ld64-351.8.tar.gz

[apple/ld64.git] / src / ld / SymbolTable.cpp

diff --git a/src/ld/SymbolTable.cpp b/src/ld/SymbolTable.cpp
index 3c12a777d930e6e38915dca081c034d30a3b3cf1..e12c1e4460e7478fcae0417cb0e7929188b91d2d 100644 (file)
--- a/src/ld/SymbolTable.cpp
+++ b/src/ld/SymbolTable.cpp
@@ -860,6 +860,41 @@ const ld::Atom* SymbolTable::indirectAtom(IndirectBindingSlot slot) const
        return _indirectBindingTable[slot];
 }
 
+
+void SymbolTable::removeDeadUndefs(std::vector<const ld::Atom*>& allAtoms, const std::unordered_set<const ld::Atom*>& keep)
+{
+       // mark the indirect entries in use
+       std::vector<bool> indirectUsed;
+       for (size_t i=0; i < _indirectBindingTable.size(); ++i)
+               indirectUsed.push_back(false);
+       for (const ld::Atom* atom : allAtoms) {
+               for (auto it = atom->fixupsBegin(); it != atom->fixupsEnd(); ++it) {
+                       switch (it->binding) {
+                               case ld::Fixup::bindingsIndirectlyBound:
+                                       indirectUsed[it->u.bindingIndex] = true;
+                                       break;
+                               default:
+                                       break;
+                       }
+               }
+       }
+
+       // any indirect entry not in use which points to an undefined proxy can be removed
+       for (size_t slot=0; slot < indirectUsed.size(); ++slot) {
+               if ( !indirectUsed[slot] ) {
+                       const ld::Atom* atom = _indirectBindingTable[slot];
+                       if ( (atom != nullptr) && (atom->definition() == ld::Atom::definitionProxy) && (keep.count(atom) == 0) ) {
+                               const char* name = atom->name();
+                               _indirectBindingTable[slot] = NULL;
+                               _byNameReverseTable.erase(slot);
+                               _byNameTable.erase(name);
+                               allAtoms.erase(std::remove(allAtoms.begin(), allAtoms.end(), atom), allAtoms.end());
+                       }
+               }
+       }
+
+}
+
 void SymbolTable::printStatistics()
 {
 //     fprintf(stderr, "cstring table size: %lu, bucket count: %lu, hash func called %u times\n",