JPS63205740A - Program executing trace processing system - Google Patents

Abstract

PURPOSE:To efficiently execute a symbolic debug by retrieving a line number of a source program from a correspondence table and outputting it, with respect to an instruction address of an object program in case an interruption has been generated. CONSTITUTION:A symbolic tracer 3 loads an object program 2 and a correspondence table 4, and executes the object program 2 by setting a computer to a debug mode. The correspondence table 4 is constituted so as to show an address of the object program 2, and a line number of a source program corresponding thereto. An interruption processing part 1 monitors a branch of the object program 2, and shifts a control to the symbolic tracer 3, when a branch execution is detected in a program which is being executed by the debug mode. The symbolic tracer 3 retrieves the correspondence table 4 by a branch destination instruction address of the object program 2, and outputs the corresponding number to a list 5. In such a way, the symbolic debug can be executed efficiently.

Description

[Detailed Description of the Invention] [Summary] This is an improved execution trace processing method for program debugging.

A correspondence table is created between source program line numbers and object program instruction addresses, and when an interrupt occurs at a branch instruction in so-called branch tracing of object program execution, the correspondence table is used to search for the line number corresponding to that instruction address. and output it. A correspondence table is created, for example, when a source program is translated into an object program.

As described above, so-called symbolic debugging can be performed efficiently.

[Industrial application field]

The present invention relates to an execution trace processing method for program debugging in a computer.

So-called execution tracing, which traces the path of executed instructions by running a program, is used as an effective means of program debugging.

[Prior art and problems to be solved by the invention] The direct purpose of program execution tracing is to know the addresses of executed instructions. Since it is not necessary to know the address of each instruction, as is well known, only the address of the branch destination instruction when a program is branched is output, which is called, for example, branch tracing.

Many computer processing units are provided with a function of detecting the occurrence of a branch due to a branch instruction and generating a predetermined interrupt in order to support the above-mentioned branch trace.

In such a processing device, the state of a program being executed on the processing device can be controlled with respect to the execution of the program by setting it in a predetermined, e.g., debug mode, e.g. by setting predetermined control bits of a known program state word. Branch trace interrupts are enabled.

Furthermore, by activating an appropriate tracer program when an interrupt occurs, it is possible to read and output the next instruction address, that is, the branch destination instruction address, in the instruction address register of the debugged program at the time of the interrupt. ,
Trace information can be acquired relatively efficiently.

However, this trace information is of course the address of a so-called machine language instruction program that can be directly executed by a processing device, and does not correspond to the program statements of a source program written in a so-called high-level programming language. There is a problem that debugging efficiency cannot be improved because it is necessary to make a correspondence with

For this purpose, there are debug programs called symbolic debuggers that output execution trace results as information corresponding to the source program.

When debugging with a symbolic debugger, you can specify that a so-called compiler generate an object program in debug mode when translating the source program into a machine language object program. Create an object program with debugging information inserted.

When such an object program is executed, control is transferred to the symbolic debugger by executing the instructions in the debugging information part, for example, by branching, and the symbolic debugger uses the debugging information to
Outputs the line number etc. of the source program.

For this reason, when debugging is finished and the program is to be used in actual operation, it is necessary to generate a new object program from the completed source program without inserting debugging information, and as a result, debugging and execution There is a problem in that differences in the size of programs during operation can cause trouble.

[Means for solving problems]

FIG. 1 is a block diagram showing the configuration of a computer according to the present invention.

In the figure, 1 monitors the branch of the object program 2 that is being executed and generates an interrupt, and the symbolic tracer 3
4 is the symbolic tracer 3
is a correspondence table that is referred to in order to output the line number of the source program corresponding to the interrupt generation address to List 5.

[For production]

Symbolic tracer 3 is object program 2
and correspondence table 4, put the computer in debug mode, and execute object program 2.

The correspondence table 4 is constructed to show addresses of the object program 2 and line numbers of the source program corresponding thereto.

The interrupt processing unit 1 monitors branches of the object program 2, and transfers control to the symbolic tracer 3 when branch execution is detected in a program running in debug mode.

The symbolic tracer 3 searches the correspondence table 4 using the branch destination instruction address of the object program 2, and outputs the corresponding line number to the list 5.

With this method, symbolic debugging can be performed efficiently, and the same object program can be used during debugging and operation.

〔Example〕

When you start symbolic tracer 3 for debugging with a source program, symbolic tracer 3 will do the following:
The specified object program 2 and the correspondence table 4 are loaded, and the computer is set to the debug mode using a predetermined control bit of the program status word of the program 2, for example, as described above, and execution of the object program 2 is started.

For example, as shown in FIG. 2, the correspondence table 4 shows that a source program 10 written in a high-level programming language is translated by a compiler 11 to create an object program 2.
is created by the compiler 11 when generating.

In the correspondence table 4, for example, each item consisting of a line number tank and an address column as shown in the figure shows the line numbers written in the source program 10 and the instructions of the object program 2 generated from the program statements related to the line numbers. The configuration is such that the address of

The interrupt processing unit 1 monitors the instructions being executed, detects branch execution of a branch instruction, and generates an interrupt if debug mode is specified, thereby interrupting the execution of the program currently being executed. The process is interrupted and control is passed to the symbolic tracer 3.

Therefore, when the interrupt processing unit 1 detects branch execution of the object program 2 being executed in the debug mode, the symbolic tracer 3 is activated.

The symbolic tracer 3 learns the address of the next branch destination instruction to be executed from the program status word of the object program 2, and searches the correspondence table 4 using that address.
Obtain the corresponding line number and output the line number to Listing 5.

Therefore, in Listing 5, the line number on the source program 10 is
The list is arranged in the order of execution, allowing the user to easily trace the execution path on the source program.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, it is possible to efficiently perform a so-called symbolic tracer that traces the execution path of a program on a source program in a computer, and it is also possible to efficiently perform an object program for debugging and actual operation. Since there is no risk of trouble occurring due to differences in the numbers, there is a significant industrial effect of improving the efficiency of program debugging.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the present invention, and FIG. 2 is an explanatory diagram of a correspondence table. In the figure, 1 is an interrupt processing unit, 2 is an object program, 3 is a symbolic tracer, 4 is a correspondence table, 5 is a list, 10 is a source program, and 11 is a compiler. Figure 1 is a block diagram showing the configuration of the present invention. Figure 2 is an explanatory diagram of the correspondence table.

Claims (1)

[Claims] In a computer having a function of executing an object program generated by translating a source program, detecting a branch of the object program, and generating an interrupt, line number and
A correspondence table (4) showing the correspondence with the instruction address of the object program (2), and a correspondence table (4) showing the correspondence with the instruction address of the object program (2) when the interrupt occurs.
) A program execution trace processing method characterized by comprising means (3) for searching and outputting a line number of the source program from the correspondence table (4) for the instruction address of ().