<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Issue</th>
<td>
<a href=https://github.com/llvm/llvm-project/issues/56507>56507</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>
clang 14.0.5 i686-pc-windows-msvc `<coroutine>` ICE: failed to perform tail call elimination on a call site marked musttail
</td>
</tr>
<tr>
<th>Labels</th>
<td>
new issue
</td>
</tr>
<tr>
<th>Assignees</th>
<td>
</td>
</tr>
<tr>
<th>Reporter</th>
<td>
StephanTLavavej
</td>
</tr>
</table>
<pre>
Repros with VS 2022 17.3 Preview 3 containing Clang 14.0.5.
:warning: This is specific to **32-bit x86**. :warning:
```
C:\Temp>"C:\Program Files\Microsoft Visual Studio\2022\Preview\VC\Auxiliary\Build\vcvars32.bat"
**********************************************************************
** Visual Studio 2022 Developer Command Prompt v17.3.0-pre.3.0
** Copyright (c) 2022 Microsoft Corporation
**********************************************************************
[vcvarsall.bat] Environment initialized for: 'x86'
C:\Temp>type test.cpp
```
```cpp
// Copyright (c) Microsoft Corporation.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include <cassert>
#include <coroutine>
#include <cstdio>
#include <exception>
using namespace std;
int g_tasks_destroyed{0};
struct Task {
struct Promise {
int result{-1000};
coroutine_handle<> previous;
Task get_return_object() {
return Task{*this};
}
suspend_always initial_suspend() {
return {};
}
auto final_suspend() noexcept {
struct Awaiter {
bool await_ready() noexcept {
return false;
}
void await_resume() noexcept {}
coroutine_handle<> await_suspend(coroutine_handle<Promise> h) noexcept {
auto& pre = h.promise().previous;
if (pre) {
return pre; // resume awaiting coroutine
}
// If there is no previous coroutine to resume, we've reached the outermost coroutine.
// Return a noop coroutine to allow control to return back to the caller.
return noop_coroutine();
}
};
return Awaiter{};
}
void return_value(const int v) {
result = v;
}
void unhandled_exception() noexcept {
terminate();
}
};
using promise_type = Promise;
bool await_ready() const noexcept {
return false;
}
int await_resume() {
return coro.promise().result;
}
auto await_suspend(coroutine_handle<> enclosing) {
coro.promise().previous = enclosing;
return coro; // resume ourselves
}
Task(Task&& rhs) noexcept : coro(rhs.coro) {
rhs.coro = nullptr;
}
explicit Task(Promise& p) : coro(coroutine_handle<Promise>::from_promise(p)) {}
~Task() {
++g_tasks_destroyed;
if (coro) {
coro.destroy();
}
}
coroutine_handle<Promise> coro;
};
Task triangular_number(const int n) {
if (n == 0) {
co_return 0;
}
co_return n + co_await triangular_number(n - 1);
}
int main() {
assert(g_tasks_destroyed == 0);
{
Task t = triangular_number(10);
coroutine_handle<> h = t.coro;
assert(h == t.coro);
assert(h);
assert(!h.done());
h();
assert(h == t.coro);
assert(h);
assert(h.done());
assert(g_tasks_destroyed == 10); // triangular_number() called for [0, 9]
const int val = t.coro.promise().result;
assert(val == 55);
}
assert(g_tasks_destroyed == 11); // triangular_number() called for [0, 10]
puts("Done!");
}
```
```
C:\Temp>cl /EHsc /nologo /W4 /MTd /std:c++20 test.cpp && test.exe
test.cpp
Done!
C:\Temp>clang-cl /EHsc /nologo /W4 /MTd /std:c++20 test.cpp && test.exe
fatal error: error in backend: failed to perform tail call elimination on a call site marked musttail
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: "C:\\Program Files\\Microsoft Visual Studio\\2022\\Preview\\VC\\Tools\\Llvm\\bin\\clang-cl.exe" -cc1 -triple i686-pc-windows-msvc19.33.31627 -emit-obj -mrelax-all -mincremental-linker-compatible --mrelax-relocations -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name test.cpp -mrelocation-model static -mframe-pointer=all -relaxed-aliasing -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -target-cpu pentium4 -mllvm -x86-asm-syntax=intel -tune-cpu generic -mllvm -treat-scalable-fixed-error-as-warning -D_DEBUG -D_MT -flto-visibility-public-std --dependent-lib=libcmtd --dependent-lib=oldnames -stack-protector 2 -fcxx-exceptions -fexceptions -fexternc-nounwind -fms-volatile -fdiagnostics-format msvc -fcoverage-compilation-dir=C:\\Temp -resource-dir "C:\\Program Files\\Microsoft Visual Studio\\2022\\Preview\\VC\\Tools\\Llvm\\lib\\clang\\14.0.5" -c-isystem C:\\MinGW\\include -c-isystem C:\\MinGW\\include\\freetype2 -cxx-isystem C:\\MinGW\\include -cxx-isystem C:\\MinGW\\include\\freetype2 -internal-isystem "C:\\Program Files\\Microsoft Visual Studio\\2022\\Preview\\VC\\Tools\\Llvm\\lib\\clang\\14.0.5\\include" -internal-isystem "C:\\Program Files\\Microsoft Visual Studio\\2022\\Preview\\VC\\Tools\\MSVC\\14.33.31627\\include" -internal-isystem "C:\\Program Files\\Microsoft Visual Studio\\2022\\Preview\\VC\\Auxiliary\\VS\\include" -internal-isystem "C:\\Program Files (x86)\\Windows Kits\\10\\include\\10.0.22000.0\\ucrt" -internal-isystem "C:\\Program Files (x86)\\Windows Kits\\10\\\\include\\10.0.22000.0\\\\um" -internal-isystem "C:\\Program Files (x86)\\Windows Kits\\10\\\\include\\10.0.22000.0\\\\shared" -internal-isystem "C:\\Program Files (x86)\\Windows Kits\\10\\\\include\\10.0.22000.0\\\\winrt" -internal-isystem "C:\\Program Files (x86)\\Windows Kits\\10\\\\include\\10.0.22000.0\\\\cppwinrt" -internal-isystem "C:\\Program Files\\Microsoft Visual Studio\\2022\\Preview\\VC\\Tools\\MSVC\\14.33.31627\\include" -internal-isystem "C:\\Program Files\\Microsoft Visual Studio\\2022\\Preview\\VC\\Auxiliary\\VS\\include" -internal-isystem "C:\\Program Files (x86)\\Windows Kits\\10\\include\\10.0.22000.0\\ucrt" -internal-isystem "C:\\Program Files (x86)\\Windows Kits\\10\\\\include\\10.0.22000.0\\\\um" -internal-isystem "C:\\Program Files (x86)\\Windows Kits\\10\\\\include\\10.0.22000.0\\\\shared" -internal-isystem "C:\\Program Files (x86)\\Windows Kits\\10\\\\include\\10.0.22000.0\\\\winrt" -internal-isystem "C:\\Program Files (x86)\\Windows Kits\\10\\\\include\\10.0.22000.0\\\\cppwinrt" -WCL4 -fdeprecated-macro -fdebug-compilation-dir=C:\\Temp -ferror-limit 19 -fmessage-length=120 -fno-use-cxa-atexit -fms-extensions -fms-compatibility -fms-compatibility-version=19.33.31627 -std=c++20 -fdelayed-template-parsing -fno-implicit-modules -fcolor-diagnostics -faddrsig -o C:\\Users\\stl\\AppData\\Local\\Temp\\test-792971.obj -x c++ test.cpp
1. <eof> parser at end of file
2. Code generation
3. Running pass 'Function Pass Manager' on module 'test.cpp'.
4. Running pass 'X86 DAG->DAG Instruction Selection' on function '@"?triangular_number@@YA?AUTask@@H@Z.resume"'
clang-cl: error: clang frontend command failed with exit code 70 (use -v to see invocation)
clang version 14.0.5
Target: i686-pc-windows-msvc
Thread model: posix
InstalledDir: C:\Program Files\Microsoft Visual Studio\2022\Preview\VC\Tools\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: C:\Users\stl\AppData\Local\Temp\test-67198e.cpp
clang-cl: note: diagnostic msg: C:\Users\stl\AppData\Local\Temp\test-67198e.sh
clang-cl: note: diagnostic msg:
********************
```
This test case was slightly reduced from https://github.com/microsoft/STL/blob/969b2e250df56690768fdf8344293624d6ab0d6c/tests/std/tests/P0912R5_coroutine/test.cpp .
Here's a zip of the original source, preprocessed source, and run script: [repro.zip](https://github.com/llvm/llvm-project/files/9099979/repro.zip)
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJztWllz2zgS_jXyCwoqirIk68EPsmQnrnU2rthJZvfFBZGghAmvAkBZnl-_X4OkqIOylZnJTmpqVDYPHN2NvtDdxDwLXy4_yVxnhj0ru2RfHpjv-T7rjbp9dq_lSsln1mdBllqhUpUu2DQWuPbOu1530O14s443qa79ybPQNAZP7HGpDMOfyWWgIhUwm7GOP8Ff3-dzZdn6Yli-d9nOzB2QQ6_6c69T6h5MH2WSd_rXHd-vGu51ttAiYTcqlgbvH1SABWWRZV-UKUTMHmwRqgw9tDY3wS0MT1-muEyKtYqV0C94vipUHOK-ClZCm77fnQsLTBU9_t_ub2tdu9wq9WAmVzLOcqnZNEsSkYZQiizJLVuRhnQ9nmtJ9x040yx_0WqxtJD4RdDxxyWsRizTTOeZFlZl6d-csYOrUpFEHDtNGszYdbpSOksTmVoGk7JKxOo3GbIo02Q4HX_kTGO0bQi7mm9fcsmsNLYb5HmrpWxemwH-Df5aRNMqle7OpIf72S_8TgUyNZLfhiAcFi0dtZNcBEvJ_a7Hvt4-vmd3d18-cLkOZL4l3ApWX6VBXIQS9j4NhDFSWzLjtt5MZ4VVqTzWbyzZc3tng73uLww5rlQk0oBcyTC707_aJk5BFosnK8w38xSCsTp7kWFndOV1RrO9oegsAsseMZZhRNnI8Ks6yD6Ukbt99CMcWpoitujiPc_bAV6P2iz9aQlri8EByP6a5eSxssLsEVPPctQspH3S0hY6fcrmv8oAfuuCJHxACf3KgW4i9fsTC4fdRhC1tWA0BTx7Gj6J-Fm8mFqRn6rmEzBT3-noRIH9I1LpAYo0K-XdjquSCbYXZeHDWsfQb55lMRM0ChwU4ctJwPcWFInYyIP1vLGu-rfKVLghwBSJbKPgdRBHNKcE2jCtZVilsjR6efqySSQdf0iqCbObsWU3r-A40rsHKtsGREXkiDD0qLq0cJqG969Y5Z1KfpXrJDtvnMdRWG9w0g0pgd9GzC4lVohQJs02ZtggobimltiUPeM6Wkm0kFsMaS7DOKmTzNhmUvdNvJ_KlQogzfJdbNhKsmcXkWkorUPvxs5F8I1eCWeAQVK_gqaaQ9CfGoY5wb2twvuN7T5pC01lf99n8s4kKn-2EnEhnfKmxjpPunrFv5CPdSq5-i5cRVpaRPjUbCGn-AESLzyTPca_Hb6186vcoSr7eXL7O9G_McyDCUccVsmf4-QedVUtfCEut3ikYzBJi_Y8QLXbvYHHufYTvBS5J4ltPiNetVLSQsLGYImdzex9EW2t4dCzZIU2Ml4htXhtGW4n9S_K25Aco16aXeVBvOQw-Bfo6paPbQytOh3NaRHHudVvMVGu81gFytZk1JpD_tkhaXC_ugFQnNmfRHh_ahhJEGpKD1F3RtcV0tbVdHxEF1eHwVW70yj3g6Os2Ui5gnOqxe1hen0PrLSgmnRgry7WslohDS5ioZ_SIpnDt207p_SA-HJdKYmUpOod0d8qfkP_G_JuhqbEYXp3JtRKWMo4623zaQ8gkZwgvW8TYRWn-xcHEtxeS4s0D1ZX8o3t_ghAG8k9r02uR7zCsgTT3RXcbvxYL2NZk21rAzzA0ox9tbfj95bdMNtsm61coN9yT0t_OGWnkfW2ZGsh1P6wTVBu16FowyWwDAmvR4HQGJluG9KtDVzEW2J7fec4QngFgqAMBvscadtp3l5x73evGMw6XHJeWOOm-DMnkR6VkloN8Uj-Xr7upv9BTORdvzcB3dMszhZUW7v5ek7XD48h3VyOOwlK7-t7m3IBqzYn9y7XVZC8W0yoad1azD4F4Ar_AXREwkKmUuuyFuIeoC0utqXAAG2RUMR6xAy51BBAwixanESYjJWLxBC5sYyiZ9dqEHvCv-lvmJYUxtL4Et393fXk4Rq57DyB6xRsXiyw6eeZtgR_aW1uaN1OFxbKLos5lDXBSxyv6huH5pbJ9o0ypkCUAL2hQlldknDxuBZm6VZhtQhcqoDIBDMDCZ0MmUGMUTbTTOhpFigElIh_i5SZQKvcVsH8g6UwPyxIDpVsvG5pF3UZVOhFQdUlU5aT6ippS6H01VppUy7dqZjWRVPSBgShFZg7Yoh7mmMfcQ-1kjjp-j7jQdBjHBaVx0inhhdDngf8WaVh9mx4YlZBb9zt97v93tAfMS4hEZ7Nf2U80TIWa06S5JBuoCUtTsQ8Vuk3qTkkkkPkc0Dl9WBcs8DpgWE8VEagl0daYkgQS6G5MJbPJdRH8kq3mnFOqiupXZHLNQdCh9zlINxVkUAItksegY2uodFqR0CFmidZKKF-Fm8BeiKwXvI8g_ej4tnMrcjRK0MsTwmXBPAoEXbJofrIN3kU5dylegIa1odhoinNOLbBNMRoTmMB2rlVKnVkuoRENFoogrQ8yAuYSmpVkZxjKK2O8TXYL0zCzQtYuQZkIgrk2CKVbsZCpuBAsJlgkWZYDk7EJS8VEe3sE3B4Vb5nfPY0u776_I4ePjyC1thmfKWMmqtY2ReeF3OEqRxOAbIKJQX7oAySnIMEXIOktSeLw4rvhtSfTM5KWiyDWkXBet2UHDEm2nsBt9OAp2AZaRsx2PBVFkMqpDJRqMQiRXquAsPJnwgEQ9BGApxBC8RCOhVTcSnUUJHsGpsil0hiLE2Yuv__NkdcamyufCy_0JSGx5V5MVYmrCHrg0rffS0fa0d14rjyhYyJ8lQCD_6fiODEkQconMmksPl69s_E4h3K_b-Q2g8PdSMoq13pX0ze9rc1an74Q_RQEuW-jozLzq_l9sH-pWxFK4VhB5rU8yAo3_c83MuWIqBA8EchP4mEipDkpyDDLIVGUv4zkAIn_ZPIBhv67yLmH6P-x6h_BjL-Meq3jPrr9O6cQkCkYjKghAsBNczCNSEZPCHwi8oYmBJPy3pjii6R0lHQGMt0YZeY0kPa66L2wiCUXAsORGuMdoEohaepqWJVvNfZjIuXW5ooMTHu4_ZsJ19yefasybNpBbF4wYrA4xxLQOYhdJVhgBaVlAVjSlIK4jWFuzFWshUOo02EISZhTrYVsH02oKFSMRtXLiHPZ0jey5c7ZEBxw6XyiXIkPhr741Gv6xK7NavI3TvL0OvWtcGpzCL39RuUIxVDZE6JWhYxyrzKwX41eIpcq0xato6V9KvOT0Xq0pMcmTUdsLgp0sAVCe6p4YNIIS-NdioalPygURuq_FGVfJ8fgffLxZDNJu84aMWN3VbJGGF4kLEMyk9JDnxUo6YTHuce1YP6N4dlJvSce_-ZoG_y2VXXXcN7_P-3W3-O8TeHROpUe1MzceV-d1Ar0sgeiWtBdX6nqp-4015ODQPi3MgjY4OCMr6i2odBqqzSVZXJkgU2iFilgtUhsLoqTskm4W1L7asxS_pWxVxaTCPzzKh12UUsczW1mXLE_0knu-p9tIrjqTZxwLAUuSTdG8VH_rd1Eu2PHwLarjVNHh8n0_fs8f01u_l4d_fx6-2_37Gb27vrB_b40TVT-vzp-v7jp8cNDfdttaIL93XpaL1oM0BL5ioS6BV2A_IkDtRiqA2-tPbG1Gs7r4zcWfhw1BtfyMaafzQis_x-kf5Zgt0r2lZKroxzaCwQMKdnYZiJ6cRV_MKwGxcB1Y11lrxWXkxqNcfzw-MdrvM4m-M2Ho7nvvQHXhgNhsOxNxpeRGF00T8_98f9oX8eDsXcC4fwqzdEgqkKsM3bvTfu-Z8G29_8bzbFq53jnO8lHcoYGSbYbyonp-sOM2i1oFM4WxXLVwqZW9pIpcjBlRvaBTyqlfsX311hjZwfAB-88Xg8GuOpgeiPz8LLfjjuj8WZVTaWl8HWUdVWt8RIdnvHzYYeu51e_3mV5rNCx5e_v5Q8GA680dnycnQxhrqPh72e53ujUdAfStmfy2B8Ppf9Ub93Fou5jM0lmIydIZXPzIGgXWIwO1OX5B-9Ua_vjaArg653PhwPRsFgjh1-dD4IsbHIBNR2iY5uphdn-tKRhCjIoDNW0J-mEx5HLVIpHTrAF4VdZvrywcp8KdLHO7ESK_nrmSPh0i3hf27Y4iE">