Noop in sys::getDefaultTargetTriple()?

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#1

Hello,

I was looking at sys::getDefaultTargetTriple() (file:
lib/Support/Unix/Host.inc ) and there is something
unclear to me.

std::string sys::getDefaultTargetTriple() {
  StringRef TargetTripleString(LLVM_DEFAULT_TARGET_TRIPLE);
  std::pair<StringRef, StringRef> ArchSplit = TargetTripleString.split('-');
      
  // Normalize the arch, since the target triple may not actually match the
  // target.
  std::string Arch = ArchSplit.first;

  std::string Triple(Arch);
  Triple += '-';
  Triple += ArchSplit.second;
[...]

Does content of Tripe = TargetTripleString? Of course
with the difference of the container type.

Do I miss something?

#2

Hi Kamil,

Do I miss something?

Very well spotted. I don't think you've missed anything, it's
pointless. Looking through the git history the split served some
purpose in the past, but we should probably just remove it now.

Do you want to or shall I?

Cheers.

Tim.

#3

Hmm.

  • The code segment indeed seems to do nothing.

  • Even then, std::string Arch not required at all.

  • iN86 logic lives in Triple::ArchType parseArch which is called by Triple::normalize anyhow.

  • The darwin logic means clang ignores whatever version LLVM_DEFAULT_TARGET_TRIPLE provides, replacing it with what uname says for this host. that on purpose? is this also done for other triples such as passed from command line?

#4

Tim Northover wrote:

Hi Kamil,

> Do I miss something?

Very well spotted. I don't think you've missed anything, it's
pointless. Looking through the git history the split served some
purpose in the past, but we should probably just remove it now.

Do you want to or shall I?

A cleanup patch was sent in a private mail. Please push it forward for trunk.

#5

A cleanup patch was sent in a private mail. Please push it forward for trunk.

Thanks Kamil, I've committed it as r228926.

Tim.