Use default instead of a specific case to fix the MSVC warning in sysinfo.cc

[dpaoliello]

#147357 attempted to fix an MSVC in sysinfo.cc by adding a case block for a missing enum value.

However, this resulted in CI failures:

4.170 [148/4/9] Building CXX object third-party/benchmark/src/CMakeFiles/benchmark.dir/sysinfo.cc.obj
FAILED: third-party/benchmark/src/CMakeFiles/benchmark.dir/sysinfo.cc.obj 
C:\Users\tcwg\scoop\shims\ccache.exe C:\Users\tcwg\scoop\apps\llvm-arm64\current\bin\clang-cl.exe  /nologo -TP -DBENCHMARK_STATIC_DEFINE -DEXPERIMENTAL_KEY_INSTRUCTIONS -DHAVE_STD_REGEX -DHAVE_STEADY_CLOCK -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_HAS_EXCEPTIONS=0 -D_SCL_SECURE_NO_DEPRECATE -D_SCL_SECURE_NO_WARNINGS -D_UNICODE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -IC:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/build/third-party/benchmark/src -IC:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/llvm-project/third-party/benchmark/src -IC:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/build/include -IC:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/llvm-project/llvm/include -IC:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/llvm-project/third-party/benchmark/include /DWIN32 /D_WINDOWS   /Zc:inline /Zc:__cplusplus /Oi /Brepro /bigobj /permissive- -Werror=unguarded-availability-new   -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported /Gw /W4  -EHs-  -EHa- /O2 /Ob2  -std:c++14 -MD -UNDEBUG /showIncludes /Fothird-party/benchmark/src/CMakeFiles/benchmark.dir/sysinfo.cc.obj /Fdthird-party\benchmark\src\CMakeFiles\benchmark.dir\benchmark.pdb -c -- C:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/llvm-project/third-party/benchmark/src/sysinfo.cc
C:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/llvm-project/third-party/benchmark/src/sysinfo.cc(374,12): error: use of undeclared identifier 'CacheUnknown'
  374 |       case CacheUnknown:
      |            ^
1 error generated.

The root cause is that the enum being switched on is defined in the Windows SDK, so depending on which version of the SDK you are using CacheUnknown may or may not be defined.

The correct fix here is to use a default block in the switch statement instead.

[llvmbot]

@llvm/pr-subscribers-third-party-benchmark

Author: Daniel Paoliello (dpaoliello)

Changes

#147357 attempted to fix an MSVC in sysinfo.cc by adding a case block for a missing enum value.

However, this resulted in CI failures:

4.170 [148/4/9] Building CXX object third-party/benchmark/src/CMakeFiles/benchmark.dir/sysinfo.cc.obj
FAILED: third-party/benchmark/src/CMakeFiles/benchmark.dir/sysinfo.cc.obj 
C:\Users\tcwg\scoop\shims\ccache.exe C:\Users\tcwg\scoop\apps\llvm-arm64\current\bin\clang-cl.exe  /nologo -TP -DBENCHMARK_STATIC_DEFINE -DEXPERIMENTAL_KEY_INSTRUCTIONS -DHAVE_STD_REGEX -DHAVE_STEADY_CLOCK -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_HAS_EXCEPTIONS=0 -D_SCL_SECURE_NO_DEPRECATE -D_SCL_SECURE_NO_WARNINGS -D_UNICODE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -IC:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/build/third-party/benchmark/src -IC:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/llvm-project/third-party/benchmark/src -IC:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/build/include -IC:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/llvm-project/llvm/include -IC:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/llvm-project/third-party/benchmark/include /DWIN32 /D_WINDOWS   /Zc:inline /Zc:__cplusplus /Oi /Brepro /bigobj /permissive- -Werror=unguarded-availability-new   -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported /Gw /W4  -EHs-  -EHa- /O2 /Ob2  -std:c++14 -MD -UNDEBUG /showIncludes /Fothird-party/benchmark/src/CMakeFiles/benchmark.dir/sysinfo.cc.obj /Fdthird-party\benchmark\src\CMakeFiles\benchmark.dir\benchmark.pdb -c -- C:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/llvm-project/third-party/benchmark/src/sysinfo.cc
C:/Users/tcwg/llvm-worker/flang-arm64-windows-msvc/llvm-project/third-party/benchmark/src/sysinfo.cc(374,12): error: use of undeclared identifier 'CacheUnknown'
  374 |       case CacheUnknown:
      |            ^
1 error generated.

The root cause is that the enum being switched on is defined in the Windows SDK, so depending on which version of the SDK you are using CacheUnknown may or may not be defined.

The correct fix here is to use a default block in the switch statement instead.

---

Full diff: https://github.com/llvm/llvm-project/pull/149159.diff

1 Files Affected:

• (modified) third-party/benchmark/src/sysinfo.cc (+1-1)

diff --git a/third-party/benchmark/src/sysinfo.cc b/third-party/benchmark/src/sysinfo.cc
index 837be8f9cf891..d1ae6cc82b943 100644
--- a/third-party/benchmark/src/sysinfo.cc
+++ b/third-party/benchmark/src/sysinfo.cc
@@ -371,7 +371,7 @@ std::vector<CPUInfo::CacheInfo> GetCacheSizesWindows() {
       case CacheTrace:
         C.type = "Trace";
         break;
-      case CacheUnknown:
+      default:
         C.type = "Unknown";
         break;
     }

[dyung]

If this will fix the Windows build, can we get this in soon? My Windows bot is still failing and I'd like to get it green again: https://lab.llvm.org/buildbot/#/builders/46

[AaronBallman]

Thank you for the quick fix!