JPH0731616B2 - Program debug device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a program debugging device, and more particularly to an improved display method during execution tracing of a program.

<Outline of the Invention> The present invention displays a source program list of execution parts on a display screen at the time of execution trace of a program to be debugged, and the statements currently being executed on the displayed list are sequentially displayed in the center of the screen. It is possible to confirm the execution process of the program at the level of the source program by displaying it in a display mode in which the statement is located at the position and distinguishable from other statements.

<Background of the Invention> At present, a so-called "symbolic debugger" is often used as a program development support means in a high-level language. As one of the debug functions of such a symbolic debugger, a trace function is known in which the execution status of a program is sequentially traced and the trace status is displayed.

However, the above-mentioned trace display is a method of sequentially displaying indirect information of a currently executed part such as a file name, a function name, and a line number of a source program in response to executed machine language level instructions. Since it is general, when trying to confirm the execution process at the high-level language level, it is necessary to follow the program execution order on the source program list again based on the displayed information, which makes tracing work extremely complicated. there were.

On the other hand, it has been attempted to display the execution trace display in addition to the indirect information of "file name, function name, line number" of the source program, and also the source statement of the corresponding line, but the program is generally The flow is often understood in the connection of several lines of statements, and merely displaying the executed source statements sequentially in time series has a limit in making the program understand the flow of the entire program. Therefore, it is proposed to display a series of source program list according to the execution of the program on the display screen, and to notify the programmer of the movement of the program by changing the brightness of the display of the statement currently being executed. (JP-A-57-103549). However, with this method, when the statement being executed comes to the top or bottom of the display screen, the statement before or after that statement is not displayed, so it is not possible for the programmer to grasp the flow of the program quickly and reliably. It is possible.

<Object of the Invention> The present invention has been made in view of the above problems, and at the time of execution trace of a program to be debugged, the statement currently being executed can be positioned in the center of the display screen and can be distinguished from other statements. It is an object of the present invention to provide a debugging device that allows a program to visually recognize the flow of a program in a more natural form by displaying a source program list in a stable state and to quickly and surely grasp the flow of the entire program. .

<Structure and Effect of the Invention> In order to achieve the above object, the program debug device of the present invention executes a program to be debugged, trace means for tracing the execution process, and a series of sources within a certain range on the display screen. Display means for displaying the program list and the trace status by the tracing means, and judging means for judging whether or not the statement currently being executed by the tracing means is within the range of the display means and the source program list being displayed. When the determination result of the determination means is affirmative, the display of the source program list is scrolled so that the display of the statement currently being executed is positioned at the center of the display screen, and the statement currently being executed is distinguished from other statements. It is displayed in a possible display mode, and when the judgment result is negative, the current Display control means for displaying the source program list including the statement being executed so that the statement currently being executed is located at the center of the display screen, and for displaying the statement currently being executed in a display mode distinguishable from other statements. Is equipped with.

According to the present invention, with the above configuration, the procedure in which the program to be debugged is executed can be directly observed while checking the relationship before and after the statement on the list of the source program. This has the effect of making it possible to grasp the information and thus improve the efficiency of the debugging work.

<Description of Embodiments> The present invention will be specifically described below based on the embodiments illustrated in the drawings.

In the embodiment, a general-purpose computer is used, and an example in which the present invention is applied to a C language debug system in which the scope of application is expanded by replacing peripheral devices and software according to the purpose of debugging is shown. Needless to say, it can be carried out in a similar manner to a dedicated debug machine or the like that operates independently, and the language for the program to be debugged can be changed to various high-level languages other than "C".

As shown in FIG. 3, the debugging system embodying the present invention includes an engineering workstation 11 using a general-purpose computer, and a terminal device 12 that enables an operator to directly access the workstation 11.
And a debug execution device 13 which is executed under the control of the program to be debugged developed using the workstation 11 and which can be debugged at the assembler level.

The workstation 11 includes an internal storage device 22 composed of RAM and an external storage device 23 such as a hard disk drive, centering on an arithmetic and control unit 21 using a microprocessor.
And an input / output device 24 having an interface circuit for peripheral devices are connected via various buses 25. Further, the workstation 11 is connected to the terminal device 12 and the debug execution device 13 through the input / output device 24. Are connected.

The terminal device 12 displays the keyboard 26 that enables direct access to the workstation 11 and the data processing status in the workstation 11 in a visually recognizable manner.
It is composed of a display device 27 such as a CRT and the like, which is stored in advance in the external storage device 23 by a command input from the keyboard 26. The execution program of the compiler 31, the symbolic debugger 32, etc. shown in FIG. The data generated from the module 34 etc. is stored in the internal storage device 22.
Program 31 in the arithmetic and control unit 21 after loading
・ Work station by sequentially executing 32
11 operates as a debug system as a whole while controlling the debug execution device 13.

The debug execution device 13 includes a debugged device 28 such as an electronic cash register using a microprocessor capable of running a program to be debugged as a control unit, and the debugged device.
Device to be debugged between 28 and workstation 11
An emulator 29 that directly controls the debugged device 28 instead of the 28 CPU. The emulator 29 alone enables debugging at the assembler level, but in the present embodiment, the emulator 29 is debugged according to the command given from the workstation 11 side through the input / output device 24. The contents of the memory on the device 28 are displayed and updated, or various controls such as executing and stopping the program on the device to be debugged 28 are performed, and then the results are returned to the workstation 11 side, The station 11 side enables debug processing at the level of the source program 33 in a high-level language.

FIG. 4 schematically shows the flow of processing mainly by software inside the workstation 11 until the source program 33 written in C language is translated into a machine language and further symbolically debugged.

First of all, a source program consisting of multiple files
33 is compiled by the compiler 31 inside the workstation 11 to form a load module 34. The load module 34 is described on the source program 33, line number information indicating the correspondence between the address of the machine language and the line number of the source program 33, in addition to the machine language that the microprocessor of the device to be debugged 28 can execute. Symbol information indicating the correspondence between the variable and the memory address on the device 28 to be debugged. The file format is, for example, the operating system UNIX SYSTEM.
It is configured in accordance with V COFF (Common Object File Format).

Next, the symbolic debugger 32 is activated, and the terminal device 12
When a predetermined command is input from the keyboard 26, the emulator commands necessary for processing the command are sent to the emulator 29. The emulator 29 interprets and executes the emulator command, and then returns the result to the debugger 32.

The symbolic debugger 32 has a line number table in its internal memory, based on the line number information of the load module 34, consisting of records of machine language addresses and corresponding file names, function names, and line numbers. The debugger 32 edits the processing result returned from the emulator 29 with reference to the row table and the source program file 33, and displays it on the display device 27 of the terminal device 12.

The present invention resides in the debug system having the above-described configuration, and is characterized by the method of displaying the result of the trace status during the execution trace of the program.

FIG. 1 shows an example of a screen display suitable for implementing the present invention. Of the display screen 41 on the display device 27 of the terminal device 12, the program counter value of the instruction currently being executed in the lowermost stage 42. 43, the file name 44, the function name 45, and the line number 46 of the corresponding source program are displayed in the format of "file name-function name-line number <PC value>".

The second from the bottom is a command input area 47 for inputting disk commands from the keyboard 26 of the terminal device 12, and a prompt (>) 48 and a cursor (_) 49 are displayed when the workstation 11 can be accessed. Is displayed,
Predetermined commands can be input. Furthermore, the area 47
The upper part is used as the trace status display area 51.

In the trace status display area 51, the line number 46 of the source program 33 corresponding to the current program counter value 43 is located in the center during execution trace of the program to be debugged, and the source program list 52 near the line number 46 is located. Is displayed. Further, on the list 52, the line number 46 corresponding to the current program counter value 43 is specified as the white inverted line 53. Further, the source program list 52 is sequentially scrolled up or down in accordance with the change of the program counter value 43 to display the source program so that the line number 46 being executed is always located in the center of the display screen 41, and the white outline is displayed. By sequentially moving the line 53 in response to the change in the program counter value 43, the source program 33
The execution trace status of the program is displayed on the list 52 of.

FIG. 2 is an example showing a control flow for displaying the above-mentioned display. At the “start” of step 61, the operator inputs the command input area 47 of the display screen 41 through the keyboard 26.
Enter the trace execution start command in to indicate the state where trace execution has started.

In cooperation with the start of trace execution, in step 62, the debugger 32 sends a predetermined emulator command "STP" to the emulator 29 for step execution of the machine language program. Then, the emulator 29 causes the program of the device to be debugged 28 to execute only one machine language in response to the command, and then returns the executed program counter value (PC) to the cipheric debugger 32. When such a program counter value is received by the debugger 32 (step 63), the line number table created in advance inside the debugger 32 is searched, and the file name 44 of the source program 33 corresponding to the address indicated by the program counter value 44. , Function name 45, line number 46 is checked (step 6
Four). In the following step 65, if the judgment of "Is the line number corresponding to PC?" Is "NO", it is judged that a blank line has been executed, so the process returns to step 62 again to execute a valid machine language. The above operation is repeated until.

On the other hand, if it is determined in step 65 that "there is a line number corresponding to the program counter value", then in step 66, "is the line number within the range of the source program currently displayed on the display?" Judgment is made. If the determination is “YES”, the source program list 52 including the executed part has already been displayed on the display screen 41. Therefore, the process moves to step 67, and the program in the source program list 52 displayed on the screen is The display screen 41 is scrolled so that the line number 46 corresponding to the counter value 43 is located at the center of the screen, and the line number 46 is highlighted in white 53 to identify the source statement 54 currently being executed.

On the other hand, if the determination in step 66 is "NO", it is determined that the program list 52 is not displayed at all, or that a part outside the currently executed part is displayed, so the execution statement 54 is changed. Program list including 52
Should be displayed. Therefore, in step 68, it is first determined whether or not the file name corresponding to the program counter value is the same as the currently displayed file name. If "YES", then in step 69, the corresponding line number in the file is determined. If the judgment is "NO", an error message is displayed to call the operator's attention (step 70), while if the judgment is "YES", the line number is centered, The source program list 52 in the vicinity and 20 lines are displayed on the screen (step 71), and the corresponding lines are displayed in white 53 as in the above.

If it is determined in step 68 that "the file name corresponding to the PC value and the currently displayed file name are different", it is further determined in step 72 "whether the source file exists in the external storage device." If it does not exist, an error message stating "source file does not exist" is displayed and the operator is alerted (step 73). If the file exists, it is opened so that the file can be referenced. After that (step 74), the above display operation is repeated until the execution of all the programs to be debugged.

In the above embodiment, as a method of clearly displaying the statement 54 being executed, the entire line is outlined, but it is also possible to add a mark at the beginning of the line to identify the execution line. Is.

[Brief description of drawings]

FIG. 1 is a front view of a display screen showing a display example of an execution trace status in a debug device according to the present invention, FIG. 2 is a flow chart for explaining the display procedure shown in FIG. 1, and FIG. FIG. 4 is a block diagram showing an example of a debug system for doing so, and FIG. 4 is a schematic diagram for explaining the flow of processing in the system of FIG. 11 …… Workstation 12 …… Terminal device 27 …… Display device 33 …… Source program 41 …… Display screen 52 …… Source program list 53 …… White line

Claims (1)

[Claims] 1. A trace means for executing a program to be debugged and tracing its execution process, a display means for displaying a series of source program lists within a certain range and a trace status by the trace means on a display screen. Determining means for determining whether the statement currently being executed by the tracing means is within the range of the source program list displayed on the display means, and the statement currently being executed when the result of the determination by the determining means is affirmative While scrolling the display of the source program list so that the display of is located in the center of the display screen, the currently executing statement is displayed in a display mode that can be distinguished from other statements, and when the determination result is negative, the current execution is executed. The source program listing containing the statement in Causes display such that the instrument is positioned at the center of the display screen, the program debugging device comprising a display control means for displaying the currently running statement distinguishable display mode with other statements.