Bug Report: Extra Increment on Generator::iterator After Completion Causes Crash Using Clang15

[faker2048]

Bug Report: Extra Increment on Generator::iterator After Completion Causes Crash Using Clang15

[ChuanqiXu9]

I feel this is a compiler bug. There are several bugs in clang15 related to coroutines. It may be fine to use Lazy. But generator is more complex.

I'll close this issue and update the document later.

[faker2048]

@ChuanqiXu9
umm... I forgot to mention: this issue will result in one of the consequences being that with the latest macos default apple-clang (currently version 15), ctest fails to pass a unit test --async_simple_coro_test.

3: Test command: /Users/yxb/workspace/async_simple/build/async_simple/coro/test/async_simple_coro_test
3: Working Directory: /Users/yxb/workspace/async_simple/build/async_simple/coro/test
3: Test timeout computed to be: 10000000
3: Note: Google Test filter = GeneratorTest.testExample
3: [==========] Running 1 test from 1 test suite.
3: [----------] Global test environment set-up.
3: [----------] 1 test from GeneratorTest
3: [ RUN      ] GeneratorTest.testExample
3: start
3: foo!
3: bar!
3: bar!
3: unknown file: Failure
3: C++ exception with description "Can't increment generator end iterator" thrown in the test body.
3: 
3: [  FAILED  ] GeneratorTest.testExample (0 ms)
3: [----------] 1 test from GeneratorTest (0 ms total)
3: 
3: [----------] Global test environment tear-down
3: [==========] 1 test from 1 test suite ran. (0 ms total)
3: [  PASSED  ] 0 tests.
3: [  FAILED  ] 1 test, listed below:
3: [  FAILED  ] GeneratorTest.testExample
3: 
3:  1 FAILED TEST
3/5 Test #3: run_async_simple_coro_test .......***Failed    0.00 sec
test 4
    Start 4: run_async_simple_executor_test

[ChuanqiXu9]

@ChuanqiXu9 umm... I forgot to mention: this issue will result in one of the consequences being that with the latest macos default apple-clang (currently version 15), ctest fails to pass a unit test --async_simple_coro_test.

3: Test command: /Users/yxb/workspace/async_simple/build/async_simple/coro/test/async_simple_coro_test
3: Working Directory: /Users/yxb/workspace/async_simple/build/async_simple/coro/test
3: Test timeout computed to be: 10000000
3: Note: Google Test filter = GeneratorTest.testExample
3: [==========] Running 1 test from 1 test suite.
3: [----------] Global test environment set-up.
3: [----------] 1 test from GeneratorTest
3: [ RUN      ] GeneratorTest.testExample
3: start
3: foo!
3: bar!
3: bar!
3: unknown file: Failure
3: C++ exception with description "Can't increment generator end iterator" thrown in the test body.
3: 
3: [  FAILED  ] GeneratorTest.testExample (0 ms)
3: [----------] 1 test from GeneratorTest (0 ms total)
3: 
3: [----------] Global test environment tear-down
3: [==========] 1 test from 1 test suite ran. (0 ms total)
3: [  PASSED  ] 0 tests.
3: [  FAILED  ] 1 test, listed below:
3: [  FAILED  ] GeneratorTest.testExample
3: 
3:  1 FAILED TEST
3/5 Test #3: run_async_simple_coro_test .......***Failed    0.00 sec
test 4
    Start 4: run_async_simple_executor_test

Thanks for reporting this. I think we can only comment out these tests (the Generator Test) conditionally if the compiler is apple-clang15. Would you like to contribute that? Since it is not easy for me to test it locally.

[faker2048]

@ChuanqiXu9 umm... I forgot to mention: this issue will result in one of the consequences being that with the latest macos default apple-clang (currently version 15), ctest fails to pass a unit test --async_simple_coro_test.

3: Test command: /Users/yxb/workspace/async_simple/build/async_simple/coro/test/async_simple_coro_test
3: Working Directory: /Users/yxb/workspace/async_simple/build/async_simple/coro/test
3: Test timeout computed to be: 10000000
3: Note: Google Test filter = GeneratorTest.testExample
3: [==========] Running 1 test from 1 test suite.
3: [----------] Global test environment set-up.
3: [----------] 1 test from GeneratorTest
3: [ RUN      ] GeneratorTest.testExample
3: start
3: foo!
3: bar!
3: bar!
3: unknown file: Failure
3: C++ exception with description "Can't increment generator end iterator" thrown in the test body.
3: 
3: [  FAILED  ] GeneratorTest.testExample (0 ms)
3: [----------] 1 test from GeneratorTest (0 ms total)
3: 
3: [----------] Global test environment tear-down
3: [==========] 1 test from 1 test suite ran. (0 ms total)
3: [  PASSED  ] 0 tests.
3: [  FAILED  ] 1 test, listed below:
3: [  FAILED  ] GeneratorTest.testExample
3: 
3:  1 FAILED TEST
3/5 Test #3: run_async_simple_coro_test .......***Failed    0.00 sec
test 4
    Start 4: run_async_simple_executor_test

Thanks for reporting this. I think we can only comment out these tests (the Generator Test) conditionally if the compiler is apple-clang15. Would you like to contribute that? Since it is not easy for me to test it locally.

Sure

[faker2048]

@ChuanqiXu9
I think solution is to conditionally remove GeneratorTest.cpp from Bazel and CMake files.

But should we do more, to prevent users from using Generator.h when compiling with Clang-15, adding like the following to the very top of Generator.h:

#if defined(__clang__)
#if __clang_major__ == 15
#error "Clang 15 is not supported due to some issues."
#endif
#endif

[ChuanqiXu9]

@ChuanqiXu9 I think solution is to conditionally remove GeneratorTest.cpp from Bazel and CMake files.

But should we do more, to prevent users from using Generator.h when compiling with Clang-15, adding like the following to the very top of Generator.h:

#if defined(__clang__)
#if __clang_major__ == 15
#error "Clang 15 is not supported due to some issues."
#endif
#endif

It sounds good. Maybe a #warning is better.