Created by: Xreki

fetch_op报错信息增强 [仅C++端]

1. 使用OP_INOUT_CHECK，增加输入、输出是否设置的检查

由于fetch_op继承的是OperatorBase，当输入或者输出没有设置时，在进入RunImpl函数之前就会报错，因此修改前后报错信息一样，具体如下：

• 没有设置输入

  Error: Operator fetch's input, X, is not set at (/paddle/paddle/fluid/framework/operator.cc:382)

• 没有设置输出

  Error: Operator fetch's output, Out, is not set at (/paddle/paddle/fluid/framework/operator.cc:390)

2. 增强scope中，输入、输出变量是否存在的检查

• 检查scope中输入变量是否存在
  • 修改前

  Error: Cannot find fetch variable in scope, fetch_var_name is in_0 at (/paddle/paddle/fluid/operators/controlflow/fetch_op.cc:38)
    [operator < fetch > error]

  • 修改后

  NotFoundError: Input variable(in_0) cannot be found in scope for operator 'Fetch'.
    [Hint: fetch_var should not be null.] at (/paddle/paddle/fluid/operators/controlflow/fetch_op.cc:43)
    [operator < fetch > error]

• 检查scope中输出变量是否存在
  • 修改前

  Error: Cannot find out_var in scope, out_var_name is fetch at (/paddle/paddle/fluid/operators/controlflow/fetch_op.cc:44)
  [operator < fetch > error]

  • 修改后

  NotFoundError: Output variable(fetch) cannot be found in scope for operator 'Fetch'.
    [Hint: out_var should not be null.] at (/paddle/paddle/fluid/operators/controlflow/fetch_op.cc:50)
    [operator < fetch > error]

3. 增加属性col >= 0的检查
   • 修改前

   W0408 05:43:54.087884 59585 operator.cc:187] fetch raises an exception std::out_of_range, vector::_M_range_check

   • 修改后

   InvalidArgumentError: Expected the column index (the attribute 'col' of operator 'Fetch') of current fetching variable to be no less than 0. But received column index = -1.
     [Hint: Expected col >= 0, but received col:-1 < 0:0.] at (/paddle/paddle/fluid/operators/controlflow/fetch_op.cc:59)
     [operator < fetch > error]

说明

fetch op不是普通op，使用executor执行时，由executor根据用户的fetch需求自动插入fetch_op来取回计算的结果数据。没有Python API，错误示例难以构造，因此不提供错误示例。