[llvm-objcopy] Add --localize-hidden option

This change adds support in llvm-objcopy for GNU objcopy's --localize-hidden
option. This option changes every hidden or internal symbol into a local symbol.

llvm-svn: 321884

1 files changed, 19 insertions, 0 deletions

diff --git a/llvm/tools/llvm-objcopy/Object.cpp b/llvm/tools/llvm-objcopy/Object.cpp
index 9e82448187e..a0708ed59b4 100644
--- a/llvm/tools/llvm-objcopy/Object.cpp
+++ b/llvm/tools/llvm-objcopy/Object.cpp
@@ -175,6 +175,25 @@ void SymbolTableSection::removeSectionReferences(const SectionBase *Sec) {
   Symbols.erase(Iter, std::end(Symbols));
 }
 
+void SymbolTableSection::localize(
+    std::function<bool(const Symbol &)> ToLocalize) {
+  for (const auto &Sym : Symbols) {
+    if (ToLocalize(*Sym))
+      Sym->Binding = STB_LOCAL;
+  }
+
+  // Now that the local symbols aren't grouped at the start we have to reorder
+  // the symbols to respect this property.
+  std::stable_partition(
+      std::begin(Symbols), std::end(Symbols),
+      [](const SymPtr &Sym) { return Sym->Binding == STB_LOCAL; });
+
+  // Lastly we fix the symbol indexes.
+  uint32_t Index = 0;
+  for (auto &Sym : Symbols)
+    Sym->Index = Index++;
+}
+
 void SymbolTableSection::initialize(SectionTableRef SecTable) {
   Size = 0;
   setStrTab(SecTable.getSectionOfType<StringTableSection>(