[Clang][driver][cc1] Fix handling of of C++20 modules in ObjectiveC++ #6015
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| Default<!strconcat("(", fmodules_ts.KeyPath, "||", fcxx_modules.KeyPath, | ||
| ") && !LangOpts->ObjC")>, |
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Let's either enhance the TableGen infrastructure so that this doesn't have to be string concatenation, or parse/generate these flags manually in CompilerInvocation.cpp.
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I just updated this patch to better handle the overall situation. Defaults to no LSV and no C++20 modules. Adds -cc1 overrides to change this, but rejects invalid combinations. I didn't switch off of |
Bigcheese
changed the title
| @@ -1516,8 +1517,8 @@ defm async_exceptions: BoolFOption<"async-exceptions", | |||
| LangOpts<"EHAsynch">, DefaultFalse, | |||
| PosFlag<SetTrue, [CC1Option], "Enable EH Asynchronous exceptions">, NegFlag<SetFalse>>; | |||
| defm cxx_modules : BoolFOption<"cxx-modules", | |||
| LangOpts<"CPlusPlusModules">, Default<cpp20.KeyPath>, | |||
| NegFlag<SetFalse, [CC1Option], "Disable">, PosFlag<SetTrue, [], "Enable">, | |||
| LangOpts<"CPlusPlusModules">, Default<!strconcat(cpp20.KeyPath, " && !", objc.KeyPath)>, | |||
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Please leave a FIXME behind to teach TableGen to handle this in a more structured way.
| Default<!strconcat("(", fmodules_ts.KeyPath, "||", fcxx_modules.KeyPath, | ||
| ") && !", objc.KeyPath)>, |
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As discussed offline, it's no longer necessary to have !ObjC here since it's covered by the defm cxx_modules logic.
| if ((Opts.ModulesTS || Opts.CPlusPlusModules) && !Opts.ModulesLocalVisibility) | ||
| Diags.Report(diag::err_modules_no_lsv) << (Opts.CPlusPlusModules ? 0 : 1); |
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Please add tests that cover all the cases.
Unfortunately, ObjectiveC++ does not currently support C++20 modules. This is because ObjectiveC requires Local Submodule Visibility in practice, which is not compatible with C++20 modules. Given our options are to either drop ObjectiveC compatibility, or C++20 modules compatibility, we currently choose to disable C++20 modules to allow using other C++20 features in ObjectiveC++20 mode. This patch also allows enabling LSV and C++20 modules in ObjectiveC++20 mode for the few cases it does work. It adds errors for incompatible configurations.
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@swift-ci test |
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Previous failures looked unrelated. @swift-ci test |
Currently there is no way to have Objective-C++20 without LSV. This is a problem because some existing ObjectiveC code is not compatible with LSV. This patch provides a way to disable LSV even in C++20 mode and makes it the default for ObjC++20.
I intend to cherry-pick this into stable/20220421 and stable/20221013.