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

[Peter Smith via cfe-commits]

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@@ -311,11 +311,15 @@ ARMBaseTargetMachine::getSubtargetImpl(const Function &F) const {
     // function that reside in TargetOptions.
     resetTargetOptions(F);
     I = std::make_unique<ARMSubtarget>(TargetTriple, CPU, FS, *this, isLittle,
-                                        F.hasMinSize());
+                                       F.hasMinSize());
 
     if (!I->isThumb() && !I->hasARMOps())
       F.getContext().emitError("Function '" + F.getName() + "' uses ARM "
           "instructions, but the target does not support ARM mode execution.");
+
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smithp35 wrote:

IIUC [*] TargetMachine::getSubtargetImpl is the "global" subtarget. It has been a long time since I've looked at the area so I could be wrong.

Putting the warning here makes me nervous as individual functions have their own subtargets. It is common for LTO to rely entirely on the per function subtarget. I can remember an Android problem that was caused by using the global subtarget for a per-function property.

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