JPH05334125A - Method for verifying specification of software - Google Patents

Abstract

PURPOSE:To completely inspect the non-contradiction of a function using method at the time of preparing the specification of software or charging the specifica tion, and at the time of detecting an error, to provide effective information for correcting the specification to a designer. CONSTITUTION:A transition extracting mean 2 extracts transition from the specification of software to be verified which is described based upon a status transition model and a function extracting means 3 extracts the function used in the specification. An inspection means 7 verifies whether restriction is canceled or not by paying its attention to the extracted function and virtually and reversely tracing the transition used for the function and detects a loop unnecessary for the inspection based upon relation between the used function and the restriction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a software specification verification method for improving the quality of use of software used in a system and improving the efficiency of specification correction work when an error is included.

[0002]

2. Description of the Related Art Currently, the cost of developing and maintaining system software is extremely high.
Therefore, it is very important to improve the efficiency and quality of the system software design process. Therefore, it is urgently necessary to verify the software specifications.

A state transition model is one of the description formats of the software specification. This state transition model is, for example, as shown in FIG. 4, internal states Q1, Q2, Q3, Q4, Q.
5 shows that, for example, when the input C is input in the state Q2, the output D is output and the state changes to the state Q3. in this case,
The directional branch from state Q2 to state Q3 is a transition, and C / D
Is an event / action (hereinafter referred to as a function).

For the verification of software specifications by such a state transition model, there is a method of defining an error standard and inspecting while sequentially transiting from an initial state. However, in such software specifications, there are often infinite number of state transition sequences, and there is no probable technique as a verification method for performing effective inspection.

[0005]

As described above, in the software specification based on the state transition model, the sequence of state transitions is often infinite, and there is a possibility that verification may be missed or effective inspection cannot be performed. ..

In view of the above, the present invention is a software which can check the consistency of the usage of functions at the time of creating a software specification or changing the specification and, when an error is detected, provide the designer with effective information for modifying the specification. The purpose is to provide a method of verifying the specifications of.

[0007]

SUMMARY OF THE INVENTION The present invention is a software for checking whether or not an error is included in the use of a function used on the specification of software to be verified described based on a state transition model. In the specification verification method,

Transition extracting means for extracting a transition in the specification of the verification target software, function extracting means for extracting a function used in the specification of the verification target software, and a constraint for holding a constraint on the use of the function Focusing on the holding means and the extracted function, it is checked whether the constraint is abandoned by tracing the transition in the reverse direction from the used transition of this function, and the used function This is a software specification verification method comprising an inspection means for detecting a loop unnecessary for inspection in relation to constraints.

[0009]

By having such means, the transition is extracted from the specification of the verification target software described based on the state transition model by the transition extraction means, and is used in the specification of the verification target software together therewith. The existing function is extracted by the function extracting means. Here, the checking means pays attention to the extracted function, checks whether the constraint is abandoned by tracing the transition in the reverse direction from the used transition of this function, and is used. Detect loops unnecessary for inspection from the relationship between functions and constraints. As a result, the inspection method has a mechanism (loop processing) that avoids the infiniteness of the state transition series, so that there is no omission in inspection, the progress of inspection is retained, and the reason for constraint cancellation is given to the designer. You can

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an apparatus to which a software specification verification method is applied. The verification target specification holding unit 1 holds the verification target software specifications input by the designer. The transition information extraction unit 2 and the used function extraction unit 3 are connected to the verification target specification holding unit 1.

Of these, the transition information extraction unit 2 has a function of extracting all transitions in the specifications of the software to be verified and holding them in the transition information base unit 4, and the use function extraction unit 3 is the software to be verified. The function information base unit 5 has a function of extracting all the functions used in the specifications of the above.

Further, the function use constraint database section 6 includes
The constraint regarding the use of the function input by the designer in advance is held. That is, the function described in the software to be verified holds what condition is satisfied. Actually, in order to use the function, the functions that must be used in the transition series up to that point and the functions that should not be used are held.

The checking unit 7 receives the transition from the transition information base unit 4 and the function from the function information base unit 5, receives the constraint from the function use constraint database unit 6, and pays attention to the extracted function. A function that checks if constraints are not discarded by tracing the transition in the reverse direction from the used transitions of the above, and detects unnecessary loops from the relation between the used functions and the constraints. have. Specifically, the inspection state position holding unit 7-
1, a reverse transition realizing unit 7-2, a constraint checking unit 7-3, and a transition checking process holding unit 7-4. The inspection state position holding unit 7-1 holds a state where the inspection is in progress and a set of constraints that must be satisfied in that state.

The reverse transition realization unit 7-2 has a function of shifting the state of the verification target software in the reverse direction from the state of the verification target software using the transition information of the transition information base unit 4.

The constraint checking unit 7-3 includes a check state and function use constraint database unit 6 from the check state position holding unit 7-1.
It has a function of inspecting the usage method of the function in the transition on the software to be verified from the constraint of.

The transition inspection process holding unit 7-4 has a function of holding an inspection process in which the states inspected by the a priori inspection unit 7-3 and the constraints that must be satisfied in each state are paired.

Further, the error information presenting unit 8 includes a constraint checking unit 7-
3 has a function of presenting information to the designer for the specification correction from the transition inspection process holding unit 7-4 when an error is detected. Next, the operation of the apparatus configured as described above will be described with reference to the flow chart of the inspection operation shown in FIG.

The verification target software created by the designer is held in the verification target specification holding unit 1. The transition information extraction unit 2 extracts all the transitions in the specifications of the verification target software from the verification target specification holding unit 1 and causes the transition information base unit 4 to hold them. At the same time, the used function extraction unit 3 extracts all the functions used in the specification of the verification target software from the verification target specification holding unit 1 and causes the function information base unit 5 to hold the functions.

When the operation of verifying the specifications of the verification target software is started, the inspection state position holding unit 7-1 uses the function of the verification target software and its function from the transition information base unit 4 in step # 1. From the existing transition, the state of the transition source is extracted. At the same time, the constraint checking unit 7-3 extracts the constraint set of the target function from the function use constraint database 6. Also, the inspection state and the constraint set are passed to the transition inspection process holding unit 7-4 as the inspection starting state. Next, in step # 2, the state and the constraint set are passed to the inspection state position holding unit 7-1 as the inspection state. In the next step # 3, it is determined whether or not the inspection has been performed on all transition series. If the inspection has not been performed, the process proceeds to step # 4. In step # 4, the reverse transition realization unit 7-2
Extracts all the states that transit to the inspection target state from the transition information base unit 4.

Next, in step # 5, the constraint checking unit 7-
3 determines the error transition series from the constraint set that must be satisfied with the function used for all the extracted transitions, that is, whether the discard of the constraint is detected from the transition function.

As a result of this judgment, when the constraint discard is detected from the transition function, the process proceeds to step # 6, and the constraint checking unit 7
-3 takes out the transition sequence that has been inspected and the discarded constraint from the transition inspection process holding unit 7-4 and passes it to the error information presenting unit 8. The error information presenting unit 8 receives the transition series and the discarded constraint and presents the information to the designer for the specification correction.

Further, if the constraint discard is not detected from the transition function, the process proceeds to step # 7, and the constraint checking unit 7-3 checks that the checked transition sequence is correct, that is, all the transition functions are checked. It is judged whether or not the constraint is approved. If the result of this determination is that the constraint is established, the procedure moves to step # 8, and the constraint checking unit 7-3 deletes that state from the set of check states.

If the constraint is not confirmed, the process proceeds to step # 9, where the constraint checking unit 7-3 determines that the loop does not need to be checked, that is, the transition sequence that has been checked is in the loop. Determine if is unnecessary.
That is, in the case where the same state as the state that was inspected in the past is set as the inspection target from the information of the transition inspection process section 7-4, if the constraint that must be satisfied is exactly the same, the inspection is further proceeded from there. No need.

For example, in the state transition diagram shown in FIG. 3, the repetition of the function T1.fwdarw.T2 appears in the transitions examined in the series "2" to series "n". If it is not recognized that the function T1 → T2 sequence includes the function for satisfying the target constraint and the function for discarding the target constraint, even if the transition is further executed, the inspection result is changed. There is no.
In other words, the inspection of this series is the same as the inspection result of the series of the function T0 → T1 → T3, and the inspection after the function T0 → T1 → T3 should be continued. Therefore, such a loop is determined to be a loop that does not require inspection. When it is detected that the loop does not require further inspection, the process proceeds to step # 8, and if not detected, the next step # 10 is performed.
Move on to.

If the function used in the target transition in step # 10 is included in the constraint set that must be satisfied, that element is removed to make a new constraint set.

Then, the procedure returns to step # 2 again and repeats the check whether the sequence is correct or contains an error,
It ends when all the sequences can be checked for correctness or for errors.

As described above, according to the above-described embodiment, when the designer describes the software specification based on the state transition model, the function constraint in the specification is described, so that the designer can use the software in the specification. It is possible to automatically check whether or not the function to be used is correctly used, and it is possible to realize specification verification that guarantees the correctness of the inspection result without omission of the inspection. In addition, even if the inspection fails, by keeping the inspection process, it is possible to give the designer what reason the constraints were discarded, and it is possible to help the specification modification, improve the quality of software specifications, and The effort of creating wear specifications can be reduced. It should be noted that the present invention is not limited to the above-mentioned embodiment, and may be modified within the scope of the invention.

[0029]

As described above in detail, according to the present invention, when the software specifications are created or the specifications are changed, all the consistency of the usage of the function is inspected, and if an error is detected, the effective information for the specification correction is obtained. It is possible to provide a software specification verification method that can be given to a designer.

[Brief description of drawings]

FIG. 1 is a block configuration diagram showing an embodiment of an apparatus to which a software specification verification method according to the present invention is applied.

FIG. 2 is a flow chart of an inspection operation in the device.

FIG. 3 is a state transition diagram for explaining the detection operation of the inspection unnecessary loop in the same device.

FIG. 4 is a state transition diagram for explaining a conventional software specification verification method.

[Explanation of symbols]

1 ... Verification target specification holding unit 1, 2 ... Transition information extraction unit, 3 ...
Use function extraction unit, 4 ... Transition information base unit, 5 ... Function information base unit, 6 ... Function use constraint database unit, 7 ... Checking unit, 7-1 ... Check state position holding unit, 7-2 ... Reverse transition realizing unit , 7-3 ... Constraint checking unit, 7-4 ... Transition checking process holding unit, 8 ... Error information presenting unit.

Claims (1)

[Claims] 1. A software specification verification method for inspecting whether or not there is an error in the use of a function used on the specification of software to be verified described based on a state transition model, Transition extraction means for extracting transitions in software specifications, function extraction means for extracting the functions used in the verification target software specifications, and constraint holding means for holding constraints regarding the use of the functions And paying attention to the extracted function, inspecting whether the constraint is abandoned by tracing a transition from the used transition of this function to a virtual reverse direction, and A specification verification method for software, comprising: an inspection unit that detects a loop unnecessary for inspection based on a relationship between a function and the constraint.