Support checking synthetic stubs for Kotlin default argument

Summary:
# Context:

Kotlin support default arguments. To implement that in bytecode, `kotlinc` synthesizes a stub with a `$default` suffix in its name to supply the default argument value to the actual method. The synthesized stub does not carry the same param annotation from its callee. Out of the box, our Typedef annotation checker doesn't properly cover this case.

# Solution

The `SynthAccessorPatcher` can patch the param annotation for the `$default` stub similar to what it does to the synthetic accessor. Here we simply remove the guard that excludes the `$default` stubs from the checker logic.

We also added new tests to cover both the calls to the `$default` stubs as well as the calls from the `$default` stubs.

Reviewed By: itang00

Differential Revision: D51904548

fbshipit-source-id: cd3cecb390dceca1bee986d89840374675a817f0

opt/typedef-anno-checker/TypedefAnnoCheckerPass.cpp

@@ -107,7 +107,7 @@ void SynthAccessorPatcher::collect_accessors(DexMethod* m) {
     return;
   }
 
-  always_assert(code->editable_cfg_built());
+  always_assert_log(code->editable_cfg_built(), "%s has no cfg built", SHOW(m));
   auto& cfg = code->cfg();
   type_inference::TypeInference inference(cfg, false, m_typedef_annos);
   inference.run(m);
@@ -192,19 +192,12 @@ void TypedefAnnoChecker::check_instruction(
   case OPCODE_INVOKE_DIRECT:
   case OPCODE_INVOKE_STATIC:
   case OPCODE_INVOKE_INTERFACE: {
-    auto def_method = resolve_method(m, insn);
-    if (!def_method) {
-      return;
-    }
-    // some methods are called through their access or defaul
-    // counterpart, which do not retain the typedef annotation.
-    // In these cases, we will skip the checker
-    if (!def_method->get_param_anno() ||
-        def_method->get_simple_deobfuscated_name() + DEFAULT_SUFFIX ==
-            m->get_simple_deobfuscated_name()) {
+    auto* callee_def = resolve_method(m, insn);
+    if (!callee_def || !callee_def->get_param_anno()) {
+      // Callee does not expect any Typedef value. Nothing to do.
       return;
     }
-    for (auto const& param_anno : *def_method->get_param_anno()) {
+    for (auto const& param_anno : *callee_def->get_param_anno()) {
       auto annotation = inference->get_typedef_annotation(
           param_anno.second->get_annotations());
       if (annotation == boost::none) {
@@ -221,7 +214,7 @@ void TypedefAnnoChecker::check_instruction(
       if (anno_type && anno_type != annotation) {
         std::ostringstream out;
         if (anno_type.value() == type::java_lang_Object()) {
-          out << "TypedefAnnoCheckerPass: while invoking " << SHOW(def_method)
+          out << "TypedefAnnoCheckerPass: while invoking " << SHOW(callee_def)
               << "\n in method " << SHOW(m) << "\n parameter "
               << param_anno.first << "should have the annotation "
               << annotation.value()->get_name()->c_str()
@@ -232,7 +225,7 @@ void TypedefAnnoChecker::check_instruction(
                  "should not be mixed.\n"
               << " failed instruction: " << SHOW(insn) << "\n\n";
         } else {
-          out << "TypedefAnnoCheckerPass: while invoking " << SHOW(def_method)
+          out << "TypedefAnnoCheckerPass: while invoking " << SHOW(callee_def)
               << "\n in method " << SHOW(m) << "\n parameter "
               << param_anno.first << " has the annotation " << SHOW(anno_type)
               << "\n but the method expects the annotation to be "
@@ -247,7 +240,7 @@ void TypedefAnnoChecker::check_instruction(
             << "\n annotates a parameter with an incompatible type "
             << SHOW(type) << "\n or a non-constant parameter in method "
             << SHOW(m) << "\n while trying to invoke the method "
-            << SHOW(def_method) << ".\n failed instruction: " << SHOW(insn)
+            << SHOW(callee_def) << ".\n failed instruction: " << SHOW(insn)
             << "\n\n";
         m_error += out.str();
         m_good = false;
@@ -257,10 +250,10 @@ void TypedefAnnoChecker::check_instruction(
                                         param_index, inference, envs);
         if (!good) {
           std::ostringstream out;
-          out << " Error invoking " << SHOW(def_method) << "\n";
+          out << " Error invoking " << SHOW(callee_def) << "\n";
           out << " Incorrect parameter's index: " << param_index << "\n\n";
           m_error += out.str();
-          TRACE(TAC, 1, "invoke method: %s", SHOW(def_method));
+          TRACE(TAC, 1, "invoke method: %s", SHOW(callee_def));
         }
       }
     }
@@ -367,8 +360,9 @@ bool TypedefAnnoChecker::check_typedef_value(
 
   live_range::Use use_of_id{insn, src};
   auto udchains_it = ud_chains->find(use_of_id);
+  auto defs_set = udchains_it->second;
 
-  for (IRInstruction* def : udchains_it->second) {
+  for (IRInstruction* def : defs_set) {
     switch (def->opcode()) {
     case OPCODE_CONST_STRING: {
       auto const const_value = def->get_string();