JPH04248634A - Debugger - Google Patents

Abstract

PURPOSE:To easily find latent bugs by eliminating a need to recognize the arrangement of addresses belonging to data in plural data structures of a prescribed data structure and a non-data structure and efficiently finding overrun from the prescribed data structure at the time of program execution. CONSTITUTION:A means 11 which generates data of the non-data structure to which a label is added is provided. Non-data structure data in a source code 2 is interposed between labels of dummy data of global variables. A data arrangement information generating means 12 is provided to generate arrangement information of data of non-data structure data to which the label is added. An access data detecting means 13 is provided to collate data arrangement information and detects that the accessed address is within the range of the area of non-data structure data to which the label is added.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a debugger, and more particularly to a debugger for debugging programs of computers such as microprocessors.

0002

[Prior Art] When a program such as a microprocessor to be debugged accesses data in a main memory device, etc., a conventional debugger uses a debugger that does not belong to a data structure related to the program (hereinafter referred to as a "predetermined data structure"). There was no way to efficiently detect that data of a data type was accessed.

FIG. 6 shows an example of array data on the main memory. This is an example of the data type of the link expression type, and the array data such as A to C is part of a predetermined data structure, and the array data such as L to N is data of a data type that does not belong to the predetermined data structure. (hereinafter referred to as non-data structure data).

[0004] To access such data, create a table like the one shown in Figure 7 using a link editor (linker), which is a tool for linking programs, and use a pointer pointing to the first address of each array data. It is common to do so. In the example of FIG. 7, the first address of array data A is 100 and the data size is 10 bytes, the first address of array data B is 200 and the data size is 20 bytes, and the first address of array data C is is 300
This indicates that the data size is 30 bytes or the like.

In conventional debuggers, detection of whether non-data structure data has been accessed is performed manually as shown in FIG.

First, in step P1, disassembly is performed, which is a process of converting program execution instructions from machine language to assembler language.

Next, the address accessed by the instruction is checked (step P2).

Next, check whether the address is within the range of the table created by the linker (step P3)
.

Next, it is determined whether the address is an address of non-data structure data (step P4). If YES, it is an error, and the process proceeds to step P5, where an error message is output, the corresponding command name is recorded in the program counter (hereinafter referred to as PC), and the process is interrupted. If no, the process proceeds to step P6 and executes that one instruction.

Next, it is determined whether the program has ended (step P7). If yes, exit. If the answer is no, the process returns to step P1 and the same process as the above flow is repeated for the next command.

[0011]

[Problems to be Solved by the Invention] In the conventional debugger described above, in order to access data of a non-data structure data type and execute debugging, a debugger needs to understand the difference between a predetermined data structure and its non-data structure data. This method has the disadvantage that it is necessary to grasp the arrangement of addresses belonging to data in multiple data structures. Furthermore, since overruns from a predetermined data structure during program execution cannot be efficiently discovered, there is a drawback that it is difficult to discover potential bugs.

0012

[Means for Solving the Problems] The debugger of the first invention includes a label that is dummy data of a global variable before and after non-data structure data that is data that does not belong to a predetermined data structure in a source code. a labeled non-data structure data creation means for creating labeled non-data structure data sandwiched between the labeled non-data structure data; a data arrangement information creation means for creating data arrangement information that is arrangement information of the labeled non-data structure data; and access data detection means that collates the arrangement information and detects that the address to be accessed is within the area of the labeled non-data structure data.

[0013]

Embodiments Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the debugger of the present invention.

As shown in FIG. 1, the debugger 1 of this embodiment includes a labeled non-data structure data creation means 11, a data arrangement information creation means 12, and an access data detection means 13. .

Label-added non-data structure data creation means 1
1 is a label that consists of dummy data of global variables that are common variables in the system before and after non-data structure data, data that does not belong to a certain data structure data in source code 2. This method creates non-data structure data with insert labels added.

The data arrangement information creation means 12 is for creating data arrangement information that is arrangement information of labeled non-data structure data.

The access data detection means 13 detects that the address to be accessed is within the area of labeled non-data structure data.

Next, the operation of this embodiment will be explained.

FIG. 2 shows an example of array data including labeled non-data structure data in which a label is added to the non-data structure data in the source code 2 by the labeled non-data structure data creation means 11. This is an example of the data type of the link expression type similar to the conventional example, and A to C
etc. is a part of a predetermined data structure, and L~
Array data such as N is part of non-data structure data. Then, labels S1 and E1 are placed before and after data L, labels S2 and E2 are placed before and after data M, and data N
Labels S3 and E3 are added before and after, respectively.

FIG. 3 is a diagram showing an example of the array data table shown in FIG. 2 created by the linker. In this example, as in the conventional example, the starting address of array data A having a predetermined data structure is 100, indicating that the data size is 10 bytes or the like. The first address of the front label S1 of the non-data structure data L is 110 and the size is 1 byte, and the first address of the rear label E1 is 199 and the size is 1 byte.

FIG. 4 is an example of data arrangement information of labeled non-data structure data created by the data arrangement information creation means 12 by converting the data in the table shown in FIG.

In FIG. 4, the first non-data structure data area is S1 to E1, and the first address is 110,
The final address is shown as 199.

FIG. 5 is a flowchart showing the operation flow of the access data detection means 13 of the debugger of this embodiment.

First, in step S1, disassembly is performed, which is a process of converting program execution instructions from machine language to assembler language.

Next, the address accessed by the instruction is checked (step S2).

Next, it is checked whether the address is within the range of the data arrangement information table in FIG. 4 (step S3).

Next, it is determined whether the address is within the range of the data location information table (step S4). If YES, it is an error, so the process proceeds to step S5, where an error message is output, the name of the corresponding command on the program counter (hereinafter referred to as PC) is displayed, and the process is interrupted. If no, the process advances to step S6 and the one instruction is executed.

Next, it is determined whether the program has ended (step S7). If yes, the process ends. If no, the process returns to step S1 and the same operations as the above flow are repeated for the next command.

[0030]

As explained above, the debugger of the present invention has a function of detecting access to an area of non-data structure data, so that multiple data structures of a predetermined data structure and its non-data structure data can be detected. This has the effect that there is no need to know the arrangement of addresses belonging to the data. Furthermore, since overruns from a predetermined data structure during program execution can be efficiently discovered, potential bugs can be easily discovered.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a debugger of the present invention.

FIG. 2 is a diagram illustrating an example of array data including labeled non-data structure data.

FIG. 3 is a diagram showing an example of a table of array data shown in FIG. 2 created by a linker.

FIG. 4 is a diagram showing an example of a table of data arrangement information created from the table shown in FIG. 3;

FIG. 5 is a flow chart showing an example of the operation of access data detection means in the debugger of this embodiment.

FIG. 6 is a diagram showing an example of array data on a main storage device.

FIG. 7 is a diagram showing an example of a table of array data shown in FIG. 6 created by a linker.

FIG. 8 is a flow chart showing an example of the operation of a conventional debugger.

[Explanation of symbols]

1 Debugger 2 Source code 11 Labeled non-data structure data creation means 1
2 Data arrangement information creation means 13 Access data detection means

Claims (1)

[Claims] Claim 1: Create labeled non-data structure data by sandwiching the front and back of non-data structure data, which is data that does not belong to data in a predetermined data structure in the source code, with labels, which are dummy data of global variables. a labeled non-data structure data creation means for creating labeled non-data structure data; a data arrangement information creation means for creating data arrangement information that is arrangement information of the labeled non-data structure data; A debugger comprising access data detection means for detecting that the access data is within the range of additional non-data structure data.