[PATCH] D30977: [CodeGen] Emit a CoreFoundation link guard when @available is used

[Alex Lorenz via Phabricator via cfe-commits]

arphaman added inline comments.


================
Comment at: lib/CodeGen/CGObjC.cpp:3428
+  // CoreFoundation is not used in the code, the linker won't link the
+  // framework.
+  auto &Context = getLLVMContext();
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rjmccall wrote:
> Can you explain why compiler-rt has to load the symbol at runtime?  Is this just some compiler-rt testing thing?  Because it seems like a shame to pay a code-size cost — even a negligible one — for something like that.
Because compiler-rt is linked into some internal projects that use the `-all_load` flag, so the linker loads `__isOSVersionAtLeast` that references the CoreFoundation symbols even when it's not used in code.


Repository:
  rL LLVM

https://reviews.llvm.org/D30977