[all-commits] [llvm/llvm-project] 1454c2: Syndicate, test and fix base64 implementation

[serge-sans-paille via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 1454c27b60447d969d0c1ecaf20b2186fe9d85ec
      https://github.com/llvm/llvm-project/commit/1454c27b60447d969d0c1ecaf20b2186fe9d85ec
  Author: serge-sans-paille <sguelton at redhat.com>
  Date:   2020-03-03 (Tue, 03 Mar 2020)

  Changed paths:
    M clang-tools-extra/clangd/SemanticHighlighting.cpp
    M compiler-rt/lib/fuzzer/FuzzerUtil.cpp
    A llvm/include/llvm/Support/Base64.h
    A llvm/unittests/Support/Base64Test.cpp
    M llvm/unittests/Support/CMakeLists.txt

  Log Message:
  -----------
  Syndicate, test and fix base64 implementation

llvm/Support/Base64, fix its implementation and provide a decent test suite.

Previous implementation code was using + operator instead of | to combine

results, which is a problem when shifting signed values. (0xFF << 16) is
implicitly converted to a (signed) int, and thus results in 0xffff0000,
h is
negative. Combining negative numbers with a + in that context is not what we
want to do.

This is a recommit of 5a1958f2673f8c771e406a7e309e160b432c9a79 with UB removved.

This fixes https://github.com/llvm/llvm-project/issues/149.

Differential Revision: https://reviews.llvm.org/D75057