30 results about "Assignment" patented technology

The invention discloses an interprocedural static slice extracting method based on an idUCf quinary structure. The extracting method comprises the following steps: expressing static slices in a procedure according the type of variables and the positions of the static slices, and establishing an expression; according to the assignment values of the variables, performing backward type searching in the expression; extracting the static slices of which the variable values are equal to the assignment values. The extracting method disclosed by the invention can increase the utilization ratio of computer spaces and times, and improves the extracting efficiency of the slices.

The invention relates to a programming method for CAN-LonWorks protocol conversion logic, comprising the following steps: defining operators and defining the priority of each operator; defining unique digital codes corresponding to protocol variables; according to CAN-LonWorks protocol conversion requirements, using Operands and operators, and formulate the explicit assignment expressions of each protocol variable through operator rules; compress and convert the explicit assignment expressions, so as to encode the explicit assignment expressions into implicit assignment expressions; The assignment expression is checked, if the parsing is correct, the check is passed and a line of end mark "END" is appended at the end of the assignment expression. The programming method of the CAN-LonWorks protocol conversion logic provided by the present invention performs on-demand programming on the conversion logic to adapt to different application occasions.

Methods and systems are provided for reducing the number of copies in execution of routines written in a procedural language using assignment-by-value semantics. During routine assembly, each statement in a routine is classified as either copy-sensitive or non-copy-sensitive, depending on the operations that the statement contains. During routine execution, a lazy copy strategy is used to determine when a variable should be copied: copying is not performed on variable assignments, but is delayed until the variable is used in a copy-sensitive statement. If a variable is never used in a copy-sensitive statement, it will not be copied, thus saving computation time and storage.

The invention discloses a tracking method and device of a variable object. The method comprises the following steps: when carrying out bug search on a control flow diagram based on a detected program, finding out a first manipulation language of the variable object, wherein the first manipulation statement is used for indicating to carry out assignment operation and valuing operation on the variable object; obtaining a statement set of the variable object from a pre-collected variable information set, wherein the statement set comprises a plurality of second manipulation statements, and manipulation which is indicated by the second manipulation statements and is carried out on the variable object is opposite to manipulation which is indicated by the first manipulation statement and is carried out on the variable object; determining a third manipulation statement, having function calling relation with the first manipulation statement, in the plurality of second manipulation statements according to the control flow diagram; by taking a statement position of the determined third manipulation statement as a starting point, tracking the variable object. By adopting the tracking method and device of the variable object, the technical problem that missed reports of bugs are caused by the fact that the variable object cannot be tracked in a bug scanning process is solved.

The invention discloses a method for realizing definite software operating time in a single task operating environment, which is characterized by comprising the following steps of: (1) programming a function meeting requirements by using a conventional programming method; (2) dividing external input, external output and algorithm of the function definitely; (3) establishing a local variable for the external output; (4) finding out all switch statements in the function; (5) establishing local variables for the external output of all the switch statements; (6) cutting the programs of all the switch statements out of the switch statements, and modifying the output of the switch statements into the local variables of the output of the switch statements; (7) in the switch statements, adding the local variables of the output of the switch statements to an assignment statement output by a switch statement operation result and an assignment statement for a global variable; (8) adding the switch statement operation result to follow-up program operation; (9) assigning the local variable of the external output to the external output; and finally (10) modifying functions called in the program. The invention can ensure that the operating time of the same function is definite without change when outputs and routes are different.

An extracting unit randomly extracts a block from among the blocks of instruction strings constituting the byte code of a first program and, at the time of execution of the first program, extracts the blocks which are invariably executed before the randomly-extracted block. A dividing unit randomly divides, into a plurality of blocks, the instruction strings constituting the byte code of a second program which enables detection of tampering of the first program. An inserting unit inserts the plurality of blocks, which are obtained by division by the dividing unit, at different positions in the block extracted by the extracting unit, while maintaining the execution sequence written in the second program.

The invention discloses a SAT solver, comprising: a two-way transmission chain module (102), used for two-way transmission of variables to be solved; an implication circuit module (104), used for providing implied values ​​for the variables to be solved; conflict detection Module (106), for detecting whether the current assignment of the assignment module (108) will cause conflict; assignment module (108), for assigning a value to the variable to be solved, and its output value is determined by the state machine of the variable to be solved The current state of and the input signal of the assignment input are jointly determined. The solution of the present invention can solve the problem of low processing efficiency of the SAT solver based on software in the prior art, and achieve the effect of improving the processing efficiency.

A software patch detection method based on data flow analysis, using Extractor to analyze the patch code, and sequentially select and detect the modification semantics of assignment statements and conditional statements, function call statements, type-related statements, and other types of statements in the patch code. It is the feature of the patch to be detected; the mapping relationship between the binary code and the source code is established; VEX‑IR is selected as the intermediate code of the binary code promotion of the device firmware in the Internet of Things environment, and the binary code is analyzed using the open source Angr to extract the Control flow, the control flow takes functions as units, each of the functions includes nodes as basic blocks, and the control flow of program jump semantics as edges; the data flow in the basic block is analyzed, and the basic block The code is reversely analyzed one by one, and the use chain of variables in each statement is extracted; the data flow across the basic block is analyzed; the extracted data flow is optimized; the patch feature is obtained from the basic block, and it is multi-stage match.

A compiler transforms the source code into object code, but it will postpone the assignment of all of the machine language jumps until installed time. This can be performed by labeling the jumps during compiled time, similarly to how variables are labeled for later indexing by the debugger. At installation time, given a random key, the installer will take the jump labels and assign random ordering of the code and data using the key as a seed. The final effect is that the same source code can potentially generate an infinite number of object codes, with the exact same functionality of execution. The main difference, however, is that as more jump labels are included, less fixed offsets between buffers are available to the black hat.

The application provides a java program dynamic analysis method, comprising: modifying the predetermined method of the character string class in the java development kit; assigning values ​​to the incoming parameters of the program to be analyzed, the assignment including pre-embedded strings; dynamically executing the pending method an analysis program that determines whether the two character strings being compared contain a pre-embedded character string, responsive to one of the two character strings being a pre-embedded character string, converting the other of the two character strings to As the key parameter value of the program to be analyzed. The method provided by this application can directly perform dynamic analysis of programs without performing syntax and semantic analysis.