* add is_empty_grad_op for OpTest, test=develop

* add ci check in check_api_approvals.sh, test=develop

* fix typo and refine error information test=document_fix, test=develop

* fix typo test=document_fix test=develop

* fix bug test=document_fix test=develop

* test the equality between running-time and compiling time

* add white_list for compile_vs_runtime check test=develop

* add check of new-registered op on compile&runtime-lodEquality test=develop

* test=develop

* test=develop

* update white-list test=develop

* merge with new code test=develop

* fix code style test=develop

* test=devleop

* test=develop

* test=develop

* test=develop

* add more ops to white_list test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* fix code_style: add comments test=develop

* test=develop

test=develop test=document_fix

* ci_check
test=develop
test=document_fix

* test error
test=develop
test=document_fix

* check another op accuracy ci
test=develop
test=document_fix

* converge to one if
test=develop
test=document_fix

* remove test case
test=develop
test=document_fix

* simplify ci check
test=develop
test=document_fix

* remove test case
test=develop
test=document_fix

* optimize ci check
test=develop
test=document_fix

* optimize ci check
test=develop
test=document_fix

* remove test case
test=develop
test=document_fix

test=develop test=document_fix

* add shell scripts. test=develop

* rename test_pybind_inference to test_pybind_interface and print repeat process in check_op_desc.py. test=develop

* add approval RD. test=develop

* add data_type register CI test=develop

* add op add test case test=develop

* add test case for register op kernel test=develop

* fix shell script bug test=develop

* fix checkout branch test=develop

* remove test case code test=develop

* fix op_type.spec name test=develop

test=develop test=document_fix

* add unused input vars check for OpWithKernel, test=develop

* remove unused vars in some ops, test=develop

* fix batch_norm, test=develop

* add white list, test=develop

* add CI check for white list, test=develop

* :ove white list to c++, test=develop

* solve failure of CI, test=develop

* add unittest for unused_var_check, test=develop

* refine code, enable check in operator_test, test=develop

* skip mkldnn, test=develop

* extend white list, test=develop

* refine condition of mkldnn, test=develop

* fix paddle_build, test=develop

* follow comments, test=develop

* fix GetExpectedKernelType

* add wiki ref to err_msg, test=develop

* follow comment, test=develop

* optimization check_api_approvals

* change echo line

* echo_line

* update

* test=develop;test=document_fix

* change api document review;test=develop;test=document_fix

* test=develop;test=document_fix

* fix PADDLE_ENFORCE ci check bug, test=develop, test=document_fix

* fix PADDLE_ENFORCE match error, test=develop, test=document_fix

* add ci check for error message specification, test=develop, test=document_fix

* replace spec url & refine failed message, test=develop, test=document_fix

* split api_spec document;test=document_fix

* change tools

* test=develop;test=document_fix

* test=develop;test=document_fix

* add op indicate var type method call check

* add error test example, test=develop, test=document_fix

* add count judge, test=develop, test=document_fix

* polish example detail, test=develop, test=document_fix

* test indicate var data type method, test=develop, test=document_fix

* test no get expect kernel type, test=develop, test=document_fix

* remove test case, test=develop test=document_fix