Index: lib/sanitizer_common/sanitizer_win_defs.h
===================================================================
--- lib/sanitizer_common/sanitizer_win_defs.h
+++ lib/sanitizer_common/sanitizer_win_defs.h
@@ -43,6 +43,8 @@
 #define STRINGIFY_(A) #A
 #define STRINGIFY(A) STRINGIFY_(A)
 
+#if !SANITIZER_GO
+
 // ----------------- A workaround for the absence of weak symbols --------------
 // We don't have a direct equivalent of weak symbols when using MSVC, but we can
 // use the /alternatename directive to tell the linker to default a specific
@@ -158,5 +160,15 @@
 //     return a >= b;
 //   }
 //
+
+#else // SANITIZER_GO
+
+// Go neither needs nor wants weak references.
+// The shenanigans above don't work for gcc.
+# define WIN_WEAK_EXPORT_DEF(ReturnType, Name, ...)                            \
+  extern "C" ReturnType Name(__VA_ARGS__)
+
+#endif // SANITIZER_GO
+
 #endif // SANITIZER_WINDOWS
 #endif // SANITIZER_WIN_DEFS_H
Index: lib/tsan/go/build.bat
===================================================================
--- lib/tsan/go/build.bat
+++ lib/tsan/go/build.bat
@@ -1,4 +1,61 @@
-type tsan_go.cpp ..\rtl\tsan_interface_atomic.cpp ..\rtl\tsan_clock.cpp ..\rtl\tsan_flags.cpp ..\rtl\tsan_md5.cpp ..\rtl\tsan_mutex.cpp ..\rtl\tsan_report.cpp ..\rtl\tsan_rtl.cpp ..\rtl\tsan_rtl_mutex.cpp ..\rtl\tsan_rtl_report.cpp ..\rtl\tsan_rtl_thread.cpp ..\rtl\tsan_rtl_proc.cpp ..\rtl\tsan_stat.cpp ..\rtl\tsan_suppressions.cpp ..\rtl\tsan_sync.cpp ..\rtl\tsan_stack_trace.cpp ..\..\sanitizer_common\sanitizer_allocator.cpp ..\..\sanitizer_common\sanitizer_common.cpp ..\..\sanitizer_common\sanitizer_flags.cpp ..\..\sanitizer_common\sanitizer_stacktrace.cpp ..\..\sanitizer_common\sanitizer_libc.cpp ..\..\sanitizer_common\sanitizer_printf.cpp ..\..\sanitizer_common\sanitizer_suppressions.cpp ..\..\sanitizer_common\sanitizer_thread_registry.cpp ..\rtl\tsan_platform_windows.cpp ..\..\sanitizer_common\sanitizer_win.cpp ..\..\sanitizer_common\sanitizer_deadlock_detector1.cpp ..\..\sanitizer_common\sanitizer_stackdepot.cpp ..\..\sanitizer_common\sanitizer_persistent_allocator.cpp ..\..\sanitizer_common\sanitizer_flag_parser.cpp ..\..\sanitizer_common\sanitizer_symbolizer.cpp ..\..\sanitizer_common\sanitizer_termination.cpp > gotsan.cpp
-
-gcc -c -o race_windows_amd64.syso gotsan.cpp -I..\rtl -I..\.. -I..\..\sanitizer_common -I..\..\..\include -m64 -Wall -fno-exceptions -fno-rtti -DSANITIZER_GO=1 -Wno-error=attributes -Wno-attributes -Wno-format -Wno-maybe-uninitialized -DSANITIZER_DEBUG=0 -O3 -fomit-frame-pointer -std=c++11
+type ^
+  tsan_go.cpp ^
+  ..\rtl\tsan_interface_atomic.cpp ^
+  ..\rtl\tsan_clock.cpp ^
+  ..\rtl\tsan_flags.cpp ^
+  ..\rtl\tsan_md5.cpp ^
+  ..\rtl\tsan_mutex.cpp ^
+  ..\rtl\tsan_report.cpp ^
+  ..\rtl\tsan_rtl.cpp ^
+  ..\rtl\tsan_rtl_mutex.cpp ^
+  ..\rtl\tsan_rtl_report.cpp ^
+  ..\rtl\tsan_rtl_thread.cpp ^
+  ..\rtl\tsan_rtl_proc.cpp ^
+  ..\rtl\tsan_stat.cpp ^
+  ..\rtl\tsan_suppressions.cpp ^
+  ..\rtl\tsan_sync.cpp ^
+  ..\rtl\tsan_stack_trace.cpp ^
+  ..\..\sanitizer_common\sanitizer_allocator.cpp ^
+  ..\..\sanitizer_common\sanitizer_common.cpp ^
+  ..\..\sanitizer_common\sanitizer_flags.cpp ^
+  ..\..\sanitizer_common\sanitizer_stacktrace.cpp ^
+  ..\..\sanitizer_common\sanitizer_libc.cpp ^
+  ..\..\sanitizer_common\sanitizer_printf.cpp ^
+  ..\..\sanitizer_common\sanitizer_suppressions.cpp ^
+  ..\..\sanitizer_common\sanitizer_thread_registry.cpp ^
+  ..\rtl\tsan_platform_windows.cpp ^
+  ..\..\sanitizer_common\sanitizer_win.cpp ^
+  ..\..\sanitizer_common\sanitizer_deadlock_detector1.cpp ^
+  ..\..\sanitizer_common\sanitizer_stackdepot.cpp ^
+  ..\..\sanitizer_common\sanitizer_persistent_allocator.cpp ^
+  ..\..\sanitizer_common\sanitizer_flag_parser.cpp ^
+  ..\..\sanitizer_common\sanitizer_symbolizer.cpp ^
+  ..\..\sanitizer_common\sanitizer_termination.cpp ^
+  ..\..\sanitizer_common\sanitizer_file.cpp ^
+  ..\..\sanitizer_common\sanitizer_symbolizer_report.cpp ^
+  ..\rtl\tsan_external.cpp ^
+  > gotsan.cpp
 
+gcc ^
+  -c ^
+  -o race_windows_amd64.syso ^
+  gotsan.cpp ^
+  -I..\rtl ^
+  -I..\.. ^
+  -I..\..\sanitizer_common ^
+  -I..\..\..\include ^
+  -m64 ^
+  -Wall ^
+  -fno-exceptions ^
+  -fno-rtti ^
+  -DSANITIZER_GO=1 ^
+  -DWINVER=0x0600 -D_WIN32_WINNT=0x0600 ^
+  -DGetProcessMemoryInfo=K32GetProcessMemoryInfo ^
+  -Wno-error=attributes ^
+  -Wno-attributes ^
+  -Wno-format ^
+  -Wno-maybe-uninitialized ^
+  -DSANITIZER_DEBUG=0 ^
+  -O3 ^
+  -fomit-frame-pointer ^
+  -std=c++11