diff --git a/src/google/protobuf/compiler/command_line_interface.cc b/src/google/protobuf/compiler/command_line_interface.cc index a611fceef6..9a91b8c2bc 100644 --- a/src/google/protobuf/compiler/command_line_interface.cc +++ b/src/google/protobuf/compiler/command_line_interface.cc @@ -61,6 +61,8 @@ #include #include #include +#include +#include namespace google { @@ -132,6 +134,45 @@ void SetFdToBinaryMode(int fd) { // (Text and binary are the same on non-Windows platforms.) } +void AddTrailingSlash(string* path) { + if (!path->empty() && path->at(path->size() - 1) != '/') { + path->push_back('/'); + } +} + +bool VerifyDirectoryExists(const string& path) { + if (path.empty()) return true; + + if (access(path.c_str(), W_OK) == -1) { + cerr << path << ": " << strerror(errno) << endl; + return false; + } else { + return true; + } +} + +// Try to create the parent directory of the given file, creating the parent's +// parent if necessary, and so on. The full file name is actually +// (prefix + filename), but we assume |prefix| already exists and only create +// directories listed in |filename|. +void TryCreateParentDirectory(const string& prefix, const string& filename) { + // Recursively create parent directories to the output file. + vector parts; + SplitStringUsing(filename, "/", &parts); + string path_so_far = prefix; + for (int i = 0; i < parts.size() - 1; i++) { + path_so_far += parts[i]; + if (mkdir(path_so_far.c_str(), 0777) != 0) { + if (errno != EEXIST) { + cerr << filename << ": while trying to create directory " + << path_so_far << ": " << strerror(errno) << endl; + return; + } + } + path_so_far += '/'; + } +} + } // namespace // A MultiFileErrorCollector that prints errors to stderr. @@ -176,15 +217,12 @@ class CommandLineInterface::ErrorPrinter : public MultiFileErrorCollector, // ------------------------------------------------------------------- // An OutputDirectory implementation that writes to disk. -class CommandLineInterface::DiskOutputDirectory : public OutputDirectory { +class CommandLineInterface::MemoryOutputDirectory : public OutputDirectory { public: - DiskOutputDirectory(const string& root); - ~DiskOutputDirectory(); + MemoryOutputDirectory(); + ~MemoryOutputDirectory(); - bool VerifyExistence(); - - inline bool had_error() { return had_error_; } - inline void set_had_error(bool value) { had_error_ = value; } + bool WriteAllToDisk(); // implements OutputDirectory -------------------------------------- io::ZeroCopyOutputStream* Open(const string& filename); @@ -192,362 +230,264 @@ class CommandLineInterface::DiskOutputDirectory : public OutputDirectory { const string& filename, const string& insertion_point); private: - string root_; + friend class MemoryOutputStream; + + hash_map files_; bool had_error_; }; -// A FileOutputStream that checks for errors in the destructor and reports -// them. We extend FileOutputStream via wrapping rather than inheritance -// for two reasons: -// 1) Implementation inheritance is evil. -// 2) We need to close the file descriptor *after* the FileOutputStream's -// destructor is run to make sure it flushes the file contents. -class CommandLineInterface::ErrorReportingFileOutput - : public io::ZeroCopyOutputStream { +// OutputDirectory that just adds some prefix to every file name. +class CommandLineInterface::SubOutputDirectory : public OutputDirectory { public: - ErrorReportingFileOutput(int file_descriptor, - const string& filename, - DiskOutputDirectory* directory); - ~ErrorReportingFileOutput(); + SubOutputDirectory(OutputDirectory* parent, const string& prefix) + : parent_(parent), prefix_(prefix) {} + ~SubOutputDirectory() {} - // implements ZeroCopyOutputStream --------------------------------- - bool Next(void** data, int* size) { return file_stream_->Next(data, size); } - void BackUp(int count) { file_stream_->BackUp(count); } - int64 ByteCount() const { return file_stream_->ByteCount(); } + // implements OutputDirectory -------------------------------------- + io::ZeroCopyOutputStream* Open(const string& filename) { + // TODO(kenton): This is not the cleanest place to deal with creation of + // parent directories, but it does the right thing given the way this + // class is used, and this class is private to this file anyway, so it's + // probably not worth fixing for now. + TryCreateParentDirectory(prefix_, filename); + return parent_->Open(prefix_ + filename); + } + io::ZeroCopyOutputStream* OpenForInsert( + const string& filename, const string& insertion_point) { + return parent_->OpenForInsert(prefix_ + filename, insertion_point); + } private: - scoped_ptr file_stream_; - string filename_; - DiskOutputDirectory* directory_; + OutputDirectory* parent_; + string prefix_; }; -// Kind of like ErrorReportingFileOutput, but used when inserting -// (OutputDirectory::OpenForInsert()). In this case, we are writing to a -// temporary file, since we must copy data from the original. We copy the -// data up to the insertion point in the constructor, and the remainder in the -// destructor. We then replace the original file with the temporary, also in -// the destructor. -class CommandLineInterface::InsertionOutputStream +class CommandLineInterface::MemoryOutputStream : public io::ZeroCopyOutputStream { public: - InsertionOutputStream( - const string& filename, - const string& temp_filename, - const string& insertion_point, - int original_file_descriptor, // Takes ownership. - int temp_file_descriptor, // Takes ownership. - DiskOutputDirectory* directory); // Does not take ownership. - ~InsertionOutputStream(); + MemoryOutputStream(MemoryOutputDirectory* directory, const string& filename); + MemoryOutputStream(MemoryOutputDirectory* directory, const string& filename, + const string& insertion_point); + virtual ~MemoryOutputStream(); // implements ZeroCopyOutputStream --------------------------------- - bool Next(void** data, int* size) { return temp_file_->Next(data, size); } - void BackUp(int count) { temp_file_->BackUp(count); } - int64 ByteCount() const { return temp_file_->ByteCount(); } + virtual bool Next(void** data, int* size) { return inner_->Next(data, size); } + virtual void BackUp(int count) { inner_->BackUp(count); } + virtual int64 ByteCount() const { return inner_->ByteCount(); } private: - scoped_ptr original_file_; - scoped_ptr temp_file_; - + // Where to insert the string when it's done. + MemoryOutputDirectory* directory_; string filename_; - string temp_filename_; - DiskOutputDirectory* directory_; + string insertion_point_; - // The contents of the line containing the insertion point. - string magic_line_; + // The string we're building. + string data_; + + // StringOutputStream writing to data_. + scoped_ptr inner_; }; // ------------------------------------------------------------------- -CommandLineInterface::DiskOutputDirectory::DiskOutputDirectory( - const string& root) - : root_(root), had_error_(false) { - // Add a '/' to the end if it doesn't already have one. But don't add a - // '/' to an empty string since this probably means the current directory. - if (!root_.empty() && root[root_.size() - 1] != '/') { - root_ += '/'; - } -} +CommandLineInterface::MemoryOutputDirectory::MemoryOutputDirectory() + : had_error_(false) {} -CommandLineInterface::DiskOutputDirectory::~DiskOutputDirectory() { +CommandLineInterface::MemoryOutputDirectory::~MemoryOutputDirectory() { + STLDeleteValues(&files_); } -bool CommandLineInterface::DiskOutputDirectory::VerifyExistence() { - if (!root_.empty()) { - // Make sure the directory exists. If it isn't a directory, this will fail - // because we added a '/' to the end of the name in the constructor. - if (access(root_.c_str(), W_OK) == -1) { - cerr << root_ << ": " << strerror(errno) << endl; - return false; - } +bool CommandLineInterface::MemoryOutputDirectory::WriteAllToDisk() { + if (had_error_) { + return false; } - return true; -} - -// ------------------------------------------------------------------- + for (hash_map::const_iterator iter = files_.begin(); + iter != files_.end(); ++iter) { + const string& filename = iter->first; + const char* data = iter->second->data(); + int size = iter->second->size(); + + // Create the output file. + int file_descriptor; + do { + file_descriptor = + open(filename.c_str(), O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0666); + } while (file_descriptor < 0 && errno == EINTR); + + if (file_descriptor < 0) { + int error = errno; + cerr << filename << ": " << strerror(error); + return false; + } -io::ZeroCopyOutputStream* CommandLineInterface::DiskOutputDirectory::Open( - const string& filename) { - // Recursively create parent directories to the output file. - vector parts; - SplitStringUsing(filename, "/", &parts); - string path_so_far = root_; - for (int i = 0; i < parts.size() - 1; i++) { - path_so_far += parts[i]; - if (mkdir(path_so_far.c_str(), 0777) != 0) { - if (errno != EEXIST) { - cerr << filename << ": while trying to create directory " - << path_so_far << ": " << strerror(errno) << endl; - had_error_ = true; - // Return a dummy stream. - return new io::ArrayOutputStream(NULL, 0); + // Write the file. + while (size > 0) { + int write_result; + do { + write_result = write(file_descriptor, data, size); + } while (write_result < 0 && errno == EINTR); + + if (write_result <= 0) { + // Write error. + + // FIXME(kenton): According to the man page, if write() returns zero, + // there was no error; write() simply did not write anything. It's + // unclear under what circumstances this might happen, but presumably + // errno won't be set in this case. I am confused as to how such an + // event should be handled. For now I'm treating it as an error, + // since retrying seems like it could lead to an infinite loop. I + // suspect this never actually happens anyway. + + if (write_result < 0) { + int error = errno; + cerr << filename << ": write: " << strerror(error); + } else { + cerr << filename << ": write() returned zero?" << endl; + } + return false; } + + data += write_result; + size -= write_result; } - path_so_far += '/'; - } - // Create the output file. - int file_descriptor; - do { - file_descriptor = - open((root_ + filename).c_str(), - O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0666); - } while (file_descriptor < 0 && errno == EINTR); - - if (file_descriptor < 0) { - // Failed to open. - cerr << filename << ": " << strerror(errno) << endl; - had_error_ = true; - // Return a dummy stream. - return new io::ArrayOutputStream(NULL, 0); + if (close(file_descriptor) != 0) { + int error = errno; + cerr << filename << ": close: " << strerror(error); + return false; + } } - return new ErrorReportingFileOutput(file_descriptor, filename, this); + return true; } -CommandLineInterface::ErrorReportingFileOutput::ErrorReportingFileOutput( - int file_descriptor, - const string& filename, - DiskOutputDirectory* directory) - : file_stream_(new io::FileOutputStream(file_descriptor)), - filename_(filename), - directory_(directory) {} - -CommandLineInterface::ErrorReportingFileOutput::~ErrorReportingFileOutput() { - // Check if we had any errors while writing. - if (file_stream_->GetErrno() != 0) { - cerr << filename_ << ": " << strerror(file_stream_->GetErrno()) << endl; - directory_->set_had_error(true); - } - - // Close the file stream. - if (!file_stream_->Close()) { - cerr << filename_ << ": " << strerror(file_stream_->GetErrno()) << endl; - directory_->set_had_error(true); - } +io::ZeroCopyOutputStream* CommandLineInterface::MemoryOutputDirectory::Open( + const string& filename) { + return new MemoryOutputStream(this, filename); } -// ------------------------------------------------------------------- - io::ZeroCopyOutputStream* -CommandLineInterface::DiskOutputDirectory::OpenForInsert( +CommandLineInterface::MemoryOutputDirectory::OpenForInsert( const string& filename, const string& insertion_point) { - string path = root_ + filename; - - // Put the temp file in the same directory so that we can simply rename() it - // into place later. - string temp_path = path + ".protoc_temp"; - - // Open the original file. - int original_file; - do { - original_file = open(path.c_str(), O_RDONLY | O_BINARY); - } while (original_file < 0 && errno == EINTR); + return new MemoryOutputStream(this, filename, insertion_point); +} - if (original_file < 0) { - // Failed to open. - cerr << path << ": " << strerror(errno) << endl; - had_error_ = true; - // Return a dummy stream. - return new io::ArrayOutputStream(NULL, 0); - } +// ------------------------------------------------------------------- - // Create the temp file. - int temp_file; - do { - temp_file = - open(temp_path.c_str(), - O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0666); - } while (temp_file < 0 && errno == EINTR); - - if (temp_file < 0) { - // Failed to open. - cerr << temp_path << ": " << strerror(errno) << endl; - had_error_ = true; - close(original_file); - // Return a dummy stream. - return new io::ArrayOutputStream(NULL, 0); - } +CommandLineInterface::MemoryOutputStream::MemoryOutputStream( + MemoryOutputDirectory* directory, const string& filename) + : directory_(directory), + filename_(filename), + inner_(new io::StringOutputStream(&data_)) { +} - return new InsertionOutputStream( - path, temp_path, insertion_point, original_file, temp_file, this); +CommandLineInterface::MemoryOutputStream::MemoryOutputStream( + MemoryOutputDirectory* directory, const string& filename, + const string& insertion_point) + : directory_(directory), + filename_(filename), + insertion_point_(insertion_point), + inner_(new io::StringOutputStream(&data_)) { } -namespace { +CommandLineInterface::MemoryOutputStream::~MemoryOutputStream() { + // Make sure all data has been written. + inner_.reset(); -// Helper for reading lines from a ZeroCopyInputStream. -// TODO(kenton): Put somewhere reusable? -class LineReader { - public: - LineReader(io::ZeroCopyInputStream* input) - : input_(input), buffer_(NULL), size_(0) {} + // Insert into the directory. + string** map_slot = &directory_->files_[filename_]; - ~LineReader() { - if (size_ > 0) { - input_->BackUp(size_); + if (insertion_point_.empty()) { + // This was just a regular Open(). + if (*map_slot != NULL) { + cerr << filename_ << ": Tried to write the same file twice." << endl; + directory_->had_error_ = true; + return; } - } - - bool ReadLine(string* line) { - line->clear(); - while (true) { - for (int i = 0; i < size_; i++) { - if (buffer_[i] == '\n') { - line->append(buffer_, i + 1); - buffer_ += i + 1; - size_ -= i + 1; - return true; - } - } - - line->append(buffer_, size_); - - const void* void_buffer; - if (!input_->Next(&void_buffer, &size_)) { - buffer_ = NULL; - size_ = 0; - return false; - } + *map_slot = new string; + (*map_slot)->swap(data_); + } else { + // This was an OpenForInsert(). - buffer_ = reinterpret_cast(void_buffer); + // If the data doens't end with a clean line break, add one. + if (!data_.empty() && data_[data_.size() - 1] != '\n') { + data_.push_back('\n'); } - } - private: - io::ZeroCopyInputStream* input_; - const char* buffer_; - int size_; -}; - -} // namespace - -CommandLineInterface::InsertionOutputStream::InsertionOutputStream( - const string& filename, - const string& temp_filename, - const string& insertion_point, - int original_file_descriptor, - int temp_file_descriptor, - DiskOutputDirectory* directory) - : original_file_(new io::FileInputStream(original_file_descriptor)), - temp_file_(new io::FileOutputStream(temp_file_descriptor)), - filename_(filename), - temp_filename_(temp_filename), - directory_(directory) { - string magic_string = strings::Substitute( - "@@protoc_insertion_point($0)", insertion_point); - - LineReader reader(original_file_.get()); - io::Printer writer(temp_file_.get(), '$'); - string line; - - while (true) { - if (!reader.ReadLine(&line)) { - int error = temp_file_->GetErrno(); - if (error == 0) { - cerr << filename << ": Insertion point not found: " - << insertion_point << endl; - } else { - cerr << filename << ": " << strerror(error) << endl; - } - original_file_->Close(); - original_file_.reset(); - // Will finish handling error in the destructor. - break; + // Find the file we are going to insert into. + if (*map_slot == NULL) { + cerr << filename_ << ": Tried to insert into file that doesn't exist." + << endl; + directory_->had_error_ = true; + return; } - - if (line.find(magic_string) != string::npos) { - // Found the magic line. Since we want to insert before it, save it for - // later. - magic_line_ = line; - break; + string* target = *map_slot; + + // Find the insertion point. + string magic_string = strings::Substitute( + "@@protoc_insertion_point($0)", insertion_point_); + string::size_type pos = target->find(magic_string); + + if (pos == string::npos) { + cerr << filename_ << ": insertion point \"" << insertion_point_ + << "\" not found." << endl; + directory_->had_error_ = true; + return; } - writer.PrintRaw(line); - } -} - -CommandLineInterface::InsertionOutputStream::~InsertionOutputStream() { - // C-style error handling is teh best. - bool had_error = false; - - if (original_file_ == NULL) { - // We had an error in the constructor. - had_error = true; - } else { - // Use CodedOutputStream for convenience, so we don't have to deal with - // copying buffers ourselves. - io::CodedOutputStream out(temp_file_.get()); - out.WriteRaw(magic_line_.data(), magic_line_.size()); - - // Write the rest of the original file. - const void* buffer; - int size; - while (original_file_->Next(&buffer, &size)) { - out.WriteRaw(buffer, size); + // Seek backwards to the beginning of the line, which is where we will + // insert the data. Note that this has the effect of pushing the insertion + // point down, so the data is inserted before it. This is intentional + // because it means that multiple insertions at the same point will end + // up in the expected order in the final output. + pos = target->find_last_of('\n', pos); + if (pos == string::npos) { + // Insertion point is on the first line. + pos = 0; + } else { + // Advance to character after '\n'. + ++pos; } - // Close the original file. - if (!original_file_->Close()) { - cerr << filename_ << ": " << strerror(original_file_->GetErrno()) << endl; - had_error = true; - } - } + // Extract indent. + string indent_(*target, pos, target->find_first_not_of(" \t", pos) - pos); - // Check if we had any errors while writing. - if (temp_file_->GetErrno() != 0) { - cerr << filename_ << ": " << strerror(temp_file_->GetErrno()) << endl; - had_error = true; - } + if (indent_.empty()) { + // No indent. This makes things easier. + target->insert(pos, data_); + } else { + // Calculate how much space we need. + int indent_size = 0; + for (int i = 0; i < data_.size(); i++) { + if (data_[i] == '\n') indent_size += indent_.size(); + } - // Close the temp file. - if (!temp_file_->Close()) { - cerr << filename_ << ": " << strerror(temp_file_->GetErrno()) << endl; - had_error = true; - } + // Make a hole for it. + target->insert(pos, data_.size() + indent_size, '\0'); + + // Now copy in the data. + string::size_type data_pos = 0; + char* target_ptr = string_as_array(target) + pos; + while (data_pos < data_.size()) { + // Copy indent. + memcpy(target_ptr, indent_.data(), indent_.size()); + target_ptr += indent_.size(); + + // Copy line from data_. + // We already guaranteed that data_ ends with a newline (above), so this + // search can't fail. + string::size_type line_length = + data_.find_first_of('\n', data_pos) + 1 - data_pos; + memcpy(target_ptr, data_.data() + data_pos, line_length); + target_ptr += line_length; + data_pos += line_length; + } - // If everything was successful, overwrite the original file with the temp - // file. - if (!had_error) { -#ifdef _WIN32 - // rename() on Windows fails if the file exists. - if (!MoveFileEx(temp_filename_.c_str(), filename_.c_str(), - MOVEFILE_REPLACE_EXISTING)) { - cerr << filename_ << ": MoveFileEx: " - << Subprocess::Win32ErrorMessage(GetLastError()) << endl; - } -#else // _WIN32 - if (rename(temp_filename_.c_str(), filename_.c_str()) < 0) { - cerr << filename_ << ": rename: " << strerror(errno) << endl; - had_error = true; + GOOGLE_CHECK_EQ(target_ptr, + string_as_array(target) + pos + data_.size() + indent_size); } -#endif // !_WIN32 - } - - if (had_error) { - // We had some sort of error so let's try to delete the temp file. - remove(temp_filename_.c_str()); - directory_->set_had_error(true); } } @@ -613,14 +553,20 @@ int CommandLineInterface::Run(int argc, const char* const argv[]) { } // Generate output. + MemoryOutputDirectory output_directory; if (mode_ == MODE_COMPILE) { for (int i = 0; i < output_directives_.size(); i++) { - if (!GenerateOutput(parsed_files, output_directives_[i])) { + if (!GenerateOutput(parsed_files, output_directives_[i], + &output_directory)) { return 1; } } } + if (!output_directory.WriteAllToDisk()) { + return 1; + } + if (!descriptor_set_name_.empty()) { if (!WriteDescriptorSet(parsed_files)) { return 1; @@ -1062,14 +1008,15 @@ void CommandLineInterface::PrintHelpText() { bool CommandLineInterface::GenerateOutput( const vector& parsed_files, - const OutputDirective& output_directive) { - // Create the output directory. - DiskOutputDirectory output_directory(output_directive.output_location); - if (!output_directory.VerifyExistence()) { + const OutputDirective& output_directive, + OutputDirectory* parent_output_directory) { + // Set up the OutputDirectory. + string path = output_directive.output_location; + AddTrailingSlash(&path); + if (!VerifyDirectoryExists(path)) { return false; } - - // Opened successfully. Write it. + SubOutputDirectory output_directory(parent_output_directory, path); // Call the generator. string error; @@ -1103,11 +1050,6 @@ bool CommandLineInterface::GenerateOutput( } } - // Check for write errors. - if (output_directory.had_error()) { - return false; - } - return true; } diff --git a/src/google/protobuf/compiler/command_line_interface.h b/src/google/protobuf/compiler/command_line_interface.h index 1070a83bb8..1a75ec8523 100644 --- a/src/google/protobuf/compiler/command_line_interface.h +++ b/src/google/protobuf/compiler/command_line_interface.h @@ -174,9 +174,9 @@ class LIBPROTOC_EXPORT CommandLineInterface { // ----------------------------------------------------------------- class ErrorPrinter; - class DiskOutputDirectory; - class ErrorReportingFileOutput; - class InsertionOutputStream; + class MemoryOutputDirectory; + class SubOutputDirectory; + class MemoryOutputStream; // Clear state from previous Run(). void Clear(); @@ -212,7 +212,8 @@ class LIBPROTOC_EXPORT CommandLineInterface { // Generate the given output file from the given input. struct OutputDirective; // see below bool GenerateOutput(const vector& parsed_files, - const OutputDirective& output_directive); + const OutputDirective& output_directive, + OutputDirectory* parent_output_directory); bool GeneratePluginOutput(const vector& parsed_files, const string& plugin_name, const string& parameter, diff --git a/src/google/protobuf/compiler/command_line_interface_unittest.cc b/src/google/protobuf/compiler/command_line_interface_unittest.cc index 2ea48b7ec0..9129ebf066 100644 --- a/src/google/protobuf/compiler/command_line_interface_unittest.cc +++ b/src/google/protobuf/compiler/command_line_interface_unittest.cc @@ -933,7 +933,10 @@ TEST_F(CommandLineInterfaceTest, OutputWriteError) { Run("protocol_compiler --test_out=$tmpdir " "--proto_path=$tmpdir foo.proto"); - ExpectErrorSubstring("MockCodeGenerator detected write error."); + // MockCodeGenerator no longer detects an error because we actually write to + // an in-memory location first, then dump to disk at the end. This is no + // big deal. + // ExpectErrorSubstring("MockCodeGenerator detected write error."); #if defined(_WIN32) && !defined(__CYGWIN__) // Windows with MSVCRT.dll produces EPERM instead of EISDIR. diff --git a/src/google/protobuf/compiler/mock_code_generator.cc b/src/google/protobuf/compiler/mock_code_generator.cc index cd951ad57c..83d5a4e457 100644 --- a/src/google/protobuf/compiler/mock_code_generator.cc +++ b/src/google/protobuf/compiler/mock_code_generator.cc @@ -50,7 +50,7 @@ static const char* kSecondInsertionPointName = "second_mock_insertion_point"; static const char* kFirstInsertionPoint = "# @@protoc_insertion_point(first_mock_insertion_point) is here\n"; static const char* kSecondInsertionPoint = - "# @@protoc_insertion_point(second_mock_insertion_point) is here\n"; + " # @@protoc_insertion_point(second_mock_insertion_point) is here\n"; MockCodeGenerator::MockCodeGenerator(const string& name) : name_(name) {} @@ -94,8 +94,10 @@ void MockCodeGenerator::ExpectGenerated( EXPECT_EQ(GetOutputFileContent(insertion_list[i], "first_insert", file, first_message_name), lines[1 + i]); - EXPECT_EQ(GetOutputFileContent(insertion_list[i], "second_insert", - file, first_message_name), + // Second insertion point is indented, so the inserted text should + // automatically be indented too. + EXPECT_EQ(" " + GetOutputFileContent(insertion_list[i], "second_insert", + file, first_message_name), lines[2 + insertion_list.size() + i]); } } diff --git a/src/google/protobuf/compiler/plugin.proto b/src/google/protobuf/compiler/plugin.proto index 2db9574c41..d91c06e476 100644 --- a/src/google/protobuf/compiler/plugin.proto +++ b/src/google/protobuf/compiler/plugin.proto @@ -123,6 +123,13 @@ message CodeGeneratorResponse { // insertion_point "package_level_decls" to generate additional classes or // other declarations that should be placed in this scope. // + // Note that if the line containing the insertion point begins with + // whitespace, the same whitespace will be added to every line of the + // inserted text. This is useful for languages like Python, where + // indentation matters. In these languages, the insertion point comment + // should be indented the same amount as any inserted code will need to be + // in order to work correctly in that context. + // // If |insertion_point| is present, |name| must also be present. optional string insertion_point = 2;