1 files changed, 73 insertions, 3 deletions

diff --git a/runtime/dex_file-inl.h b/runtime/dex_file-inl.h
index dee80269d6..3b2135c2cd 100644
--- a/runtime/dex_file-inl.h
+++ b/runtime/dex_file-inl.h
@@ -29,19 +29,89 @@ inline int32_t DexFile::GetStringLength(const StringId& string_id) const {
   return DecodeUnsignedLeb128(&ptr);
 }
 
-inline const char* DexFile::GetStringDataAndLength(const StringId& string_id, uint32_t* length) const {
-  DCHECK(length != NULL) << GetLocation();
+inline const char* DexFile::GetStringDataAndUtf16Length(const StringId& string_id,
+                                                        uint32_t* utf16_length) const {
+  DCHECK(utf16_length != NULL) << GetLocation();
   const byte* ptr = begin_ + string_id.string_data_off_;
-  *length = DecodeUnsignedLeb128(&ptr);
+  *utf16_length = DecodeUnsignedLeb128(&ptr);
   return reinterpret_cast<const char*>(ptr);
 }
 
+inline const Signature DexFile::GetMethodSignature(const MethodId& method_id) const {
+  return Signature(this, GetProtoId(method_id.proto_idx_));
+}
+
 inline const DexFile::TryItem* DexFile::GetTryItems(const CodeItem& code_item, uint32_t offset) {
   const uint16_t* insns_end_ = &code_item.insns_[code_item.insns_size_in_code_units_];
   return reinterpret_cast<const TryItem*>
       (RoundUp(reinterpret_cast<uint32_t>(insns_end_), 4)) + offset;
 }
 
+static inline bool DexFileStringEquals(const DexFile* df1, uint32_t sidx1,
+                                       const DexFile* df2, uint32_t sidx2) {
+  uint32_t s1_len;  // Note: utf16 length != mutf8 length.
+  const char* s1_data = df1->StringDataAndUtf16LengthByIdx(sidx1, &s1_len);
+  uint32_t s2_len;
+  const char* s2_data = df2->StringDataAndUtf16LengthByIdx(sidx2, &s2_len);
+  return (s1_len == s2_len) && (strcmp(s1_data, s2_data) == 0);
+}
+
+inline bool Signature::operator==(const Signature& rhs) const {
+  if (dex_file_ == nullptr) {
+    return rhs.dex_file_ == nullptr;
+  }
+  if (rhs.dex_file_ == nullptr) {
+    return false;
+  }
+  if (dex_file_ == rhs.dex_file_) {
+    return proto_id_ == rhs.proto_id_;
+  }
+  uint32_t lhs_shorty_len;  // For a shorty utf16 length == mutf8 length.
+  const char* lhs_shorty_data = dex_file_->StringDataAndUtf16LengthByIdx(proto_id_->shorty_idx_,
+                                                                         &lhs_shorty_len);
+  StringPiece lhs_shorty(lhs_shorty_data, lhs_shorty_len);
+  {
+    uint32_t rhs_shorty_len;
+    const char* rhs_shorty_data =
+        rhs.dex_file_->StringDataAndUtf16LengthByIdx(rhs.proto_id_->shorty_idx_,
+                                                     &rhs_shorty_len);
+    StringPiece rhs_shorty(rhs_shorty_data, rhs_shorty_len);
+    if (lhs_shorty != rhs_shorty) {
+      return false;  // Shorty mismatch.
+    }
+  }
+  if (lhs_shorty[0] == 'L') {
+    const DexFile::TypeId& return_type_id = dex_file_->GetTypeId(proto_id_->return_type_idx_);
+    const DexFile::TypeId& rhs_return_type_id =
+        rhs.dex_file_->GetTypeId(rhs.proto_id_->return_type_idx_);
+    if (!DexFileStringEquals(dex_file_, return_type_id.descriptor_idx_,
+                             rhs.dex_file_, rhs_return_type_id.descriptor_idx_)) {
+      return false;  // Return type mismatch.
+    }
+  }
+  if (lhs_shorty.find('L', 1) != StringPiece::npos) {
+    const DexFile::TypeList* params = dex_file_->GetProtoParameters(*proto_id_);
+    const DexFile::TypeList* rhs_params = rhs.dex_file_->GetProtoParameters(*rhs.proto_id_);
+    // Both lists are empty or have contents, or else shorty is broken.
+    DCHECK_EQ(params == nullptr, rhs_params == nullptr);
+    if (params != nullptr) {
+      uint32_t params_size = params->Size();
+      DCHECK_EQ(params_size, rhs_params->Size());  // Parameter list size must match.
+      for (uint32_t i = 0; i < params_size; ++i) {
+        const DexFile::TypeId& param_id = dex_file_->GetTypeId(params->GetTypeItem(i).type_idx_);
+        const DexFile::TypeId& rhs_param_id =
+            rhs.dex_file_->GetTypeId(rhs_params->GetTypeItem(i).type_idx_);
+        if (!DexFileStringEquals(dex_file_, param_id.descriptor_idx_,
+                                 rhs.dex_file_, rhs_param_id.descriptor_idx_)) {
+          return false;  // Parameter type mismatch.
+        }
+      }
+    }
+  }
+  return true;
+}
+
+
 }  // namespace art
 
 #endif  // ART_RUNTIME_DEX_FILE_INL_H_