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      1 /*
      2  * Copyright (C) 2015 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include "lambda/art_lambda_method.h"
     18 
     19 #include "base/logging.h"
     20 #include "lambda/shorty_field_type.h"
     21 
     22 namespace art {
     23 namespace lambda {
     24 
     25 ArtLambdaMethod::ArtLambdaMethod(ArtMethod* target_method,
     26                                  const char* captured_variables_type_descriptor,
     27                                  const char* captured_variables_shorty,
     28                                  bool innate_lambda)
     29     : method_(target_method),
     30       captured_variables_type_descriptor_(captured_variables_type_descriptor),
     31       captured_variables_shorty_(captured_variables_shorty),
     32       innate_lambda_(innate_lambda) {
     33   DCHECK(target_method != nullptr);
     34   DCHECK(captured_variables_type_descriptor != nullptr);
     35   DCHECK(captured_variables_shorty != nullptr);
     36 
     37   // Calculate the static closure size from the captured variables.
     38   size_t size = sizeof(ArtLambdaMethod*);  // Initial size is just this method.
     39   bool static_size = true;
     40   const char* shorty = captured_variables_shorty_;
     41   while (shorty != nullptr && *shorty != '\0') {
     42     // Each captured variable also appends to the size.
     43     ShortyFieldType shorty_field{*shorty};  // NOLINT [readability/braces] [4]
     44     size += shorty_field.GetStaticSize();
     45     static_size &= shorty_field.IsStaticSize();
     46     ++shorty;
     47   }
     48   closure_size_ = size;
     49 
     50   // We determine whether or not the size is dynamic by checking for nested lambdas.
     51   //
     52   // This is conservative, since in theory an optimization could determine the size
     53   // of the nested lambdas recursively. In practice it's probably better to flatten out
     54   // nested lambdas and inline all their code if they are known statically.
     55   dynamic_size_ = !static_size;
     56 
     57   if (kIsDebugBuild) {
     58     // Double check that the number of captured variables match in both strings.
     59     size_t shorty_count = strlen(captured_variables_shorty);
     60 
     61     size_t long_count = 0;
     62     const char* long_type = captured_variables_type_descriptor;
     63     ShortyFieldType out;
     64     while ((long_type = ShortyFieldType::ParseFromFieldTypeDescriptor(long_type, &out))
     65            != nullptr) {
     66       ++long_count;
     67     }
     68 
     69     DCHECK_EQ(shorty_count, long_count)
     70         << "number of captured variables in long type '" << captured_variables_type_descriptor
     71         << "' (" << long_count << ")" << " did not match short type '"
     72         << captured_variables_shorty << "' (" << shorty_count << ")";
     73   }
     74 }
     75 
     76 }  // namespace lambda
     77 }  // namespace art
     78