[Fuzzer] SetThreadName implementation for Windows

[devnexen]

Summary

Api available since Windows Server 2016/Windows 10 1607

[vitalybuka]

compiler-rt/lib/fuzzer/FuzzerUtilWindows.cpp

239

Why just 16?

[devnexen]

compiler-rt/lib/fuzzer/FuzzerUtilWindows.cpp

239

just precaution, the real limit is probably higher I just do not know, we can always adjust later.

[vitalybuka]

https://lab.llvm.org/buildbot/#/builders/127/builds/52381/steps/8/logs/stdio

[devnexen]

Not sure I really get the fuzzer failure, what s going on about gtest ?

[vitalybuka]

compiler-rt/lib/fuzzer/FuzzerUtilWindows.cpp

240

[devnexen]

ah right your changes make sense

[vitalybuka]

Not big deal, as a very few bots run libFuzzer on Windows, but asking for review is not quick fix.

From https://llvm.org/docs/DeveloperPolicy.html#id18

If you break a buildbot in a way which can’t be quickly fixed, please revert.

[vitalybuka]

compiler-rt/lib/fuzzer/FuzzerUtilWindows.cpp

240

I don't have Windows, about is a guess, I am not sure if it's compile as-is.

[vitalybuka]

compiler-rt/lib/fuzzer/FuzzerUtilWindows.cpp

240

https://learn.microsoft.com/en-us/windows/win32/api/stringapiset/nf-stringapiset-multibytetowidechar
from the example int the doc
wname[0] -> nullptr in the fist call

[vitalybuka]

compiler-rt/lib/fuzzer/FuzzerUtilWindows.cpp

240

and obviously wname[0] -> &wname[0] in the second call

[devnexen]

compiler-rt/lib/fuzzer/FuzzerUtilWindows.cpp

240

in fact, in the first call wname[0] is not even needed no ? according to the example.

[devnexen]

compiler-rt/lib/fuzzer/FuzzerUtilWindows.cpp

240

ah you said it already.. ok I ll get to it soonish

[devnexen]

advices from vitalybuka

[vitalybuka]

rebases

[phosek]

This broke the Windows build, would it be possible to take a look and revert if necessary?

/b/s/w/ir/x/w/llvm_build/./bin/clang-cl --target=x86_64-pc-windows-msvc  /nologo -TP -DUNICODE -D_CRT_NONSTDC_NO_DEPRECATE -D_CRT_NONSTDC_NO_WARNINGS -D_CRT_SECURE_NO_DEPRECATE -D_CRT_SECURE_NO_WARNINGS -D_GLIBCXX_ASSERTIONS -D_LIBCPP_ENABLE_HARDENED_MODE -D_SCL_SECURE_NO_DEPRECATE -D_SCL_SECURE_NO_WARNINGS -D_UNICODE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/b/s/w/ir/x/w/llvm-llvm-project/compiler-rt/lib/fuzzer/../../include -Xclang -ivfsoverlay -Xclang /b/s/w/ir/cache/windows_sdk/llvm-vfsoverlay.yaml /winsysroot /b/s/w/ir/cache/windows_sdk /Zc:inline /Zc:__cplusplus /Oi /bigobj /permissive- -wd4141 -wd4146 -wd4244 -wd4267 -wd4291 -wd4351 -wd4456 -wd4457 -wd4458 -wd4459 -wd4503 -wd4624 -wd4722 -wd4100 -wd4127 -wd4512 -wd4505 -wd4610 -wd4510 -wd4702 -wd4245 -wd4706 -wd4310 -wd4701 -wd4703 -wd4389 -wd4611 -wd4805 -wd4204 -wd4577 -wd4091 -wd4592 -wd4319 -wd4709 -wd5105 -wd4324 -w14062 -we4238 /Gw -no-canonical-prefixes /W4 -Wno-unused-parameter  /Z7 /O2 /Ob1  -std:c++17 -MT -fno-builtin -fno-sanitize=safe-stack -fno-lto /Oy- /GS- /Zc:threadSafeInit- -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta /Z7 -Wno-gnu -Wno-variadic-macros -Wno-c99-extensions /wd4146 /wd4291 /wd4391 /wd4722 /wd4800 -D_HAS_EXCEPTIONS=0 /showIncludes /Focompiler-rt/lib/fuzzer/CMakeFiles/RTfuzzer.x86_64.dir/FuzzerUtilWindows.cpp.obj /Fdcompiler-rt/lib/fuzzer/CMakeFiles/RTfuzzer.x86_64.dir/ -c -- /b/s/w/ir/x/w/llvm-llvm-project/compiler-rt/lib/fuzzer/FuzzerUtilWindows.cpp
/b/s/w/ir/x/w/llvm-llvm-project/compiler-rt/lib/fuzzer/FuzzerUtilWindows.cpp(239,16): error: no matching constructor for initialization of 'std::wstring' (aka 'basic_string<wchar_t, char_traits<wchar_t>, allocator<wchar_t>>')
  239 |   std::wstring wname(sz);
      |                ^     ~~
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(2619,27): note: candidate constructor not viable: no known conversion from 'int' to 'const std::allocator<wchar_t>' for 1st argument
 2619 |     _CONSTEXPR20 explicit basic_string(const _Alloc& _Al) noexcept : _Mypair(_One_then_variadic_args_t{}, _Al) {
      |                           ^            ~~~~~~~~~~~~~~~~~
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(2624,18): note: candidate constructor not viable: no known conversion from 'int' to 'const basic_string<wchar_t>' for 1st argument
 2624 |     _CONSTEXPR20 basic_string(const basic_string& _Right)
      |                  ^            ~~~~~~~~~~~~~~~~~~~~~~~~~~
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(2673,18): note: candidate constructor not viable: no known conversion from 'int' to 'const wchar_t *const' for 1st argument
 2673 |     _CONSTEXPR20 basic_string(_In_z_ const _Elem* const _Ptr) : _Mypair(_Zero_then_variadic_args_t{}) {
      |                  ^                   ~~~~~~~~~~~~~~~~~~~~~~~
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(2887,18): note: candidate constructor not viable: no known conversion from 'int' to 'basic_string<wchar_t>' for 1st argument
 2887 |     _CONSTEXPR20 basic_string(basic_string&& _Right) noexcept
      |                  ^            ~~~~~~~~~~~~~~~~~~~~~
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(3221,18): note: candidate constructor not viable: no known conversion from 'int' to 'initializer_list<wchar_t>' for 1st argument
 3221 |     _CONSTEXPR20 basic_string(initializer_list<_Elem> _Ilist, const _Alloc& _Al = allocator_type())
      |                  ^            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(3021,27): note: candidate template ignored: requirement 'conjunction_v<std::is_convertible<const int &, std::basic_string_view<wchar_t, std::char_traits<wchar_t>>>, std::negation<std::is_convertible<const int &, const wchar_t *>>>' was not satisfied [with _StringViewIsh = int]
 3021 |     _CONSTEXPR20 explicit basic_string(const _StringViewIsh& _Right, const _Alloc& _Al = _Alloc())
      |                           ^
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(2613,18): note: candidate constructor not viable: requires 0 arguments, but 1 was provided
 2613 |     _CONSTEXPR20 basic_string() noexcept(is_nothrow_default_constructible_v<_Alty>)
      |                  ^
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(2629,18): note: candidate constructor not viable: requires 2 arguments, but 1 was provided
 2629 |     _CONSTEXPR20 basic_string(const basic_string& _Right, const _Alloc& _Al)
      |                  ^            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(2662,18): note: candidate constructor not viable: requires 2 arguments, but 1 was provided
 2662 |     _CONSTEXPR20 basic_string(_In_reads_(_Count) const _Elem* const _Ptr, _CRT_GUARDOVERFLOW const size_type _Count)
      |                  ^                               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(2684,18): note: candidate constructor template not viable: requires 2 arguments, but 1 was provided
 2684 |     _CONSTEXPR20 basic_string(_In_z_ const _Elem* const _Ptr, const _Alloc& _Al)
      |                  ^                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(2689,18): note: candidate constructor not viable: requires 2 arguments, but 1 was provided
 2689 |     _CONSTEXPR20 basic_string(_CRT_GUARDOVERFLOW const size_type _Count, const _Elem _Ch)
      |                  ^                               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(2893,18): note: candidate constructor not viable: requires 2 arguments, but 1 was provided
 2893 |     _CONSTEXPR20 basic_string(basic_string&& _Right, const _Alloc& _Al) noexcept(
      |                  ^            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(2634,18): note: candidate constructor not viable: requires at least 2 arguments, but 1 was provided
 2634 |     _CONSTEXPR20 basic_string(const basic_string& _Right, const size_type _Roff, const _Alloc& _Al = _Alloc())
      |                  ^            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(2667,18): note: candidate constructor not viable: requires 3 arguments, but 1 was provided
 2668 |     _CONSTEXPR20 basic_string(
      |                  ^
 2669 |         _In_reads_(_Count) const _Elem* const _Ptr, _CRT_GUARDOVERFLOW const size_type _Count, const _Alloc& _Al)
      |                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(2697,18): note: candidate constructor template not viable: requires 3 arguments, but 1 was provided
 2697 |     _CONSTEXPR20 basic_string(_CRT_GUARDOVERFLOW const size_type _Count, const _Elem _Ch, const _Alloc& _Al)
      |                  ^                               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(2703,18): note: candidate constructor template not viable: requires at least 2 arguments, but 1 was provided
 2703 |     _CONSTEXPR20 basic_string(_Iter _First, _Iter _Last, const _Alloc& _Al = _Alloc())
      |                  ^            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(2945,18): note: candidate constructor not viable: requires 3 arguments, but 1 was provided
 2945 |     _CONSTEXPR20 basic_string(_String_constructor_concat_tag, basic_string& _Left, basic_string& _Right)
      |                  ^            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(2641,18): note: candidate constructor not viable: requires at least 3 arguments, but 1 was provided
 2642 |     _CONSTEXPR20 basic_string(
      |                  ^
 2643 |         const basic_string& _Right, const size_type _Roff, const size_type _Count, const _Alloc& _Al = _Alloc())
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(3028,18): note: candidate constructor template not viable: requires at least 3 arguments, but 1 was provided
 3029 |     _CONSTEXPR20 basic_string(
      |                  ^
 3030 |         const _Ty& _Right, const size_type _Roff, const size_type _Count, const _Alloc& _Al = _Alloc())
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/b/s/w/ir/cache/windows_sdk/VC/Tools/MSVC/14.34.31933/include/xstring(2908,18): note: candidate constructor not viable: requires 6 arguments, but 1 was provided
 2908 |     _CONSTEXPR20 basic_string(_String_constructor_concat_tag, const basic_string& _Source_of_al,
      |                  ^            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 2909 |         const _Elem* const _Left_ptr, const size_type _Left_size, const _Elem* const _Right_ptr,
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 2910 |         const size_type _Right_size)
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.

[devnexen]

@phosek done
@vitalybuka almost there :) what about ?

std::wstring wname;
wname.resize(sz);

[devnexen]

new attempt

[Prabhuk]

if (sz == MultiByteToWideChar(CP_UTF8, 0, name.data, name.size, &wname[0], sz) > 0)

Compilation failures on name.data and name.size invocations without paranthesis is breaking the builds.
Can you please fix this ASAP or revert? Thank you.

[vitalybuka]

Now it fails with

---------------------------
fuzzer-oom.test.tmp-OutOfMemoryTest.exe - Entry Point Not Found
---------------------------
The procedure entry point SetThreadDescription could not be located in the dynamic link library C:\b\slave\sanitizer-windows\build\stage1\projects\compiler-rt\test\fuzzer\X86_64DefaultWindowsConfig\Output\fuzzer-oom.test.tmp-OutOfMemoryTest.exe. 
---------------------------
OK   
---------------------------

[vitalybuka]

Reverted with dd3aa26fc8e9de37a39611f7a6a602bcb4153784

[devnexen]

oh it feels like you can t call it directly but maybe via a dlopen/dlsym sort of mechanism. getting complicated :) but we ll see.

compiler-rt/lib/fuzzer/FuzzerUtilWindows.cpp

 }
 
 void SetThreadName(std::thread &thread, const std::string &name) {
-  // TODO ?
-  // to UTF-8 then SetThreadDescription ?
+  std::wstring wname;
+  auto sz = MultiByteToWideChar(CP_UTF8, 0, name.data(), name.size(), nullptr, 0);
+  wname.resize(sz);
+  if (sz == MultiByteToWideChar(CP_UTF8, 0, name.data, name.size, &wname[0], sz) > 0) {
+      wname.resize(sz - 1);
+      (void)SetThreadDescription(thread.native_handle(), wname.c_str());
+  }
 }
 
 } // namespace fuzzer