Fix compiler error in CoreFoundation when building in C++ mode #5081
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| Boolean __CFAllocatorRespectsHintZeroWhenAllocating(CFAllocatorRef _Nullable allocator); | ||
| _CF_EXPORT_SCOPE_END |
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Will making this CF_EXPORT like the others also fix the issue?
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Good question! CF_EXPORT seems to expand into extern on Linux, not extern "C":
I'm wondering if this is an oversight, I can tweak the CF_EXPORT macro to expand into extern "C" in C++ language mode, and then use CF_EXPORT for this function.
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In truth no one is supposed to be using CoreFoundation except Foundation.
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Usually our CF headers start with the macro the begin extern “C” but since this one is internal to Foundation it doesn’t have it.
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I think this header file is included by a public Foundation header, so it ends up being parsed when someone is including Foundation.
There are a few _CF_EXPORT_SCOPE_BEGIN/_CF_EXPORT_SCOPE_END blocks below in this file, so I thought that this is the preferred solution. But I'm happy to switch to CF_EXPORT if you think that's better.
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To avoid this turning into a tar pit of changes, let's just extend the begin/end to cover this 'group' of functions. Lines 60 - 75
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Sounds good, done.
`__CFAllocatorRespectsHintZeroWhenAllocating` has two declarations in different headers: `ForFoundationOnly.h` and `ForSwiftFoundationOnly.h`. One of the declarations was under `extern "C"` block, the other one wasn't. Clang accepts this in C language mode, but it is a hard compiler error in C++ language mode due to a linkage mismatch. This was blocking clients from using CoreFoundation in Swift projects that enable C++ interoperability. This change makes sure that both declarations of `__CFAllocatorRespectsHintZeroWhenAllocating` are under `extern "C"` blocks.
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__CFAllocatorRespectsHintZeroWhenAllocatinghas two declarations in different headers:ForFoundationOnly.handForSwiftFoundationOnly.h. One of the declarations was underextern "C"block, the other one wasn't. Clang accepts this in C language mode, but it is a hard compiler error in C++ language mode due to a linkage mismatch.This was blocking clients from using CoreFoundation in Swift projects that enable C++ interoperability.
This change makes sure that both declarations of
__CFAllocatorRespectsHintZeroWhenAllocatingare underextern "C"blocks.