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[docs][clang-tidy] Correct StrictMode example in modernize-use-std-print #2

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@MainakSil MainakSil commented Sep 15, 2024

Updated the example in the StrictMode section of the clang-tidy check modernize-use-std-print.

The previous example incorrectly swapped the cast of signed and unsigned integers. Specifically:

  • The signed integer i was being cast to unsigned int, and
  • The unsigned integer u was being cast to int.

This correction ensures that the behavior of std::print with StrictMode enabled matches that of printf, by reversing the casts to maintain the correct signedness.

Issue Refference
It solves #llvm#101397

@MainakSil MainakSil closed this Sep 16, 2024
MainakSil pushed a commit that referenced this pull request Sep 16, 2024
When SPARC Asan testing is enabled by PR llvm#107405, many Linux/sparc64
tests just hang like
```
#0  0xf7ae8e90 in syscall () from /usr/lib32/libc.so.6
#1  0x701065e8 in __sanitizer::FutexWait(__sanitizer::atomic_uint32_t*, unsigned int) ()
    at compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp:766
#2  0x70107c90 in Wait ()
    at compiler-rt/lib/sanitizer_common/sanitizer_mutex.cpp:35
#3  0x700f7cac in Lock ()
    at compiler-rt/lib/asan/../sanitizer_common/sanitizer_mutex.h:196
llvm#4  Lock ()
    at compiler-rt/lib/asan/../sanitizer_common/sanitizer_thread_registry.h:98
llvm#5  LockThreads ()
    at compiler-rt/lib/asan/asan_thread.cpp:489
llvm#6  0x700e9c8c in __asan::BeforeFork() ()
    at compiler-rt/lib/asan/asan_posix.cpp:157
llvm#7  0xf7ac83f4 in ?? () from /usr/lib32/libc.so.6
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
```
It turns out that this happens in tests using `internal_fork` (e.g.
invoking `llvm-symbolizer`): unlike most other Linux targets, which use
`clone`, Linux/sparc64 has to use `__fork` instead. While `clone`
doesn't trigger `pthread_atfork` handlers, `__fork` obviously does,
causing the hang.

To avoid this, this patch disables `InstallAtForkHandler` and lets the
ASan tests run to completion.

Tested on `sparc64-unknown-linux-gnu`.
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