[llvm] [IR] Add TargetExtType::CanBeLocal property (PR #99016)

[Nikita Popov via llvm-commits]

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@@ -4285,6 +4291,12 @@ void Verifier::visitAllocaInst(AllocaInst &AI) {
   SmallPtrSet<Type*, 4> Visited;
   Check(AI.getAllocatedType()->isSized(&Visited),
         "Cannot allocate unsized type", &AI);
+  // Check if it's a target extension type that disallows being used on the
+  // stack.
+  if (auto *TTy = dyn_cast<TargetExtType>(AI.getAllocatedType())) {
+    Check(TTy->hasProperty(TargetExtType::CanBeLocal),
+          "Alloca has illegal target extension type", &AI);
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nikic wrote:

Also applies to the existing CanBeGlobal check, but this probably needs to be recursive? We'd not want to forbid `target("foo")` but then allow `{ target("foo") }`.

https://github.com/llvm/llvm-project/pull/99016