commit be2487a2ba43f3929c894e8cf8fe3ddb0b9c6a24
author David Bolvansky <david.bolvansky@gmail.com> Tue Sep 17 10:12:48 2019 +0000
committer David Bolvansky <david.bolvansky@gmail.com> Tue Sep 17 10:12:48 2019 +0000
tree 342efda7d6566f80cd109f3b6576a49da36d6d0a
parent 3a3dddd9d72edecc774efaee153e876fe74fed6c

[InstCombine] Annotate strdup with deref_or_null

llvm-svn: 372098

llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index e96e45e..9043818 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -4208,6 +4208,12 @@
       Call.addAttribute(AttributeList::ReturnIndex,
                         Attribute::getWithDereferenceableOrNullBytes(
                             Call.getContext(), Size.getZExtValue()));
+  } else if (isStrdupLikeFn(&Call, TLI) && Call.getNumArgOperands() == 1) {
+    // TODO: handle strndup
+    if (uint64_t Len = GetStringLength(Call.getOperand(0)))
+      Call.addAttribute(
+          AttributeList::ReturnIndex,
+          Attribute::getWithDereferenceableOrNullBytes(Call.getContext(), Len));
   }
 }