[llvm] [ARM] Emit a warning when the hard-float ABI is enabled but can't be used. (PR #111334)

[Chris Copeland via llvm-commits]

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@@ -791,7 +791,9 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
       setAllExpand(MVT::f32);
     if (!Subtarget->hasFP64())
       setAllExpand(MVT::f64);
-  }
+  } else if (TM.Options.FloatABIType == FloatABI::Hard)
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chrisnc wrote:

The specific case of concern was this one, which is still ultimately due to not requesting the correct attributes at link time, and so the tool has to sometimes guess if it needs to create a new function that didn't already exist in the input. I don't see an obvious way around that problem. I would contend that users should be invoking their linker with the correct settings to avoid issues like this in general, so in some sense it exposes a potential problem in such builds anyway.
https://github.com/llvm/llvm-project/pull/111334#discussion_r1900369088

https://github.com/llvm/llvm-project/pull/111334