ART: Refactor String.init binding

Do not use JNI infrastructure, and move the initialization to
the classlinker's FinishInit. This means the binding is available
after the minimal set of initializations.

We could consider moving the functionality even earlier, as soon
as String methods are known and StringFactory can be loaded, but
this placement works well enough and is nicely isolated.

Bug: 79902155
Test: m test-art-host
Change-Id: If4e9f1424668eb200ff5544bc21f5cea6151e4b3

1 files changed, 25 insertions, 13 deletions

diff --git a/runtime/well_known_classes.cc b/runtime/well_known_classes.cc
index 4843061be6..f7cdf3920a 100644
--- a/runtime/well_known_classes.cc
+++ b/runtime/well_known_classes.cc
@@ -23,6 +23,8 @@
 #include <android-base/logging.h>
 #include <android-base/stringprintf.h>
 
+#include "base/enums.h"
+#include "class_linker.h"
 #include "entrypoints/quick/quick_entrypoints_enum.h"
 #include "hidden_api.h"
 #include "jni/jni_internal.h"
@@ -30,6 +32,7 @@
 #include "mirror/throwable.h"
 #include "nativehelper/scoped_local_ref.h"
 #include "obj_ptr-inl.h"
+#include "runtime.h"
 #include "scoped_thread_state_change-inl.h"
 #include "thread-current-inl.h"
 
@@ -231,19 +234,28 @@ static jmethodID CachePrimitiveBoxingMethod(JNIEnv* env, char prim_name, const c
   V(java_lang_String_init_StringBuilder, "(Ljava/lang/StringBuilder;)V", newStringFromStringBuilder, "newStringFromStringBuilder", "(Ljava/lang/StringBuilder;)Ljava/lang/String;", NewStringFromStringBuilder) \
 
 #define STATIC_STRING_INIT(init_runtime_name, init_signature, new_runtime_name, ...) \
-    static ArtMethod* init_runtime_name; \
-    static ArtMethod* new_runtime_name;
+    static ArtMethod* init_runtime_name = nullptr; \
+    static ArtMethod* new_runtime_name = nullptr;
     STRING_INIT_LIST(STATIC_STRING_INIT)
 #undef STATIC_STRING_INIT
 
-void WellKnownClasses::InitStringInit(JNIEnv* env) {
-  ScopedObjectAccess soa(Thread::Current());
-  #define LOAD_STRING_INIT(init_runtime_name, init_signature, new_runtime_name,             \
-                           new_java_name, new_signature, ...)                               \
-      init_runtime_name = jni::DecodeArtMethod(                                             \
-          CacheMethod(env, java_lang_String, false, "<init>", init_signature));             \
-      new_runtime_name = jni::DecodeArtMethod(                                              \
-          CacheMethod(env, java_lang_StringFactory, true, new_java_name, new_signature));
+void WellKnownClasses::InitStringInit(ObjPtr<mirror::Class> string_class,
+                                      ObjPtr<mirror::Class> string_builder_class) {
+  PointerSize p_size = Runtime::Current()->GetClassLinker()->GetImagePointerSize();
+  auto find_method = [p_size](ObjPtr<mirror::Class> klass,
+                              const char* name,
+                              const char* sig,
+                              bool expext_static) REQUIRES_SHARED(Locks::mutator_lock_) {
+    ArtMethod* ret = klass->FindClassMethod(name, sig, p_size);
+    CHECK(ret != nullptr);
+    CHECK_EQ(expext_static, ret->IsStatic());
+    return ret;
+  };
+
+  #define LOAD_STRING_INIT(init_runtime_name, init_signature, new_runtime_name,                  \
+                           new_java_name, new_signature, ...)                                    \
+      init_runtime_name = find_method(string_class, "<init>", init_signature, false);            \
+      new_runtime_name = find_method(string_builder_class, new_java_name, new_signature, true);
       STRING_INIT_LIST(LOAD_STRING_INIT)
   #undef LOAD_STRING_INIT
 }
@@ -252,6 +264,7 @@ void Thread::InitStringEntryPoints() {
   QuickEntryPoints* qpoints = &tlsPtr_.quick_entrypoints;
   #define SET_ENTRY_POINT(init_runtime_name, init_signature, new_runtime_name,              \
                           new_java_name, new_signature, entry_point_name)                   \
+      DCHECK(!Runtime::Current()->IsStarted() || (new_runtime_name) != nullptr);            \
       qpoints->p ## entry_point_name = reinterpret_cast<void(*)()>(new_runtime_name);
       STRING_INIT_LIST(SET_ENTRY_POINT)
   #undef SET_ENTRY_POINT
@@ -260,7 +273,9 @@ void Thread::InitStringEntryPoints() {
 ArtMethod* WellKnownClasses::StringInitToStringFactory(ArtMethod* string_init) {
   #define TO_STRING_FACTORY(init_runtime_name, init_signature, new_runtime_name,            \
                             new_java_name, new_signature, entry_point_name)                 \
+      DCHECK((init_runtime_name) != nullptr);                                               \
       if (string_init == (init_runtime_name)) {                                             \
+        DCHECK((new_runtime_name) != nullptr);                                              \
         return (new_runtime_name);                                                          \
       }
       STRING_INIT_LIST(TO_STRING_FACTORY)
@@ -410,9 +425,6 @@ void WellKnownClasses::Init(JNIEnv* env) {
   java_lang_Integer_valueOf = CachePrimitiveBoxingMethod(env, 'I', "java/lang/Integer");
   java_lang_Long_valueOf = CachePrimitiveBoxingMethod(env, 'J', "java/lang/Long");
   java_lang_Short_valueOf = CachePrimitiveBoxingMethod(env, 'S', "java/lang/Short");
-
-  InitStringInit(env);
-  Thread::Current()->InitStringEntryPoints();
 }
 
 void WellKnownClasses::LateInit(JNIEnv* env) {