Index: lib/asan/asan_rtl.cc
===================================================================
--- lib/asan/asan_rtl.cc
+++ lib/asan/asan_rtl.cc
@@ -46,6 +46,7 @@
     // Don't die twice - run a busy loop.
     while (1) { }
   }
+  if (common_flags()->print_module_map >= 1) PrintModuleMap();
   if (flags()->sleep_before_dying) {
     Report("Sleeping for %d second(s)\n", flags()->sleep_before_dying);
     SleepForSeconds(flags()->sleep_before_dying);
Index: lib/sanitizer_common/sanitizer_common.h
===================================================================
--- lib/sanitizer_common/sanitizer_common.h
+++ lib/sanitizer_common/sanitizer_common.h
@@ -283,6 +283,7 @@
 void CacheBinaryName();
 void DisableCoreDumperIfNecessary();
 void DumpProcessMap();
+void PrintModuleMap();
 bool FileExists(const char *filename);
 const char *GetEnv(const char *name);
 bool SetEnv(const char *name, const char *value);
@@ -658,6 +659,30 @@
   kModuleArchARM64
 };
 
+inline const char *ModuleArchToString(ModuleArch arch) {
+  switch (arch) {
+    case kModuleArchUnknown:
+      return "";
+    case kModuleArchI386:
+      return "i386";
+    case kModuleArchX86_64:
+      return "x86_64";
+    case kModuleArchX86_64H:
+      return "x86_64h";
+    case kModuleArchARMV6:
+      return "armv6";
+    case kModuleArchARMV7:
+      return "armv7";
+    case kModuleArchARMV7S:
+      return "armv7s";
+    case kModuleArchARMV7K:
+      return "armv7k";
+    case kModuleArchARM64:
+      return "arm64";
+  }
+  CHECK(0 && "Invalid module arch");
+}
+
 const uptr kModuleUUIDSize = 16;
 
 // Represents a binary loaded into virtual memory (e.g. this can be an
@@ -665,7 +690,10 @@
 class LoadedModule {
  public:
   LoadedModule()
-      : full_name_(nullptr), base_address_(0), arch_(kModuleArchUnknown) {
+      : full_name_(nullptr),
+        base_address_(0),
+        max_executable_address_(0),
+        arch_(kModuleArchUnknown) {
     internal_memset(uuid_, 0, kModuleUUIDSize);
     ranges_.clear();
   }
@@ -678,6 +706,7 @@
 
   const char *full_name() const { return full_name_; }
   uptr base_address() const { return base_address_; }
+  uptr max_executable_address() const { return max_executable_address_; }
   ModuleArch arch() const { return arch_; }
   const u8 *uuid() const { return uuid_; }
 
@@ -696,6 +725,7 @@
  private:
   char *full_name_;  // Owned.
   uptr base_address_;
+  uptr max_executable_address_;
   ModuleArch arch_;
   u8 uuid_[kModuleUUIDSize];
   IntrusiveList<AddressRange> ranges_;
Index: lib/sanitizer_common/sanitizer_common.cc
===================================================================
--- lib/sanitizer_common/sanitizer_common.cc
+++ lib/sanitizer_common/sanitizer_common.cc
@@ -268,6 +268,8 @@
 
 void LoadedModule::clear() {
   InternalFree(full_name_);
+  base_address_ = 0;
+  max_executable_address_ = 0;
   full_name_ = nullptr;
   arch_ = kModuleArchUnknown;
   internal_memset(uuid_, 0, kModuleUUIDSize);
@@ -282,6 +284,8 @@
   void *mem = InternalAlloc(sizeof(AddressRange));
   AddressRange *r = new(mem) AddressRange(beg, end, executable);
   ranges_.push_back(r);
+  if (executable && end > max_executable_address_)
+    max_executable_address_ = end;
 }
 
 bool LoadedModule::containsAddress(uptr address) const {
Index: lib/sanitizer_common/sanitizer_flags.inc
===================================================================
--- lib/sanitizer_common/sanitizer_flags.inc
+++ lib/sanitizer_common/sanitizer_flags.inc
@@ -74,6 +74,9 @@
 COMMON_FLAG(bool, print_summary, true,
             "If false, disable printing error summaries in addition to error "
             "reports.")
+COMMON_FLAG(int, print_module_map, 0,
+            "OS X only. 0 = don't print, 1 = print only once before process "
+            "exits, 2 = print after each report.")
 COMMON_FLAG(bool, check_printf, true, "Check printf arguments.")
 COMMON_FLAG(bool, handle_segv, true,
             "If set, registers the tool's custom SIGSEGV/SIGBUS handler.")
Index: lib/sanitizer_common/sanitizer_linux.cc
===================================================================
--- lib/sanitizer_common/sanitizer_linux.cc
+++ lib/sanitizer_common/sanitizer_linux.cc
@@ -1393,6 +1393,8 @@
   // No need to re-exec on Linux.
 }
 
+void PrintModuleMap() { }
+
 uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding) {
   UNREACHABLE("FindAvailableMemoryRange is not available");
   return 0;
Index: lib/sanitizer_common/sanitizer_mac.cc
===================================================================
--- lib/sanitizer_common/sanitizer_mac.cc
+++ lib/sanitizer_common/sanitizer_mac.cc
@@ -52,6 +52,7 @@
 #endif
 
 #include <asl.h>
+#include <ctype.h>
 #include <dlfcn.h>  // for dladdr()
 #include <errno.h>
 #include <fcntl.h>
@@ -845,6 +846,41 @@
 # undef DUMPREG
 }
 
+static inline bool CompareBaseAddress(const LoadedModule &a,
+                                      const LoadedModule &b) {
+  return a.base_address() < b.base_address();
+}
+
+void FormatUUID(char *out, uptr size, const u8 *uuid) {
+  internal_snprintf(out, size,
+          "<%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-"
+          "%02x%02x%02x%02x%02x%02x>",
+          uuid[0], uuid[1], uuid[2], uuid[3], uuid[4], uuid[5], uuid[6],
+          uuid[7], uuid[8], uuid[9], uuid[10], uuid[11], uuid[12], uuid[13],
+          uuid[14], uuid[15]);
+  // Now convert to uppercase.
+  while (*out) {
+    *out = toupper(*out);
+    out++;
+  }
+}
+
+void PrintModuleMap() {
+  Printf("Process module map:\n");
+  MemoryMappingLayout memory_mapping(false);
+  InternalMmapVector<LoadedModule> modules(/*initial_capacity*/ 128);
+  memory_mapping.DumpListOfModules(&modules);
+  InternalSort(&modules, modules.size(), CompareBaseAddress);
+  for (uptr i = 0; i < modules.size(); ++i) {
+    char uuid_str[128];
+    FormatUUID(uuid_str, sizeof(uuid_str), modules[i].uuid());
+    Printf("0x%llx-0x%llx %s (%s) %s\n", modules[i].base_address(),
+           modules[i].max_executable_address(), modules[i].full_name(),
+           ModuleArchToString(modules[i].arch()), uuid_str);
+  }
+  Printf("End of module map.\n");
+}
+
 }  // namespace __sanitizer
 
 #endif  // SANITIZER_MAC
Index: lib/sanitizer_common/sanitizer_win.cc
===================================================================
--- lib/sanitizer_common/sanitizer_win.cc
+++ lib/sanitizer_common/sanitizer_win.cc
@@ -373,6 +373,8 @@
 }
 #endif
 
+void PrintModuleMap() { }
+
 void DisableCoreDumperIfNecessary() {
   // Do nothing.
 }
Index: lib/tsan/rtl/tsan_report.cc
===================================================================
--- lib/tsan/rtl/tsan_report.cc
+++ lib/tsan/rtl/tsan_report.cc
@@ -358,6 +358,8 @@
       ReportErrorSummary(rep_typ_str, frame->info);
   }
 
+  if (common_flags()->print_module_map == 2) PrintModuleMap();
+
   Printf("==================\n");
 }
 
Index: lib/tsan/rtl/tsan_rtl.cc
===================================================================
--- lib/tsan/rtl/tsan_rtl.cc
+++ lib/tsan/rtl/tsan_rtl.cc
@@ -404,6 +404,8 @@
 int Finalize(ThreadState *thr) {
   bool failed = false;
 
+  if (common_flags()->print_module_map == 1) PrintModuleMap();
+
   if (flags()->atexit_sleep_ms > 0 && ThreadCount(thr) > 1)
     SleepForMillis(flags()->atexit_sleep_ms);