Closed
Description
Repros with VS 2022 17.3 Preview 3 containing Clang 14.0.5.
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
// 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