Optimize JDWP stack local values access

The StackFrame.GetValues and StackFrame.SetValues JDWP commands can refer to
multiple variables at the same time in a given frame. However we used to walk
the stack until getting to the requested frame for each variable.

Now, we walk the stack only once until getting to the frame so the context is
initialized. Then we read/write value for each variable from this context.

Bug: 17343501
Bug: 15680615

Change-Id: I2a4128f29a3c5856b994e280037c0a09eb48c5c8

1 files changed, 303 insertions, 274 deletions

diff --git a/runtime/debugger.cc b/runtime/debugger.cc
index aced95465b..02064bef9d 100644
--- a/runtime/debugger.cc
+++ b/runtime/debugger.cc
@@ -2475,300 +2475,329 @@ JDWP::JdwpError Dbg::GetThisObject(JDWP::ObjectId thread_id, JDWP::FrameId frame
   return JDWP::ERR_NONE;
 }
 
-JDWP::JdwpError Dbg::GetLocalValue(JDWP::ObjectId thread_id, JDWP::FrameId frame_id, int slot,
-                                   JDWP::JdwpTag tag, uint8_t* buf, size_t width) {
-  struct GetLocalVisitor : public StackVisitor {
-    GetLocalVisitor(const ScopedObjectAccessUnchecked& soa, Thread* thread, Context* context,
-                    JDWP::FrameId frame_id, int slot, JDWP::JdwpTag tag, uint8_t* buf, size_t width)
-        SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
-        : StackVisitor(thread, context), soa_(soa), frame_id_(frame_id), slot_(slot), tag_(tag),
-          buf_(buf), width_(width), error_(JDWP::ERR_NONE) {}
-
-    // TODO: Enable annotalysis. We know lock is held in constructor, but abstraction confuses
-    // annotalysis.
-    bool VisitFrame() NO_THREAD_SAFETY_ANALYSIS {
-      if (GetFrameId() != frame_id_) {
-        return true;  // Not our frame, carry on.
-      }
-      // TODO: check that the tag is compatible with the actual type of the slot!
-      // TODO: check slot is valid for this method or return INVALID_SLOT error.
-      mirror::ArtMethod* m = GetMethod();
-      if (m->IsNative()) {
-        // We can't read local value from native method.
-        error_ = JDWP::ERR_OPAQUE_FRAME;
-        return false;
-      }
-      uint16_t reg = DemangleSlot(slot_, m);
-      constexpr JDWP::JdwpError kFailureErrorCode = JDWP::ERR_ABSENT_INFORMATION;
-      switch (tag_) {
-        case JDWP::JT_BOOLEAN: {
-          CHECK_EQ(width_, 1U);
-          uint32_t intVal;
-          if (GetVReg(m, reg, kIntVReg, &intVal)) {
-            VLOG(jdwp) << "get boolean local " << reg << " = " << intVal;
-            JDWP::Set1(buf_+1, intVal != 0);
-          } else {
-            VLOG(jdwp) << "failed to get boolean local " << reg;
-            error_ = kFailureErrorCode;
-          }
-          break;
-        }
-        case JDWP::JT_BYTE: {
-          CHECK_EQ(width_, 1U);
-          uint32_t intVal;
-          if (GetVReg(m, reg, kIntVReg, &intVal)) {
-            VLOG(jdwp) << "get byte local " << reg << " = " << intVal;
-            JDWP::Set1(buf_+1, intVal);
-          } else {
-            VLOG(jdwp) << "failed to get byte local " << reg;
-            error_ = kFailureErrorCode;
-          }
-          break;
-        }
-        case JDWP::JT_SHORT:
-        case JDWP::JT_CHAR: {
-          CHECK_EQ(width_, 2U);
-          uint32_t intVal;
-          if (GetVReg(m, reg, kIntVReg, &intVal)) {
-            VLOG(jdwp) << "get short/char local " << reg << " = " << intVal;
-            JDWP::Set2BE(buf_+1, intVal);
-          } else {
-            VLOG(jdwp) << "failed to get short/char local " << reg;
-            error_ = kFailureErrorCode;
-          }
-          break;
-        }
-        case JDWP::JT_INT: {
-          CHECK_EQ(width_, 4U);
-          uint32_t intVal;
-          if (GetVReg(m, reg, kIntVReg, &intVal)) {
-            VLOG(jdwp) << "get int local " << reg << " = " << intVal;
-            JDWP::Set4BE(buf_+1, intVal);
-          } else {
-            VLOG(jdwp) << "failed to get int local " << reg;
-            error_ = kFailureErrorCode;
-          }
-          break;
-        }
-        case JDWP::JT_FLOAT: {
-          CHECK_EQ(width_, 4U);
-          uint32_t intVal;
-          if (GetVReg(m, reg, kFloatVReg, &intVal)) {
-            VLOG(jdwp) << "get float local " << reg << " = " << intVal;
-            JDWP::Set4BE(buf_+1, intVal);
-          } else {
-            VLOG(jdwp) << "failed to get float local " << reg;
-            error_ = kFailureErrorCode;
-          }
-          break;
-        }
-        case JDWP::JT_ARRAY:
-        case JDWP::JT_CLASS_LOADER:
-        case JDWP::JT_CLASS_OBJECT:
-        case JDWP::JT_OBJECT:
-        case JDWP::JT_STRING:
-        case JDWP::JT_THREAD:
-        case JDWP::JT_THREAD_GROUP: {
-          CHECK_EQ(width_, sizeof(JDWP::ObjectId));
-          uint32_t intVal;
-          if (GetVReg(m, reg, kReferenceVReg, &intVal)) {
-            mirror::Object* o = reinterpret_cast<mirror::Object*>(intVal);
-            VLOG(jdwp) << "get " << tag_ << " object local " << reg << " = " << o;
-            if (!Runtime::Current()->GetHeap()->IsValidObjectAddress(o)) {
-              LOG(FATAL) << "Register " << reg << " expected to hold " << tag_ << " object: " << o;
-            }
-            tag_ = TagFromObject(soa_, o);
-            JDWP::SetObjectId(buf_+1, gRegistry->Add(o));
-          } else {
-            VLOG(jdwp) << "failed to get " << tag_ << " object local " << reg;
-            error_ = kFailureErrorCode;
-          }
-          break;
-        }
-        case JDWP::JT_DOUBLE: {
-          CHECK_EQ(width_, 8U);
-          uint64_t longVal;
-          if (GetVRegPair(m, reg, kDoubleLoVReg, kDoubleHiVReg, &longVal)) {
-            VLOG(jdwp) << "get double local " << reg << " = " << longVal;
-            JDWP::Set8BE(buf_+1, longVal);
-          } else {
-            VLOG(jdwp) << "failed to get double local " << reg;
-            error_ = kFailureErrorCode;
-          }
-          break;
-        }
-        case JDWP::JT_LONG: {
-          CHECK_EQ(width_, 8U);
-          uint64_t longVal;
-          if (GetVRegPair(m, reg, kLongLoVReg, kLongHiVReg, &longVal)) {
-            VLOG(jdwp) << "get long local " << reg << " = " << longVal;
-            JDWP::Set8BE(buf_+1, longVal);
-          } else {
-            VLOG(jdwp) << "failed to get long local " << reg;
-            error_ = kFailureErrorCode;
-          }
-          break;
-        }
-        default:
-          LOG(FATAL) << "Unknown tag " << tag_;
-          break;
-      }
+// Walks the stack until we find the frame with the given FrameId.
+class FindFrameVisitor FINAL : public StackVisitor {
+ public:
+  FindFrameVisitor(Thread* thread, Context* context, JDWP::FrameId frame_id)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
+      : StackVisitor(thread, context), frame_id_(frame_id), error_(JDWP::ERR_INVALID_FRAMEID) {}
 
-      // Prepend tag, which may have been updated.
-      JDWP::Set1(buf_, tag_);
-      return false;
+  // TODO: Enable annotalysis. We know lock is held in constructor, but abstraction confuses
+  // annotalysis.
+  bool VisitFrame() NO_THREAD_SAFETY_ANALYSIS {
+    if (GetFrameId() != frame_id_) {
+      return true;  // Not our frame, carry on.
     }
-    const ScopedObjectAccessUnchecked& soa_;
-    const JDWP::FrameId frame_id_;
-    const int slot_;
-    JDWP::JdwpTag tag_;
-    uint8_t* const buf_;
-    const size_t width_;
-    JDWP::JdwpError error_;
-  };
+    mirror::ArtMethod* m = GetMethod();
+    if (m->IsNative()) {
+      // We can't read/write local value from/into native method.
+      error_ = JDWP::ERR_OPAQUE_FRAME;
+    } else {
+      // We found our frame.
+      error_ = JDWP::ERR_NONE;
+    }
+    return false;
+  }
+
+  JDWP::JdwpError GetError() const {
+    return error_;
+  }
+
+ private:
+  const JDWP::FrameId frame_id_;
+  JDWP::JdwpError error_;
+};
+
+JDWP::JdwpError Dbg::GetLocalValues(JDWP::Request* request, JDWP::ExpandBuf* pReply) {
+  JDWP::ObjectId thread_id = request->ReadThreadId();
+  JDWP::FrameId frame_id = request->ReadFrameId();
 
   ScopedObjectAccessUnchecked soa(Thread::Current());
-  MutexLock mu(soa.Self(), *Locks::thread_list_lock_);
-  JDWP::JdwpError error;
-  Thread* thread = DecodeThread(soa, thread_id, &error);
-  if (error != JDWP::ERR_NONE) {
-    return error;
+  Thread* thread;
+  {
+    MutexLock mu(soa.Self(), *Locks::thread_list_lock_);
+    JDWP::JdwpError error;
+    thread = DecodeThread(soa, thread_id, &error);
+    if (error != JDWP::ERR_NONE) {
+      return error;
+    }
   }
-  // TODO check thread is suspended by the debugger ?
+  // Find the frame with the given frame_id.
   std::unique_ptr<Context> context(Context::Create());
-  GetLocalVisitor visitor(soa, thread, context.get(), frame_id, slot, tag, buf, width);
+  FindFrameVisitor visitor(thread, context.get(), frame_id);
   visitor.WalkStack();
-  return visitor.error_;
-}
+  if (visitor.GetError() != JDWP::ERR_NONE) {
+    return visitor.GetError();
+  }
 
-JDWP::JdwpError Dbg::SetLocalValue(JDWP::ObjectId thread_id, JDWP::FrameId frame_id, int slot,
-                                   JDWP::JdwpTag tag, uint64_t value, size_t width) {
-  struct SetLocalVisitor : public StackVisitor {
-    SetLocalVisitor(Thread* thread, Context* context,
-                    JDWP::FrameId frame_id, int slot, JDWP::JdwpTag tag, uint64_t value,
-                    size_t width)
-        SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
-        : StackVisitor(thread, context),
-          frame_id_(frame_id), slot_(slot), tag_(tag), value_(value), width_(width),
-          error_(JDWP::ERR_NONE) {}
+  // Read the values from visitor's context.
+  int32_t slot_count = request->ReadSigned32("slot count");
+  expandBufAdd4BE(pReply, slot_count);     /* "int values" */
+  for (int32_t i = 0; i < slot_count; ++i) {
+    uint32_t slot = request->ReadUnsigned32("slot");
+    JDWP::JdwpTag reqSigByte = request->ReadTag();
 
-    // TODO: Enable annotalysis. We know lock is held in constructor, but abstraction confuses
-    // annotalysis.
-    bool VisitFrame() NO_THREAD_SAFETY_ANALYSIS {
-      if (GetFrameId() != frame_id_) {
-        return true;  // Not our frame, carry on.
+    VLOG(jdwp) << "    --> slot " << slot << " " << reqSigByte;
+
+    size_t width = Dbg::GetTagWidth(reqSigByte);
+    uint8_t* ptr = expandBufAddSpace(pReply, width+1);
+    JDWP::JdwpError error = Dbg::GetLocalValue(visitor, soa, slot, reqSigByte, ptr, width);
+    if (error != JDWP::ERR_NONE) {
+      return error;
+    }
+  }
+  return JDWP::ERR_NONE;
+}
+
+JDWP::JdwpError Dbg::GetLocalValue(const StackVisitor& visitor, ScopedObjectAccessUnchecked& soa,
+                                   int slot, JDWP::JdwpTag tag, uint8_t* buf, size_t width) {
+  mirror::ArtMethod* m = visitor.GetMethod();
+  uint16_t reg = DemangleSlot(slot, m);
+  // TODO: check that the tag is compatible with the actual type of the slot!
+  // TODO: check slot is valid for this method or return INVALID_SLOT error.
+  constexpr JDWP::JdwpError kFailureErrorCode = JDWP::ERR_ABSENT_INFORMATION;
+  switch (tag) {
+    case JDWP::JT_BOOLEAN: {
+      CHECK_EQ(width, 1U);
+      uint32_t intVal;
+      if (visitor.GetVReg(m, reg, kIntVReg, &intVal)) {
+        VLOG(jdwp) << "get boolean local " << reg << " = " << intVal;
+        JDWP::Set1(buf + 1, intVal != 0);
+      } else {
+        VLOG(jdwp) << "failed to get boolean local " << reg;
+        return kFailureErrorCode;
       }
-      // TODO: check that the tag is compatible with the actual type of the slot!
-      // TODO: check slot is valid for this method or return INVALID_SLOT error.
-      mirror::ArtMethod* m = GetMethod();
-      if (m->IsNative()) {
-        // We can't read local value from native method.
-        error_ = JDWP::ERR_OPAQUE_FRAME;
-        return false;
+      break;
+    }
+    case JDWP::JT_BYTE: {
+      CHECK_EQ(width, 1U);
+      uint32_t intVal;
+      if (visitor.GetVReg(m, reg, kIntVReg, &intVal)) {
+        VLOG(jdwp) << "get byte local " << reg << " = " << intVal;
+        JDWP::Set1(buf + 1, intVal);
+      } else {
+        VLOG(jdwp) << "failed to get byte local " << reg;
+        return kFailureErrorCode;
       }
-      uint16_t reg = DemangleSlot(slot_, m);
-      constexpr JDWP::JdwpError kFailureErrorCode = JDWP::ERR_ABSENT_INFORMATION;
-      switch (tag_) {
-        case JDWP::JT_BOOLEAN:
-        case JDWP::JT_BYTE:
-          CHECK_EQ(width_, 1U);
-          if (!SetVReg(m, reg, static_cast<uint32_t>(value_), kIntVReg)) {
-            VLOG(jdwp) << "failed to set boolean/byte local " << reg << " = "
-                       << static_cast<uint32_t>(value_);
-            error_ = kFailureErrorCode;
-          }
-          break;
-        case JDWP::JT_SHORT:
-        case JDWP::JT_CHAR:
-          CHECK_EQ(width_, 2U);
-          if (!SetVReg(m, reg, static_cast<uint32_t>(value_), kIntVReg)) {
-            VLOG(jdwp) << "failed to set short/char local " << reg << " = "
-                       << static_cast<uint32_t>(value_);
-            error_ = kFailureErrorCode;
-          }
-          break;
-        case JDWP::JT_INT:
-          CHECK_EQ(width_, 4U);
-          if (!SetVReg(m, reg, static_cast<uint32_t>(value_), kIntVReg)) {
-            VLOG(jdwp) << "failed to set int local " << reg << " = "
-                       << static_cast<uint32_t>(value_);
-            error_ = kFailureErrorCode;
-          }
-          break;
-        case JDWP::JT_FLOAT:
-          CHECK_EQ(width_, 4U);
-          if (!SetVReg(m, reg, static_cast<uint32_t>(value_), kFloatVReg)) {
-            VLOG(jdwp) << "failed to set float local " << reg << " = "
-                       << static_cast<uint32_t>(value_);
-            error_ = kFailureErrorCode;
-          }
-          break;
-        case JDWP::JT_ARRAY:
-        case JDWP::JT_CLASS_LOADER:
-        case JDWP::JT_CLASS_OBJECT:
-        case JDWP::JT_OBJECT:
-        case JDWP::JT_STRING:
-        case JDWP::JT_THREAD:
-        case JDWP::JT_THREAD_GROUP: {
-          CHECK_EQ(width_, sizeof(JDWP::ObjectId));
-          JDWP::JdwpError error;
-          mirror::Object* o =
-              gRegistry->Get<mirror::Object*>(static_cast<JDWP::ObjectId>(value_), &error);
-          if (error != JDWP::ERR_NONE) {
-            VLOG(jdwp) << tag_ << " object " << value_ << " is an invalid object";
-            error_ = JDWP::ERR_INVALID_OBJECT;
-          } else if (!SetVReg(m, reg, static_cast<uint32_t>(reinterpret_cast<uintptr_t>(o)),
-                              kReferenceVReg)) {
-            VLOG(jdwp) << "failed to set " << tag_ << " object local " << reg << " = " << o;
-            error_ = kFailureErrorCode;
-          }
-          break;
-        }
-        case JDWP::JT_DOUBLE: {
-          CHECK_EQ(width_, 8U);
-          bool success = SetVRegPair(m, reg, value_, kDoubleLoVReg, kDoubleHiVReg);
-          if (!success) {
-            VLOG(jdwp) << "failed to set double local " << reg << " = " << value_;
-            error_ = kFailureErrorCode;
-          }
-          break;
-        }
-        case JDWP::JT_LONG: {
-          CHECK_EQ(width_, 8U);
-          bool success = SetVRegPair(m, reg, value_, kLongLoVReg, kLongHiVReg);
-          if (!success) {
-            VLOG(jdwp) << "failed to set double local " << reg << " = " << value_;
-            error_ = kFailureErrorCode;
-          }
-          break;
+      break;
+    }
+    case JDWP::JT_SHORT:
+    case JDWP::JT_CHAR: {
+      CHECK_EQ(width, 2U);
+      uint32_t intVal;
+      if (visitor.GetVReg(m, reg, kIntVReg, &intVal)) {
+        VLOG(jdwp) << "get short/char local " << reg << " = " << intVal;
+        JDWP::Set2BE(buf + 1, intVal);
+      } else {
+        VLOG(jdwp) << "failed to get short/char local " << reg;
+        return kFailureErrorCode;
+      }
+      break;
+    }
+    case JDWP::JT_INT: {
+      CHECK_EQ(width, 4U);
+      uint32_t intVal;
+      if (visitor.GetVReg(m, reg, kIntVReg, &intVal)) {
+        VLOG(jdwp) << "get int local " << reg << " = " << intVal;
+        JDWP::Set4BE(buf + 1, intVal);
+      } else {
+        VLOG(jdwp) << "failed to get int local " << reg;
+        return kFailureErrorCode;
+      }
+      break;
+    }
+    case JDWP::JT_FLOAT: {
+      CHECK_EQ(width, 4U);
+      uint32_t intVal;
+      if (visitor.GetVReg(m, reg, kFloatVReg, &intVal)) {
+        VLOG(jdwp) << "get float local " << reg << " = " << intVal;
+        JDWP::Set4BE(buf + 1, intVal);
+      } else {
+        VLOG(jdwp) << "failed to get float local " << reg;
+        return kFailureErrorCode;
+      }
+      break;
+    }
+    case JDWP::JT_ARRAY:
+    case JDWP::JT_CLASS_LOADER:
+    case JDWP::JT_CLASS_OBJECT:
+    case JDWP::JT_OBJECT:
+    case JDWP::JT_STRING:
+    case JDWP::JT_THREAD:
+    case JDWP::JT_THREAD_GROUP: {
+      CHECK_EQ(width, sizeof(JDWP::ObjectId));
+      uint32_t intVal;
+      if (visitor.GetVReg(m, reg, kReferenceVReg, &intVal)) {
+        mirror::Object* o = reinterpret_cast<mirror::Object*>(intVal);
+        VLOG(jdwp) << "get " << tag << " object local " << reg << " = " << o;
+        if (!Runtime::Current()->GetHeap()->IsValidObjectAddress(o)) {
+          LOG(FATAL) << "Register " << reg << " expected to hold " << tag << " object: " << o;
         }
-        default:
-          LOG(FATAL) << "Unknown tag " << tag_;
-          break;
+        tag = TagFromObject(soa, o);
+        JDWP::SetObjectId(buf + 1, gRegistry->Add(o));
+      } else {
+        VLOG(jdwp) << "failed to get " << tag << " object local " << reg;
+        return kFailureErrorCode;
       }
-      return false;
+      break;
     }
+    case JDWP::JT_DOUBLE: {
+      CHECK_EQ(width, 8U);
+      uint64_t longVal;
+      if (visitor.GetVRegPair(m, reg, kDoubleLoVReg, kDoubleHiVReg, &longVal)) {
+        VLOG(jdwp) << "get double local " << reg << " = " << longVal;
+        JDWP::Set8BE(buf + 1, longVal);
+      } else {
+        VLOG(jdwp) << "failed to get double local " << reg;
+        return kFailureErrorCode;
+      }
+      break;
+    }
+    case JDWP::JT_LONG: {
+      CHECK_EQ(width, 8U);
+      uint64_t longVal;
+      if (visitor.GetVRegPair(m, reg, kLongLoVReg, kLongHiVReg, &longVal)) {
+        VLOG(jdwp) << "get long local " << reg << " = " << longVal;
+        JDWP::Set8BE(buf + 1, longVal);
+      } else {
+        VLOG(jdwp) << "failed to get long local " << reg;
+        return kFailureErrorCode;
+      }
+      break;
+    }
+    default:
+      LOG(FATAL) << "Unknown tag " << tag;
+      break;
+  }
 
-    const JDWP::FrameId frame_id_;
-    const int slot_;
-    const JDWP::JdwpTag tag_;
-    const uint64_t value_;
-    const size_t width_;
-    JDWP::JdwpError error_;
-  };
+  // Prepend tag, which may have been updated.
+  JDWP::Set1(buf, tag);
+  return JDWP::ERR_NONE;
+}
+
+JDWP::JdwpError Dbg::SetLocalValues(JDWP::Request* request) {
+  JDWP::ObjectId thread_id = request->ReadThreadId();
+  JDWP::FrameId frame_id = request->ReadFrameId();
 
   ScopedObjectAccessUnchecked soa(Thread::Current());
-  MutexLock mu(soa.Self(), *Locks::thread_list_lock_);
-  JDWP::JdwpError error;
-  Thread* thread = DecodeThread(soa, thread_id, &error);
-  if (error != JDWP::ERR_NONE) {
-    return error;
+  Thread* thread;
+  {
+    MutexLock mu(soa.Self(), *Locks::thread_list_lock_);
+    JDWP::JdwpError error;
+    thread = DecodeThread(soa, thread_id, &error);
+    if (error != JDWP::ERR_NONE) {
+      return error;
+    }
   }
-  // TODO check thread is suspended by the debugger ?
+  // Find the frame with the given frame_id.
   std::unique_ptr<Context> context(Context::Create());
-  SetLocalVisitor visitor(thread, context.get(), frame_id, slot, tag, value, width);
+  FindFrameVisitor visitor(thread, context.get(), frame_id);
   visitor.WalkStack();
-  return visitor.error_;
+  if (visitor.GetError() != JDWP::ERR_NONE) {
+    return visitor.GetError();
+  }
+
+  // Writes the values into visitor's context.
+  int32_t slot_count = request->ReadSigned32("slot count");
+  for (int32_t i = 0; i < slot_count; ++i) {
+    uint32_t slot = request->ReadUnsigned32("slot");
+    JDWP::JdwpTag sigByte = request->ReadTag();
+    size_t width = Dbg::GetTagWidth(sigByte);
+    uint64_t value = request->ReadValue(width);
+
+    VLOG(jdwp) << "    --> slot " << slot << " " << sigByte << " " << value;
+    JDWP::JdwpError error = Dbg::SetLocalValue(visitor, slot, sigByte, value, width);
+    if (error != JDWP::ERR_NONE) {
+      return error;
+    }
+  }
+  return JDWP::ERR_NONE;
+}
+
+JDWP::JdwpError Dbg::SetLocalValue(StackVisitor& visitor, int slot, JDWP::JdwpTag tag,
+                                   uint64_t value, size_t width) {
+  mirror::ArtMethod* m = visitor.GetMethod();
+  uint16_t reg = DemangleSlot(slot, m);
+  // TODO: check that the tag is compatible with the actual type of the slot!
+  // TODO: check slot is valid for this method or return INVALID_SLOT error.
+  constexpr JDWP::JdwpError kFailureErrorCode = JDWP::ERR_ABSENT_INFORMATION;
+  switch (tag) {
+    case JDWP::JT_BOOLEAN:
+    case JDWP::JT_BYTE:
+      CHECK_EQ(width, 1U);
+      if (!visitor.SetVReg(m, reg, static_cast<uint32_t>(value), kIntVReg)) {
+        VLOG(jdwp) << "failed to set boolean/byte local " << reg << " = "
+                   << static_cast<uint32_t>(value);
+        return kFailureErrorCode;
+      }
+      break;
+    case JDWP::JT_SHORT:
+    case JDWP::JT_CHAR:
+      CHECK_EQ(width, 2U);
+      if (!visitor.SetVReg(m, reg, static_cast<uint32_t>(value), kIntVReg)) {
+        VLOG(jdwp) << "failed to set short/char local " << reg << " = "
+                   << static_cast<uint32_t>(value);
+        return kFailureErrorCode;
+      }
+      break;
+    case JDWP::JT_INT:
+      CHECK_EQ(width, 4U);
+      if (!visitor.SetVReg(m, reg, static_cast<uint32_t>(value), kIntVReg)) {
+        VLOG(jdwp) << "failed to set int local " << reg << " = "
+                   << static_cast<uint32_t>(value);
+        return kFailureErrorCode;
+      }
+      break;
+    case JDWP::JT_FLOAT:
+      CHECK_EQ(width, 4U);
+      if (!visitor.SetVReg(m, reg, static_cast<uint32_t>(value), kFloatVReg)) {
+        VLOG(jdwp) << "failed to set float local " << reg << " = "
+                   << static_cast<uint32_t>(value);
+        return kFailureErrorCode;
+      }
+      break;
+    case JDWP::JT_ARRAY:
+    case JDWP::JT_CLASS_LOADER:
+    case JDWP::JT_CLASS_OBJECT:
+    case JDWP::JT_OBJECT:
+    case JDWP::JT_STRING:
+    case JDWP::JT_THREAD:
+    case JDWP::JT_THREAD_GROUP: {
+      CHECK_EQ(width, sizeof(JDWP::ObjectId));
+      JDWP::JdwpError error;
+      mirror::Object* o = gRegistry->Get<mirror::Object*>(static_cast<JDWP::ObjectId>(value),
+                                                          &error);
+      if (error != JDWP::ERR_NONE) {
+        VLOG(jdwp) << tag << " object " << o << " is an invalid object";
+        return JDWP::ERR_INVALID_OBJECT;
+      } else if (!visitor.SetVReg(m, reg, static_cast<uint32_t>(reinterpret_cast<uintptr_t>(o)),
+                          kReferenceVReg)) {
+        VLOG(jdwp) << "failed to set " << tag << " object local " << reg << " = " << o;
+        return kFailureErrorCode;
+      }
+      break;
+    }
+    case JDWP::JT_DOUBLE: {
+      CHECK_EQ(width, 8U);
+      if (!visitor.SetVRegPair(m, reg, value, kDoubleLoVReg, kDoubleHiVReg)) {
+        VLOG(jdwp) << "failed to set double local " << reg << " = " << value;
+        return kFailureErrorCode;
+      }
+      break;
+    }
+    case JDWP::JT_LONG: {
+      CHECK_EQ(width, 8U);
+      if (!visitor.SetVRegPair(m, reg, value, kLongLoVReg, kLongHiVReg)) {
+        VLOG(jdwp) << "failed to set double local " << reg << " = " << value;
+        return kFailureErrorCode;
+      }
+      break;
+    }
+    default:
+      LOG(FATAL) << "Unknown tag " << tag;
+      break;
+  }
+  return JDWP::ERR_NONE;
 }
 
 static void SetEventLocation(JDWP::EventLocation* location, mirror::ArtMethod* m, uint32_t dex_pc)