[lld] [lld-macho] Fix compatibility between --icf=safe_thunks and --keep-icf-stabs (PR #116687)

[Ellis Hoag via llvm-commits]

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@@ -1204,6 +1205,17 @@ void SymtabSection::emitEndFunStab(Defined *defined) {
   stabs.emplace_back(std::move(stab));
 }
 
+// Given a pointer to a function symbol, return the symbol that points to the
+// actual function body that will go in the final binary. Generally this is the
+// symbol itself, but if the symbol was folded using a thunk, we retrieve the
+// target function body from the thunk.
+Defined *SymtabSection::getFuncBodySym(Defined *originalSym) {
+  if (originalSym->identicalCodeFoldingKind != Symbol::ICFFoldKind::Thunk)
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ellishg wrote:

Oh sorry, I meant that you should flip the condition and the return. So that if it is a thunk, we return the thunk. Otherwise we return the original symbol. 

https://github.com/llvm/llvm-project/pull/116687