Disable coroutine support for GCC 10.2 and earlier #466
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GCC 10.2 coroutine support is not great. In particular, this version of GCC does not handle promise type constructors that accept the coroutine function parameters correctly. GCC passes a reference to the pre-copy object to the promise type constructor rather than a reference to the coroutine function argument after it's been copied to the coroutine frame. connect_awaitable relies on this working correctly, so we will require GCC 10.3 or newer to use coroutines with unifex.
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| * GCC, 10.3 and later | ||
| * Clang, 10.x and later | ||
| * MSVC not currently supported |
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Judging from unifex_flags.cmake, MSVC is not supported (explicitly disabled). I imagine MSVC these days does have better coroutine support. I don't use it/have access to MSVC myself.
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@lewissbaker may be able to answer the MSVC question.
I am OK with Clang, GCC targeting. Should we aim for versions supported by the compiler maintainers or current major and one previous major version?
As of today GCC lists 10.4 and Clang last released 10.x branch is 10.0.1 from Aug 2020.
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We dropped older GCC support in #576, should be OK to close now.
| coroutine support are required: | ||
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| * GCC, 10.3 and later | ||
| * Clang, 10.x and later |
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I'm also not sure what version of clang would be sufficient to be considered "stable" to use coroutines with libunifex, so I've left it at the minimum version of support for libunifex as stated above.
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Closing per #576 |
GCC 10.2 coroutine support is not great. In particular, this version of GCC does not handle promise type constructors that accept the coroutine function parameters correctly. GCC passes a reference to the pre-copy object to the promise type constructor rather than a reference to the coroutine function argument after it's been copied to the coroutine frame. connect_awaitable relies on this working correctly, so we will require GCC 10.3 or newer to use coroutines with unifex.
Replaces #443