[Bug] ndk clang building release raise error `declaration does not match` while llvm upstream compiles

[yujincheng08]

Description

PoC: https://github.com/yujincheng08/ndkPoC

When we run buildCMakeRelWithDebInfo it raises the error while running buildCmakeDebug it compiles.

However, the upstream does work: https://godbolt.org/z/MMfq84rcK

Error message:

Execution failed for task ':app:buildCMakeRelWithDebInfo[x86_64]'.
> com.android.ide.common.process.ProcessException: ninja: Entering directory `C:\Users\loves\AndroidStudioProjects\NativeTest\app\.cxx\RelWithDebInfo\1i6i364f\x86_64'
  [1/2] Building CXX object CMakeFiles/test.dir/foo.cc.o
  FAILED: CMakeFiles/test.dir/foo.cc.o 
  D:\Android\SDK\ndk\28.0.11699160\toolchains\llvm\prebuilt\windows-x86_64\bin\clang++.exe --target=x86_64-none-linux-android24 --sysroot=D:/Android/SDK/ndk/28.0.11699160/toolchains/llvm/prebuilt/windows-x86_64/sysroot -Dtest_EXPORTS  -g -DANDROID -fdata-sections -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -D_FORTIFY_SOURCE=2 -Wformat -Werror=format-security   -O2 -g -DNDEBUG -std=gnu++20 -fPIC -MD -MT CMakeFiles/test.dir/foo.cc.o -MF CMakeFiles\test.dir\foo.cc.o.d @CMakeFiles\test.dir\foo.cc.o.modmap -o CMakeFiles/test.dir/foo.cc.o -c C:/Users/loves/AndroidStudioProjects/NativeTest/app/src/main/cpp/foo.cc
  In module 'bar' imported from C:/Users/loves/AndroidStudioProjects/NativeTest/app/src/main/cpp/foo.cc:3:
  C:/Users/loves/AndroidStudioProjects/NativeTest/app/src/main/cpp/h.hpp:6:34: error: 'S::s' from module 'bar.<global>' is not present in definition of 'S<c...>' provided earlier
      6 |     inline static constexpr char s[]{c...};
        |                                  ^
  C:/Users/loves/AndroidStudioProjects/NativeTest/app/src/main/cpp/h.hpp:6:34: note: declaration of 's' does not match
      6 |     inline static constexpr char s[]{c...};
        |                                  ^
  1 error generated.
  ninja: build stopped: subcommand failed.
  
  C++ build system [build] failed while executing:
      @echo off
      "C:\\Program Files\\CMake\\bin\\ninja.exe" ^
        -C ^
        "C:\\Users\\loves\\AndroidStudioProjects\\NativeTest\\app\\.cxx\\RelWithDebInfo\\1i6i364f\\x86_64" ^
        test
    from C:\Users\loves\AndroidStudioProjects\NativeTest\app

Upstream bug

llvm/llvm-project#79240

Commit to cherry-pick

llvm/llvm-project#80249

Affected versions

Canary

Canary version

28.0.11706545

Host OS

Linux, Windows

Host OS version

11

Affected ABIs

armeabi-v7a, arm64-v8a, x86, x86_64

[appujee]

It doesn't look like a regression from previous compiler: https://godbolt.org/z/P8j4GnhYE This has been fixed recently in upstream clang.

[yujincheng08]

@appujee yes, and i have bisected the commit that fixed this issue. so maybe we need to cherry-pick this fix.

[DanAlbert]

I'll defer to the LLVM folks on whether or not that's innocuous enough to cherry-pick to r27. It's already in QA, so the bar for cherry-picks of non-regressions has gone up.

[pirama-arumuga-nainar]

a0e1cc0aefbc mentioned in the original report is the back port to the llvm-18 branch. a0b6747804e466 is the patch to the main branch of llvm-project.

[yujincheng08]

So is it possible to pick it to r27?

[pirama-arumuga-nainar]

https://android-review.googlesource.com/c/toolchain/llvm_android/+/3042676 is the cherry-pick to AOSP clang. Let's see if it passes presubmit and tests.

The fix seems reasonable. However, since this is not a regression, it doesn't meet the bar for a compiler respin. If there is another bug in the compiler that requires updating the r27 clang, we'll include the fix for this as well.

[DanAlbert]

(and there almost always is another bug, so it's likely)

[yujincheng08]

Confirmed 28.0.11744028 works.