[Lldb-commits] [PATCH] Update ObjectFileELF to detect ELF triple based on ELF notes and the ELF header.

[Ed Maste]

> I'm not sure how you were doing the entire setup above
This wasn't using llgs at all, just the local core file support
```
bin/lldb /bin/sleep -c sleep.core
```

Last night I discovered that the triple is `x86_64-unknown-freebsd` with the patch, and `x86_64-unknown-freebsd10.0` without.  The latter matches the platform triple reported by `platform status`.

With the patch, in `ModuleList::GetSharedModule` the `module_sp->GetObjectFile()` fails.

================
Comment at: source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp:1075
@@ -983,1 +1074,3 @@
+        // Process FreeBSD ELF notes.
+        if (note.n_namesz == LLDB_NT_OWNER_FREEBSD_LENGTH && note.n_name == LLDB_NT_OWNER_FREEBSD)
         {
----------------
Todd Fiala wrote:
> Ed Maste wrote:
> > n_name is a std::string and the length (namesz) should be handled in the note parser so you should be able to just do note.n_name == LLDB_NT_OWNER_FREEBSD, no?
> > 
> > Also for the purpose of this parsing we'll generally have just one case in each of the switch statements - maybe it'd be more concise to just check note.n_type == LLDB_NT_FREEBSD_ABI_TAG in the if() as well?
> > Also for the purpose of this parsing we'll generally have just one case in each of the switch statements - maybe it'd be more concise to just check note.n_type == LLDB_NT_FREEBSD_ABI_TAG in the if() as well?
> 
> Sure, I think it's only GNU that is using multiple ones.   I can change that for the others.
> 
> > n_name is a std::string and the length (namesz) should be handled in the note parser so you should be able to just do note.n_name == LLDB_NT_OWNER_FREEBSD, no?
> 
> Yes, but I was looking to avoid the string compare if the length wasn't equal.  That would stop needing to get the string length of the constant.  Overall this is likely very minor compared to the cost of scanning the entire contents though, so probably worth the simplification.
> Yes, but I was looking to avoid the string compare if the length wasn't equal. That would stop needing to get the string length of the constant. Overall this is likely very minor compared to the cost of scanning the entire contents though, so probably worth the simplification.

Oh, good point.  I was probably reading something else into it from my previous investigations into ELF notes and having to deal with a special case for the Linux core note n_namesz.

http://reviews.llvm.org/D4302