Deleting ditto dead code

Summary: Moving large number of classes to the longtail module caused a crash. The final step of loading secondary dex files was verifying  the canary class. https://fburl.com/code/98pp1ymx. This canary class’s initializer (P898179371) caused the demand of longtail classes when voltron and fallback loader wasn’t available. It turned out to be dead which we should delete.

Reviewed By: agampe

Differential Revision: D51939733

fbshipit-source-id: 26123a1f4202d61e9c090fd5109b5542a8ece4a1

opt/interdex/InterDex.cpp

@@ -1113,66 +1113,6 @@ void InterDex::add_dexes_from_store(const DexStore& store) {
   post_process_dex(m_emitting_state, fodr);
 }
 
-void InterDex::set_clinit_methods_if_needed(DexClass* cls) const {
-  using namespace dex_asm;
-
-  if (m_methods_for_canary_clinit_reference.empty()) {
-    // No methods to call from clinit; don't create clinit.
-    return;
-  }
-
-  if (cls->get_clinit()) {
-    // We already created and added a clinit.
-    return;
-  }
-
-  // Create a clinit static method.
-  auto proto =
-      DexProto::make_proto(type::_void(), DexTypeList::make_type_list({}));
-  DexMethod* clinit =
-      DexMethod::make_method(cls->get_type(),
-                             DexString::make_string("<clinit>"), proto)
-          ->make_concrete(ACC_STATIC | ACC_CONSTRUCTOR, false);
-  clinit->set_code(std::make_unique<IRCode>());
-  cls->add_method(clinit);
-  clinit->set_deobfuscated_name(show_deobfuscated(clinit));
-
-  // Add code to clinit to call the other methods.
-  auto code = clinit->get_code();
-  size_t max_size = 0;
-  for (const auto& method_name : m_methods_for_canary_clinit_reference) {
-    // No need to do anything if this method isn't present in the build.
-    if (DexMethodRef* method = DexMethod::get_method(method_name)) {
-      std::vector<Operand> reg_operands;
-      int64_t reg = 0;
-      for (auto* dex_type : *method->get_proto()->get_args()) {
-        Operand reg_operand = {VREG, reg};
-        switch (dex_type->get_name()->c_str()[0]) {
-        case 'J':
-        case 'D':
-          // 8 bytes
-          code->push_back(dasm(OPCODE_CONST_WIDE, {reg_operand, 0_L}));
-          reg_operands.push_back(reg_operand);
-          reg += 2;
-          break;
-        default:
-          // 4 or fewer bytes
-          code->push_back(dasm(OPCODE_CONST, {reg_operand, 0_L}));
-          reg_operands.push_back(reg_operand);
-          ++reg;
-          break;
-        }
-      }
-      max_size = std::max(max_size, (size_t)reg);
-      code->push_back(dasm(OPCODE_INVOKE_STATIC, method, reg_operands.begin(),
-                           reg_operands.end()));
-    }
-  }
-  code->set_registers_size(max_size);
-  code->push_back(dasm(OPCODE_RETURN_VOID));
-  code->build_cfg();
-}
-
 // Creates a canary class if necessary. (In particular, the primary dex never
 // has a canary class.) This method should be called after flush_out_dex when
 // beginning a new dex. As canary classes are added in the end without checks,
@@ -1189,7 +1129,6 @@ DexClass* InterDex::get_canary_cls(EmittingState& emitting_state,
     static std::mutex canary_mutex;
     std::lock_guard<std::mutex> lock_guard(canary_mutex);
     canary_cls = create_canary(dexnum);
-    set_clinit_methods_if_needed(canary_cls);
   }
   MethodRefs clazz_mrefs;
   FieldRefs clazz_frefs;

opt/interdex/InterDex.h

@@ -53,7 +53,6 @@ class InterDex {
            const ReserveRefsInfo& reserve_refs,
            const XStoreRefs* xstore_refs,
            int min_sdk,
-           std::vector<std::string> methods_for_canary_clinit_reference,
            const init_classes::InitClassesWithSideEffects&
                init_classes_with_side_effects,
            bool transitively_close_interdex_order,
@@ -80,8 +79,6 @@ class InterDex {
         m_original_scope(original_scope),
         m_scope(build_class_scope(m_dexen)),
         m_xstore_refs(xstore_refs),
-        m_methods_for_canary_clinit_reference(
-            std::move(methods_for_canary_clinit_reference)),
         m_transitively_close_interdex_order(transitively_close_interdex_order),
         m_minimize_cross_dex_refs_explore_alternatives(
             minimize_cross_dex_refs_explore_alternatives),
@@ -189,8 +186,6 @@ class InterDex {
   void post_process_dex(EmittingState& emitting_state,
                         const FlushOutDexResult&) const;
 
-  void set_clinit_methods_if_needed(DexClass* cls) const;
-
   /**
    * Stores in m_interdex_order a list of coldstart types. It will only contain:
    * * classes that still exist in the current scope
@@ -237,7 +232,6 @@ class InterDex {
   std::vector<DexType*> m_interdex_types;
   const XStoreRefs* m_xstore_refs;
   size_t m_current_classes_when_emitting_remaining{0};
-  std::vector<std::string> m_methods_for_canary_clinit_reference;
 
   size_t m_transitive_closure_added{0};
   size_t m_transitive_closure_moved{0};

opt/interdex/InterDexPass.cpp

@@ -107,10 +107,6 @@ void InterDexPass::bind_config() {
   bind("can_touch_coldstart_extended_cls", false,
        m_can_touch_coldstart_extended_cls);
   bind("expect_order_list", false, m_expect_order_list);
-  bind("methods_for_canary_clinit_reference", {},
-       m_methods_for_canary_clinit_reference,
-       "If set, canary classes will have a clinit generated which call the "
-       "specified methods, if they exist");
 
   bind("transitively_close_interdex_order", m_transitively_close_interdex_order,
        m_transitively_close_interdex_order);
@@ -153,15 +149,15 @@ void InterDexPass::run_pass(
   bool force_single_dex = conf.get_json_config().get("force_single_dex", false);
   mgr.set_metric("config.force_single_dex", force_single_dex);
 
-  InterDex interdex(
-      original_scope, dexen, mgr.asset_manager(), conf, plugins,
-      m_linear_alloc_limit, m_static_prune, m_normal_primary_dex,
-      m_keep_primary_order, force_single_dex, m_order_interdex, m_emit_canaries,
-      m_minimize_cross_dex_refs, m_fill_last_coldstart_dex,
-      m_minimize_cross_dex_refs_config, refs_info, &xstore_refs,
-      mgr.get_redex_options().min_sdk, m_methods_for_canary_clinit_reference,
-      init_classes_with_side_effects, m_transitively_close_interdex_order,
-      m_minimize_cross_dex_refs_explore_alternatives, cache);
+  InterDex interdex(original_scope, dexen, mgr.asset_manager(), conf, plugins,
+                    m_linear_alloc_limit, m_static_prune, m_normal_primary_dex,
+                    m_keep_primary_order, force_single_dex, m_order_interdex,
+                    m_emit_canaries, m_minimize_cross_dex_refs,
+                    m_fill_last_coldstart_dex, m_minimize_cross_dex_refs_config,
+                    refs_info, &xstore_refs, mgr.get_redex_options().min_sdk,
+                    init_classes_with_side_effects,
+                    m_transitively_close_interdex_order,
+                    m_minimize_cross_dex_refs_explore_alternatives, cache);
 
   if (m_expect_order_list) {
     always_assert_log(
@@ -251,8 +247,7 @@ void InterDexPass::run_pass_on_nonroot_store(
       false /* emit canaries */, false /* minimize_cross_dex_refs */,
       /* fill_last_coldstart_dex=*/false, cross_dex_refs_config, refs_info,
       &xstore_refs, mgr.get_redex_options().min_sdk,
-      m_methods_for_canary_clinit_reference, init_classes_with_side_effects,
-      m_transitively_close_interdex_order,
+      init_classes_with_side_effects, m_transitively_close_interdex_order,
       m_minimize_cross_dex_refs_explore_alternatives, cache);
 
   interdex.run_on_nonroot_store();