JP3694872B2 - Dependent subroutine search support device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a subordinate subroutine search support apparatus that supports analysis of subordinate dependency relationships.
[0002]
[Prior art]
A computer program is usually defined as a collection of subroutines that call each other. Some subroutines have functions dependent on a subroutine. For example, when calling the subroutine A for accessing the database, it is necessary to call the subroutine B for exclusive processing before and after. Subroutine B having such a relationship can be considered to be subordinate to subroutine A.
[0003]
In the maintenance work of a computer program, it is important to know the subroutines that are subordinate to the subroutines that are focused on in this way. However, with respect to old programs, there are cases where documents for storing such information are out of alignment with the actual program, or are not fully prepared due to omission or loss of description. In such a case, conventionally, it has been necessary to manually analyze the enormous source code of the program in order to examine the dependency relationship between the subroutines.
[0004]
[Problems to be solved by the invention]
As described above, manually analyzing the dependency relationship of subroutines in a program with insufficient documentation has a problem that work efficiency is low, analysis errors are likely to occur, and reliability is lacking.
[0005]
The object of the present invention is to semi-automate the dependency analysis of subroutines of programs with insufficient documents, improve the work efficiency when searching for subroutines subordinate to the subroutine of interest, and obtain highly reliable analysis results. Another object of the present invention is to provide a subordinate subroutine search support apparatus that can contribute to the efficiency of program maintenance and the like.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a call flow analysis means for generating a call flow graph and a reverse call flow graph from a source code of a program, and a subroutine to be noted from the generated call flow graph and reverse call flow graph. And a candidate subroutine extracting means for extracting a candidate of a subordinate subroutine.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a dependent subroutine search support device of the present invention will be described in detail based on embodiments shown in the drawings.
FIG. 1 is a functional block diagram showing an embodiment of a dependent subroutine search support apparatus of the present invention. The dependent subroutine search support device of this embodiment includes a call flow analysis device 101 that generates a call flow graph 104 and an inverse call flow graph 105 from a source code 103 of a program, and a generated call flow graph 104 and an inverse call flow graph 105. And a candidate subroutine extracting device 102 for extracting a subroutine candidate 106 subordinate to the subroutine of interest.
[0008]
FIG. 2 is a block diagram showing details of the call flow analysis apparatus 101.
As shown in FIG. 2, the call flow analysis apparatus 101 analyzes a syntax of the program source code 103, a syntax analysis apparatus 1011 for analyzing a subroutine call from a syntax analysis result by the syntax analysis apparatus 1011, and a call flow graph. A call flow graph generation device 1012 for generating a reverse call flow graph, and a reverse call flow graph generation device 1013 for generating a reverse call flow graph from the generated call flow graph.
[0009]
FIG. 3 is a block diagram showing details of the candidate subroutine extracting apparatus 102. As shown in FIG. 3, the candidate subroutine extracting apparatus 102 includes a route subroutine selecting apparatus 1021, a candidate subroutine marking apparatus 1022, and a candidate subroutine selecting apparatus 1023.
[0010]
FIG. 4 is a flowchart showing details of the operation of the call flow analysis apparatus 101. As shown in this flowchart, the call flow analysis apparatus 101 first parses the program source code 103 to be analyzed (step 401). The analysis result becomes a syntax tree of a subroutine included in the program source code 103. This step is executed by the syntax analysis apparatus 1011. Subsequently, a subroutine call sentence is extracted from the syntax tree of each subroutine included in the source program 103 to be analyzed, and an adjacency matrix of a directed graph (call flow graph) having the subroutine as a vertex and an edge of the call relation is created (step) 402). This step is executed by the call flow graph generation device 1012. Further, an adjacency matrix of a directed graph (reverse call flow graph) in which the start point and end point of each side of the generated call flow graph are reversed is created (step 403). This step is executed by the reverse call flow graph generation device 1013.
[0011]
FIG. 5 shows an example of the program source code 103, which includes subroutines P00, p10, P20, P01, P02, P03, P04, P05PEX, and PDB. It is assumed that the program shown in this example performs exclusive processing accompanying database access. PDB is a database access subroutine, and PEX is an exclusive processing subroutine. Here, since there are only insufficient documents, it is known that PDB is a database access subroutine, but PEX is not known to be an exclusive processing subroutine. It is assumed that it is known that there is only one exclusive processing subroutine.
[0012]
FIG. 6 is an adjacency matrix representing a call flow graph created by the processing of steps 401 and 402 in FIG. 4 from the program source code 103 shown in FIG. There is an edge where there is a circle at the intersection of the row and column in FIG.
[0013]
FIG. 7 describes the same call flow graph 701 in a diagram format. Further, FIG. 8 describes the reverse call flow graph 801 created by the processing of step 403 in FIG. 4 in a diagram format.
[0014]
FIG. 9 is a flowchart showing details of the operation of the candidate subroutine extraction apparatus 102. In candidate subroutine extraction apparatus 102, the user first designates a target subroutine (step 901). Subsequently, a list of route subroutines (attention route subroutines) that directly or indirectly call the attention subroutine is created (step 902). The processing of these two steps is executed by the route subroutine selection device 1021. Next, the subroutine on the call flow graph that is called directly or indirectly from each target route subroutine is marked (step 903). The processing in this step is executed by the candidate subroutine marking device 1022. Finally, subroutines marked with all the root subroutines are selected and set as candidate subroutines (step 904). The processing in this step is executed by the candidate subroutine selection device 1023.
[0015]
FIG. 10 shows a state in which subroutines that may be exclusive processing subroutines are narrowed down from the call flow graph 701 in FIG. 7 by the processing in FIG. First, in step 901, the database access subroutine PDB is designated as the subroutine of interest. Subsequently, in step 902, the route subroutine selecting device 1021 selects the route subroutines P00 and P20 that are calling the PDB directly or indirectly. Subsequently, in step 903, first, a subroutine on the call flow graph that is called directly or indirectly by the attention route subroutine P00 is marked (indicated by a solid underline in FIG. 10), and the attention route subroutine P20. Marks a subroutine on the call flow graph that is called directly or indirectly by (indicated by a dotted underline in FIG. 10). Finally, in step 904, subroutines marked with both route subroutines P00 and P20 are selected, and PEX and P05 are set as candidate subroutines. Here, the PDB which is the target subroutine is known and thus excluded. Thereafter, the source code of each of PEX and P05 is visually inspected to confirm that it is an exclusive processing subroutine required by PEX.
[0016]
If the number of subordinate subroutines to be searched is unknown and there are a plurality of possibilities, in step 904 of the flowchart in FIG. 9, one of the subroutines marked with the attention route subroutine is selected as a candidate subroutine. It may be extracted as
[0017]
In the above embodiment, needless to say, the call flow graph or reverse call flow graph is output to the display device or the printing device in a form that can be confirmed by the person in charge of analysis. Also, the notice subroutine can be notified in various forms such as shaded display, flicker display, and color-coded display instead of underlining.
[0018]
【The invention's effect】
As described above, according to the present invention, it is possible to efficiently narrow down subroutine candidates subordinate to the subroutine of interest in the source code of the program, and obtain highly reliable analysis results. Therefore, it is possible to improve the efficiency of maintenance work for programs with insufficient documents and the like.
[Brief description of the drawings]
FIG. 1 is a functional block diagram showing an embodiment of the present invention.
FIG. 2 is a block diagram showing a detailed configuration of a call flow analysis apparatus.
FIG. 3 is a block diagram showing a detailed configuration of a candidate subroutine extraction apparatus.
FIG. 4 is a flowchart showing details of the operation of the call flow analysis apparatus.
FIG. 5 is a diagram illustrating an example of a source code of a program.
FIG. 6 is a diagram illustrating an example of an adjacency matrix representing a call flow graph.
FIG. 7 is a diagram showing an example of a call flow graph described in a diagram format.
FIG. 8 is a diagram illustrating an example of a reverse call flow graph described in a diagram format.
FIG. 9 is a flowchart showing details of the operation of the candidate subroutine extraction apparatus.
FIG. 10 is a diagram illustrating an example of marking of a dependent subroutine candidate on a call flow graph.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 101 ... Call flow analysis apparatus, 102 ... Candidate subroutine extraction apparatus, 103 ... Program source code, 104 ... Call flow graph, 105 ... Inverse call flow graph, 106 ... Subordinate subroutine candidate, 1011 ... Syntax analysis apparatus, 1012 ... Call Flow graph generation device, 1013 ... Reverse call flow graph generation device, 1021 ... Route subroutine selection device, 1022 ... Candidate subroutine marking device, 1023 ... Candidate subroutine selection device.

Claims (1)

Call flow analysis means for generating a call flow graph from the source code of the program, route subroutine selection means for extracting a plurality of target route subroutines that call the target subroutine directly or indirectly from the generated call flow graph , and Based on the call flow graph, a subroutine that is directly or indirectly called from each extracted target route subroutine is extracted based on the call flow graph, and a subroutine that is commonly called from each target route subroutine among the extracted subroutines is searched. A subordinate subroutine search support device, comprising: candidate subroutine selection means for extracting as a candidate for the subroutine .

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