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<base href="https://bugs.llvm.org/">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - miscompile with templated coroutine"
href="https://bugs.llvm.org/show_bug.cgi?id=50863">50863</a>
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<th>Summary</th>
<td>miscompile with templated coroutine
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
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<th>Version</th>
<td>trunk
</td>
</tr>
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<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>Linux
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>-New Bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>bhalevy@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>htmldeveloper@gmail.com, llvm-bugs@lists.llvm.org, neeilans@live.com, richard-llvm@metafoo.co.uk
</td>
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<p>
<div>
<pre>The following program miscompiles, <a href="https://godbolt.org/z/9nPze58xj">https://godbolt.org/z/9nPze58xj</a>
// Coroutine miscompile reproducer.
//
// clang version 12.0.0
// Target: x86_64-unknown-linux-gnu
//
// Compile with `clang++ -std=c++20 -stdlib=libc++ -fsanitize=undefined -O0`.
#include <experimental/coroutine>
struct task{
struct promise_type {
task get_return_object() { return {}; }
std::experimental::suspend_never initial_suspend() { return {}; }
std::experimental::suspend_never final_suspend() noexcept { return {}; }
void return_void() {}
void unhandled_exception() {}
};
};
namespace std::experimental {
template <typename ...Args>
struct coroutine_traits<task, Args...> {
using promise_type = typename task::promise_type;
};
}
template <typename T>
task foo(T) noexcept {
co_return;
}
int main() {
foo(0);
}
Compiler output:
ASM generation compiler returned: 0
error: Cannot represent a difference across sections
error: Cannot represent a difference across sections
error: Cannot represent a difference across sections
3 errors generated.
Execution build compiler returned: 1</pre>
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