diff --git a/libc/malloc_debug/BacktraceData.cpp b/libc/malloc_debug/BacktraceData.cpp
index 3d46bf0..752d507 100644
--- a/libc/malloc_debug/BacktraceData.cpp
+++ b/libc/malloc_debug/BacktraceData.cpp
@@ -51,26 +51,26 @@
 
 BacktraceData::BacktraceData(DebugData* debug_data, const Config& config, size_t* offset)
     : OptionData(debug_data) {
-  size_t hdr_len = sizeof(BacktraceHeader) + sizeof(uintptr_t) * config.backtrace_frames;
+  size_t hdr_len = sizeof(BacktraceHeader) + sizeof(uintptr_t) * config.backtrace_frames();
   alloc_offset_ = *offset;
   *offset += BIONIC_ALIGN(hdr_len, MINIMUM_ALIGNMENT_BYTES);
 }
 
 bool BacktraceData::Initialize(const Config& config) {
-  enabled_ = config.backtrace_enabled;
-  if (config.backtrace_enable_on_signal) {
+  enabled_ = config.backtrace_enabled();
+  if (config.backtrace_enable_on_signal()) {
     struct sigaction enable_act;
     memset(&enable_act, 0, sizeof(enable_act));
 
     enable_act.sa_sigaction = EnableToggle;
     enable_act.sa_flags = SA_RESTART | SA_SIGINFO | SA_ONSTACK;
     sigemptyset(&enable_act.sa_mask);
-    if (sigaction(config.backtrace_signal, &enable_act, nullptr) != 0) {
+    if (sigaction(config.backtrace_signal(), &enable_act, nullptr) != 0) {
       error_log("Unable to set up backtrace signal enable function: %s", strerror(errno));
       return false;
     }
     info_log("%s: Run: 'kill -%d %d' to enable backtracing.", getprogname(),
-             config.backtrace_signal, getpid());
+             config.backtrace_signal(), getpid());
   }
   return true;
 }
diff --git a/libc/malloc_debug/BacktraceData.h b/libc/malloc_debug/BacktraceData.h
index dbc3989..6dee505 100644
--- a/libc/malloc_debug/BacktraceData.h
+++ b/libc/malloc_debug/BacktraceData.h
@@ -36,7 +36,7 @@
 #include "OptionData.h"
 
 // Forward declarations.
-struct Config;
+class Config;
 
 class BacktraceData : public OptionData {
  public:
diff --git a/libc/malloc_debug/Config.cpp b/libc/malloc_debug/Config.cpp
index cb75bd6..df453a9 100644
--- a/libc/malloc_debug/Config.cpp
+++ b/libc/malloc_debug/Config.cpp
@@ -26,6 +26,7 @@
  * SUCH DAMAGE.
  */
 
+#include <assert.h>
 #include <ctype.h>
 #include <errno.h>
 #include <limits.h>
@@ -66,174 +67,227 @@
 static constexpr size_t MAX_RECORD_ALLOCS = 50000000;
 static constexpr const char DEFAULT_RECORD_ALLOCS_FILE[] = "/data/local/tmp/record_allocs.txt";
 
-struct Option {
-  Option(std::string name, uint64_t option, bool combo_option = false, bool* config = nullptr)
-      : name(name), option(option), combo_option(combo_option), config(config) {}
-  virtual ~Option() = default;
+const std::unordered_map<std::string, Config::OptionInfo> Config::kOptions = {
+    {"guard",
+      {FRONT_GUARD | REAR_GUARD, &Config::SetGuard},
+    },
+    {"front_guard",
+      {FRONT_GUARD, &Config::SetFrontGuard},
+    },
+    {"rear_guard",
+      {REAR_GUARD, &Config::SetRearGuard},
+    },
 
-  std::string name;
+    {"backtrace",
+      {BACKTRACE | TRACK_ALLOCS, &Config::SetBacktrace},
+    },
+    {"backtrace_enable_on_signal",
+      {BACKTRACE | TRACK_ALLOCS, &Config::SetBacktraceEnableOnSignal},
+    },
 
-  uint64_t option;
-  // If set to true, then all of the options following are set on until
-  // the combo_option value is set to false.
-  bool combo_option = false;
-  bool* config;
+    {"fill",
+      {FILL_ON_ALLOC | FILL_ON_FREE, &Config::SetFill},
+    },
+    {"fill_on_alloc",
+      {FILL_ON_ALLOC, &Config::SetFillOnAlloc},
+    },
+    {"fill_on_free",
+      {FILL_ON_FREE, &Config::SetFillOnFree},
+    },
 
-  virtual bool ParseValue(const std::string& option_name, const std::string& value) const;
+    {"expand_alloc",
+      {EXPAND_ALLOC, &Config::SetExpandAlloc},
+    },
 
-  virtual void SetDefault() const { }
+    {"free_track",
+      {FREE_TRACK | FILL_ON_FREE, &Config::SetFreeTrack},
+    },
+    {"free_track_backtrace_num_frames",
+      {0, &Config::SetFreeTrackBacktraceNumFrames},
+    },
+
+    {"leak_track",
+      {LEAK_TRACK | TRACK_ALLOCS, &Config::VerifyValueEmpty},
+    },
+
+    {"record_allocs",
+      {RECORD_ALLOCS, &Config::SetRecordAllocs},
+    },
+    {"record_allocs_file",
+      {0, &Config::SetRecordAllocsFile},
+    },
 };
 
-bool Option::ParseValue(const std::string& option_name, const std::string& raw_value) const {
-  if (!raw_value.empty()) {
-    error_log("%s: value set for option '%s' which does not take a value",
-              getprogname(), option_name.c_str());
-    return false;
-  }
-  return true;
-}
-
-struct OptionString : public Option {
-  OptionString(std::string name, uint64_t option, std::string default_value,
-                std::string* value, bool combo_option = false,
-                bool* config = nullptr)
-      : Option(name, option, combo_option, config), default_value(default_value), value(value) {}
-  virtual ~OptionString() = default;
-
-  std::string default_value;
-  std::string* value;
-
-  bool ParseValue(const std::string& option_name, const std::string& value) const override;
-
-  void SetDefault() const override { if (value) *value = default_value; }
-};
-
-bool OptionString::ParseValue(const std::string&, const std::string& raw_value) const {
-  if (!raw_value.empty()) {
-    *value = raw_value;
-  }
-  return true;
-}
-
-struct OptionSizeT : public Option {
-  OptionSizeT(std::string name, size_t default_value, size_t min_value, size_t max_value,
-          uint64_t option, size_t* value, bool combo_option = false, bool* config = nullptr)
-      : Option(name, option, combo_option, config), default_value(default_value),
-        min_value(min_value), max_value(max_value), value(value) {}
-  virtual ~OptionSizeT() = default;
-
-  size_t default_value;
-  size_t min_value;
-  size_t max_value;
-
-  size_t* value;
-
-  bool ParseValue(const std::string& option_name, const std::string& value) const override;
-
-  void SetDefault() const override { if (value) *value = default_value; }
-};
-
-bool OptionSizeT::ParseValue(const std::string& option_name, const std::string& raw_value) const {
-  if (raw_value.empty()) {
-    // Value should have been set by the SetDefault() pass.
-    return true;
-  }
+bool Config::ParseValue(const std::string& option, const std::string& value,
+                        size_t min_value, size_t max_value, size_t* parsed_value) const {
+  assert(!value.empty());
 
   // Parse the value into a size_t value.
   errno = 0;
   char* end;
-  long parsed_value = strtol(raw_value.c_str(), &end, 10);
+  long long_value = strtol(value.c_str(), &end, 10);
   if (errno != 0) {
-    error_log("%s: bad value for option '%s': %s", getprogname(), option_name.c_str(),
+    error_log("%s: bad value for option '%s': %s", getprogname(), option.c_str(),
               strerror(errno));
     return false;
   }
-  if (end == raw_value.c_str()) {
-    error_log("%s: bad value for option '%s'", getprogname(), option_name.c_str());
+  if (end == value.c_str()) {
+    error_log("%s: bad value for option '%s'", getprogname(), option.c_str());
     return false;
   }
-  if (static_cast<size_t>(end - raw_value.c_str()) != raw_value.size()) {
+  if (static_cast<size_t>(end - value.c_str()) != value.size()) {
     error_log("%s: bad value for option '%s', non space found after option: %s",
-              getprogname(), option_name.c_str(), end);
+              getprogname(), option.c_str(), end);
     return false;
   }
-  if (parsed_value < 0) {
+  if (long_value < 0) {
     error_log("%s: bad value for option '%s', value cannot be negative: %ld",
-              getprogname(), option_name.c_str(), parsed_value);
+              getprogname(), option.c_str(), long_value);
     return false;
   }
 
-  if (static_cast<size_t>(parsed_value) < min_value) {
+  if (static_cast<size_t>(long_value) < min_value) {
     error_log("%s: bad value for option '%s', value must be >= %zu: %ld",
-              getprogname(), option_name.c_str(), min_value, parsed_value);
+              getprogname(), option.c_str(), min_value, long_value);
     return false;
   }
-  if (static_cast<size_t>(parsed_value) > max_value) {
+  if (static_cast<size_t>(long_value) > max_value) {
     error_log("%s: bad value for option '%s', value must be <= %zu: %ld",
-              getprogname(), option_name.c_str(), max_value, parsed_value);
+              getprogname(), option.c_str(), max_value, long_value);
     return false;
   }
-  *value = static_cast<size_t>(parsed_value);
+  *parsed_value = static_cast<size_t>(long_value);
   return true;
 }
 
-class PropertyParser {
- public:
-  explicit PropertyParser(const char* property) : cur_(property) {}
+bool Config::ParseValue(const std::string& option, const std::string& value, size_t default_value,
+                        size_t min_value, size_t max_value, size_t* new_value) const {
+  if (value.empty()) {
+    *new_value = default_value;
+    return true;
+  }
+  return ParseValue(option, value, min_value, max_value, new_value);
+}
 
-  bool Get(std::string* property, std::string* value);
+bool Config::SetGuard(const std::string& option, const std::string& value) {
+  if (value.empty()) {
+    // Set the defaults.
+    front_guard_bytes_ = DEFAULT_GUARD_BYTES;
+    rear_guard_bytes_ = DEFAULT_GUARD_BYTES;
+    return true;
+  }
 
-  bool Done() { return done_; }
-
-  void LogUsage();
-
- private:
-  const char* cur_ = nullptr;
-
-  bool done_ = false;
-
-  DISALLOW_COPY_AND_ASSIGN(PropertyParser);
-};
-
-bool PropertyParser::Get(std::string* property, std::string* value) {
-  // Process each property name we can find.
-  while (isspace(*cur_))
-    ++cur_;
-
-  if (*cur_ == '\0') {
-    done_ = true;
+  if (!ParseValue(option, value, 1, MAX_GUARD_BYTES, &rear_guard_bytes_)) {
     return false;
   }
 
-  const char* start = cur_;
-  while (!isspace(*cur_) && *cur_ != '=' && *cur_ != '\0')
-    ++cur_;
+  // It's necessary to align the front guard to MINIMUM_ALIGNMENT_BYTES to
+  // make sure that the header is aligned properly.
+  front_guard_bytes_ = BIONIC_ALIGN(rear_guard_bytes_, MINIMUM_ALIGNMENT_BYTES);
+  return true;
+}
 
-  *property = std::string(start, cur_ - start);
+bool Config::SetFrontGuard(const std::string& option, const std::string& value) {
+  if (!ParseValue(option, value, DEFAULT_GUARD_BYTES, 1, MAX_GUARD_BYTES, &front_guard_bytes_)) {
+    return false;
+  }
+  // It's necessary to align the front guard to MINIMUM_ALIGNMENT_BYTES to
+  // make sure that the header is aligned properly.
+  front_guard_bytes_ = BIONIC_ALIGN(front_guard_bytes_, MINIMUM_ALIGNMENT_BYTES);
+  return true;
+}
 
-  // Skip any spaces after the name.
-  while (isspace(*cur_))
-    ++cur_;
+bool Config::SetRearGuard(const std::string& option, const std::string& value) {
+  return ParseValue(option, value, DEFAULT_GUARD_BYTES, 1, MAX_GUARD_BYTES, &rear_guard_bytes_);
+}
 
-  value->clear();
-  if (*cur_ == '=') {
-    ++cur_;
-    // Skip the space after the equal.
-    while (isspace(*cur_))
-      ++cur_;
+bool Config::SetFill(const std::string& option, const std::string& value) {
+  if (value.empty()) {
+    // Set the defaults.
+    fill_on_alloc_bytes_ = SIZE_MAX;
+    fill_on_free_bytes_ = SIZE_MAX;
+    return true;
+  }
 
-    start = cur_;
-    while (!isspace(*cur_) && *cur_ != '\0')
-      ++cur_;
+  if (!ParseValue(option, value, 1, SIZE_MAX, &fill_on_alloc_bytes_)) {
+    return false;
+  }
+  fill_on_free_bytes_ = fill_on_alloc_bytes_;
+  return true;
+}
 
-    if (cur_ != start) {
-      *value = std::string(start, cur_ - start);
-    }
+bool Config::SetFillOnAlloc(const std::string& option, const std::string& value) {
+  return ParseValue(option, value, SIZE_MAX, 1, SIZE_MAX, &fill_on_alloc_bytes_);
+}
+
+bool Config::SetFillOnFree(const std::string& option, const std::string& value) {
+  return ParseValue(option, value, SIZE_MAX, 1, SIZE_MAX, &fill_on_free_bytes_);
+}
+
+bool Config::SetBacktrace(const std::string& option, const std::string& value) {
+  backtrace_enabled_ = true;
+  return ParseValue(option, value, DEFAULT_BACKTRACE_FRAMES, 1, MAX_BACKTRACE_FRAMES,
+                    &backtrace_frames_);
+}
+
+bool Config::SetBacktraceEnableOnSignal(const std::string& option, const std::string& value) {
+  backtrace_enable_on_signal_ = true;
+  return ParseValue(option, value, DEFAULT_BACKTRACE_FRAMES, 1, MAX_BACKTRACE_FRAMES,
+                    &backtrace_frames_);
+}
+
+bool Config::SetExpandAlloc(const std::string& option, const std::string& value) {
+  return ParseValue(option, value, DEFAULT_EXPAND_BYTES, 1, MAX_EXPAND_BYTES, &expand_alloc_bytes_);
+}
+
+bool Config::SetFreeTrack(const std::string& option, const std::string& value) {
+  // This option enables fill on free, so set the bytes to the default value.
+  if (fill_on_free_bytes_ == 0) {
+    fill_on_free_bytes_ = SIZE_MAX;
+  }
+  if (free_track_backtrace_num_frames_ == 0) {
+    free_track_backtrace_num_frames_ = DEFAULT_BACKTRACE_FRAMES;
+  }
+
+  return ParseValue(option, value, DEFAULT_FREE_TRACK_ALLOCATIONS, 1, MAX_FREE_TRACK_ALLOCATIONS,
+                    &free_track_allocations_);
+}
+
+bool Config::SetFreeTrackBacktraceNumFrames(const std::string& option, const std::string& value) {
+  return ParseValue(option, value, DEFAULT_BACKTRACE_FRAMES, 0, MAX_BACKTRACE_FRAMES,
+                    &free_track_backtrace_num_frames_);
+}
+
+bool Config::SetRecordAllocs(const std::string& option, const std::string& value) {
+  if (record_allocs_file_.empty()) {
+    record_allocs_file_ = DEFAULT_RECORD_ALLOCS_FILE;
+  }
+  return ParseValue(option, value, DEFAULT_RECORD_ALLOCS, 1, MAX_RECORD_ALLOCS,
+                    &record_allocs_num_entries_);
+}
+
+bool Config::SetRecordAllocsFile(const std::string&, const std::string& value) {
+  if (value.empty()) {
+    // Set the default.
+    record_allocs_file_ = DEFAULT_RECORD_ALLOCS_FILE;
+    return true;
+  }
+  record_allocs_file_ = value;
+  return true;
+}
+
+bool Config::VerifyValueEmpty(const std::string& option, const std::string& value) {
+  if (!value.empty()) {
+    // This is not valid.
+    error_log("%s: value set for option '%s' which does not take a value",
+              getprogname(), option.c_str());
+    return false;
   }
   return true;
 }
 
-void PropertyParser::LogUsage() {
+
+void Config::LogUsage() const {
   error_log("malloc debug options usage:");
   error_log("");
   error_log("  front_guard[=XX]");
@@ -325,155 +379,85 @@
   error_log("    The default is %s.", DEFAULT_RECORD_ALLOCS_FILE);
 }
 
-// This function is designed to be called once. A second call will not
-// reset all variables.
-bool Config::Set(const char* options_str) {
-  // Initialize a few default values.
-  fill_alloc_value = DEFAULT_FILL_ALLOC_VALUE;
-  fill_free_value = DEFAULT_FILL_FREE_VALUE;
-  front_guard_value = DEFAULT_FRONT_GUARD_VALUE;
-  rear_guard_value = DEFAULT_REAR_GUARD_VALUE;
-  backtrace_signal = SIGRTMAX - 19;
-  record_allocs_signal = SIGRTMAX - 18;
-  free_track_backtrace_num_frames = 0;
-  record_allocs_file.clear();
+bool Config::GetOption(const char** options_str, std::string* option, std::string* value) {
+  const char* cur = *options_str;
+  // Process each property name we can find.
+  while (isspace(*cur))
+    ++cur;
 
-  // Parse the options are of the format:
-  //   option_name or option_name=XX
-
-  // Supported options:
-  const OptionSizeT option_guard(
-      "guard", DEFAULT_GUARD_BYTES, 1, MAX_GUARD_BYTES, 0, nullptr, true);
-  // Enable front guard. Value is the size of the guard.
-  const OptionSizeT option_front_guard(
-      "front_guard", DEFAULT_GUARD_BYTES, 1, MAX_GUARD_BYTES, FRONT_GUARD,
-      &this->front_guard_bytes, true);
-  // Enable end guard. Value is the size of the guard.
-  const OptionSizeT option_rear_guard(
-      "rear_guard", DEFAULT_GUARD_BYTES, 1, MAX_GUARD_BYTES, REAR_GUARD, &this->rear_guard_bytes,
-      true);
-
-  // Enable logging the backtrace on allocation. Value is the total
-  // number of frames to log.
-  const OptionSizeT option_backtrace(
-      "backtrace", DEFAULT_BACKTRACE_FRAMES, 1, MAX_BACKTRACE_FRAMES, BACKTRACE | TRACK_ALLOCS,
-      &this->backtrace_frames, false, &this->backtrace_enabled);
-  // Enable gathering backtrace values on a signal.
-  const OptionSizeT option_backtrace_enable_on_signal(
-      "backtrace_enable_on_signal", DEFAULT_BACKTRACE_FRAMES, 1, MAX_BACKTRACE_FRAMES,
-      BACKTRACE | TRACK_ALLOCS, &this->backtrace_frames, false, &this->backtrace_enable_on_signal);
-
-  const OptionSizeT option_fill("fill", SIZE_MAX, 1, SIZE_MAX, 0, nullptr, true);
-  // Fill the allocation with an arbitrary pattern on allocation.
-  // Value is the number of bytes of the allocation to fill
-  // (default entire allocation).
-  const OptionSizeT option_fill_on_alloc(
-      "fill_on_alloc", SIZE_MAX, 1, SIZE_MAX, FILL_ON_ALLOC, &this->fill_on_alloc_bytes, true);
-  // Fill the allocation with an arbitrary pattern on free.
-  // Value is the number of bytes of the allocation to fill
-  // (default entire allocation).
-  const OptionSizeT option_fill_on_free(
-      "fill_on_free", SIZE_MAX, 1, SIZE_MAX, FILL_ON_FREE, &this->fill_on_free_bytes, true);
-
-  // Expand the size of every alloc by this number bytes. Value is
-  // the total number of bytes to expand every allocation by.
-  const OptionSizeT option_expand_alloc(
-      "expand_alloc", DEFAULT_EXPAND_BYTES, 1, MAX_EXPAND_BYTES, EXPAND_ALLOC,
-      &this->expand_alloc_bytes);
-
-  // Keep track of the freed allocations and verify at a later date
-  // that they have not been used. Turning this on, also turns on
-  // fill on free.
-  const OptionSizeT option_free_track(
-      "free_track", DEFAULT_FREE_TRACK_ALLOCATIONS, 1, MAX_FREE_TRACK_ALLOCATIONS,
-      FREE_TRACK | FILL_ON_FREE, &this->free_track_allocations);
-  // Number of backtrace frames to keep when free_track is enabled. If this
-  // value is set to zero, no backtrace will be kept.
-  const OptionSizeT option_free_track_backtrace_num_frames(
-      "free_track_backtrace_num_frames", DEFAULT_BACKTRACE_FRAMES, 0, MAX_BACKTRACE_FRAMES, 0,
-      &this->free_track_backtrace_num_frames);
-
-  // Enable printing leaked allocations.
-  const Option option_leak_track("leak_track", LEAK_TRACK | TRACK_ALLOCS);
-
-  const OptionSizeT option_record_allocs(
-      "record_allocs", DEFAULT_RECORD_ALLOCS, 1, MAX_RECORD_ALLOCS, RECORD_ALLOCS,
-      &this->record_allocs_num_entries);
-  const OptionString option_record_allocs_file(
-      "record_allocs_file", 0, DEFAULT_RECORD_ALLOCS_FILE, &this->record_allocs_file);
-
-  const Option* option_list[] = {
-    &option_guard, &option_front_guard, &option_rear_guard,
-    &option_backtrace, &option_backtrace_enable_on_signal,
-    &option_fill, &option_fill_on_alloc, &option_fill_on_free,
-    &option_expand_alloc,
-    &option_free_track, &option_free_track_backtrace_num_frames,
-    &option_leak_track,
-    &option_record_allocs, &option_record_allocs_file,
-  };
-
-  // Set defaults for all of the options.
-  for (size_t i = 0; i < sizeof(option_list)/sizeof(Option*); i++) {
-    option_list[i]->SetDefault();
+  if (*cur == '\0') {
+    *options_str = cur;
+    return false;
   }
 
-  // Process each property name we can find.
-  PropertyParser parser(options_str);
-  bool valid = true;
-  std::string property;
-  std::string value;
-  while (valid && parser.Get(&property, &value)) {
-    bool found = false;
-    for (size_t i = 0; i < sizeof(option_list)/sizeof(Option*); i++) {
-      if (property == option_list[i]->name) {
-        if (option_list[i]->option == 0 && option_list[i]->combo_option) {
-          const std::string* option_name = &option_list[i]->name;
-          i++;
-          for (; i < sizeof(option_list)/sizeof(Option*) && option_list[i]->combo_option; i++) {
-            if (!option_list[i]->ParseValue(*option_name, value)) {
-              valid = false;
-              break;
-            }
-            if (option_list[i]->config) {
-              *option_list[i]->config = true;
-            }
-            options |= option_list[i]->option;
-          }
-          if (!valid) {
-            break;
-          }
-        } else {
-          if (!option_list[i]->ParseValue(option_list[i]->name, value)) {
-            valid = false;
-            break;
-          }
-          if (option_list[i]->config) {
-            *option_list[i]->config = true;
-          }
-          options |= option_list[i]->option;
-        }
-        found = true;
-        break;
-      }
+  const char* start = cur;
+  while (!isspace(*cur) && *cur != '=' && *cur != '\0')
+    ++cur;
+
+  *option = std::string(start, cur - start);
+
+  // Skip any spaces after the name.
+  while (isspace(*cur))
+    ++cur;
+
+  value->clear();
+  if (*cur == '=') {
+    ++cur;
+    // Skip the space after the equal.
+    while (isspace(*cur))
+      ++cur;
+
+    start = cur;
+    while (!isspace(*cur) && *cur != '\0')
+      ++cur;
+
+    if (cur != start) {
+      *value = std::string(start, cur - start);
     }
-    if (valid && !found) {
-      error_log("%s: unknown option %s", getprogname(), property.c_str());
+  }
+  *options_str = cur;
+  return true;
+}
+
+bool Config::Init(const char* options_str) {
+  // Initialize a few default values.
+  fill_alloc_value_ = DEFAULT_FILL_ALLOC_VALUE;
+  fill_free_value_ = DEFAULT_FILL_FREE_VALUE;
+  front_guard_value_ = DEFAULT_FRONT_GUARD_VALUE;
+  rear_guard_value_ = DEFAULT_REAR_GUARD_VALUE;
+  backtrace_signal_ = SIGRTMAX - 19;
+  record_allocs_signal_ = SIGRTMAX - 18;
+  free_track_backtrace_num_frames_ = 0;
+  record_allocs_file_.clear();
+  fill_on_free_bytes_ = 0;
+  backtrace_enable_on_signal_ = false;
+  backtrace_enabled_ = false;
+
+  // Process each option name we can find.
+  std::string option;
+  std::string value;
+  bool valid = true;
+  while (GetOption(&options_str, &option, &value)) {
+    auto entry = kOptions.find(option);
+    if (entry == kOptions.end()) {
+      error_log("%s: unknown option %s", getprogname(), option.c_str());
       valid = false;
       break;
     }
-  }
 
-  valid = valid && parser.Done();
-
-  if (valid) {
-    // It's necessary to align the front guard to MINIMUM_ALIGNMENT_BYTES to
-    // make sure that the header is aligned properly.
-    if (options & FRONT_GUARD) {
-      front_guard_bytes = BIONIC_ALIGN(front_guard_bytes, MINIMUM_ALIGNMENT_BYTES);
+    const OptionInfo* info = &entry->second;
+    auto process_func = info->process_func;
+    if (process_func != nullptr && !(this->*process_func)(option, value)) {
+      valid = false;
+      break;
     }
-  } else {
-    parser.LogUsage();
+    options_ |= info->option;
   }
 
-  return valid;
+  if (!valid || *options_str != '\0') {
+    LogUsage();
+    return false;
+  }
+
+  return true;
 }
diff --git a/libc/malloc_debug/Config.h b/libc/malloc_debug/Config.h
index ca56dc8..d8a7069 100644
--- a/libc/malloc_debug/Config.h
+++ b/libc/malloc_debug/Config.h
@@ -32,6 +32,7 @@
 #include <stdint.h>
 
 #include <string>
+#include <unordered_map>
 
 constexpr uint64_t FRONT_GUARD = 0x1;
 constexpr uint64_t REAR_GUARD = 0x2;
@@ -55,34 +56,100 @@
 // If one or more of these options is set, then a special header is needed.
 constexpr uint64_t HEADER_OPTIONS = FRONT_GUARD | REAR_GUARD | BACKTRACE | FREE_TRACK | LEAK_TRACK;
 
-struct Config {
-  bool Set(const char* str);
+class Config {
+ public:
+  bool Init(const char* options_str);
 
-  size_t front_guard_bytes = 0;
-  size_t rear_guard_bytes = 0;
+  void LogUsage() const;
 
-  bool backtrace_enable_on_signal = false;
-  int backtrace_signal = 0;
-  bool backtrace_enabled = false;
-  size_t backtrace_frames = 0;
+  uint64_t options() const { return options_; }
 
-  size_t fill_on_alloc_bytes = 0;
-  size_t fill_on_free_bytes = 0;
+  int backtrace_signal() const { return backtrace_signal_; }
+  size_t backtrace_frames() const { return backtrace_frames_; }
+  size_t backtrace_enabled() const { return backtrace_enabled_; }
+  size_t backtrace_enable_on_signal() const { return backtrace_enable_on_signal_; }
 
-  size_t expand_alloc_bytes = 0;
+  size_t front_guard_bytes() const { return front_guard_bytes_; }
+  size_t rear_guard_bytes() const { return rear_guard_bytes_; }
+  uint8_t front_guard_value() const { return front_guard_value_; }
+  uint8_t rear_guard_value() const { return rear_guard_value_; }
 
-  size_t free_track_allocations = 0;
-  size_t free_track_backtrace_num_frames = 0;
+  size_t expand_alloc_bytes() const { return expand_alloc_bytes_; }
 
-  int record_allocs_signal = 0;
-  size_t record_allocs_num_entries = 0;
-  std::string record_allocs_file;
+  size_t free_track_allocations() const { return free_track_allocations_; }
+  size_t free_track_backtrace_num_frames() const { return free_track_backtrace_num_frames_; }
 
-  uint64_t options = 0;
-  uint8_t fill_alloc_value;
-  uint8_t fill_free_value;
-  uint8_t front_guard_value;
-  uint8_t rear_guard_value;
+  size_t fill_on_alloc_bytes() const { return fill_on_alloc_bytes_; }
+  size_t fill_on_free_bytes() const { return fill_on_free_bytes_; }
+  uint8_t fill_alloc_value() const { return fill_alloc_value_; }
+  uint8_t fill_free_value() const { return fill_free_value_; }
+
+  int record_allocs_signal() const { return record_allocs_signal_; }
+  size_t record_allocs_num_entries() const { return record_allocs_num_entries_; }
+  const std::string& record_allocs_file() const { return record_allocs_file_; }
+
+ private:
+  struct OptionInfo {
+    uint64_t option;
+    bool (Config::*process_func)(const std::string&, const std::string&);
+  };
+
+  bool ParseValue(const std::string& option, const std::string& value, size_t default_value,
+                  size_t min_value, size_t max_value, size_t* new_value) const;
+
+  bool ParseValue(const std::string& option, const std::string& value, size_t min_value,
+                  size_t max_value, size_t* parsed_value) const;
+
+  bool SetGuard(const std::string& option, const std::string& value);
+  bool SetFrontGuard(const std::string& option, const std::string& value);
+  bool SetRearGuard(const std::string& option, const std::string& value);
+
+  bool SetFill(const std::string& option, const std::string& value);
+  bool SetFillOnAlloc(const std::string& option, const std::string& value);
+  bool SetFillOnFree(const std::string& option, const std::string& value);
+
+  bool SetBacktrace(const std::string& option, const std::string& value);
+  bool SetBacktraceEnableOnSignal(const std::string& option, const std::string& value);
+
+  bool SetExpandAlloc(const std::string& option, const std::string& value);
+
+  bool SetFreeTrack(const std::string& option, const std::string& value);
+  bool SetFreeTrackBacktraceNumFrames(const std::string& option, const std::string& value);
+
+  bool SetRecordAllocs(const std::string& option, const std::string& value);
+  bool SetRecordAllocsFile(const std::string& option, const std::string& value);
+
+  bool VerifyValueEmpty(const std::string& option, const std::string& value);
+
+  static bool GetOption(const char** option_str, std::string* option, std::string* value);
+
+  const static std::unordered_map<std::string, OptionInfo> kOptions;
+
+  size_t front_guard_bytes_ = 0;
+  size_t rear_guard_bytes_ = 0;
+
+  bool backtrace_enable_on_signal_ = false;
+  int backtrace_signal_ = 0;
+  bool backtrace_enabled_ = false;
+  size_t backtrace_frames_ = 0;
+
+  size_t fill_on_alloc_bytes_ = 0;
+  size_t fill_on_free_bytes_ = 0;
+
+  size_t expand_alloc_bytes_ = 0;
+
+  size_t free_track_allocations_ = 0;
+  size_t free_track_backtrace_num_frames_ = 0;
+
+  int record_allocs_signal_ = 0;
+  size_t record_allocs_num_entries_ = 0;
+  std::string record_allocs_file_;
+
+  uint64_t options_ = 0;
+  uint8_t fill_alloc_value_;
+  uint8_t fill_free_value_;
+  uint8_t front_guard_value_;
+  uint8_t rear_guard_value_;
 };
 
 #endif  // MALLOC_DEBUG_CONFIG_H
diff --git a/libc/malloc_debug/DebugData.cpp b/libc/malloc_debug/DebugData.cpp
index 339efdf..e9974d7 100644
--- a/libc/malloc_debug/DebugData.cpp
+++ b/libc/malloc_debug/DebugData.cpp
@@ -38,54 +38,54 @@
 #include "TrackData.h"
 
 bool DebugData::Initialize(const char* options) {
-  if (!config_.Set(options)) {
+  if (!config_.Init(options)) {
     return false;
   }
 
   // Check to see if the options that require a header are enabled.
-  if (config_.options & HEADER_OPTIONS) {
+  if (config_.options() & HEADER_OPTIONS) {
     need_header_ = true;
 
     // Initialize all of the static header offsets.
     pointer_offset_ = BIONIC_ALIGN(sizeof(Header), MINIMUM_ALIGNMENT_BYTES);
 
-    if (config_.options & BACKTRACE) {
+    if (config_.options() & BACKTRACE) {
       backtrace.reset(new BacktraceData(this, config_, &pointer_offset_));
       if (!backtrace->Initialize(config_)) {
         return false;
       }
     }
 
-    if (config_.options & FRONT_GUARD) {
+    if (config_.options() & FRONT_GUARD) {
       front_guard.reset(new FrontGuardData(this, config_, &pointer_offset_));
     }
 
     extra_bytes_ = pointer_offset_;
 
     // Initialize all of the non-header data.
-    if (config_.options & REAR_GUARD) {
+    if (config_.options() & REAR_GUARD) {
       rear_guard.reset(new RearGuardData(this, config_));
-      extra_bytes_ += config_.rear_guard_bytes;
+      extra_bytes_ += config_.rear_guard_bytes();
     }
 
-    if (config_.options & FREE_TRACK) {
+    if (config_.options() & FREE_TRACK) {
       free_track.reset(new FreeTrackData(this, config_));
     }
 
-    if (config_.options & TRACK_ALLOCS) {
+    if (config_.options() & TRACK_ALLOCS) {
       track.reset(new TrackData(this));
     }
   }
 
-  if (config_.options & RECORD_ALLOCS) {
+  if (config_.options() & RECORD_ALLOCS) {
     record.reset(new RecordData());
     if (!record->Initialize(config_)) {
       return false;
     }
   }
 
-  if (config_.options & EXPAND_ALLOC) {
-    extra_bytes_ += config_.expand_alloc_bytes;
+  if (config_.options() & EXPAND_ALLOC) {
+    extra_bytes_ += config_.expand_alloc_bytes();
   }
   return true;
 }
diff --git a/libc/malloc_debug/FreeTrackData.cpp b/libc/malloc_debug/FreeTrackData.cpp
index 8e6502e..e8e7a67 100644
--- a/libc/malloc_debug/FreeTrackData.cpp
+++ b/libc/malloc_debug/FreeTrackData.cpp
@@ -37,15 +37,15 @@
 #include "malloc_debug.h"
 
 FreeTrackData::FreeTrackData(DebugData* debug, const Config& config)
-    : OptionData(debug), backtrace_num_frames_(config.free_track_backtrace_num_frames) {
+    : OptionData(debug), backtrace_num_frames_(config.free_track_backtrace_num_frames()) {
   cmp_mem_.resize(4096);
-  memset(cmp_mem_.data(), config.fill_free_value, cmp_mem_.size());
+  memset(cmp_mem_.data(), config.fill_free_value(), cmp_mem_.size());
 }
 
 void FreeTrackData::LogFreeError(const Header* header, const uint8_t* pointer) {
   error_log(LOG_DIVIDER);
   error_log("+++ ALLOCATION %p USED AFTER FREE", pointer);
-  uint8_t fill_free_value = debug_->config().fill_free_value;
+  uint8_t fill_free_value = debug_->config().fill_free_value();
   for (size_t i = 0; i < header->usable_size; i++) {
     if (pointer[i] != fill_free_value) {
       error_log("  allocation[%zu] = 0x%02x (expected 0x%02x)", i, pointer[i], fill_free_value);
@@ -69,8 +69,8 @@
   } else {
     const uint8_t* memory = reinterpret_cast<const uint8_t*>(pointer);
     size_t bytes = header->usable_size;
-    bytes = (bytes < debug_->config().fill_on_free_bytes) ? bytes
-        : debug_->config().fill_on_free_bytes;
+    bytes = (bytes < debug_->config().fill_on_free_bytes()) ? bytes
+        : debug_->config().fill_on_free_bytes();
     while (bytes > 0) {
       size_t bytes_to_cmp = (bytes < cmp_mem_.size()) ? bytes : cmp_mem_.size();
       if (memcmp(memory, cmp_mem_.data(), bytes_to_cmp) != 0) {
@@ -92,7 +92,7 @@
 
 void FreeTrackData::Add(const Header* header) {
   pthread_mutex_lock(&mutex_);
-  if (list_.size() == debug_->config().free_track_allocations) {
+  if (list_.size() == debug_->config().free_track_allocations()) {
     const Header* old_header = list_.back();
     VerifyAndFree(old_header);
     list_.pop_back();
diff --git a/libc/malloc_debug/FreeTrackData.h b/libc/malloc_debug/FreeTrackData.h
index 21f845f..1758ef5 100644
--- a/libc/malloc_debug/FreeTrackData.h
+++ b/libc/malloc_debug/FreeTrackData.h
@@ -42,7 +42,7 @@
 
 // Forward declarations.
 struct BacktraceHeader;
-struct Config;
+class Config;
 class DebugData;
 struct Header;
 
diff --git a/libc/malloc_debug/GuardData.cpp b/libc/malloc_debug/GuardData.cpp
index e207b86..d6cef85 100644
--- a/libc/malloc_debug/GuardData.cpp
+++ b/libc/malloc_debug/GuardData.cpp
@@ -70,13 +70,13 @@
 }
 
 FrontGuardData::FrontGuardData(DebugData* debug_data, const Config& config, size_t* offset)
-   : GuardData(debug_data, config.front_guard_value, config.front_guard_bytes) {
+   : GuardData(debug_data, config.front_guard_value(), config.front_guard_bytes()) {
   // Create a buffer for fast comparisons of the front guard.
-  cmp_mem_.resize(config.front_guard_bytes);
-  memset(cmp_mem_.data(), config.front_guard_value, cmp_mem_.size());
+  cmp_mem_.resize(config.front_guard_bytes());
+  memset(cmp_mem_.data(), config.front_guard_value(), cmp_mem_.size());
   // Assumes that front_bytes is a multiple of MINIMUM_ALIGNMENT_BYTES.
   offset_ = *offset;
-  *offset += config.front_guard_bytes;
+  *offset += config.front_guard_bytes();
 }
 
 bool FrontGuardData::Valid(const Header* header) {
@@ -88,7 +88,7 @@
 }
 
 RearGuardData::RearGuardData(DebugData* debug_data, const Config& config)
-    : GuardData(debug_data, config.rear_guard_value, config.rear_guard_bytes) {
+    : GuardData(debug_data, config.rear_guard_value(), config.rear_guard_bytes()) {
 }
 
 bool RearGuardData::Valid(const Header* header) {
diff --git a/libc/malloc_debug/GuardData.h b/libc/malloc_debug/GuardData.h
index bfb3949..ddf6ce1 100644
--- a/libc/malloc_debug/GuardData.h
+++ b/libc/malloc_debug/GuardData.h
@@ -41,7 +41,7 @@
 // Forward declarations.
 class DebugData;
 struct Header;
-struct Config;
+class Config;
 
 class GuardData : public OptionData {
  public:
diff --git a/libc/malloc_debug/RecordData.cpp b/libc/malloc_debug/RecordData.cpp
index c0f3486..5a68deb 100644
--- a/libc/malloc_debug/RecordData.cpp
+++ b/libc/malloc_debug/RecordData.cpp
@@ -185,20 +185,20 @@
   dump_act.sa_sigaction = RecordDump;
   dump_act.sa_flags = SA_RESTART | SA_SIGINFO | SA_ONSTACK;
   sigemptyset(&dump_act.sa_mask);
-  if (sigaction(config.record_allocs_signal, &dump_act, nullptr) != 0) {
+  if (sigaction(config.record_allocs_signal(), &dump_act, nullptr) != 0) {
     error_log("Unable to set up record dump signal function: %s", strerror(errno));
     return false;
   }
   pthread_setspecific(key_, nullptr);
 
   info_log("%s: Run: 'kill -%d %d' to dump the allocation records.", getprogname(),
-           config.record_allocs_signal, getpid());
+           config.record_allocs_signal(), getpid());
 
-  num_entries_ = config.record_allocs_num_entries;
+  num_entries_ = config.record_allocs_num_entries();
   entries_ = new const RecordEntry*[num_entries_];
   cur_index_ = 0;
   dump_ = false;
-  dump_file_ = config.record_allocs_file;
+  dump_file_ = config.record_allocs_file();
 
   return true;
 }
diff --git a/libc/malloc_debug/RecordData.h b/libc/malloc_debug/RecordData.h
index 741afd5..6e19923 100644
--- a/libc/malloc_debug/RecordData.h
+++ b/libc/malloc_debug/RecordData.h
@@ -144,7 +144,7 @@
   DISALLOW_COPY_AND_ASSIGN(MemalignEntry);
 };
 
-struct Config;
+class Config;
 
 class RecordData {
  public:
diff --git a/libc/malloc_debug/TrackData.cpp b/libc/malloc_debug/TrackData.cpp
index d4064f8..7ce477c 100644
--- a/libc/malloc_debug/TrackData.cpp
+++ b/libc/malloc_debug/TrackData.cpp
@@ -92,7 +92,7 @@
   for (const auto& header : list) {
     error_log("+++ %s leaked block of size %zu at %p (leak %zu of %zu)", getprogname(),
               header->real_size(), debug_->GetPointer(header), ++track_count, list.size());
-    if (debug_->config().options & BACKTRACE) {
+    if (debug_->config().options() & BACKTRACE) {
       BacktraceHeader* back_header = debug_->GetAllocBacktrace(header);
       if (back_header->num_frames > 0) {
         error_log("Backtrace at time of allocation:");
@@ -111,7 +111,7 @@
     return;
   }
 
-  *backtrace_size = debug_->config().backtrace_frames;
+  *backtrace_size = debug_->config().backtrace_frames();
   *info_size = sizeof(size_t) * 2 + sizeof(uintptr_t) * *backtrace_size;
   *info = reinterpret_cast<uint8_t*>(g_dispatch->calloc(*info_size, total_backtrace_allocs_));
   if (*info == nullptr) {
diff --git a/libc/malloc_debug/TrackData.h b/libc/malloc_debug/TrackData.h
index fcd8f2a..e4c8951 100644
--- a/libc/malloc_debug/TrackData.h
+++ b/libc/malloc_debug/TrackData.h
@@ -41,7 +41,7 @@
 
 // Forward declarations.
 struct Header;
-struct Config;
+class Config;
 class DebugData;
 
 class TrackData : public OptionData {
diff --git a/libc/malloc_debug/malloc_debug.cpp b/libc/malloc_debug/malloc_debug.cpp
index bb16faa..addb5d4 100644
--- a/libc/malloc_debug/malloc_debug.cpp
+++ b/libc/malloc_debug/malloc_debug.cpp
@@ -118,7 +118,7 @@
   error_log(LOG_DIVIDER);
   if (header->tag == DEBUG_FREE_TAG) {
     error_log("+++ ALLOCATION %p USED AFTER FREE (%s)", pointer, name);
-    if (g_debug->config().options & FREE_TRACK) {
+    if (g_debug->config().options() & FREE_TRACK) {
       g_debug->free_track->LogBacktrace(header);
     }
   } else {
@@ -147,32 +147,32 @@
   header->usable_size -= g_debug->pointer_offset() +
       reinterpret_cast<uintptr_t>(header) - reinterpret_cast<uintptr_t>(orig_pointer);
 
-  if (g_debug->config().options & FRONT_GUARD) {
+  if (g_debug->config().options() & FRONT_GUARD) {
     uint8_t* guard = g_debug->GetFrontGuard(header);
-    memset(guard, g_debug->config().front_guard_value, g_debug->config().front_guard_bytes);
+    memset(guard, g_debug->config().front_guard_value(), g_debug->config().front_guard_bytes());
   }
 
-  if (g_debug->config().options & REAR_GUARD) {
+  if (g_debug->config().options() & REAR_GUARD) {
     uint8_t* guard = g_debug->GetRearGuard(header);
-    memset(guard, g_debug->config().rear_guard_value, g_debug->config().rear_guard_bytes);
+    memset(guard, g_debug->config().rear_guard_value(), g_debug->config().rear_guard_bytes());
     // If the rear guard is enabled, set the usable size to the exact size
     // of the allocation.
     header->usable_size = header->real_size();
   }
 
   bool backtrace_found = false;
-  if (g_debug->config().options & BACKTRACE) {
+  if (g_debug->config().options() & BACKTRACE) {
     BacktraceHeader* back_header = g_debug->GetAllocBacktrace(header);
     if (g_debug->backtrace->enabled()) {
       back_header->num_frames = backtrace_get(
-          &back_header->frames[0], g_debug->config().backtrace_frames);
+          &back_header->frames[0], g_debug->config().backtrace_frames());
       backtrace_found = back_header->num_frames > 0;
     } else {
       back_header->num_frames = 0;
     }
   }
 
-  if (g_debug->config().options & TRACK_ALLOCS) {
+  if (g_debug->config().options() & TRACK_ALLOCS) {
     g_debug->track->Add(header, backtrace_found);
   }
 
@@ -215,11 +215,11 @@
     return;
   }
 
-  if (g_debug->config().options & FREE_TRACK) {
+  if (g_debug->config().options() & FREE_TRACK) {
     g_debug->free_track->VerifyAll();
   }
 
-  if (g_debug->config().options & LEAK_TRACK) {
+  if (g_debug->config().options() & LEAK_TRACK) {
     g_debug->track->DisplayLeaks();
   }
 
@@ -250,7 +250,7 @@
   *total_memory = 0;
   *backtrace_size = 0;
 
-  if (!(g_debug->config().options & BACKTRACE)) {
+  if (!(g_debug->config().options() & BACKTRACE)) {
     error_log("get_malloc_leak_info: Allocations not being tracked, to enable "
               "set the option 'backtrace'.");
     return;
@@ -315,11 +315,11 @@
     pointer = g_dispatch->malloc(real_size);
   }
 
-  if (pointer != nullptr && g_debug->config().options & FILL_ON_ALLOC) {
+  if (pointer != nullptr && g_debug->config().options() & FILL_ON_ALLOC) {
     size_t bytes = internal_malloc_usable_size(pointer);
-    size_t fill_bytes = g_debug->config().fill_on_alloc_bytes;
+    size_t fill_bytes = g_debug->config().fill_on_alloc_bytes();
     bytes = (bytes < fill_bytes) ? bytes : fill_bytes;
-    memset(pointer, g_debug->config().fill_alloc_value, bytes);
+    memset(pointer, g_debug->config().fill_alloc_value(), bytes);
   }
   return pointer;
 }
@@ -332,7 +332,7 @@
 
   void* pointer = internal_malloc(size);
 
-  if (g_debug->config().options & RECORD_ALLOCS) {
+  if (g_debug->config().options() & RECORD_ALLOCS) {
     g_debug->record->AddEntry(new MallocEntry(pointer, size));
   }
 
@@ -351,20 +351,20 @@
     }
     free_pointer = header->orig_pointer;
 
-    if (g_debug->config().options & FRONT_GUARD) {
+    if (g_debug->config().options() & FRONT_GUARD) {
       if (!g_debug->front_guard->Valid(header)) {
         g_debug->front_guard->LogFailure(header);
       }
     }
-    if (g_debug->config().options & REAR_GUARD) {
+    if (g_debug->config().options() & REAR_GUARD) {
       if (!g_debug->rear_guard->Valid(header)) {
         g_debug->rear_guard->LogFailure(header);
       }
     }
 
-    if (g_debug->config().options & TRACK_ALLOCS) {
+    if (g_debug->config().options() & TRACK_ALLOCS) {
       bool backtrace_found = false;
-      if (g_debug->config().options & BACKTRACE) {
+      if (g_debug->config().options() & BACKTRACE) {
         BacktraceHeader* back_header = g_debug->GetAllocBacktrace(header);
         backtrace_found = back_header->num_frames > 0;
       }
@@ -377,13 +377,13 @@
     bytes = g_dispatch->malloc_usable_size(pointer);
   }
 
-  if (g_debug->config().options & FILL_ON_FREE) {
-    size_t fill_bytes = g_debug->config().fill_on_free_bytes;
+  if (g_debug->config().options() & FILL_ON_FREE) {
+    size_t fill_bytes = g_debug->config().fill_on_free_bytes();
     bytes = (bytes < fill_bytes) ? bytes : fill_bytes;
-    memset(pointer, g_debug->config().fill_free_value, bytes);
+    memset(pointer, g_debug->config().fill_free_value(), bytes);
   }
 
-  if (g_debug->config().options & FREE_TRACK) {
+  if (g_debug->config().options() & FREE_TRACK) {
     // Do not add the allocation until we are done modifying the pointer
     // itself. This avoids a race if a lot of threads are all doing
     // frees at the same time and we wind up trying to really free this
@@ -401,7 +401,7 @@
   }
   ScopedDisableDebugCalls disable;
 
-  if (g_debug->config().options & RECORD_ALLOCS) {
+  if (g_debug->config().options() & RECORD_ALLOCS) {
     g_debug->record->AddEntry(new FreeEntry(pointer));
   }
 
@@ -466,14 +466,14 @@
     pointer = g_dispatch->memalign(alignment, real_size);
   }
 
-  if (pointer != nullptr && g_debug->config().options & FILL_ON_ALLOC) {
+  if (pointer != nullptr && g_debug->config().options() & FILL_ON_ALLOC) {
     size_t bytes = internal_malloc_usable_size(pointer);
-    size_t fill_bytes = g_debug->config().fill_on_alloc_bytes;
+    size_t fill_bytes = g_debug->config().fill_on_alloc_bytes();
     bytes = (bytes < fill_bytes) ? bytes : fill_bytes;
-    memset(pointer, g_debug->config().fill_alloc_value, bytes);
+    memset(pointer, g_debug->config().fill_alloc_value(), bytes);
   }
 
-  if (g_debug->config().options & RECORD_ALLOCS) {
+  if (g_debug->config().options() & RECORD_ALLOCS) {
     g_debug->record->AddEntry(new MemalignEntry(pointer, bytes, alignment));
   }
 
@@ -488,14 +488,14 @@
 
   if (pointer == nullptr) {
     pointer = internal_malloc(bytes);
-    if (g_debug->config().options & RECORD_ALLOCS) {
+    if (g_debug->config().options() & RECORD_ALLOCS) {
       g_debug->record->AddEntry(new ReallocEntry(pointer, bytes, nullptr));
     }
     return pointer;
   }
 
   if (bytes == 0) {
-    if (g_debug->config().options & RECORD_ALLOCS) {
+    if (g_debug->config().options() & RECORD_ALLOCS) {
       g_debug->record->AddEntry(new ReallocEntry(nullptr, bytes, pointer));
     }
 
@@ -504,8 +504,8 @@
   }
 
   size_t real_size = bytes;
-  if (g_debug->config().options & EXPAND_ALLOC) {
-    real_size += g_debug->config().expand_alloc_bytes;
+  if (g_debug->config().options() & EXPAND_ALLOC) {
+    real_size += g_debug->config().expand_alloc_bytes();
     if (real_size < bytes) {
       // Overflow.
       errno = ENOMEM;
@@ -539,12 +539,12 @@
       if (*g_malloc_zygote_child) {
         header->set_zygote();
       }
-      if (g_debug->config().options & REAR_GUARD) {
+      if (g_debug->config().options() & REAR_GUARD) {
         // Don't bother allocating a smaller pointer in this case, simply
         // change the header usable_size and reset the rear guard.
         header->usable_size = header->real_size();
-        memset(g_debug->GetRearGuard(header), g_debug->config().rear_guard_value,
-               g_debug->config().rear_guard_bytes);
+        memset(g_debug->GetRearGuard(header), g_debug->config().rear_guard_value(),
+               g_debug->config().rear_guard_bytes());
       }
       // Do not bother recording, this is essentially a nop.
       return pointer;
@@ -568,18 +568,18 @@
     }
   }
 
-  if (g_debug->config().options & FILL_ON_ALLOC) {
+  if (g_debug->config().options() & FILL_ON_ALLOC) {
     size_t bytes = internal_malloc_usable_size(new_pointer);
-    if (bytes > g_debug->config().fill_on_alloc_bytes) {
-      bytes = g_debug->config().fill_on_alloc_bytes;
+    if (bytes > g_debug->config().fill_on_alloc_bytes()) {
+      bytes = g_debug->config().fill_on_alloc_bytes();
     }
     if (bytes > prev_size) {
       memset(reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(new_pointer) + prev_size),
-             g_debug->config().fill_alloc_value, bytes - prev_size);
+             g_debug->config().fill_alloc_value(), bytes - prev_size);
     }
   }
 
-  if (g_debug->config().options & RECORD_ALLOCS) {
+  if (g_debug->config().options() & RECORD_ALLOCS) {
     g_debug->record->AddEntry(new ReallocEntry(new_pointer, bytes, pointer));
   }
 
@@ -629,7 +629,7 @@
   } else {
     pointer = g_dispatch->calloc(1, real_size);
   }
-  if (g_debug->config().options & RECORD_ALLOCS) {
+  if (g_debug->config().options() & RECORD_ALLOCS) {
     g_debug->record->AddEntry(new CallocEntry(pointer, bytes, nmemb));
   }
   return pointer;
@@ -668,7 +668,7 @@
         const void* pointer = reinterpret_cast<void*>(base);
         if (g_debug->need_header()) {
           const Header* header = reinterpret_cast<const Header*>(pointer);
-          if (g_debug->config().options & TRACK_ALLOCS) {
+          if (g_debug->config().options() & TRACK_ALLOCS) {
             if (g_debug->track->Contains(header)) {
               // Return just the body of the allocation if we're sure the header exists
               ctx->callback(reinterpret_cast<uintptr_t>(g_debug->GetPointer(header)),
@@ -704,7 +704,7 @@
 
   if (g_debug->need_header()) {
     Header* header;
-    if (g_debug->config().options & TRACK_ALLOCS) {
+    if (g_debug->config().options() & TRACK_ALLOCS) {
       header = g_debug->GetHeader(pointer);
       if (!g_debug->track->Contains(header)) {
         return 0;
@@ -715,7 +715,7 @@
     if (header->tag != DEBUG_TAG) {
       return 0;
     }
-    if (g_debug->config().options & BACKTRACE) {
+    if (g_debug->config().options() & BACKTRACE) {
       BacktraceHeader* back_header = g_debug->GetAllocBacktrace(header);
       if (back_header->num_frames > 0) {
         if (frame_count > back_header->num_frames) {
diff --git a/libc/malloc_debug/tests/malloc_debug_config_tests.cpp b/libc/malloc_debug/tests/malloc_debug_config_tests.cpp
index f988124..77dc848 100644
--- a/libc/malloc_debug/tests/malloc_debug_config_tests.cpp
+++ b/libc/malloc_debug/tests/malloc_debug_config_tests.cpp
@@ -31,14 +31,11 @@
     resetLogs();
   }
 
-  void TearDown() override {
-  }
-
   std::unique_ptr<Config> config;
 
   bool InitConfig(const char* options) {
     config.reset(new Config);
-    return config->Set(options);
+    return config->Init(options);
   }
 };
 
@@ -201,8 +198,8 @@
 
 TEST_F(MallocDebugConfigTest, space_before_equal) {
   ASSERT_TRUE(InitConfig("backtrace  =10")) << getFakeLogPrint();
-  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS, config->options);
-  ASSERT_EQ(10U, config->backtrace_frames);
+  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS, config->options());
+  ASSERT_EQ(10U, config->backtrace_frames());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -210,8 +207,8 @@
 
 TEST_F(MallocDebugConfigTest, space_after_equal) {
   ASSERT_TRUE(InitConfig("backtrace=  10")) << getFakeLogPrint();
-  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS, config->options);
-  ASSERT_EQ(10U, config->backtrace_frames);
+  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS, config->options());
+  ASSERT_EQ(10U, config->backtrace_frames());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -219,8 +216,8 @@
 
 TEST_F(MallocDebugConfigTest, extra_space) {
   ASSERT_TRUE(InitConfig("   backtrace=64   ")) << getFakeLogPrint();
-  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS, config->options);
-  ASSERT_EQ(64U, config->backtrace_frames);
+  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS, config->options());
+  ASSERT_EQ(64U, config->backtrace_frames());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -228,9 +225,9 @@
 
 TEST_F(MallocDebugConfigTest, multiple_options) {
   ASSERT_TRUE(InitConfig("  backtrace=64   front_guard=48")) << getFakeLogPrint();
-  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS | FRONT_GUARD, config->options);
-  ASSERT_EQ(64U, config->backtrace_frames);
-  ASSERT_EQ(48U, config->front_guard_bytes);
+  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS | FRONT_GUARD, config->options());
+  ASSERT_EQ(64U, config->backtrace_frames());
+  ASSERT_EQ(48U, config->front_guard_bytes());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -238,24 +235,24 @@
 
 TEST_F(MallocDebugConfigTest, front_guard) {
   ASSERT_TRUE(InitConfig("front_guard=48")) << getFakeLogPrint();
-  ASSERT_EQ(FRONT_GUARD, config->options);
-  ASSERT_EQ(48U, config->front_guard_bytes);
+  ASSERT_EQ(FRONT_GUARD, config->options());
+  ASSERT_EQ(48U, config->front_guard_bytes());
 
   ASSERT_TRUE(InitConfig("front_guard")) << getFakeLogPrint();
-  ASSERT_EQ(FRONT_GUARD, config->options);
-  ASSERT_EQ(32U, config->front_guard_bytes);
+  ASSERT_EQ(FRONT_GUARD, config->options());
+  ASSERT_EQ(32U, config->front_guard_bytes());
 
   ASSERT_TRUE(InitConfig("front_guard=39")) << getFakeLogPrint();
-  ASSERT_EQ(FRONT_GUARD, config->options);
+  ASSERT_EQ(FRONT_GUARD, config->options());
 #if defined(__LP64__)
-  ASSERT_EQ(48U, config->front_guard_bytes);
+  ASSERT_EQ(48U, config->front_guard_bytes());
 #else
-  ASSERT_EQ(40U, config->front_guard_bytes);
+  ASSERT_EQ(40U, config->front_guard_bytes());
 #endif
 
   ASSERT_TRUE(InitConfig("front_guard=41")) << getFakeLogPrint();
-  ASSERT_EQ(FRONT_GUARD, config->options);
-  ASSERT_EQ(48U, config->front_guard_bytes);
+  ASSERT_EQ(FRONT_GUARD, config->options());
+  ASSERT_EQ(48U, config->front_guard_bytes());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -263,12 +260,12 @@
 
 TEST_F(MallocDebugConfigTest, rear_guard) {
   ASSERT_TRUE(InitConfig("rear_guard=50")) << getFakeLogPrint();
-  ASSERT_EQ(REAR_GUARD, config->options);
-  ASSERT_EQ(50U, config->rear_guard_bytes);
+  ASSERT_EQ(REAR_GUARD, config->options());
+  ASSERT_EQ(50U, config->rear_guard_bytes());
 
   ASSERT_TRUE(InitConfig("rear_guard")) << getFakeLogPrint();
-  ASSERT_EQ(REAR_GUARD, config->options);
-  ASSERT_EQ(32U, config->rear_guard_bytes);
+  ASSERT_EQ(REAR_GUARD, config->options());
+  ASSERT_EQ(32U, config->rear_guard_bytes());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -276,14 +273,14 @@
 
 TEST_F(MallocDebugConfigTest, guard) {
   ASSERT_TRUE(InitConfig("guard=32")) << getFakeLogPrint();
-  ASSERT_EQ(FRONT_GUARD | REAR_GUARD, config->options);
-  ASSERT_EQ(32U, config->front_guard_bytes);
-  ASSERT_EQ(32U, config->rear_guard_bytes);
+  ASSERT_EQ(FRONT_GUARD | REAR_GUARD, config->options());
+  ASSERT_EQ(32U, config->front_guard_bytes());
+  ASSERT_EQ(32U, config->rear_guard_bytes());
 
   ASSERT_TRUE(InitConfig("guard")) << getFakeLogPrint();
-  ASSERT_EQ(FRONT_GUARD | REAR_GUARD, config->options);
-  ASSERT_EQ(32U, config->front_guard_bytes);
-  ASSERT_EQ(32U, config->rear_guard_bytes);
+  ASSERT_EQ(FRONT_GUARD | REAR_GUARD, config->options());
+  ASSERT_EQ(32U, config->front_guard_bytes());
+  ASSERT_EQ(32U, config->rear_guard_bytes());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -291,12 +288,16 @@
 
 TEST_F(MallocDebugConfigTest, backtrace) {
   ASSERT_TRUE(InitConfig("backtrace=64")) << getFakeLogPrint();
-  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS, config->options);
-  ASSERT_EQ(64U, config->backtrace_frames);
+  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS, config->options());
+  ASSERT_EQ(64U, config->backtrace_frames());
+  ASSERT_TRUE(config->backtrace_enabled());
+  ASSERT_FALSE(config->backtrace_enable_on_signal());
 
   ASSERT_TRUE(InitConfig("backtrace")) << getFakeLogPrint();
-  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS, config->options);
-  ASSERT_EQ(16U, config->backtrace_frames);
+  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS, config->options());
+  ASSERT_EQ(16U, config->backtrace_frames());
+  ASSERT_TRUE(config->backtrace_enabled());
+  ASSERT_FALSE(config->backtrace_enable_on_signal());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -304,12 +305,50 @@
 
 TEST_F(MallocDebugConfigTest, backtrace_enable_on_signal) {
   ASSERT_TRUE(InitConfig("backtrace_enable_on_signal=64")) << getFakeLogPrint();
-  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS, config->options);
-  ASSERT_EQ(64U, config->backtrace_frames);
+  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS, config->options());
+  ASSERT_EQ(64U, config->backtrace_frames());
+  ASSERT_FALSE(config->backtrace_enabled());
+  ASSERT_TRUE(config->backtrace_enable_on_signal());
 
   ASSERT_TRUE(InitConfig("backtrace_enable_on_signal")) << getFakeLogPrint();
-  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS, config->options);
-  ASSERT_EQ(16U, config->backtrace_frames);
+  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS, config->options());
+  ASSERT_EQ(16U, config->backtrace_frames());
+  ASSERT_FALSE(config->backtrace_enabled());
+  ASSERT_TRUE(config->backtrace_enable_on_signal());
+
+  ASSERT_STREQ("", getFakeLogBuf().c_str());
+  ASSERT_STREQ("", getFakeLogPrint().c_str());
+}
+
+TEST_F(MallocDebugConfigTest, backtrace_enable_on_signal_init) {
+  ASSERT_TRUE(InitConfig("backtrace_enable_on_signal=64")) << getFakeLogPrint();
+  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS, config->options());
+  ASSERT_EQ(64U, config->backtrace_frames());
+  ASSERT_FALSE(config->backtrace_enabled());
+  ASSERT_TRUE(config->backtrace_enable_on_signal());
+
+  ASSERT_TRUE(InitConfig("backtrace")) << getFakeLogPrint();
+  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS, config->options());
+  ASSERT_EQ(16U, config->backtrace_frames());
+  ASSERT_TRUE(config->backtrace_enabled());
+  ASSERT_FALSE(config->backtrace_enable_on_signal());
+
+  ASSERT_STREQ("", getFakeLogBuf().c_str());
+  ASSERT_STREQ("", getFakeLogPrint().c_str());
+}
+
+TEST_F(MallocDebugConfigTest, backtrace_enable_and_backtrace) {
+  ASSERT_TRUE(InitConfig("backtrace_enable_on_signal backtrace")) << getFakeLogPrint();
+  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS, config->options());
+  ASSERT_EQ(16U, config->backtrace_frames());
+  ASSERT_TRUE(config->backtrace_enabled());
+  ASSERT_TRUE(config->backtrace_enable_on_signal());
+
+  ASSERT_TRUE(InitConfig("backtrace backtrace_enable_on_signal")) << getFakeLogPrint();
+  ASSERT_EQ(BACKTRACE | TRACK_ALLOCS, config->options());
+  ASSERT_EQ(16U, config->backtrace_frames());
+  ASSERT_TRUE(config->backtrace_enabled());
+  ASSERT_TRUE(config->backtrace_enable_on_signal());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -317,12 +356,12 @@
 
 TEST_F(MallocDebugConfigTest, fill_on_alloc) {
   ASSERT_TRUE(InitConfig("fill_on_alloc=64")) << getFakeLogPrint();
-  ASSERT_EQ(FILL_ON_ALLOC, config->options);
-  ASSERT_EQ(64U, config->fill_on_alloc_bytes);
+  ASSERT_EQ(FILL_ON_ALLOC, config->options());
+  ASSERT_EQ(64U, config->fill_on_alloc_bytes());
 
   ASSERT_TRUE(InitConfig("fill_on_alloc")) << getFakeLogPrint();
-  ASSERT_EQ(FILL_ON_ALLOC, config->options);
-  ASSERT_EQ(SIZE_MAX, config->fill_on_alloc_bytes);
+  ASSERT_EQ(FILL_ON_ALLOC, config->options());
+  ASSERT_EQ(SIZE_MAX, config->fill_on_alloc_bytes());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -330,12 +369,12 @@
 
 TEST_F(MallocDebugConfigTest, fill_on_free) {
   ASSERT_TRUE(InitConfig("fill_on_free=64")) << getFakeLogPrint();
-  ASSERT_EQ(FILL_ON_FREE, config->options);
-  ASSERT_EQ(64U, config->fill_on_free_bytes);
+  ASSERT_EQ(FILL_ON_FREE, config->options());
+  ASSERT_EQ(64U, config->fill_on_free_bytes());
 
   ASSERT_TRUE(InitConfig("fill_on_free")) << getFakeLogPrint();
-  ASSERT_EQ(FILL_ON_FREE, config->options);
-  ASSERT_EQ(SIZE_MAX, config->fill_on_free_bytes);
+  ASSERT_EQ(FILL_ON_FREE, config->options());
+  ASSERT_EQ(SIZE_MAX, config->fill_on_free_bytes());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -343,14 +382,14 @@
 
 TEST_F(MallocDebugConfigTest, fill) {
   ASSERT_TRUE(InitConfig("fill=64")) << getFakeLogPrint();
-  ASSERT_EQ(FILL_ON_ALLOC | FILL_ON_FREE, config->options);
-  ASSERT_EQ(64U, config->fill_on_alloc_bytes);
-  ASSERT_EQ(64U, config->fill_on_free_bytes);
+  ASSERT_EQ(FILL_ON_ALLOC | FILL_ON_FREE, config->options());
+  ASSERT_EQ(64U, config->fill_on_alloc_bytes());
+  ASSERT_EQ(64U, config->fill_on_free_bytes());
 
   ASSERT_TRUE(InitConfig("fill")) << getFakeLogPrint();
-  ASSERT_EQ(FILL_ON_ALLOC | FILL_ON_FREE, config->options);
-  ASSERT_EQ(SIZE_MAX, config->fill_on_alloc_bytes);
-  ASSERT_EQ(SIZE_MAX, config->fill_on_free_bytes);
+  ASSERT_EQ(FILL_ON_ALLOC | FILL_ON_FREE, config->options());
+  ASSERT_EQ(SIZE_MAX, config->fill_on_alloc_bytes());
+  ASSERT_EQ(SIZE_MAX, config->fill_on_free_bytes());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -358,12 +397,12 @@
 
 TEST_F(MallocDebugConfigTest, expand_alloc) {
   ASSERT_TRUE(InitConfig("expand_alloc=1234")) << getFakeLogPrint();
-  ASSERT_EQ(EXPAND_ALLOC, config->options);
-  ASSERT_EQ(1234U, config->expand_alloc_bytes);
+  ASSERT_EQ(EXPAND_ALLOC, config->options());
+  ASSERT_EQ(1234U, config->expand_alloc_bytes());
 
   ASSERT_TRUE(InitConfig("expand_alloc")) << getFakeLogPrint();
-  ASSERT_EQ(EXPAND_ALLOC, config->options);
-  ASSERT_EQ(16U, config->expand_alloc_bytes);
+  ASSERT_EQ(EXPAND_ALLOC, config->options());
+  ASSERT_EQ(16U, config->expand_alloc_bytes());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -371,16 +410,16 @@
 
 TEST_F(MallocDebugConfigTest, free_track) {
   ASSERT_TRUE(InitConfig("free_track=1234")) << getFakeLogPrint();
-  ASSERT_EQ(FREE_TRACK | FILL_ON_FREE, config->options);
-  ASSERT_EQ(1234U, config->free_track_allocations);
-  ASSERT_EQ(SIZE_MAX, config->fill_on_free_bytes);
-  ASSERT_EQ(16U, config->free_track_backtrace_num_frames);
+  ASSERT_EQ(FREE_TRACK | FILL_ON_FREE, config->options());
+  ASSERT_EQ(1234U, config->free_track_allocations());
+  ASSERT_EQ(SIZE_MAX, config->fill_on_free_bytes());
+  ASSERT_EQ(16U, config->free_track_backtrace_num_frames());
 
   ASSERT_TRUE(InitConfig("free_track")) << getFakeLogPrint();
-  ASSERT_EQ(FREE_TRACK | FILL_ON_FREE, config->options);
-  ASSERT_EQ(100U, config->free_track_allocations);
-  ASSERT_EQ(SIZE_MAX, config->fill_on_free_bytes);
-  ASSERT_EQ(16U, config->free_track_backtrace_num_frames);
+  ASSERT_EQ(FREE_TRACK | FILL_ON_FREE, config->options());
+  ASSERT_EQ(100U, config->free_track_allocations());
+  ASSERT_EQ(SIZE_MAX, config->fill_on_free_bytes());
+  ASSERT_EQ(16U, config->free_track_backtrace_num_frames());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -388,16 +427,23 @@
 
 TEST_F(MallocDebugConfigTest, free_track_and_fill_on_free) {
   ASSERT_TRUE(InitConfig("free_track=1234 fill_on_free=32")) << getFakeLogPrint();
-  ASSERT_EQ(FREE_TRACK | FILL_ON_FREE, config->options);
-  ASSERT_EQ(1234U, config->free_track_allocations);
-  ASSERT_EQ(32U, config->fill_on_free_bytes);
-  ASSERT_EQ(16U, config->free_track_backtrace_num_frames);
+  ASSERT_EQ(FREE_TRACK | FILL_ON_FREE, config->options());
+  ASSERT_EQ(1234U, config->free_track_allocations());
+  ASSERT_EQ(32U, config->fill_on_free_bytes());
+  ASSERT_EQ(16U, config->free_track_backtrace_num_frames());
 
   ASSERT_TRUE(InitConfig("free_track fill_on_free=60")) << getFakeLogPrint();
-  ASSERT_EQ(FREE_TRACK | FILL_ON_FREE, config->options);
-  ASSERT_EQ(100U, config->free_track_allocations);
-  ASSERT_EQ(60U, config->fill_on_free_bytes);
-  ASSERT_EQ(16U, config->free_track_backtrace_num_frames);
+  ASSERT_EQ(FREE_TRACK | FILL_ON_FREE, config->options());
+  ASSERT_EQ(100U, config->free_track_allocations());
+  ASSERT_EQ(60U, config->fill_on_free_bytes());
+  ASSERT_EQ(16U, config->free_track_backtrace_num_frames());
+
+  // Now reverse the arguments.
+  ASSERT_TRUE(InitConfig("fill_on_free=32 free_track=1234")) << getFakeLogPrint();
+  ASSERT_EQ(FREE_TRACK | FILL_ON_FREE, config->options());
+  ASSERT_EQ(1234U, config->free_track_allocations());
+  ASSERT_EQ(32U, config->fill_on_free_bytes());
+  ASSERT_EQ(16U, config->free_track_backtrace_num_frames());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -406,12 +452,12 @@
 TEST_F(MallocDebugConfigTest, free_track_backtrace_num_frames) {
   ASSERT_TRUE(InitConfig("free_track_backtrace_num_frames=123")) << getFakeLogPrint();
 
-  ASSERT_EQ(0U, config->options);
-  ASSERT_EQ(123U, config->free_track_backtrace_num_frames);
+  ASSERT_EQ(0U, config->options());
+  ASSERT_EQ(123U, config->free_track_backtrace_num_frames());
 
   ASSERT_TRUE(InitConfig("free_track_backtrace_num_frames")) << getFakeLogPrint();
-  ASSERT_EQ(0U, config->options);
-  ASSERT_EQ(16U, config->free_track_backtrace_num_frames);
+  ASSERT_EQ(0U, config->options());
+  ASSERT_EQ(16U, config->free_track_backtrace_num_frames());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -420,8 +466,8 @@
 TEST_F(MallocDebugConfigTest, free_track_backtrace_num_frames_zero) {
   ASSERT_TRUE(InitConfig("free_track_backtrace_num_frames=0")) << getFakeLogPrint();
 
-  ASSERT_EQ(0U, config->options);
-  ASSERT_EQ(0U, config->free_track_backtrace_num_frames);
+  ASSERT_EQ(0U, config->options());
+  ASSERT_EQ(0U, config->free_track_backtrace_num_frames());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -429,12 +475,12 @@
 
 TEST_F(MallocDebugConfigTest, free_track_backtrace_num_frames_and_free_track) {
   ASSERT_TRUE(InitConfig("free_track free_track_backtrace_num_frames=123")) << getFakeLogPrint();
-  ASSERT_EQ(FREE_TRACK | FILL_ON_FREE, config->options);
-  ASSERT_EQ(123U, config->free_track_backtrace_num_frames);
+  ASSERT_EQ(FREE_TRACK | FILL_ON_FREE, config->options());
+  ASSERT_EQ(123U, config->free_track_backtrace_num_frames());
 
   ASSERT_TRUE(InitConfig("free_track free_track_backtrace_num_frames")) << getFakeLogPrint();
-  ASSERT_EQ(FREE_TRACK | FILL_ON_FREE, config->options);
-  ASSERT_EQ(16U, config->free_track_backtrace_num_frames);
+  ASSERT_EQ(FREE_TRACK | FILL_ON_FREE, config->options());
+  ASSERT_EQ(16U, config->free_track_backtrace_num_frames());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -442,7 +488,7 @@
 
 TEST_F(MallocDebugConfigTest, leak_track) {
   ASSERT_TRUE(InitConfig("leak_track")) << getFakeLogPrint();
-  ASSERT_EQ(LEAK_TRACK | TRACK_ALLOCS, config->options);
+  ASSERT_EQ(LEAK_TRACK | TRACK_ALLOCS, config->options());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -460,14 +506,14 @@
 
 TEST_F(MallocDebugConfigTest, record_allocs) {
   ASSERT_TRUE(InitConfig("record_allocs=1234")) << getFakeLogPrint();
-  ASSERT_EQ(RECORD_ALLOCS, config->options);
-  ASSERT_EQ(1234U, config->record_allocs_num_entries);
-  ASSERT_STREQ("/data/local/tmp/record_allocs.txt", config->record_allocs_file.c_str());
+  ASSERT_EQ(RECORD_ALLOCS, config->options());
+  ASSERT_EQ(1234U, config->record_allocs_num_entries());
+  ASSERT_STREQ("/data/local/tmp/record_allocs.txt", config->record_allocs_file().c_str());
 
   ASSERT_TRUE(InitConfig("record_allocs")) << getFakeLogPrint();
-  ASSERT_EQ(RECORD_ALLOCS, config->options);
-  ASSERT_EQ(8000000U, config->record_allocs_num_entries);
-  ASSERT_STREQ("/data/local/tmp/record_allocs.txt", config->record_allocs_file.c_str());
+  ASSERT_EQ(RECORD_ALLOCS, config->options());
+  ASSERT_EQ(8000000U, config->record_allocs_num_entries());
+  ASSERT_STREQ("/data/local/tmp/record_allocs.txt", config->record_allocs_file().c_str());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());
@@ -475,10 +521,10 @@
 
 TEST_F(MallocDebugConfigTest, record_allocs_file) {
   ASSERT_TRUE(InitConfig("record_allocs=1234 record_allocs_file=/fake/file")) << getFakeLogPrint();
-  ASSERT_STREQ("/fake/file", config->record_allocs_file.c_str());
+  ASSERT_STREQ("/fake/file", config->record_allocs_file().c_str());
 
   ASSERT_TRUE(InitConfig("record_allocs_file")) << getFakeLogPrint();
-  ASSERT_STREQ("/data/local/tmp/record_allocs.txt", config->record_allocs_file.c_str());
+  ASSERT_STREQ("/data/local/tmp/record_allocs.txt", config->record_allocs_file().c_str());
 
   ASSERT_STREQ("", getFakeLogBuf().c_str());
   ASSERT_STREQ("", getFakeLogPrint().c_str());