[PATCH] D104734: [llvm-diff] Explicitly check ConstantStructs for differences

[Bill Wendling via Phabricator via llvm-commits]

void added inline comments.


================
Comment at: llvm/tools/llvm-diff/DifferenceEngine.cpp:477
+      if (CSL->getType()->getNumElements() != CSR->getType()->getNumElements())
+        return false;
+
----------------
rjmccall wrote:
> void wrote:
> > rjmccall wrote:
> > > Hmm.  I don't think it's okay to just compare the number of elements: if the types might be different, they might have different layouts.
> > The individual elements are checked in the loop below. I made it recursive because I couldn't count on the types to be uniqued, because of the naming differences.
> Sure, I see that, but you could have different struct types with different layouts but compatible elements.  Because one is packed and the other isn't, or so on.
Ah! I see what you mean. There's a method called `isLayoutIdentical`, but it checks each element's pointer value. The only other thing it checks is the Packed attribute. I added that.


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https://reviews.llvm.org/D104734