[llvm] [FunctionAttrs] Infer noalias through a null check. (PR #226956)

[Nikita Popov via llvm-commits]

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@@ -1485,7 +1485,11 @@ static bool isFunctionMallocLike(Function *F, const SCCNodeSet &SCCNodes) {
         return false; // Did not come from an allocation.
       }
 
-    if (PointerMayBeCaptured(RetVal, /*ReturnCaptures=*/false))
+    // Checking if result is null does not prevent it from being noalias.
+    if (capturesAnything(
+            PointerMayBeCaptured(RetVal, CaptureComponents::All &
+                                             ~CaptureComponents::AddressIsNull)
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nikic wrote:

Why only AddressIsNull? Other address captures shouldn't matter for noalias either, right?

https://github.com/llvm/llvm-project/pull/226956