Revert^2 "OpenJDK 11: Add String.repeat()"

This reverts commit 48fb9f43a81fa0cab09ed4a4f3d478c1a0ecbe9e.

Reason for revert: d8 has adopted the same behaviour as the intended
implementation so tests should no longer fail when backports are
applied.

Bug: 191859202
Bug: 202962059
Test: Treehugger
Test: cherry-pick to problem branch and run tests there.
Change-Id: I734673a2c37d04e77a76496a722db1460eaf2b49

5 files changed, 63 insertions, 3 deletions

diff --git a/runtime/mirror/string-inl.h b/runtime/mirror/string-inl.h
index dd280364e1..b5b9c71de9 100644
--- a/runtime/mirror/string-inl.h
+++ b/runtime/mirror/string-inl.h
@@ -35,9 +35,9 @@ inline uint32_t String::ClassSize(PointerSize pointer_size) {
   //   lambda$codePoints$1$CharSequence
   // which were virtual functions in standalone desugar, becomes
   // direct functions with D8 desugaring.
-  uint32_t vtable_entries = Object::kVTableLength + 54;
+  uint32_t vtable_entries = Object::kVTableLength + 55;
 #else
-  uint32_t vtable_entries = Object::kVTableLength + 56;
+  uint32_t vtable_entries = Object::kVTableLength + 57;
 #endif
   return Class::ComputeClassSize(true, vtable_entries, 0, 0, 0, 1, 2, pointer_size);
 }
diff --git a/runtime/mirror/string.cc b/runtime/mirror/string.cc
index 0ce45b855b..704433aca1 100644
--- a/runtime/mirror/string.cc
+++ b/runtime/mirror/string.cc
@@ -151,6 +151,54 @@ ObjPtr<String> String::DoConcat(Thread* self, Handle<String> h_this, Handle<Stri
   return Alloc(self, length_with_flag, allocator_type, visitor);
 }
 
+template<typename T>
+static void RepeatCharacters(ObjPtr<String> new_string, Handle<String> h_this, int32_t count)
+    REQUIRES_SHARED(Locks::mutator_lock_) {
+  T *new_value, *h_this_value;
+  if constexpr (std::is_same_v<T, uint8_t>) {
+    new_value = new_string->GetValueCompressed();
+    h_this_value = h_this->GetValueCompressed();
+  } else {
+    new_value = new_string->GetValue();
+    h_this_value = h_this->GetValue();
+  }
+  int32_t length_this = h_this->GetLength();
+  if (length_this == 1) {
+    // compiler is smart enough to use memset for uint8_t
+    std::fill(new_value, new_value + count, h_this_value[0]);
+  } else {
+    memcpy(new_value, h_this_value, length_this * sizeof(T));
+    int32_t copied = length_this;
+    int32_t limit = length_this * count;
+    for (; copied < limit - copied; copied <<= 1) {
+      memcpy(new_value + copied, new_value, copied * sizeof(T));
+    }
+    memcpy(new_value + copied, new_value, (limit - copied) * sizeof(T));
+  }
+}
+
+ObjPtr<String> String::DoRepeat(Thread* self, Handle<String> h_this, int32_t count) {
+  int32_t length_this = h_this->GetLength();
+  DCHECK_GT(count, 1);
+  DCHECK_LE(length_this, std::numeric_limits<int32_t>::max() / count);
+  gc::AllocatorType allocator_type = Runtime::Current()->GetHeap()->GetCurrentAllocator();
+  const bool compressible = kUseStringCompression && (h_this->IsCompressed());
+  const int32_t length_with_flag = String::GetFlaggedCount(length_this * count, compressible);
+
+  auto visitor = [=](ObjPtr<Object> obj, size_t usable_size) REQUIRES_SHARED(Locks::mutator_lock_) {
+      SetStringCountVisitor set_string_count_visitor(length_with_flag);
+      set_string_count_visitor(obj, usable_size);
+      ObjPtr<String> new_string = obj->AsString();
+
+      if (compressible) {
+        RepeatCharacters<uint8_t>(new_string, h_this, count);
+      } else {
+        RepeatCharacters<uint16_t>(new_string, h_this, count);
+      }
+  };
+  return Alloc(self, length_with_flag, allocator_type, visitor);
+}
+
 ObjPtr<String> String::AllocFromUtf16(Thread* self,
                                       int32_t utf16_length,
                                       const uint16_t* utf16_data_in) {
diff --git a/runtime/mirror/string.h b/runtime/mirror/string.h
index 53fcf82caa..6cb560e4a2 100644
--- a/runtime/mirror/string.h
+++ b/runtime/mirror/string.h
@@ -160,6 +160,9 @@ class MANAGED String final : public Object {
   static ObjPtr<String> DoConcat(Thread* self, Handle<String> h_this, Handle<String> h_arg)
       REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!Roles::uninterruptible_);
 
+  static ObjPtr<String> DoRepeat(Thread* self, Handle<String> h_this, int32_t count)
+      REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!Roles::uninterruptible_);
+
   static ObjPtr<String> AllocFromUtf16(Thread* self,
                                        int32_t utf16_length,
                                        const uint16_t* utf16_data_in)
diff --git a/runtime/native/java_lang_String.cc b/runtime/native/java_lang_String.cc
index 86f93299d9..94ca5b53d6 100644
--- a/runtime/native/java_lang_String.cc
+++ b/runtime/native/java_lang_String.cc
@@ -109,10 +109,19 @@ static jcharArray String_toCharArray(JNIEnv* env, jobject java_this) {
   return soa.AddLocalReference<jcharArray>(mirror::String::ToCharArray(s, soa.Self()));
 }
 
+static jstring String_doRepeat(JNIEnv* env, jobject java_this, jint count) {
+  ScopedFastNativeObjectAccess soa(env);
+  StackHandleScope<1> hs(soa.Self());
+  Handle<mirror::String> string = hs.NewHandle(soa.Decode<mirror::String>(java_this));
+  ObjPtr<mirror::String> result = mirror::String::DoRepeat(soa.Self(), string, count);
+  return soa.AddLocalReference<jstring>(result);
+}
+
 static JNINativeMethod gMethods[] = {
   FAST_NATIVE_METHOD(String, charAt, "(I)C"),
   FAST_NATIVE_METHOD(String, compareTo, "(Ljava/lang/String;)I"),
   FAST_NATIVE_METHOD(String, concat, "(Ljava/lang/String;)Ljava/lang/String;"),
+  FAST_NATIVE_METHOD(String, doRepeat, "(I)Ljava/lang/String;"),
   FAST_NATIVE_METHOD(String, doReplace, "(CC)Ljava/lang/String;"),
   FAST_NATIVE_METHOD(String, fastSubstring, "(II)Ljava/lang/String;"),
   FAST_NATIVE_METHOD(String, getCharsNoCheck, "(II[CI)V"),
diff --git a/test/100-reflect2/expected-stdout.txt b/test/100-reflect2/expected-stdout.txt
index 2b57824464..0d0482aac6 100644
--- a/test/100-reflect2/expected-stdout.txt
+++ b/test/100-reflect2/expected-stdout.txt
@@ -33,7 +33,7 @@ z (class java.lang.Character)
 14 (class java.lang.Short)
 [java.lang.String(int,int,char[]), public java.lang.String(), public java.lang.String(byte[]), public java.lang.String(byte[],int), public java.lang.String(byte[],int,int), public java.lang.String(byte[],int,int,int), public java.lang.String(byte[],int,int,java.lang.String) throws java.io.UnsupportedEncodingException, public java.lang.String(byte[],int,int,java.nio.charset.Charset), public java.lang.String(byte[],java.lang.String) throws java.io.UnsupportedEncodingException, public java.lang.String(byte[],java.nio.charset.Charset), public java.lang.String(char[]), public java.lang.String(char[],int,int), public java.lang.String(int[],int,int), public java.lang.String(java.lang.String), public java.lang.String(java.lang.StringBuffer), public java.lang.String(java.lang.StringBuilder)]
 [private final int java.lang.String.count, private int java.lang.String.hash, private static final java.io.ObjectStreamField[] java.lang.String.serialPersistentFields, private static final long java.lang.String.serialVersionUID, public static final java.util.Comparator java.lang.String.CASE_INSENSITIVE_ORDER]
-[native void java.lang.String.getCharsNoCheck(int,int,char[],int), private boolean java.lang.String.nonSyncContentEquals(java.lang.AbstractStringBuilder), private int java.lang.String.indexOfSupplementary(int,int), private int java.lang.String.lastIndexOfSupplementary(int,int), private native java.lang.String java.lang.String.doReplace(char,char), private native java.lang.String java.lang.String.fastSubstring(int,int), private static int java.lang.String.indexOf(java.lang.String,java.lang.String,int), private static int java.lang.String.lastIndexOf(java.lang.String,java.lang.String,int), public boolean java.lang.String.contains(java.lang.CharSequence), public boolean java.lang.String.contentEquals(java.lang.CharSequence), public boolean java.lang.String.contentEquals(java.lang.StringBuffer), public boolean java.lang.String.endsWith(java.lang.String), public boolean java.lang.String.equals(java.lang.Object), public boolean java.lang.String.equalsIgnoreCase(java.lang.String), public boolean java.lang.String.isEmpty(), public boolean java.lang.String.matches(java.lang.String), public boolean java.lang.String.regionMatches(boolean,int,java.lang.String,int,int), public boolean java.lang.String.regionMatches(int,java.lang.String,int,int), public boolean java.lang.String.startsWith(java.lang.String), public boolean java.lang.String.startsWith(java.lang.String,int), public byte[] java.lang.String.getBytes(), public byte[] java.lang.String.getBytes(java.lang.String) throws java.io.UnsupportedEncodingException, public byte[] java.lang.String.getBytes(java.nio.charset.Charset), public int java.lang.String.codePointAt(int), public int java.lang.String.codePointBefore(int), public int java.lang.String.codePointCount(int,int), public int java.lang.String.compareTo(java.lang.Object), public int java.lang.String.compareToIgnoreCase(java.lang.String), public int java.lang.String.hashCode(), public int java.lang.String.indexOf(int), public int java.lang.String.indexOf(int,int), public int java.lang.String.indexOf(java.lang.String), public int java.lang.String.indexOf(java.lang.String,int), public int java.lang.String.lastIndexOf(int), public int java.lang.String.lastIndexOf(int,int), public int java.lang.String.lastIndexOf(java.lang.String), public int java.lang.String.lastIndexOf(java.lang.String,int), public int java.lang.String.length(), public int java.lang.String.offsetByCodePoints(int,int), public java.lang.CharSequence java.lang.String.subSequence(int,int), public java.lang.String java.lang.String.replace(char,char), public java.lang.String java.lang.String.replace(java.lang.CharSequence,java.lang.CharSequence), public java.lang.String java.lang.String.replaceAll(java.lang.String,java.lang.String), public java.lang.String java.lang.String.replaceFirst(java.lang.String,java.lang.String), public java.lang.String java.lang.String.substring(int), public java.lang.String java.lang.String.substring(int,int), public java.lang.String java.lang.String.toLowerCase(), public java.lang.String java.lang.String.toLowerCase(java.util.Locale), public java.lang.String java.lang.String.toString(), public java.lang.String java.lang.String.toUpperCase(), public java.lang.String java.lang.String.toUpperCase(java.util.Locale), public java.lang.String java.lang.String.trim(), public java.lang.String[] java.lang.String.split(java.lang.String), public java.lang.String[] java.lang.String.split(java.lang.String,int), public native char java.lang.String.charAt(int), public native char[] java.lang.String.toCharArray(), public native int java.lang.String.compareTo(java.lang.String), public native java.lang.String java.lang.String.concat(java.lang.String), public native java.lang.String java.lang.String.intern(), public static java.lang.String java.lang.String.copyValueOf(char[]), public static java.lang.String java.lang.String.copyValueOf(char[],int,int), public static java.lang.String java.lang.String.format(java.lang.String,java.lang.Object[]), public static java.lang.String java.lang.String.format(java.util.Locale,java.lang.String,java.lang.Object[]), public static java.lang.String java.lang.String.join(java.lang.CharSequence,java.lang.CharSequence[]), public static java.lang.String java.lang.String.join(java.lang.CharSequence,java.lang.Iterable), public static java.lang.String java.lang.String.valueOf(boolean), public static java.lang.String java.lang.String.valueOf(char), public static java.lang.String java.lang.String.valueOf(char[]), public static java.lang.String java.lang.String.valueOf(char[],int,int), public static java.lang.String java.lang.String.valueOf(double), public static java.lang.String java.lang.String.valueOf(float), public static java.lang.String java.lang.String.valueOf(int), public static java.lang.String java.lang.String.valueOf(java.lang.Object), public static java.lang.String java.lang.String.valueOf(long), public void java.lang.String.getBytes(int,int,byte[],int), public void java.lang.String.getChars(int,int,char[],int), static int java.lang.String.indexOf(char[],int,int,char[],int,int,int), static int java.lang.String.indexOf(char[],int,int,java.lang.String,int), static int java.lang.String.lastIndexOf(char[],int,int,char[],int,int,int), static int java.lang.String.lastIndexOf(char[],int,int,java.lang.String,int), void java.lang.String.getChars(char[],int)]
+[native void java.lang.String.getCharsNoCheck(int,int,char[],int), private boolean java.lang.String.nonSyncContentEquals(java.lang.AbstractStringBuilder), private int java.lang.String.indexOfSupplementary(int,int), private int java.lang.String.lastIndexOfSupplementary(int,int), private native java.lang.String java.lang.String.doRepeat(int), private native java.lang.String java.lang.String.doReplace(char,char), private native java.lang.String java.lang.String.fastSubstring(int,int), private static int java.lang.String.indexOf(java.lang.String,java.lang.String,int), private static int java.lang.String.lastIndexOf(java.lang.String,java.lang.String,int), public boolean java.lang.String.contains(java.lang.CharSequence), public boolean java.lang.String.contentEquals(java.lang.CharSequence), public boolean java.lang.String.contentEquals(java.lang.StringBuffer), public boolean java.lang.String.endsWith(java.lang.String), public boolean java.lang.String.equals(java.lang.Object), public boolean java.lang.String.equalsIgnoreCase(java.lang.String), public boolean java.lang.String.isEmpty(), public boolean java.lang.String.matches(java.lang.String), public boolean java.lang.String.regionMatches(boolean,int,java.lang.String,int,int), public boolean java.lang.String.regionMatches(int,java.lang.String,int,int), public boolean java.lang.String.startsWith(java.lang.String), public boolean java.lang.String.startsWith(java.lang.String,int), public byte[] java.lang.String.getBytes(), public byte[] java.lang.String.getBytes(java.lang.String) throws java.io.UnsupportedEncodingException, public byte[] java.lang.String.getBytes(java.nio.charset.Charset), public int java.lang.String.codePointAt(int), public int java.lang.String.codePointBefore(int), public int java.lang.String.codePointCount(int,int), public int java.lang.String.compareTo(java.lang.Object), public int java.lang.String.compareToIgnoreCase(java.lang.String), public int java.lang.String.hashCode(), public int java.lang.String.indexOf(int), public int java.lang.String.indexOf(int,int), public int java.lang.String.indexOf(java.lang.String), public int java.lang.String.indexOf(java.lang.String,int), public int java.lang.String.lastIndexOf(int), public int java.lang.String.lastIndexOf(int,int), public int java.lang.String.lastIndexOf(java.lang.String), public int java.lang.String.lastIndexOf(java.lang.String,int), public int java.lang.String.length(), public int java.lang.String.offsetByCodePoints(int,int), public java.lang.CharSequence java.lang.String.subSequence(int,int), public java.lang.String java.lang.String.repeat(int), public java.lang.String java.lang.String.replace(char,char), public java.lang.String java.lang.String.replace(java.lang.CharSequence,java.lang.CharSequence), public java.lang.String java.lang.String.replaceAll(java.lang.String,java.lang.String), public java.lang.String java.lang.String.replaceFirst(java.lang.String,java.lang.String), public java.lang.String java.lang.String.substring(int), public java.lang.String java.lang.String.substring(int,int), public java.lang.String java.lang.String.toLowerCase(), public java.lang.String java.lang.String.toLowerCase(java.util.Locale), public java.lang.String java.lang.String.toString(), public java.lang.String java.lang.String.toUpperCase(), public java.lang.String java.lang.String.toUpperCase(java.util.Locale), public java.lang.String java.lang.String.trim(), public java.lang.String[] java.lang.String.split(java.lang.String), public java.lang.String[] java.lang.String.split(java.lang.String,int), public native char java.lang.String.charAt(int), public native char[] java.lang.String.toCharArray(), public native int java.lang.String.compareTo(java.lang.String), public native java.lang.String java.lang.String.concat(java.lang.String), public native java.lang.String java.lang.String.intern(), public static java.lang.String java.lang.String.copyValueOf(char[]), public static java.lang.String java.lang.String.copyValueOf(char[],int,int), public static java.lang.String java.lang.String.format(java.lang.String,java.lang.Object[]), public static java.lang.String java.lang.String.format(java.util.Locale,java.lang.String,java.lang.Object[]), public static java.lang.String java.lang.String.join(java.lang.CharSequence,java.lang.CharSequence[]), public static java.lang.String java.lang.String.join(java.lang.CharSequence,java.lang.Iterable), public static java.lang.String java.lang.String.valueOf(boolean), public static java.lang.String java.lang.String.valueOf(char), public static java.lang.String java.lang.String.valueOf(char[]), public static java.lang.String java.lang.String.valueOf(char[],int,int), public static java.lang.String java.lang.String.valueOf(double), public static java.lang.String java.lang.String.valueOf(float), public static java.lang.String java.lang.String.valueOf(int), public static java.lang.String java.lang.String.valueOf(java.lang.Object), public static java.lang.String java.lang.String.valueOf(long), public void java.lang.String.getBytes(int,int,byte[],int), public void java.lang.String.getChars(int,int,char[],int), static int java.lang.String.indexOf(char[],int,int,char[],int,int,int), static int java.lang.String.indexOf(char[],int,int,java.lang.String,int), static int java.lang.String.lastIndexOf(char[],int,int,char[],int,int,int), static int java.lang.String.lastIndexOf(char[],int,int,java.lang.String,int), void java.lang.String.getChars(char[],int)]
 []
 [interface java.io.Serializable, interface java.lang.Comparable, interface java.lang.CharSequence]
 0