[PATCH] D137379: [-Wunsafe-buffer-usage] Add warnings for unsafe buffer accesses by array subscript operations

[Manoj Gupta via Phabricator via cfe-commits]

manojgupta added a comment.

This is firing even in checked length codes, is that expected?

example:
https://godbolt.org/z/Todje76ao

  std::optional<uint16_t> result;
  bool ReadDevice(uint8_t* data, size_t len) {
  if (!result)
        return false;
    memset(data, 0, len);
    if (len > 0)     data[0] = (result.value() >> 8) & 0xFF;
    if (len > 1)     data[1] = result.value() & 0xFF;
    return true;
  }

  <source>:7:26: warning: 'data' is an unsafe pointer used for buffer access [-Wunsafe-buffer-usage]
  bool ReadDevice(uint8_t* data, size_t len) {
                  ~~~~~~~~~^~~~
  <source>:13:20: note: used in buffer access here
    if (len > 1)     data[1] = result.value() & 0xFF;
                     ^~~~


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D137379/new/

https://reviews.llvm.org/D137379