[llvm] 67220c2 - [ORC] Fix serialization / deserialization of default-constructed ArrayRef<char>.

[Vitaly Buka via llvm-commits]

Ubsan is not happy after this patch
https://lab.llvm.org/buildbot/#/builders/5/builds/26239/steps/19/logs/stdio

On Mon, 18 Jul 2022 at 20:39, Lang Hames via llvm-commits <
llvm-commits at lists.llvm.org> wrote:

>
> Author: Lang Hames
> Date: 2022-07-18T20:39:01-07:00
> New Revision: 67220c2ad72e32cea18bb261366e64fe5de75b16
>
> URL:
> https://github.com/llvm/llvm-project/commit/67220c2ad72e32cea18bb261366e64fe5de75b16
> DIFF:
> https://github.com/llvm/llvm-project/commit/67220c2ad72e32cea18bb261366e64fe5de75b16.diff
>
> LOG: [ORC] Fix serialization / deserialization of default-constructed
> ArrayRef<char>.
>
> Avoids a zero-length memcpy from a null src, which caused errors on some
> of the
> sanitizer bots. Also uses null when deserializing an empty ArrayRef (rather
> than pointing to a zero length range in the middle of the input buffer).
>
> Added:
>
>
> Modified:
>
> llvm/include/llvm/ExecutionEngine/Orc/Shared/SimplePackedSerialization.h
>     llvm/unittests/ExecutionEngine/Orc/SimplePackedSerializationTest.cpp
>
> Removed:
>
>
>
>
> ################################################################################
> diff  --git
> a/llvm/include/llvm/ExecutionEngine/Orc/Shared/SimplePackedSerialization.h
> b/llvm/include/llvm/ExecutionEngine/Orc/Shared/SimplePackedSerialization.h
> index 9be58e9f0fa9d..794c07b4e4c0b 100644
> ---
> a/llvm/include/llvm/ExecutionEngine/Orc/Shared/SimplePackedSerialization.h
> +++
> b/llvm/include/llvm/ExecutionEngine/Orc/Shared/SimplePackedSerialization.h
> @@ -56,6 +56,7 @@ class SPSOutputBuffer {
>    SPSOutputBuffer(char *Buffer, size_t Remaining)
>        : Buffer(Buffer), Remaining(Remaining) {}
>    bool write(const char *Data, size_t Size) {
> +    assert(Data && "Data must not be null");
>      if (Size > Remaining)
>        return false;
>      memcpy(Buffer, Data, Size);
> @@ -349,6 +350,8 @@ template <> class
> SPSSerializationTraits<SPSSequence<char>, ArrayRef<char>> {
>    static bool serialize(SPSOutputBuffer &OB, const ArrayRef<char> &A) {
>      if (!SPSArgList<uint64_t>::serialize(OB,
> static_cast<uint64_t>(A.size())))
>        return false;
> +    if (A.empty()) // Empty ArrayRef may have null data, so bail out
> early.
> +      return true;
>      return OB.write(A.data(), A.size());
>    }
>
> @@ -358,7 +361,7 @@ template <> class
> SPSSerializationTraits<SPSSequence<char>, ArrayRef<char>> {
>        return false;
>      if (Size > std::numeric_limits<size_t>::max())
>        return false;
> -    A = {IB.data(), static_cast<size_t>(Size)};
> +    A = {Size ? IB.data() : nullptr, static_cast<size_t>(Size)};
>      return IB.skip(Size);
>    }
>  };
>
> diff  --git
> a/llvm/unittests/ExecutionEngine/Orc/SimplePackedSerializationTest.cpp
> b/llvm/unittests/ExecutionEngine/Orc/SimplePackedSerializationTest.cpp
> index 56b6ad6c81df1..f5319e3287766 100644
> --- a/llvm/unittests/ExecutionEngine/Orc/SimplePackedSerializationTest.cpp
> +++ b/llvm/unittests/ExecutionEngine/Orc/SimplePackedSerializationTest.cpp
> @@ -187,3 +187,24 @@ TEST(SimplePackedSerializationTest, ArrayRef) {
>    // Input should reference buffer.
>    EXPECT_LT(HelloIn.data() - Buffer, BufferSize);
>  }
> +
> +TEST(SimplePackedSerializationTest, ArrayRefEmpty) {
> +  // Make sure that empty ArrayRefs serialize and deserialize as expected.
> +  // Empty ArrayRefs should not succeed even when the data field is null,
> and
> +  // should deserialize to a default-constructed ArrayRef, not a pointer
> into
> +  // the stream.
> +  constexpr unsigned BufferSize = sizeof(uint64_t);
> +  char Buffer[BufferSize];
> +  memset(Buffer, 0, BufferSize);
> +
> +  ArrayRef<char> AOut;
> +  SPSOutputBuffer OB(Buffer, BufferSize);
> +  EXPECT_TRUE(SPSArgList<SPSSequence<char>>::serialize(OB, AOut));
> +
> +  ArrayRef<char> AIn;
> +  SPSInputBuffer IB(Buffer, BufferSize);
> +  EXPECT_TRUE(SPSArgList<SPSSequence<char>>::deserialize(IB, AIn));
> +
> +  EXPECT_EQ(AIn.data(), nullptr);
> +  EXPECT_EQ(AIn.size(), 0U);
> +}
>
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20220720/535f4443/attachment.html>