[clang-cl] The `[[noreturn]]` attribute causes parsing to crash by declaring a concurrent function that returns. #127327

YuHuanTin · 2025-02-15T14:25:28Z

D:\LLVM\bin\clang-cl.exe   -TP -DCRCPP_IMPORT_API -imsvcD:\Clion\vcpkg\installed\x64-windows\include /DWIN32 /D_WINDOWS /EHsc /Ob0 /Od /RTC1 -std:c++latest -MDd -Zi /clang:-Wall -Wextra -Wpedantic -Wconversion /permissive- /showIncludes /FoCMakeFiles\New.dir\main.cpp.obj /FdCMakeFiles\New.dir\ -c -- D:\Clion\Project\New\main.cpp
D:\Clion\Project\New\main.cpp(7,41): warning: function 'foo' declared 'noreturn' should not return [-Winvalid-noreturn]
    7 | [[noreturn]] concurrencpp::result<void> foo() {
      |                                         ^
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.	Program arguments: D:\\LLVM\\bin\\clang-cl.exe -TP -DCRCPP_IMPORT_API -imsvcD:\\Clion\\vcpkg\\installed\\x64-windows\\include /DWIN32 /D_WINDOWS /EHsc /Ob0 /Od /RTC1 -std:c++latest -MDd -Zi /clang:-Wall -Wextra -Wpedantic -Wconversion /permissive- /showIncludes /FoCMakeFiles\\New.dir\\main.cpp.obj /FdCMakeFiles\\New.dir\\ -c -- D:\\Clion\\Project\\New\\main.cpp
1.	<eof> parser at end of file
2.	D:\Clion\Project\New\main.cpp:7:47: parsing function body 'foo'
Exception Code: 0xC0000005
 #0 0x00007ff7e22fcd44 (D:\LLVM\bin\clang-cl.exe+0x77cd44)
 #1 0x00007ff7e22fcb30 (D:\LLVM\bin\clang-cl.exe+0x77cb30)
 #2 0x00007ff7e3a2cf6f (D:\LLVM\bin\clang-cl.exe+0x1eacf6f)
 #3 0x00007ff7e2c95037 (D:\LLVM\bin\clang-cl.exe+0x1115037)
 #4 0x00007ff7e2c9433a (D:\LLVM\bin\clang-cl.exe+0x111433a)
 #5 0x00007ff7e2c93e83 (D:\LLVM\bin\clang-cl.exe+0x1113e83)
 #6 0x00007ff7e2c90eb5 (D:\LLVM\bin\clang-cl.exe+0x1110eb5)
 #7 0x00007ff7e2c90e2a (D:\LLVM\bin\clang-cl.exe+0x1110e2a)
 #8 0x00007ff7e2d41fa8 (D:\LLVM\bin\clang-cl.exe+0x11c1fa8)
 #9 0x00007ff7e2c82167 (D:\LLVM\bin\clang-cl.exe+0x1102167)
#10 0x00007ff7e2c7f6b4 (D:\LLVM\bin\clang-cl.exe+0x10ff6b4)
#11 0x00007ff7e2c76d59 (D:\LLVM\bin\clang-cl.exe+0x10f6d59)
#12 0x00007ff7e2ae8ea5 (D:\LLVM\bin\clang-cl.exe+0xf68ea5)
#13 0x00007ff7e2ae0c12 (D:\LLVM\bin\clang-cl.exe+0xf60c12)
#14 0x00007ff7e2add88a (D:\LLVM\bin\clang-cl.exe+0xf5d88a)
#15 0x00007ff7e36e09e6 (D:\LLVM\bin\clang-cl.exe+0x1b609e6)
#16 0x00007ff7e36e064e (D:\LLVM\bin\clang-cl.exe+0x1b6064e)
#17 0x00007ff7e2143a61 (D:\LLVM\bin\clang-cl.exe+0x5c3a61)
#18 0x00007ff7e21435f2 (D:\LLVM\bin\clang-cl.exe+0x5c35f2)
#19 0x00007ff7e2140366 (D:\LLVM\bin\clang-cl.exe+0x5c0366)
#20 0x00007ff7e213d325 (D:\LLVM\bin\clang-cl.exe+0x5bd325)
#21 0x00007ff7e213bcbe (D:\LLVM\bin\clang-cl.exe+0x5bbcbe)
#22 0x00007ff7e28555cd (D:\LLVM\bin\clang-cl.exe+0xcd55cd)
#23 0x00007ff7e22c4175 (D:\LLVM\bin\clang-cl.exe+0x744175)
#24 0x00007ff7e22c3f68 (D:\LLVM\bin\clang-cl.exe+0x743f68)
#25 0x00007ff7e1fcc0c8 (D:\LLVM\bin\clang-cl.exe+0x44c0c8)
#26 0x00007ff7e1fcb44e (D:\LLVM\bin\clang-cl.exe+0x44b44e)
#27 0x00007ff7e1fcafc7 (D:\LLVM\bin\clang-cl.exe+0x44afc7)
#28 0x00007ff7e1fc2756 (D:\LLVM\bin\clang-cl.exe+0x442756)
#29 0x00007ff7e1fbfed3 (D:\LLVM\bin\clang-cl.exe+0x43fed3)
#30 0x00007ff7e3782bc8 (D:\LLVM\bin\clang-cl.exe+0x1c02bc8)
#31 0x00007ffbdf6b7374 (C:\Windows\System32\KERNEL32.DLL+0x17374)
#32 0x00007ffbe135cc91 (C:\Windows\SYSTEM32\ntdll.dll+0x4cc91)
clang-cl: error: clang frontend command failed due to signal (use -v to see invocation)
clang version 19.1.7
Target: x86_64-pc-windows-msvc
Thread model: posix
InstalledDir: D:\LLVM\bin
clang-cl: note: diagnostic msg: 
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang-cl: note: diagnostic msg: F:\Temp\WinTemp\main-efd334.cpp
clang-cl: note: diagnostic msg: F:\Temp\WinTemp\main-efd334.sh
clang-cl: note: diagnostic msg: 

********************
ninja: build stopped: subcommand failed.

The full code

#include <concurrencpp/concurrencpp.h>

concurrencpp::result<void> bar() {
    co_return;
}

[[noreturn]] concurrencpp::result<void> foo() {
    co_await bar();
}

Yes, I know it's a bad practice to flag [[noreturn]] on a function that might return, but it should get a warn or error, but the compiler crashes

the crash file

crash.zip

The text was updated successfully, but these errors were encountered:

Nerixyz · 2025-02-16T21:40:41Z

Reduced to

namespace std {
template <class = void> struct coroutine_handle {
  static constexpr coroutine_handle from_address(void *const) noexcept {
    return {};
  }
  constexpr operator coroutine_handle<>() const noexcept { return {}; }
};

struct suspend_always {
  bool await_ready() noexcept { return false; }
  void await_suspend(coroutine_handle<>) noexcept {}
  void await_resume() noexcept {}
};

template <class _Ret, class...>
struct coroutine_traits {
    using promise_type = typename _Ret::promise_type;
};
} // namespace std

struct promise;

struct awaitable {
  bool await_ready() { return false; }
  void await_suspend(std::coroutine_handle<>) {}
  void await_resume() {}
};

struct coroutine : std::coroutine_handle<> {
  using promise_type = promise;
};

struct promise {
  coroutine get_return_object() { return {}; }
  std::suspend_always initial_suspend() noexcept { return {}; }
  std::suspend_always final_suspend() noexcept { return {}; }
  void return_void() {}
  void unhandled_exception() {}
};

[[noreturn]] coroutine f() { co_await awaitable{}; }

Coroutines don't have diagnostic IDs set when CheckFallThroughForBody is called, which then tries to emit diag_AlwaysFallThrough_HasNoReturn.

A simple fix would be to use the same diagnostics as for functions. This would, however, generate two warnings:

main.cpp(41,24): warning: function 'f' declared 'noreturn' should not return [-Winvalid-noreturn]
   41 | [[noreturn]] coroutine f() { co_await awaitable{}; }
      |                        ^
main.cpp(41,52): warning: function declared 'noreturn' should not return [-Winvalid-noreturn]
   41 | [[noreturn]] coroutine f() { co_await awaitable{}; }
      |                                                    ^
2 warnings generated.

The first warning, also visible in the current output, is emitted when building the return statement, which discovers that the function is [[noreturn]].

I'd fix this, but would like to know if there is any preference for the diagnostic (i.e. should it be omitted or more descriptive - in this case we know that the function is a coroutine).

llvmbot · 2025-02-18T05:53:46Z

@llvm/issue-subscribers-clang-frontend

Author: YuHuanTin (YuHuanTin)

``` D:\LLVM\bin\clang-cl.exe -TP -DCRCPP_IMPORT_API -imsvcD:\Clion\vcpkg\installed\x64-windows\include /DWIN32 /D_WINDOWS /EHsc /Ob0 /Od /RTC1 -std:c++latest -MDd -Zi /clang:-Wall -Wextra -Wpedantic -Wconversion /permissive- /showIncludes /FoCMakeFiles\New.dir\main.cpp.obj /FdCMakeFiles\New.dir\ -c -- D:\Clion\Project\New\main.cpp D:\Clion\Project\New\main.cpp(7,41): warning: function 'foo' declared 'noreturn' should not return [-Winvalid-noreturn] 7 | [[noreturn]] concurrencpp::result<void> foo() { | ^ PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script. Stack dump: 0. Program arguments: D:\\LLVM\\bin\\clang-cl.exe -TP -DCRCPP_IMPORT_API -imsvcD:\\Clion\\vcpkg\\installed\\x64-windows\\include /DWIN32 /D_WINDOWS /EHsc /Ob0 /Od /RTC1 -std:c++latest -MDd -Zi /clang:-Wall -Wextra -Wpedantic -Wconversion /permissive- /showIncludes /FoCMakeFiles\\New.dir\\main.cpp.obj /FdCMakeFiles\\New.dir\\ -c -- D:\\Clion\\Project\\New\\main.cpp 1. <eof> parser at end of file 2. D:\Clion\Project\New\main.cpp:7:47: parsing function body 'foo' Exception Code: 0xC0000005 #0 0x00007ff7e22fcd44 (D:\LLVM\bin\clang-cl.exe+0x77cd44) #1 0x00007ff7e22fcb30 (D:\LLVM\bin\clang-cl.exe+0x77cb30) #2 0x00007ff7e3a2cf6f (D:\LLVM\bin\clang-cl.exe+0x1eacf6f) #3 0x00007ff7e2c95037 (D:\LLVM\bin\clang-cl.exe+0x1115037) #4 0x00007ff7e2c9433a (D:\LLVM\bin\clang-cl.exe+0x111433a) #5 0x00007ff7e2c93e83 (D:\LLVM\bin\clang-cl.exe+0x1113e83) #6 0x00007ff7e2c90eb5 (D:\LLVM\bin\clang-cl.exe+0x1110eb5) #7 0x00007ff7e2c90e2a (D:\LLVM\bin\clang-cl.exe+0x1110e2a) #8 0x00007ff7e2d41fa8 (D:\LLVM\bin\clang-cl.exe+0x11c1fa8) #9 0x00007ff7e2c82167 (D:\LLVM\bin\clang-cl.exe+0x1102167) #10 0x00007ff7e2c7f6b4 (D:\LLVM\bin\clang-cl.exe+0x10ff6b4) #11 0x00007ff7e2c76d59 (D:\LLVM\bin\clang-cl.exe+0x10f6d59) #12 0x00007ff7e2ae8ea5 (D:\LLVM\bin\clang-cl.exe+0xf68ea5) #13 0x00007ff7e2ae0c12 (D:\LLVM\bin\clang-cl.exe+0xf60c12) #14 0x00007ff7e2add88a (D:\LLVM\bin\clang-cl.exe+0xf5d88a) #15 0x00007ff7e36e09e6 (D:\LLVM\bin\clang-cl.exe+0x1b609e6) #16 0x00007ff7e36e064e (D:\LLVM\bin\clang-cl.exe+0x1b6064e) #17 0x00007ff7e2143a61 (D:\LLVM\bin\clang-cl.exe+0x5c3a61) #18 0x00007ff7e21435f2 (D:\LLVM\bin\clang-cl.exe+0x5c35f2) #19 0x00007ff7e2140366 (D:\LLVM\bin\clang-cl.exe+0x5c0366) #20 0x00007ff7e213d325 (D:\LLVM\bin\clang-cl.exe+0x5bd325) #21 0x00007ff7e213bcbe (D:\LLVM\bin\clang-cl.exe+0x5bbcbe) #22 0x00007ff7e28555cd (D:\LLVM\bin\clang-cl.exe+0xcd55cd) #23 0x00007ff7e22c4175 (D:\LLVM\bin\clang-cl.exe+0x744175) #24 0x00007ff7e22c3f68 (D:\LLVM\bin\clang-cl.exe+0x743f68) #25 0x00007ff7e1fcc0c8 (D:\LLVM\bin\clang-cl.exe+0x44c0c8) #26 0x00007ff7e1fcb44e (D:\LLVM\bin\clang-cl.exe+0x44b44e) #27 0x00007ff7e1fcafc7 (D:\LLVM\bin\clang-cl.exe+0x44afc7) #28 0x00007ff7e1fc2756 (D:\LLVM\bin\clang-cl.exe+0x442756) #29 0x00007ff7e1fbfed3 (D:\LLVM\bin\clang-cl.exe+0x43fed3) #30 0x00007ff7e3782bc8 (D:\LLVM\bin\clang-cl.exe+0x1c02bc8) #31 0x00007ffbdf6b7374 (C:\Windows\System32\KERNEL32.DLL+0x17374) #32 0x00007ffbe135cc91 (C:\Windows\SYSTEM32\ntdll.dll+0x4cc91) clang-cl: error: clang frontend command failed due to signal (use -v to see invocation) clang version 19.1.7 Target: x86_64-pc-windows-msvc Thread model: posix InstalledDir: D:\LLVM\bin clang-cl: note: diagnostic msg: ********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang-cl: note: diagnostic msg: F:\Temp\WinTemp\main-efd334.cpp
clang-cl: note: diagnostic msg: F:\Temp\WinTemp\main-efd334.sh
clang-cl: note: diagnostic msg:

ninja: build stopped: subcommand failed.


The full code
```c++
#include &lt;concurrencpp/concurrencpp.h&gt;

concurrencpp::result&lt;void&gt; bar() {
    co_return;
}

[[noreturn]] concurrencpp::result&lt;void&gt; foo() {
    co_await bar();
}

Yes, I know it's a bad practice to flag [[noreturn]] on a function that might return, but it should get a warn or error, but the compiler crashes

the crash file

crash.zip

llvmbot · 2025-02-18T05:53:49Z

@llvm/issue-subscribers-coroutines

Author: YuHuanTin (YuHuanTin)

``` D:\LLVM\bin\clang-cl.exe -TP -DCRCPP_IMPORT_API -imsvcD:\Clion\vcpkg\installed\x64-windows\include /DWIN32 /D_WINDOWS /EHsc /Ob0 /Od /RTC1 -std:c++latest -MDd -Zi /clang:-Wall -Wextra -Wpedantic -Wconversion /permissive- /showIncludes /FoCMakeFiles\New.dir\main.cpp.obj /FdCMakeFiles\New.dir\ -c -- D:\Clion\Project\New\main.cpp D:\Clion\Project\New\main.cpp(7,41): warning: function 'foo' declared 'noreturn' should not return [-Winvalid-noreturn] 7 | [[noreturn]] concurrencpp::result<void> foo() { | ^ PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script. Stack dump: 0. Program arguments: D:\\LLVM\\bin\\clang-cl.exe -TP -DCRCPP_IMPORT_API -imsvcD:\\Clion\\vcpkg\\installed\\x64-windows\\include /DWIN32 /D_WINDOWS /EHsc /Ob0 /Od /RTC1 -std:c++latest -MDd -Zi /clang:-Wall -Wextra -Wpedantic -Wconversion /permissive- /showIncludes /FoCMakeFiles\\New.dir\\main.cpp.obj /FdCMakeFiles\\New.dir\\ -c -- D:\\Clion\\Project\\New\\main.cpp 1. <eof> parser at end of file 2. D:\Clion\Project\New\main.cpp:7:47: parsing function body 'foo' Exception Code: 0xC0000005 #0 0x00007ff7e22fcd44 (D:\LLVM\bin\clang-cl.exe+0x77cd44) #1 0x00007ff7e22fcb30 (D:\LLVM\bin\clang-cl.exe+0x77cb30) #2 0x00007ff7e3a2cf6f (D:\LLVM\bin\clang-cl.exe+0x1eacf6f) #3 0x00007ff7e2c95037 (D:\LLVM\bin\clang-cl.exe+0x1115037) #4 0x00007ff7e2c9433a (D:\LLVM\bin\clang-cl.exe+0x111433a) #5 0x00007ff7e2c93e83 (D:\LLVM\bin\clang-cl.exe+0x1113e83) #6 0x00007ff7e2c90eb5 (D:\LLVM\bin\clang-cl.exe+0x1110eb5) #7 0x00007ff7e2c90e2a (D:\LLVM\bin\clang-cl.exe+0x1110e2a) #8 0x00007ff7e2d41fa8 (D:\LLVM\bin\clang-cl.exe+0x11c1fa8) #9 0x00007ff7e2c82167 (D:\LLVM\bin\clang-cl.exe+0x1102167) #10 0x00007ff7e2c7f6b4 (D:\LLVM\bin\clang-cl.exe+0x10ff6b4) #11 0x00007ff7e2c76d59 (D:\LLVM\bin\clang-cl.exe+0x10f6d59) #12 0x00007ff7e2ae8ea5 (D:\LLVM\bin\clang-cl.exe+0xf68ea5) #13 0x00007ff7e2ae0c12 (D:\LLVM\bin\clang-cl.exe+0xf60c12) #14 0x00007ff7e2add88a (D:\LLVM\bin\clang-cl.exe+0xf5d88a) #15 0x00007ff7e36e09e6 (D:\LLVM\bin\clang-cl.exe+0x1b609e6) #16 0x00007ff7e36e064e (D:\LLVM\bin\clang-cl.exe+0x1b6064e) #17 0x00007ff7e2143a61 (D:\LLVM\bin\clang-cl.exe+0x5c3a61) #18 0x00007ff7e21435f2 (D:\LLVM\bin\clang-cl.exe+0x5c35f2) #19 0x00007ff7e2140366 (D:\LLVM\bin\clang-cl.exe+0x5c0366) #20 0x00007ff7e213d325 (D:\LLVM\bin\clang-cl.exe+0x5bd325) #21 0x00007ff7e213bcbe (D:\LLVM\bin\clang-cl.exe+0x5bbcbe) #22 0x00007ff7e28555cd (D:\LLVM\bin\clang-cl.exe+0xcd55cd) #23 0x00007ff7e22c4175 (D:\LLVM\bin\clang-cl.exe+0x744175) #24 0x00007ff7e22c3f68 (D:\LLVM\bin\clang-cl.exe+0x743f68) #25 0x00007ff7e1fcc0c8 (D:\LLVM\bin\clang-cl.exe+0x44c0c8) #26 0x00007ff7e1fcb44e (D:\LLVM\bin\clang-cl.exe+0x44b44e) #27 0x00007ff7e1fcafc7 (D:\LLVM\bin\clang-cl.exe+0x44afc7) #28 0x00007ff7e1fc2756 (D:\LLVM\bin\clang-cl.exe+0x442756) #29 0x00007ff7e1fbfed3 (D:\LLVM\bin\clang-cl.exe+0x43fed3) #30 0x00007ff7e3782bc8 (D:\LLVM\bin\clang-cl.exe+0x1c02bc8) #31 0x00007ffbdf6b7374 (C:\Windows\System32\KERNEL32.DLL+0x17374) #32 0x00007ffbe135cc91 (C:\Windows\SYSTEM32\ntdll.dll+0x4cc91) clang-cl: error: clang frontend command failed due to signal (use -v to see invocation) clang version 19.1.7 Target: x86_64-pc-windows-msvc Thread model: posix InstalledDir: D:\LLVM\bin clang-cl: note: diagnostic msg: ********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang-cl: note: diagnostic msg: F:\Temp\WinTemp\main-efd334.cpp
clang-cl: note: diagnostic msg: F:\Temp\WinTemp\main-efd334.sh
clang-cl: note: diagnostic msg:

ninja: build stopped: subcommand failed.


The full code
```c++
#include &lt;concurrencpp/concurrencpp.h&gt;

concurrencpp::result&lt;void&gt; bar() {
    co_return;
}

[[noreturn]] concurrencpp::result&lt;void&gt; foo() {
    co_await bar();
}

Yes, I know it's a bad practice to flag [[noreturn]] on a function that might return, but it should get a warn or error, but the compiler crashes

the crash file

crash.zip

Declaring a coroutine `[[noreturn]]` doesn't make sense, because it will always return its handle. Clang previously crashed when trying to warn about this (diagnostic ID was 0). Fixes llvm#127327.

llvmbot added the new issue label Feb 15, 2025

EugeneZelenko added clang-cl `clang-cl` driver. Don't use for other compiler parts crash Prefer [crash-on-valid] or [crash-on-invalid] and removed new issue labels Feb 15, 2025

Nerixyz mentioned this issue Feb 18, 2025

[Clang] Warn about [[noreturn]] on coroutines #127623

Merged

Sirraide closed this as completed in db5bc8e Feb 18, 2025

Sirraide closed this as completed in #127623 Feb 18, 2025

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Uh oh!

[clang-cl] The `[[noreturn]]` attribute causes parsing to crash by declaring a concurrent function that returns. #127327

[clang-cl] The `[[noreturn]]` attribute causes parsing to crash by declaring a concurrent function that returns. #127327

YuHuanTin commented Feb 15, 2025

Nerixyz commented Feb 16, 2025

Uh oh!

llvmbot commented Feb 18, 2025

Uh oh!

llvmbot commented Feb 18, 2025

Uh oh!

[clang-cl] The [[noreturn]] attribute causes parsing to crash by declaring a concurrent function that returns. #127327

[clang-cl] The [[noreturn]] attribute causes parsing to crash by declaring a concurrent function that returns. #127327

Comments

YuHuanTin commented Feb 15, 2025

Nerixyz commented Feb 16, 2025

Uh oh!

llvmbot commented Feb 18, 2025

Uh oh!

llvmbot commented Feb 18, 2025

Uh oh!

[clang-cl] The `[[noreturn]]` attribute causes parsing to crash by declaring a concurrent function that returns. #127327

[clang-cl] The `[[noreturn]]` attribute causes parsing to crash by declaring a concurrent function that returns. #127327