Revert "CHA for abstract methods."

This reverts commit ae6c189b9d63ca4c2ae0e952187819c5e442e3c9.

This is causing sporadic build failures with:
dex2oatd F 01-20 15:05:33 8343 10164 cha.cc:292] Check failed: method_in_super->HasSingleImplementation() 

Change-Id: I4435ab028d3f7893e18b44347f294326c573a255

10 files changed, 38 insertions, 362 deletions

diff --git a/compiler/image_writer.cc b/compiler/image_writer.cc
index b3b1903fd7..4109345f80 100644
--- a/compiler/image_writer.cc
+++ b/compiler/image_writer.cc
@@ -2341,16 +2341,6 @@ const uint8_t* ImageWriter::GetQuickCode(ArtMethod* method,
 void ImageWriter::CopyAndFixupMethod(ArtMethod* orig,
                                      ArtMethod* copy,
                                      const ImageInfo& image_info) {
-  if (orig->IsAbstract()) {
-    // Ignore the single-implementation info for abstract method.
-    // Do this on orig instead of copy, otherwise there is a crash due to methods
-    // are copied before classes.
-    // TODO: handle fixup of single-implementation method for abstract method.
-    orig->SetHasSingleImplementation(false);
-    orig->SetSingleImplementation(
-        nullptr, Runtime::Current()->GetClassLinker()->GetImagePointerSize());
-  }
-
   memcpy(copy, orig, ArtMethod::Size(target_ptr_size_));
 
   copy->SetDeclaringClass(GetImageAddress(orig->GetDeclaringClassUnchecked()));
diff --git a/compiler/optimizing/inliner.cc b/compiler/optimizing/inliner.cc
index 7772e8f973..5d40f75618 100644
--- a/compiler/optimizing/inliner.cc
+++ b/compiler/optimizing/inliner.cc
@@ -304,8 +304,7 @@ ArtMethod* HInliner::TryCHADevirtualization(ArtMethod* resolved_method) {
     // We do not support HDeoptimize in OSR methods.
     return nullptr;
   }
-  PointerSize pointer_size = caller_compilation_unit_.GetClassLinker()->GetImagePointerSize();
-  return resolved_method->GetSingleImplementation(pointer_size);
+  return resolved_method->GetSingleImplementation();
 }
 
 bool HInliner::TryInline(HInvoke* invoke_instruction) {
diff --git a/runtime/art_method.cc b/runtime/art_method.cc
index 92f3727bfe..d7d39afa8f 100644
--- a/runtime/art_method.cc
+++ b/runtime/art_method.cc
@@ -55,13 +55,15 @@ extern "C" void art_quick_invoke_stub(ArtMethod*, uint32_t*, uint32_t, Thread*,
 extern "C" void art_quick_invoke_static_stub(ArtMethod*, uint32_t*, uint32_t, Thread*, JValue*,
                                              const char*);
 
-ArtMethod* ArtMethod::GetSingleImplementation(PointerSize pointer_size) {
+ArtMethod* ArtMethod::GetSingleImplementation() {
   DCHECK(!IsNative());
   if (!IsAbstract()) {
     // A non-abstract's single implementation is itself.
     return this;
   }
-  return reinterpret_cast<ArtMethod*>(GetDataPtrSize(pointer_size));
+  // TODO: add single-implementation logic for abstract method by storing it
+  // in ptr_sized_fields_.
+  return nullptr;
 }
 
 ArtMethod* ArtMethod::FromReflectedMethod(const ScopedObjectAccessAlreadyRunnable& soa,
diff --git a/runtime/art_method.h b/runtime/art_method.h
index a33111a343..17f343d442 100644
--- a/runtime/art_method.h
+++ b/runtime/art_method.h
@@ -456,7 +456,7 @@ class ArtMethod FINAL {
     }
   }
 
-  ArtMethod* GetSingleImplementation(PointerSize pointer_size)
+  ArtMethod* GetSingleImplementation()
       REQUIRES_SHARED(Locks::mutator_lock_);
 
   ALWAYS_INLINE void SetSingleImplementation(ArtMethod* method, PointerSize pointer_size) {
@@ -684,8 +684,7 @@ class ArtMethod FINAL {
     ArtMethod** dex_cache_resolved_methods_;
 
     // Pointer to JNI function registered to this method, or a function to resolve the JNI function,
-    // or the profiling data for non-native methods, or an ImtConflictTable, or the
-    // single-implementation of an abstract method.
+    // or the profiling data for non-native methods, or an ImtConflictTable.
     void* data_;
 
     // Method dispatch from quick compiled code invokes this pointer which may cause bridging into
diff --git a/runtime/cha.cc b/runtime/cha.cc
index a1ad58507d..d94b091ebd 100644
--- a/runtime/cha.cc
+++ b/runtime/cha.cc
@@ -185,8 +185,7 @@ class CHACheckpoint FINAL : public Closure {
 };
 
 void ClassHierarchyAnalysis::VerifyNonSingleImplementation(mirror::Class* verify_class,
-                                                           uint16_t verify_index,
-                                                           ArtMethod* excluded_method) {
+                                                           uint16_t verify_index) {
   // Grab cha_lock_ to make sure all single-implementation updates are seen.
   PointerSize image_pointer_size =
       Runtime::Current()->GetClassLinker()->GetImagePointerSize();
@@ -196,11 +195,9 @@ void ClassHierarchyAnalysis::VerifyNonSingleImplementation(mirror::Class* verify
       return;
     }
     ArtMethod* verify_method = verify_class->GetVTableEntry(verify_index, image_pointer_size);
-    if (verify_method != excluded_method) {
-      DCHECK(!verify_method->HasSingleImplementation())
-          << "class: " << verify_class->PrettyClass()
-          << " verify_method: " << verify_method->PrettyMethod(true);
-    }
+    DCHECK(!verify_method->HasSingleImplementation())
+        << "class: " << verify_class->PrettyClass()
+        << " verify_method: " << verify_method->PrettyMethod(true);
     verify_class = verify_class->GetSuperClass();
   }
 }
@@ -209,152 +206,41 @@ void ClassHierarchyAnalysis::CheckSingleImplementationInfo(
     Handle<mirror::Class> klass,
     ArtMethod* virtual_method,
     ArtMethod* method_in_super,
-    std::unordered_set<ArtMethod*>& invalidated_single_impl_methods,
-    PointerSize pointer_size) {
+    std::unordered_set<ArtMethod*>& invalidated_single_impl_methods) {
   // TODO: if klass is not instantiable, virtual_method isn't invocable yet so
   // even if it overrides, it doesn't invalidate single-implementation
   // assumption.
 
-  DCHECK((virtual_method != method_in_super) || virtual_method->IsAbstract());
+  DCHECK_NE(virtual_method, method_in_super);
   DCHECK(method_in_super->GetDeclaringClass()->IsResolved()) << "class isn't resolved";
   // If virtual_method doesn't come from a default interface method, it should
   // be supplied by klass.
-  DCHECK(virtual_method == method_in_super ||
-         virtual_method->IsCopied() ||
+  DCHECK(virtual_method->IsCopied() ||
          virtual_method->GetDeclaringClass() == klass.Get());
 
-  // To make updating single-implementation flags simple, we always maintain the following
-  // invariant:
-  // Say all virtual methods in the same vtable slot, starting from the bottom child class
-  // to super classes, is a sequence of unique methods m3, m2, m1, ... (after removing duplicate
-  // methods for inherited methods).
-  // For example for the following class hierarchy,
-  //   class A { void m() { ... } }
-  //   class B extends A { void m() { ... } }
-  //   class C extends B {}
-  //   class D extends C { void m() { ... } }
-  // the sequence is D.m(), B.m(), A.m().
-  // The single-implementation status for that sequence of methods begin with one or two true's,
-  // then become all falses. The only case where two true's are possible is for one abstract
-  // method m and one non-abstract method mImpl that overrides method m.
-  // With the invariant, when linking in a new class, we only need to at most update one or
-  // two methods in the sequence for their single-implementation status, in order to maintain
-  // the invariant.
-
+  // A new virtual_method should set method_in_super to
+  // non-single-implementation (if not set already).
+  // We don't grab cha_lock_. Single-implementation flag won't be set to true
+  // again once it's set to false.
   if (!method_in_super->HasSingleImplementation()) {
     // method_in_super already has multiple implementations. All methods in the
     // same vtable slots in its super classes should have
     // non-single-implementation already.
     if (kIsDebugBuild) {
       VerifyNonSingleImplementation(klass->GetSuperClass()->GetSuperClass(),
-                                    method_in_super->GetMethodIndex(),
-                                    nullptr /* excluded_method */);
+                                    method_in_super->GetMethodIndex());
     }
     return;
   }
 
   // Native methods don't have single-implementation flag set.
   DCHECK(!method_in_super->IsNative());
-
-  uint16_t method_index = method_in_super->GetMethodIndex();
-  if (method_in_super->IsAbstract()) {
-    if (kIsDebugBuild) {
-      // An abstract method should have made all methods in the same vtable
-      // slot above it in the class hierarchy having non-single-implementation.
-      mirror::Class* super_super = klass->GetSuperClass()->GetSuperClass();
-      VerifyNonSingleImplementation(super_super,
-                                    method_index,
-                                    method_in_super);
-    }
-
-    if (virtual_method->IsAbstract()) {
-      // SUPER: abstract, VIRTUAL: abstract.
-      if (method_in_super == virtual_method) {
-        DCHECK(klass->IsInstantiable());
-        // An instantiable subclass hasn't provided a concrete implementation of
-        // the abstract method. Invoking method_in_super may throw AbstractMethodError.
-        // This is an uncommon case, so we simply treat method_in_super as not
-        // having single-implementation.
-        invalidated_single_impl_methods.insert(method_in_super);
-        return;
-      } else {
-        // One abstract method overrides another abstract method. This is an uncommon
-        // case. We simply treat method_in_super as not having single-implementation.
-        invalidated_single_impl_methods.insert(method_in_super);
-        return;
-      }
-    } else {
-      // SUPER: abstract, VIRTUAL: non-abstract.
-      // A non-abstract method overrides an abstract method.
-      if (method_in_super->GetSingleImplementation(pointer_size) == nullptr) {
-        // Abstract method_in_super gets its first implementation. Keep it as having
-        // single-implementation and record that single implementation.
-        DCHECK(method_in_super->HasSingleImplementation());
-        method_in_super->SetSingleImplementation(virtual_method, pointer_size);
-        return;
-      } else {
-        // Abstract method_in_super already got one implementation.
-        // Invalidate method_in_super's single-implementation status.
-        invalidated_single_impl_methods.insert(method_in_super);
-        return;
-      }
-    }
-  } else {
-    if (virtual_method->IsAbstract()) {
-      // SUPER: non-abstract, VIRTUAL: abstract.
-      // An abstract method overrides a non-abstract method. This is an uncommon
-      // case, we simply treat both methods as not having single-implementation.
-      invalidated_single_impl_methods.insert(virtual_method);
-      // Fall-through to handle invalidating method_in_super of its
-      // single-implementation status.
-    }
-
-    // SUPER: non-abstract, VIRTUAL: non-abstract/abstract(fall-through from previous if).
-    // Invalidate method_in_super's single-implementation status.
-    invalidated_single_impl_methods.insert(method_in_super);
-
-    // method_in_super might be the single-implementation of another abstract method,
-    // which should be also invalidated of its single-implementation status.
-    mirror::Class* super_super = klass->GetSuperClass()->GetSuperClass();
-    while (super_super != nullptr &&
-           method_index < super_super->GetVTableLength()) {
-      ArtMethod* method_in_super_super = super_super->GetVTableEntry(method_index, pointer_size);
-      if (method_in_super_super != method_in_super) {
-        if (method_in_super_super->IsAbstract()) {
-          if (method_in_super_super->HasSingleImplementation()) {
-            // Invalidate method_in_super's single-implementation status.
-            invalidated_single_impl_methods.insert(method_in_super_super);
-            // No need to further traverse up the class hierarchy since if there
-            // are cases that one abstract method overrides another method, we
-            // should have made that method having non-single-implementation already.
-          } else {
-            // method_in_super_super is already non-single-implementation.
-            // No need to further traverse up the class hierarchy.
-          }
-        } else {
-          DCHECK(!method_in_super_super->HasSingleImplementation());
-          // No need to further traverse up the class hierarchy since two non-abstract
-          // methods (method_in_super and method_in_super_super) should have set all
-          // other methods (abstract or not) in the vtable slot to be non-single-implementation.
-        }
-
-        if (kIsDebugBuild) {
-          VerifyNonSingleImplementation(super_super->GetSuperClass(),
-                                        method_index,
-                                        method_in_super_super);
-        }
-        // No need to go any further.
-        return;
-      } else {
-        super_super = super_super->GetSuperClass();
-      }
-    }
-  }
+  // Invalidate method_in_super's single-implementation status.
+  invalidated_single_impl_methods.insert(method_in_super);
 }
 
 void ClassHierarchyAnalysis::InitSingleImplementationFlag(Handle<mirror::Class> klass,
-                                                          ArtMethod* method,
-                                                          PointerSize pointer_size) {
+                                                          ArtMethod* method) {
   DCHECK(method->IsCopied() || method->GetDeclaringClass() == klass.Get());
   if (klass->IsFinal() || method->IsFinal()) {
     // Final classes or methods do not need CHA for devirtualization.
@@ -367,21 +253,16 @@ void ClassHierarchyAnalysis::InitSingleImplementationFlag(Handle<mirror::Class>
     // cannot be inlined. It's not worthwhile to devirtualize the
     // call which can add a deoptimization point.
     DCHECK(!method->HasSingleImplementation());
-  } else if (method->IsAbstract()) {
-    if (method->GetDeclaringClass()->IsInstantiable()) {
-      // Rare case, but we do accept it (such as 800-smali/smali/b_26143249.smali).
-      // Do not attempt to devirtualize it.
-      method->SetHasSingleImplementation(false);
-    } else {
-      // Abstract method starts with single-implementation flag set and null
-      // implementation method.
-      method->SetHasSingleImplementation(true);
-      DCHECK(method->GetSingleImplementation(pointer_size) == nullptr);
-    }
   } else {
     method->SetHasSingleImplementation(true);
-    // Single implementation of non-abstract method is itself.
-    DCHECK_EQ(method->GetSingleImplementation(pointer_size), method);
+    if (method->IsAbstract()) {
+      // There is no real implementation yet.
+      // TODO: implement single-implementation logic for abstract methods.
+      DCHECK(method->GetSingleImplementation() == nullptr);
+    } else {
+      // Single implementation of non-abstract method is itself.
+      DCHECK_EQ(method->GetSingleImplementation(), method);
+    }
   }
 }
 
@@ -405,29 +286,19 @@ void ClassHierarchyAnalysis::UpdateAfterLoadingOf(Handle<mirror::Class> klass) {
     ArtMethod* method_in_super = super_class->GetVTableEntry(i, image_pointer_size);
     if (method == method_in_super) {
       // vtable slot entry is inherited from super class.
-      if (method->IsAbstract() && klass->IsInstantiable()) {
-        // An instantiable class that inherits an abstract method is treated as
-        // supplying an implementation that throws AbstractMethodError.
-        CheckSingleImplementationInfo(klass,
-                                      method,
-                                      method_in_super,
-                                      invalidated_single_impl_methods,
-                                      image_pointer_size);
-      }
       continue;
     }
-    InitSingleImplementationFlag(klass, method, image_pointer_size);
+    InitSingleImplementationFlag(klass, method);
     CheckSingleImplementationInfo(klass,
                                   method,
                                   method_in_super,
-                                  invalidated_single_impl_methods,
-                                  image_pointer_size);
+                                  invalidated_single_impl_methods);
   }
 
   // For new virtual methods that don't override.
   for (int32_t i = super_class->GetVTableLength(); i < klass->GetVTableLength(); ++i) {
     ArtMethod* method = klass->GetVTableEntry(i, image_pointer_size);
-    InitSingleImplementationFlag(klass, method, image_pointer_size);
+    InitSingleImplementationFlag(klass, method);
   }
 
   Runtime* const runtime = Runtime::Current();
diff --git a/runtime/cha.h b/runtime/cha.h
index a56a752d8c..ada5c89981 100644
--- a/runtime/cha.h
+++ b/runtime/cha.h
@@ -112,9 +112,7 @@ class ClassHierarchyAnalysis {
   void UpdateAfterLoadingOf(Handle<mirror::Class> klass) REQUIRES_SHARED(Locks::mutator_lock_);
 
  private:
-  void InitSingleImplementationFlag(Handle<mirror::Class> klass,
-                                    ArtMethod* method,
-                                    PointerSize pointer_size)
+  void InitSingleImplementationFlag(Handle<mirror::Class> klass, ArtMethod* method)
       REQUIRES_SHARED(Locks::mutator_lock_);
 
   // `virtual_method` in `klass` overrides `method_in_super`.
@@ -125,16 +123,12 @@ class ClassHierarchyAnalysis {
       Handle<mirror::Class> klass,
       ArtMethod* virtual_method,
       ArtMethod* method_in_super,
-      std::unordered_set<ArtMethod*>& invalidated_single_impl_methods,
-      PointerSize pointer_size)
+      std::unordered_set<ArtMethod*>& invalidated_single_impl_methods)
       REQUIRES_SHARED(Locks::mutator_lock_);
 
-  // For all methods in vtable slot at `verify_index` of `verify_class` and its
-  // superclasses, single-implementation status should be false, except if the
-  // method is `excluded_method`.
-  void VerifyNonSingleImplementation(mirror::Class* verify_class,
-                                     uint16_t verify_index,
-                                     ArtMethod* excluded_method)
+  // Verify all methods in the same vtable slot from verify_class and its supers
+  // don't have single-implementation.
+  void VerifyNonSingleImplementation(mirror::Class* verify_class, uint16_t verify_index)
       REQUIRES_SHARED(Locks::mutator_lock_);
 
   // A map that maps a method to a set of compiled code that assumes that method has a
diff --git a/test/616-cha-abstract/expected.txt b/test/616-cha-abstract/expected.txt
deleted file mode 100644
index 6a5618ebc6..0000000000
--- a/test/616-cha-abstract/expected.txt
+++ /dev/null
@@ -1 +0,0 @@
-JNI_OnLoad called
diff --git a/test/616-cha-abstract/info.txt b/test/616-cha-abstract/info.txt
deleted file mode 100644
index 4f7e01391d..0000000000
--- a/test/616-cha-abstract/info.txt
+++ /dev/null
@@ -1 +0,0 @@
-Test for Class Hierarchy Analysis (CHA) on abstract method.
diff --git a/test/616-cha-abstract/run b/test/616-cha-abstract/run
deleted file mode 100644
index d8b4f0d26c..0000000000
--- a/test/616-cha-abstract/run
+++ /dev/null
@@ -1,18 +0,0 @@
-#!/bin/bash
-#
-# Copyright (C) 2017 The Android Open Source Project
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-# Run without an app image to prevent the classes to be loaded at startup.
-exec ${RUN} "${@}" --no-app-image
diff --git a/test/616-cha-abstract/src/Main.java b/test/616-cha-abstract/src/Main.java
deleted file mode 100644
index e1d7db170d..0000000000
--- a/test/616-cha-abstract/src/Main.java
+++ /dev/null
@@ -1,159 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-abstract class Base {
-  abstract void foo(int i);
-
-  void printError(String msg) {
-    System.out.println(msg);
-  }
-}
-
-class Main1 extends Base {
-  void foo(int i) {
-    if (i != 1) {
-      printError("error1");
-    }
-  }
-}
-
-class Main2 extends Main1 {
-  void foo(int i) {
-    if (i != 2) {
-      printError("error2");
-    }
-  }
-}
-
-public class Main {
-  static Main1 sMain1;
-  static Main1 sMain2;
-
-  static boolean sIsOptimizing = true;
-  static boolean sHasJIT = true;
-  static volatile boolean sOtherThreadStarted;
-
-  private static void assertSingleImplementation(Class<?> clazz, String method_name, boolean b) {
-    if (hasSingleImplementation(clazz, method_name) != b) {
-      System.out.println(clazz + "." + method_name +
-          " doesn't have single implementation value of " + b);
-    }
-  }
-
-  // sMain1.foo() will be always be Main1.foo() before Main2 is loaded/linked.
-  // So sMain1.foo() can be devirtualized to Main1.foo() and be inlined.
-  // After Dummy.createMain2() which links in Main2, live testOverride() on stack
-  // should be deoptimized.
-  static void testOverride(boolean createMain2, boolean wait, boolean setHasJIT) {
-    if (setHasJIT) {
-      if (isInterpreted()) {
-        sHasJIT = false;
-      }
-      return;
-    }
-
-    if (createMain2 && (sIsOptimizing || sHasJIT)) {
-      assertIsManaged();
-    }
-
-    sMain1.foo(sMain1.getClass() == Main1.class ? 1 : 2);
-
-    if (createMain2) {
-      // Wait for the other thread to start.
-      while (!sOtherThreadStarted);
-      // Create an Main2 instance and assign it to sMain2.
-      // sMain1 is kept the same.
-      sMain2 = Dummy.createMain2();
-      // Wake up the other thread.
-      synchronized(Main.class) {
-        Main.class.notify();
-      }
-    } else if (wait) {
-      // This is the other thread.
-      synchronized(Main.class) {
-        sOtherThreadStarted = true;
-        // Wait for Main2 to be linked and deoptimization is triggered.
-        try {
-          Main.class.wait();
-        } catch (Exception e) {
-        }
-      }
-    }
-
-    // There should be a deoptimization here right after Main2 is linked by
-    // calling Dummy.createMain2(), even though sMain1 didn't change.
-    // The behavior here would be different if inline-cache is used, which
-    // doesn't deoptimize since sMain1 still hits the type cache.
-    sMain1.foo(sMain1.getClass() == Main1.class ? 1 : 2);
-    if ((createMain2 || wait) && sHasJIT && !sIsOptimizing) {
-      // This method should be deoptimized right after Main2 is created.
-      assertIsInterpreted();
-    }
-
-    if (sMain2 != null) {
-      sMain2.foo(sMain2.getClass() == Main1.class ? 1 : 2);
-    }
-  }
-
-  // Test scenarios under which CHA-based devirtualization happens,
-  // and class loading that overrides a method can invalidate compiled code.
-  public static void main(String[] args) {
-    System.loadLibrary(args[0]);
-
-    if (isInterpreted()) {
-      sIsOptimizing = false;
-    }
-
-    // sMain1 is an instance of Main1. Main2 hasn't bee loaded yet.
-    sMain1 = new Main1();
-
-    ensureJitCompiled(Main.class, "testOverride");
-    testOverride(false, false, true);
-
-    if (sHasJIT && !sIsOptimizing) {
-      assertSingleImplementation(Base.class, "foo", true);
-      assertSingleImplementation(Main1.class, "foo", true);
-    } else {
-      // Main2 is verified ahead-of-time so it's linked in already.
-    }
-
-    // Create another thread that also calls sMain1.foo().
-    // Try to test suspend and deopt another thread.
-    new Thread() {
-      public void run() {
-        testOverride(false, true, false);
-      }
-    }.start();
-
-    // This will create Main2 instance in the middle of testOverride().
-    testOverride(true, false, false);
-    assertSingleImplementation(Base.class, "foo", false);
-    assertSingleImplementation(Main1.class, "foo", false);
-  }
-
-  private static native void ensureJitCompiled(Class<?> itf, String method_name);
-  private static native void assertIsInterpreted();
-  private static native void assertIsManaged();
-  private static native boolean isInterpreted();
-  private static native boolean hasSingleImplementation(Class<?> clazz, String method_name);
-}
-
-// Put createMain2() in another class to avoid class loading due to verifier.
-class Dummy {
-  static Main1 createMain2() {
-    return new Main2();
-  }
-}