Enable Asan on Windows

[timurrrr]

[Sorry I forgot to mention - please add llvm-commits@ to subscribers for all your compiler-rt patches]

The patch looks mostly fine for me, I'll refine it slightly and commit soon (when I have some extra time).

Can you please confirm that this patch doesn't regress "ninja check-all" in your build environment?
(i.e. it's fine if most things that were broken remain broken; it's not OK if anything else starts to fail)

[timurrrr]

lib/asan/CMakeLists.txt

200

Is there an equivalent of /Zl (Omit Default Library Name) in non-MSVC compilers?

lib/asan/asan_win_dll_thunk.cc

27

maybe DEBUG_BREAK is more appropriate, what do you think?

[akhaldi]

lib/asan/CMakeLists.txt

200

Hmm I don't think so, it looks pretty MSVC centric.

lib/asan/asan_win_dll_thunk.cc

27

It's more descriptive, okay.

[rnk]

lib/asan/asan_win_dll_thunk.cc

29

I think you need volatile or some other constraint to prevent gcc from removing this.

[samsonov]

lib/asan/CMakeLists.txt

198

Instead, add a check for this flag existence in cmake/config-ix.cmake, and append it if it's known:

set(ASAN_THUNK_CFLAGS ${ASAN_CFLAGS} -DASAN_DYNAMIC_RUNTIME_THUNK)
append_if(COMPILER_RT_HAS_Zl_FLAG "-Zl" ASAN_THUNK_CFLAGS)

or if it's always available in MSVC and should be added only there, use

append_if(MSVC -Zl ASAN_THUNK_CFLAGS)

[timurrrr]

if it's always available in MSVC and should be added only there, use

append_if(MSVC -Zl ASAN_THUNK_CFLAGS)

It is available since VS2003 at least, so we can consider it as always.
Can you please use ASAN_DYNAMIC_RUNTIME_THUNK _CFLAGS?

cmake/config-ix.cmake

 if(ANDROID)
   set(OS_NAME "Android")
 else()
   set(OS_NAME "${CMAKE_SYSTEM_NAME}")
 endif()
 
 if (SANITIZER_COMMON_SUPPORTED_ARCH AND NOT LLVM_USE_SANITIZER AND
     (OS_NAME MATCHES "Android|Darwin|Linux|FreeBSD" OR
-    (OS_NAME MATCHES "Windows" AND MSVC AND CMAKE_SIZEOF_VOID_P EQUAL 4)))
+    (OS_NAME MATCHES "Windows" AND CMAKE_SIZEOF_VOID_P EQUAL 4)))
   set(COMPILER_RT_HAS_SANITIZER_COMMON TRUE)
 else()
   set(COMPILER_RT_HAS_SANITIZER_COMMON FALSE)
 endif()
 
 if (COMPILER_RT_HAS_SANITIZER_COMMON AND ASAN_SUPPORTED_ARCH)
   set(COMPILER_RT_HAS_ASAN TRUE)
 else()

lib/asan/CMakeLists.txt

 
     if (WIN32)
       add_compiler_rt_runtime(clang_rt.asan_dll_thunk-${arch} ${arch} STATIC
         SOURCES asan_win_dll_thunk.cc
                 $<TARGET_OBJECTS:RTInterception.${arch}>
         CFLAGS ${ASAN_CFLAGS} -DASAN_DLL_THUNK
         DEFS ${ASAN_COMMON_DEFINITIONS})
       add_dependencies(asan clang_rt.asan_dll_thunk-${arch})
+
+      if(MSVC)
+        set(OMIT_DEFAULT_LIB_NAME_FLAG "-Zl")
+      else()
+        set(OMIT_DEFAULT_LIB_NAME_FLAG "")
+      endif()
+
       add_compiler_rt_runtime(clang_rt.asan_dynamic_runtime_thunk-${arch} ${arch}
         STATIC
         SOURCES asan_win_dynamic_runtime_thunk.cc
-        CFLAGS ${ASAN_CFLAGS} -DASAN_DYNAMIC_RUNTIME_THUNK -Zl
+        CFLAGS ${ASAN_CFLAGS} -DASAN_DYNAMIC_RUNTIME_THUNK ${OMIT_DEFAULT_LIB_NAME_FLAG}
         DEFS ${ASAN_COMMON_DEFINITIONS})
       add_dependencies(asan clang_rt.asan_dynamic_runtime_thunk-${arch})
     endif()
   endforeach()
 endif()
 
 add_compiler_rt_resource_file(asan_blacklist asan_blacklist.txt)
 add_dependencies(asan asan_blacklist)
 add_dependencies(compiler-rt asan)
 
 add_subdirectory(scripts)
 
 if(COMPILER_RT_INCLUDE_TESTS)
   add_subdirectory(tests)
 endif()

lib/asan/asan_win_dll_thunk.cc

 
 // Only compile this code when buidling asan_dll_thunk.lib
 // Using #ifdef rather than relying on Makefiles etc.
 // simplifies the build procedure.
 #ifdef ASAN_DLL_THUNK
 #include "asan_init_version.h"
 #include "sanitizer_common/sanitizer_interception.h"
 
+#ifdef _MSC_VER
+#define DEBUG_BREAK __debugbreak()
+#else
+#define DEBUG_BREAK __asm__ __volatile__("int $3")
+#endif
+
 // ---------- Function interception helper functions and macros ----------- {{{1
 extern "C" {
 void *__stdcall GetModuleHandleA(const char *module_name);
 void *__stdcall GetProcAddress(void *module, const char *proc_name);
 void abort();
 }
 
 static void *getRealProcAddressOrDie(const char *name) {
template<> struct FunctionInterceptor<__LINE__> {                            \
     }                                                                          \
   };
 
 // Special case of hooks -- ASan own interface functions.  Those are only called
 // after __asan_init, thus an empty implementation is sufficient.
 #define INTERFACE_FUNCTION(name)                                               \
   extern "C" __declspec(noinline) void name() {                                \
     volatile int prevent_icf = (__LINE__ << 8); (void)prevent_icf;             \
-    __debugbreak();                                                            \
+    DEBUG_BREAK;                                                               \
   }                                                                            \
   INTERCEPT_WHEN_POSSIBLE(#name, name)
 
 // INTERCEPT_HOOKS must be used after the last INTERCEPT_WHEN_POSSIBLE.
 #define INTERCEPT_HOOKS FunctionInterceptor<__LINE__>::Execute
 
 // We can't define our own version of strlen etc. because that would lead to
 // link-time or even type mismatch errors.  Instead, we can declare a function