7. A system for register clearing in data flow analysis in decompilation, comprising a processor and a non-transitory storage medium accessible to the processor, the non-transitory storage medium being configured to store units comprising a reading unit, a register name judging unit, a binary tree creating unit, an end tag judging unit, an eliminating unit and a high-level language generating unit, wherein the reading unit is adapted to open a code file in assembly language before the register clearing, and to read all function statements in the code file; the register name judging unit is adapted to perform judgment on each of the read function statements sequentially to judge whether the function statement comprises a register name, and to trigger the binary tree creating unit in a case that the function statement comprises the register name; the binary tree creating unit is adapted to create a binary tree and input the function statement into the binary tree; the end tag judging unit is adapted to perform judgment on each of the function statements comprising the register name sequentially to judge whether the function statement comprises a right child end tag of the binary tree; to trigger the eliminating unit in a case that the function statement comprises the right child end tag of the binary tree; and to send a judging instruction to the register name judging unit to instruct the register name judging unit to judge whether a next function statement comprises a register name in a case that the function statement comprises no right child end tag of the binary tree; the eliminating unit is adapted to perform an elimination process on the created binary tree to remove the register name from the binary tree, to generate a simplest binary tree; and the high-level language generating unit is adapted to generate a function statement in high-level language based on the simplest binary tree.
7. A system for register clearing in data flow analysis in decompilation, comprising a processor and a non-transitory storage medium accessible to the processor, the non-transitory storage medium being configured to store units comprising a reading unit, a register name judging unit, a binary tree creating unit, an end tag judging unit, an eliminating unit and a high-level language generating unit, wherein the reading unit is adapted to open a code file in assembly language before the register clearing, and to read all function statements in the code file; the register name judging unit is adapted to perform judgment on each of the read function statements sequentially to judge whether the function statement comprises a register name, and to trigger the binary tree creating unit in a case that the function statement comprises the register name; the binary tree creating unit is adapted to create a binary tree and input the function statement into the binary tree; the end tag judging unit is adapted to perform judgment on each of the function statements comprising the register name sequentially to judge whether the function statement comprises a right child end tag of the binary tree; to trigger the eliminating unit in a case that the function statement comprises the right child end tag of the binary tree; and to send a judging instruction to the register name judging unit to instruct the register name judging unit to judge whether a next function statement comprises a register name in a case that the function statement comprises no right child end tag of the binary tree; the eliminating unit is adapted to perform an elimination process on the created binary tree to remove the register name from the binary tree, to generate a simplest binary tree; and the high-level language generating unit is adapted to generate a function statement in high-level language based on the simplest binary tree. 8. The system according to claim 7 , wherein the reading unit comprises a file opening subunit, a single linked list creating subunit and a single linked list traversing subunit, the file opening subunit is adapted to open the code file in assembly language before the register clearing; the single linked list creating subunit is adapted to create a single linked list based on all function statements in the code file; and the single linked list traversing subunit is adapted to traverse the single linked list.