCloseOnDelete(true);
+
+  Parser parser(line_consumer);
+  const void* buf;
+  int buf_len;
+  while (file_stream.Next(&buf, &buf_len)) {
+    if (buf_len == 0) {
+      continue;
+    }
+
+    if (!parser.ParseChunk(StringPiece(static_cast<const char*>(buf), buf_len))) {
+      *out_error =
+          string("error: ") + path +
+          " Line " + SimpleItoa(parser.last_line()) + ", " + parser.error_str();
+      return false;
+    }
+  }
+  return parser.Finish();
+}
+
+ImportWriter::ImportWriter(
+  const string& generate_for_named_framework,
+  const string& named_framework_to_proto_path_mappings_path)
+    : generate_for_named_framework_(generate_for_named_framework),
+      named_framework_to_proto_path_mappings_path_(
+          named_framework_to_proto_path_mappings_path),
+      need_to_parse_mapping_file_(true) {
+}
+
+ImportWriter::~ImportWriter() {}
+
+void ImportWriter::AddFile(const FileDescriptor* file,
+                           const string& header_extension) {
+  const string file_path(FilePath(file));
+
+  if (IsProtobufLibraryBundledProtoFile(file)) {
+    protobuf_framework_imports_.push_back(
+        FilePathBasename(file) + header_extension);
+    protobuf_non_framework_imports_.push_back(file_path + header_extension);
+    return;
+  }
+
+  // Lazy parse any mappings.
+  if (need_to_parse_mapping_file_) {
+    ParseFrameworkMappings();
+  }
+
+  map<string, string>::iterator proto_lookup =
+      proto_file_to_framework_name_.find(file->name());
+  if (proto_lookup != proto_file_to_framework_name_.end()) {
+    other_framework_imports_.push_back(
+        proto_lookup->second + "/" +
+        FilePathBasename(file) + header_extension);
+    return;
+  }
+
+  if (!generate_for_named_framework_.empty()) {
+    other_framework_imports_.push_back(
+        generate_for_named_framework_ + "/" +
+        FilePathBasename(file) + header_extension);
+    return;
+  }
+
+  other_imports_.push_back(file_path + header_extension);
+}
+
+void ImportWriter::Print(io::Printer* printer) const {
+  assert(protobuf_non_framework_imports_.size() ==
+         protobuf_framework_imports_.size());
+
+  bool add_blank_line = false;
+
+  if (protobuf_framework_imports_.size() > 0) {
+    const string framework_name(ProtobufLibraryFrameworkName);
+    const string cpp_symbol(ProtobufFrameworkImportSymbol(framework_name));
+
+    printer->Print(
+        "#if $cpp_symbol$\n",
+        "cpp_symbol", cpp_symbol);
+    for (vector<string>::const_iterator iter = protobuf_framework_imports_.begin();
+         iter != protobuf_framework_imports_.end(); ++iter) {
+      printer->Print(
+          " #import <$framework_name$/$header$>\n",
+          "framework_name", framework_name,
+          "header", *iter);
+    }
+    printer->Print(
+        "#else\n");
+    for (vector<string>::const_iterator iter = protobuf_non_framework_imports_.begin();
+         iter != protobuf_non_framework_imports_.end(); ++iter) {
+      printer->Print(
+          " #import \"$header$\"\n",
+          "header", *iter);
+    }
+    printer->Print(
+        "#endif\n");
+
+    add_blank_line = true;
+  }
+
+  if (other_framework_imports_.size() > 0) {
+    if (add_blank_line) {
+      printer->Print("\n");
+    }
+
+    for (vector<string>::const_iterator iter = other_framework_imports_.begin();
+         iter != other_framework_imports_.end(); ++iter) {
+      printer->Print(
+          " #import <$header$>\n",
+          "header", *iter);
+    }
+
+    add_blank_line = true;
+  }
+
+  if (other_imports_.size() > 0) {
+    if (add_blank_line) {
+      printer->Print("\n");
+    }
+
+    for (vector<string>::const_iterator iter = other_imports_.begin();
+         iter != other_imports_.end(); ++iter) {
+      printer->Print(
+          " #import \"$header$\"\n",
+          "header", *iter);
+    }
+  }
+}
+
+void ImportWriter::ParseFrameworkMappings() {
+  need_to_parse_mapping_file_ = false;
+  if (named_framework_to_proto_path_mappings_path_.empty()) {
+    return;  // Nothing to do.
+  }
+
+  ProtoFrameworkCollector collector(&proto_file_to_framework_name_);
+  string parse_error;
+  if (!ParseSimpleFile(named_framework_to_proto_path_mappings_path_,
+                       &collector, &parse_error)) {
+    cerr << "error parsing " << named_framework_to_proto_path_mappings_path_
+         << " : " << parse_error << endl;
+    cerr.flush();
+  }
+}
+
+bool ImportWriter::ProtoFrameworkCollector::ConsumeLine(
+    const StringPiece& line, string* out_error) {
+  int offset = line.find(':');
+  if (offset == StringPiece::npos) {
+    *out_error =
+        string("Framework/proto file mapping line without colon sign: '") +
+        line.ToString() + "'.";
+    return false;
+  }
+  StringPiece framework_name(line, 0, offset);
+  StringPiece proto_file_list(line, offset + 1, line.length() - offset - 1);
+  StringPieceTrimWhitespace(&framework_name);
+
+  int start = 0;
+  while (start < proto_file_list.length()) {
+    offset = proto_file_list.find(',', start);
+    if (offset == StringPiece::npos) {
+      offset = proto_file_list.length();
+    }
+
+    StringPiece proto_file(proto_file_list, start, offset - start);
+    StringPieceTrimWhitespace(&proto_file);
+    if (proto_file.size() != 0) {
+      map<string, string>::iterator existing_entry =
+          map_->find(proto_file.ToString());
+      if (existing_entry != map_->end()) {
+        cerr << "warning: duplicate proto file reference, replacing framework entry for '"
+             << proto_file.ToString() << "' with '" << framework_name.ToString()
+             << "' (was '" << existing_entry->second << "')." << endl;
+        cerr.flush();
+      }
+
+      if (proto_file.find(' ') != StringPiece::npos) {
+        cerr << "note: framework mapping file had a proto file with a space in, hopefully that isn't a missing comma: '"
+             << proto_file.ToString() << "'" << endl;
+        cerr.flush();
+      }
+
+      (*map_)[proto_file.ToString()] = framework_name.ToString();
+    }
+
+    start = offset + 1;
+  }
+
+  return true;
+}
+
+
 }  // namespace objectivec
 }  // namespace compiler
 }  // namespace protobuf