Add crashpad_info, MachOImageAnnotationsReader, and its test

snapshot/mac/mach_o_image_annotations_reader.h

Index: snapshot/mac/mach_o_image_annotations_reader.h
diff --git a/snapshot/mac/mach_o_image_annotations_reader.h b/snapshot/mac/mach_o_image_annotations_reader.h
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+// Copyright 2014 The Crashpad Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef CRASHPAD_SNAPSHOT_MAC_MACH_O_IMAGE_ANNOTATIONS_READER_H_
+#define CRASHPAD_SNAPSHOT_MAC_MACH_O_IMAGE_ANNOTATIONS_READER_H_
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+
+namespace crashpad {
+
+class MachOImageReader;
+class ProcessReader;
+
+//! \brief A reader for annotations stored in a Mach-O image mapped into another
+//!     process.
+//!
+//! These annotations are stored for the benefit of crash reporters, and provide
+//! information though to be potentially useful for crash analysis. This class
+//! can decode annotations stored in these formats:
+//!  - CrashpadInfo. This format is used by Crashpad clients. The “simple
+//!    annotations” are recovered from any module with a compatible data
+//!    section, and are included in the annotations returned by SimpleMap().
+//!  - `CrashReporterClient.h`’s `crashreporter_annotations_t`. This format is
+//!    used by Apple code. The `message` and `message2` fields can be recovered
+//!    from any module with a compatible data section, and are included in the
+//!    annotations returned by Vector().
+//!  - `dyld`’s `error_string`. This format is used exclusively by dyld,
+//!    typically for fatal errors. This string can be recovered from any
+//!    `MH_DYLINKER`-type module with this symbol, and is included in the
+//!    annotations returned by Vector().
+class MachOImageAnnotationsReader {
+ public:
+  //! \brief Constructs an object.
+  //!
+  //! \param[in] process_reader The reader for the remote process.
+  //! \param[in] image_reader The MachOImageReader for the Mach-O image file
+  //!     contained within the remote process.
+  //! \param[in] name The module’s name, a string to be used in logged messages.
+  //!     This string is for diagnostic purposes only, and may be empty.
+  MachOImageAnnotationsReader(ProcessReader* process_reader,
+                              const MachOImageReader* image_reader,
+                              const std::string& name);
+
+  ~MachOImageAnnotationsReader() {}
+
+  //! \brief Returns the module’s annotations that are organized as a vector of
+  //!     strings.
+  std::vector<std::string> Vector() const;
+
+  //! \brief Returns the module’s annotations that are organized as key-value
+  //!     pairs, where all keys and values are strings.
+  std::map<std::string, std::string> SimpleMap() const;
+
+ private:
+  // Reades crashreporter_annotations_t::message and
+  // crashreporter_annotations_t::message2 on behalf of Vector().
+  void ReadCrashReporterClientAnnotations(
+      std::vector<std::string>* vector_annotations) const;
+
+  // Reads dyld_error_string on behalf of Vector().
+  void ReadDyldErrorStringAnnotation(
+      std::vector<std::string>* vector_annotations) const;
+
+  // Reads CrashpadInfo::simple_annotations_ on behalf of SimpleMap().
+  void ReadCrashpadSimpleAnnotations(
+      std::map<std::string, std::string>* simple_map_annotations) const;
+
+  std::string name_;
+  ProcessReader* process_reader_;  // weak
+  const MachOImageReader* image_reader_;  // weak
+
+  DISALLOW_COPY_AND_ASSIGN(MachOImageAnnotationsReader);
+};
+
+}  // namespace crashpad
+
+#endif  // CRASHPAD_SNAPSHOT_MAC_MACH_O_IMAGE_ANNOTATIONS_READER_H_