[PATCH] D56215: [lld] [ELF] Include default search paths for NetBSD driver

Fri Jan 11 10:36:50 PST 2019

krytarowski added inline comments.

================
Comment at: ELF/Driver.cpp:770
+  // Start with a default initial triple
+  Config->TargetTriple = llvm::Triple(getDefaultTargetTriple());
+
----------------
krytarowski wrote:
> arichardson wrote:
> > arichardson wrote:
> > > If I invoke an unprefixed ld.lld on NetBSD but want to target a different operating system, this will cause all the NetBSD defaults to apply to that binary and will possibly cause it to crash at runtime.
> > > 
> > > I think any config changes based on a triple would need to use an explicit --target= flag instead. As @ruiu says, LLD's behaviour should not change depending on the host OS/default LLVM triple. Given the same input files and command line options the resulting binary should be identical on any host.
> > There needs to be a way to override the target triple that is not creating prefixed a symlink to ld.lld. Otherwise I can't use NetBSD ld.lld to build a non-NetBSD target without giving a value for every config option that lld supports.
> > 
> > I think there should be a command line option to override the triple (e.g. --triple= or --target=).
> > Also how will the default this interact with input files that have the OSABI field set? I feel like the options based on the target OSABI should be used instead of the default triple.
> OSABI field is not reliable way to detect OS/ABI. Everybody except FreeBSD sets UNIX SystemV.
Actually there is a FreeBSD specific hack to detect emulation name, and it has suffix `fbsd`.. if it is detected it sets FreeBSD OSABI.

We don't have a chance to use a similar hack for NetBSD in other configuration options.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D56215/new/

https://reviews.llvm.org/D56215