[PATCH] D130666: [InstCombine] Add support for strlcpy folding

[Martin Sebor via Phabricator via llvm-commits]

msebor added inline comments.


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Comment at: llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp:699
+    annotateNonNullNoUndefBasedOnAccess(CI, 0);
+    annotateNonNullNoUndefBasedOnAccess(CI, 1);
+  }
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efriedma wrote:
> strlcpy accesses the second argument no matter what the size is (so it can compute the return value).
You're absolutely right, thanks!


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Comment at: llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp:726
+  bool NulTerm = false;
+  if (NBytes > SrcLen + 1) {
+    NBytes = SrcLen + 1;
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efriedma wrote:
> `>=`?
That would work; at the same time, I was uneasy about `GetStringLength`  not differentiating between an unterminated array and a string of the same length.  I'd prefer to avoid assuming the source array is nul terminated, even though it's required to be.  So I've replaced the call to `GetStringLength` with `getConstantStringInfo` and handled that case.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D130666/new/

https://reviews.llvm.org/D130666