private int readMethod()

in src/main/java/com/amazon/corretto/hotpatch/org/objectweb/asm/ClassReader.java [1248:1520]


  private int readMethod(
      final ClassVisitor classVisitor, final Context context, final int methodInfoOffset) {
    char[] charBuffer = context.charBuffer;

    // Read the access_flags, name_index and descriptor_index fields.
    int currentOffset = methodInfoOffset;
    context.currentMethodAccessFlags = readUnsignedShort(currentOffset);
    context.currentMethodName = readUTF8(currentOffset + 2, charBuffer);
    context.currentMethodDescriptor = readUTF8(currentOffset + 4, charBuffer);
    currentOffset += 6;

    // Read the method attributes (the variables are ordered as in Section 4.7 of the JVMS).
    // Attribute offsets exclude the attribute_name_index and attribute_length fields.
    // - The offset of the Code attribute, or 0.
    int codeOffset = 0;
    // - The offset of the Exceptions attribute, or 0.
    int exceptionsOffset = 0;
    // - The strings corresponding to the Exceptions attribute, or null.
    String[] exceptions = null;
    // - Whether the method has a Synthetic attribute.
    boolean synthetic = false;
    // - The constant pool index contained in the Signature attribute, or 0.
    int signatureIndex = 0;
    // - The offset of the RuntimeVisibleAnnotations attribute, or 0.
    int runtimeVisibleAnnotationsOffset = 0;
    // - The offset of the RuntimeInvisibleAnnotations attribute, or 0.
    int runtimeInvisibleAnnotationsOffset = 0;
    // - The offset of the RuntimeVisibleParameterAnnotations attribute, or 0.
    int runtimeVisibleParameterAnnotationsOffset = 0;
    // - The offset of the RuntimeInvisibleParameterAnnotations attribute, or 0.
    int runtimeInvisibleParameterAnnotationsOffset = 0;
    // - The offset of the RuntimeVisibleTypeAnnotations attribute, or 0.
    int runtimeVisibleTypeAnnotationsOffset = 0;
    // - The offset of the RuntimeInvisibleTypeAnnotations attribute, or 0.
    int runtimeInvisibleTypeAnnotationsOffset = 0;
    // - The offset of the AnnotationDefault attribute, or 0.
    int annotationDefaultOffset = 0;
    // - The offset of the MethodParameters attribute, or 0.
    int methodParametersOffset = 0;
    // - The non standard attributes (linked with their {@link Attribute#nextAttribute} field).
    //   This list in the <i>reverse order</i> or their order in the ClassFile structure.
    Attribute attributes = null;

    int attributesCount = readUnsignedShort(currentOffset);
    currentOffset += 2;
    while (attributesCount-- > 0) {
      // Read the attribute_info's attribute_name and attribute_length fields.
      String attributeName = readUTF8(currentOffset, charBuffer);
      int attributeLength = readInt(currentOffset + 2);
      currentOffset += 6;
      // The tests are sorted in decreasing frequency order (based on frequencies observed on
      // typical classes).
      if (Constants.CODE.equals(attributeName)) {
        if ((context.parsingOptions & SKIP_CODE) == 0) {
          codeOffset = currentOffset;
        }
      } else if (Constants.EXCEPTIONS.equals(attributeName)) {
        exceptionsOffset = currentOffset;
        exceptions = new String[readUnsignedShort(exceptionsOffset)];
        int currentExceptionOffset = exceptionsOffset + 2;
        for (int i = 0; i < exceptions.length; ++i) {
          exceptions[i] = readClass(currentExceptionOffset, charBuffer);
          currentExceptionOffset += 2;
        }
      } else if (Constants.SIGNATURE.equals(attributeName)) {
        signatureIndex = readUnsignedShort(currentOffset);
      } else if (Constants.DEPRECATED.equals(attributeName)) {
        context.currentMethodAccessFlags |= Opcodes.ACC_DEPRECATED;
      } else if (Constants.RUNTIME_VISIBLE_ANNOTATIONS.equals(attributeName)) {
        runtimeVisibleAnnotationsOffset = currentOffset;
      } else if (Constants.RUNTIME_VISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
        runtimeVisibleTypeAnnotationsOffset = currentOffset;
      } else if (Constants.ANNOTATION_DEFAULT.equals(attributeName)) {
        annotationDefaultOffset = currentOffset;
      } else if (Constants.SYNTHETIC.equals(attributeName)) {
        synthetic = true;
        context.currentMethodAccessFlags |= Opcodes.ACC_SYNTHETIC;
      } else if (Constants.RUNTIME_INVISIBLE_ANNOTATIONS.equals(attributeName)) {
        runtimeInvisibleAnnotationsOffset = currentOffset;
      } else if (Constants.RUNTIME_INVISIBLE_TYPE_ANNOTATIONS.equals(attributeName)) {
        runtimeInvisibleTypeAnnotationsOffset = currentOffset;
      } else if (Constants.RUNTIME_VISIBLE_PARAMETER_ANNOTATIONS.equals(attributeName)) {
        runtimeVisibleParameterAnnotationsOffset = currentOffset;
      } else if (Constants.RUNTIME_INVISIBLE_PARAMETER_ANNOTATIONS.equals(attributeName)) {
        runtimeInvisibleParameterAnnotationsOffset = currentOffset;
      } else if (Constants.METHOD_PARAMETERS.equals(attributeName)) {
        methodParametersOffset = currentOffset;
      } else {
        Attribute attribute =
            readAttribute(
                context.attributePrototypes,
                attributeName,
                currentOffset,
                attributeLength,
                charBuffer,
                -1,
                null);
        attribute.nextAttribute = attributes;
        attributes = attribute;
      }
      currentOffset += attributeLength;
    }

    // Visit the method declaration.
    MethodVisitor methodVisitor =
        classVisitor.visitMethod(
            context.currentMethodAccessFlags,
            context.currentMethodName,
            context.currentMethodDescriptor,
            signatureIndex == 0 ? null : readUtf(signatureIndex, charBuffer),
            exceptions);
    if (methodVisitor == null) {
      return currentOffset;
    }

    // If the returned MethodVisitor is in fact a MethodWriter, it means there is no method
    // adapter between the reader and the writer. In this case, it might be possible to copy
    // the method attributes directly into the writer. If so, return early without visiting
    // the content of these attributes.
    if (methodVisitor instanceof MethodWriter) {
      MethodWriter methodWriter = (MethodWriter) methodVisitor;
      if (methodWriter.canCopyMethodAttributes(
          this,
          synthetic,
          (context.currentMethodAccessFlags & Opcodes.ACC_DEPRECATED) != 0,
          readUnsignedShort(methodInfoOffset + 4),
          signatureIndex,
          exceptionsOffset)) {
        methodWriter.setMethodAttributesSource(methodInfoOffset, currentOffset - methodInfoOffset);
        return currentOffset;
      }
    }

    // Visit the MethodParameters attribute.
    if (methodParametersOffset != 0 && (context.parsingOptions & SKIP_DEBUG) == 0) {
      int parametersCount = readByte(methodParametersOffset);
      int currentParameterOffset = methodParametersOffset + 1;
      while (parametersCount-- > 0) {
        // Read the name_index and access_flags fields and visit them.
        methodVisitor.visitParameter(
            readUTF8(currentParameterOffset, charBuffer),
            readUnsignedShort(currentParameterOffset + 2));
        currentParameterOffset += 4;
      }
    }

    // Visit the AnnotationDefault attribute.
    if (annotationDefaultOffset != 0) {
      AnnotationVisitor annotationVisitor = methodVisitor.visitAnnotationDefault();
      readElementValue(annotationVisitor, annotationDefaultOffset, null, charBuffer);
      if (annotationVisitor != null) {
        annotationVisitor.visitEnd();
      }
    }

    // Visit the RuntimeVisibleAnnotations attribute.
    if (runtimeVisibleAnnotationsOffset != 0) {
      int numAnnotations = readUnsignedShort(runtimeVisibleAnnotationsOffset);
      int currentAnnotationOffset = runtimeVisibleAnnotationsOffset + 2;
      while (numAnnotations-- > 0) {
        // Parse the type_index field.
        String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
        currentAnnotationOffset += 2;
        // Parse num_element_value_pairs and element_value_pairs and visit these values.
        currentAnnotationOffset =
            readElementValues(
                methodVisitor.visitAnnotation(annotationDescriptor, /* visible = */ true),
                currentAnnotationOffset,
                /* named = */ true,
                charBuffer);
      }
    }

    // Visit the RuntimeInvisibleAnnotations attribute.
    if (runtimeInvisibleAnnotationsOffset != 0) {
      int numAnnotations = readUnsignedShort(runtimeInvisibleAnnotationsOffset);
      int currentAnnotationOffset = runtimeInvisibleAnnotationsOffset + 2;
      while (numAnnotations-- > 0) {
        // Parse the type_index field.
        String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
        currentAnnotationOffset += 2;
        // Parse num_element_value_pairs and element_value_pairs and visit these values.
        currentAnnotationOffset =
            readElementValues(
                methodVisitor.visitAnnotation(annotationDescriptor, /* visible = */ false),
                currentAnnotationOffset,
                /* named = */ true,
                charBuffer);
      }
    }

    // Visit the RuntimeVisibleTypeAnnotations attribute.
    if (runtimeVisibleTypeAnnotationsOffset != 0) {
      int numAnnotations = readUnsignedShort(runtimeVisibleTypeAnnotationsOffset);
      int currentAnnotationOffset = runtimeVisibleTypeAnnotationsOffset + 2;
      while (numAnnotations-- > 0) {
        // Parse the target_type, target_info and target_path fields.
        currentAnnotationOffset = readTypeAnnotationTarget(context, currentAnnotationOffset);
        // Parse the type_index field.
        String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
        currentAnnotationOffset += 2;
        // Parse num_element_value_pairs and element_value_pairs and visit these values.
        currentAnnotationOffset =
            readElementValues(
                methodVisitor.visitTypeAnnotation(
                    context.currentTypeAnnotationTarget,
                    context.currentTypeAnnotationTargetPath,
                    annotationDescriptor,
                    /* visible = */ true),
                currentAnnotationOffset,
                /* named = */ true,
                charBuffer);
      }
    }

    // Visit the RuntimeInvisibleTypeAnnotations attribute.
    if (runtimeInvisibleTypeAnnotationsOffset != 0) {
      int numAnnotations = readUnsignedShort(runtimeInvisibleTypeAnnotationsOffset);
      int currentAnnotationOffset = runtimeInvisibleTypeAnnotationsOffset + 2;
      while (numAnnotations-- > 0) {
        // Parse the target_type, target_info and target_path fields.
        currentAnnotationOffset = readTypeAnnotationTarget(context, currentAnnotationOffset);
        // Parse the type_index field.
        String annotationDescriptor = readUTF8(currentAnnotationOffset, charBuffer);
        currentAnnotationOffset += 2;
        // Parse num_element_value_pairs and element_value_pairs and visit these values.
        currentAnnotationOffset =
            readElementValues(
                methodVisitor.visitTypeAnnotation(
                    context.currentTypeAnnotationTarget,
                    context.currentTypeAnnotationTargetPath,
                    annotationDescriptor,
                    /* visible = */ false),
                currentAnnotationOffset,
                /* named = */ true,
                charBuffer);
      }
    }

    // Visit the RuntimeVisibleParameterAnnotations attribute.
    if (runtimeVisibleParameterAnnotationsOffset != 0) {
      readParameterAnnotations(
          methodVisitor, context, runtimeVisibleParameterAnnotationsOffset, /* visible = */ true);
    }

    // Visit the RuntimeInvisibleParameterAnnotations attribute.
    if (runtimeInvisibleParameterAnnotationsOffset != 0) {
      readParameterAnnotations(
          methodVisitor,
          context,
          runtimeInvisibleParameterAnnotationsOffset,
          /* visible = */ false);
    }

    // Visit the non standard attributes.
    while (attributes != null) {
      // Copy and reset the nextAttribute field so that it can also be used in MethodWriter.
      Attribute nextAttribute = attributes.nextAttribute;
      attributes.nextAttribute = null;
      methodVisitor.visitAttribute(attributes);
      attributes = nextAttribute;
    }

    // Visit the Code attribute.
    if (codeOffset != 0) {
      methodVisitor.visitCode();
      readCode(methodVisitor, context, codeOffset);
    }

    // Visit the end of the method.
    methodVisitor.visitEnd();
    return currentOffset;
  }