[PATCH] D12709: [PATCH] [sanitizers] [msan] Enable MSAN for aarch64

[Renato Golin via llvm-commits]

rengolin added a comment.

In http://reviews.llvm.org/D12709#242337, @zatrazz wrote:

> In this case the variable will not be used for attribution , but instead to catch the value of 'x8'. My understanding is clang should not mark the variable as unused if it is used as a named register variable, otherwise it will not be able to catch registers values as is in function calling.


This is a lost battle, let's not go there.

> Another option that came to my mind is to use an volatile inline assembly to explicit get the register value:


Yup, that's what I was referring to.

>   uptr r8;

>   asm volatile("mov %0,x8" : "=r" (r8));

>   sret = reinterpret_cast<__sanitizer_mallinfo*>(r8);


You can use named registers here:

  register uptr x8 asm("x8");
  asm volatile("mov %0, %1\n" : "=r" (sret), "r" (x8));


http://reviews.llvm.org/D12709