[PATCH] sectiongroup support

[Shankar Kalpathi Easwaran]

================
Comment at: lib/Core/SymbolTable.cpp:61
@@ +60,3 @@
+        if (r->kindValue() == Reference::kindGroupParent) {
+          addGroupChild(atom, *(r->target()));
+          return;
----------------
kledzik at apple.com wrote:
> Shankar Kalpathi Easwaran wrote:
> > Rui Ueyama wrote:
> > > *r->target()
> > ok.
> Why is addGroupChild() called here, and what does it do? Scanning all references of all atoms will slow things down.
> 
> Instead, inside addGroup(), if the group name already exists, you choose one of the groups to use (first one?), then mark it to be replaced.   Later in Resolver::removeCoalescedAwayAtoms() you can find the child of coalesced away groups.
a) To catch a bug / error in the YAML file / reader that the user forgot to include a group child atom in the group atom.
b) When the groupChild atoms appear before the groupComdat atoms.

Do we want to track the groupChild atoms as normal atoms ? If so how do we identify an error that the atom was not included inside a group ?



http://llvm-reviews.chandlerc.com/D2961