JPH06242989A - Memory allocation tracing device - Google Patents

Abstract

PURPOSE:To enable anybody to easily investigate operation for securing a program, which advances its process while securing a memory by using a memory securing function, on a memory by inputting several commands. CONSTITUTION:When a command requesting a memory securing trace is inputted from a terminal device 13, a break point control part 6 sets a break point at the head address of the memory securing function 15 obtained by searching a symbol table 17 by a symbol table retrieval part 5 according to the memory securing function name. When the program 14 is executed and a break is made at the break point, the break point control part 6 gathers memory securing trace information on the function name with which the memory securing function is called, a line number, etc., and a memory securing trace part 7 registers the information in a memory securing state table 10. When a command requesting a display of the memory securing state is inputted from the terminal device 13, a memory securing state display part 9 outputs the memory securing trace information, stored in the memory securing state table 10, to the terminal device 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a memory allocation tracing device used when debugging a program, and more specifically, it executes a process while dynamically allocating and releasing memory by calling a memory allocating function and a memory allocating function. The present invention relates to a memory allocation tracing device capable of easily investigating how a program to be advanced secures and releases memory.

[0002]

2. Description of the Related Art When a memory problem occurs in a program that advances processing while dynamically allocating and releasing memory by calling a memory allocation function and a memory release function, what size memory should be used for debugging It is necessary to investigate the operation related to memory allocation and memory release, such as where in the program the memory is allocated and where in the program the allocated memory is released.
The following methods are generally conceivable as methods for conducting such an investigation.

The source program itself of the program to be debugged is modified, and the size and size of memory secured at which point in the program and the size and size released at which point in the program are output. A method to compile, execute, and execute the mechanism to perform.

A method in which the user himself sets a breakpoint at an appropriate location by using various debug commands provided by an existing symbolic debugger, and reads and records data at a location required at the break.

[0005]

However, in the above-described method of correcting the source program itself, there is a risk of erroneously correcting unnecessary parts. On the other hand, the method using the symbolic debugger does not cause such a problem, but the existing symbolic debugger does not have a dedicated command for investigating the operation related to memory allocation and deallocation, so a breakpoint is set. It is necessary to investigate using existing commands such as commands that output commands and stack contents. Therefore,
Secure memory unless you have considerable knowledge and experience,
At present, it is difficult to investigate the release operation.

The present invention has been made in view of the above circumstances, and an object of the present invention is to make it possible to investigate a memory securing / releasing operation of a program extremely easily without modifying a source program. An object is to provide an allocation tracing device.

[0007]

In order to achieve the above object, a memory allocation tracing device of the present invention calls a memory allocation function and a memory release function to dynamically allocate a memory,
In an information processing device that executes a program that advances processing while being released, a memory reservation state table, a memory reservation trace unit that stores the collected memory reservation trace information in the memory reservation state table, and collected memory release trace information Memory release trace means for storing the memory allocation state table, a symbol table search means for searching the symbol table in the load module file of the program, a user input / output device, and a memory allocation from the user input / output device When a command requesting a trace is input, a breakpoint is set at the start address of the memory allocation function obtained by searching the symbol table with the memory allocation function name by the symbol table searching means, and break The memory allocation trace information is sampled and stored in the memory allocation status table by the memory allocation tracing means, and a command for requesting a memory release trace is input from the user input / output device, whereby the symbol table A breakpoint is set at the start address of the memory release function obtained by searching the symbol table with the memory release function name by the search means, and memory release trace information is collected at the time of a break due to the breakpoint to obtain the memory release trace means. The breakpoint control means for storing in the memory allocation status table and the command for requesting display of the memory allocation status from the user input / output device are input, so that the memory allocation trace stored in the memory allocation status table Information and memory And a memory reservation state display means for outputting to the user input device reads the release trace information.

[0008]

In the memory allocation trace device of the present invention, when a command requesting memory allocation trace is input from the user input / output device, the breakpoint control means causes the symbol table search means to create a symbol table with the memory allocation function name. Set a breakpoint at the start address of the memory allocation function obtained by searching. When a command requesting a memory release trace is input from the user input / output device, the break point control means searches the symbol table with the memory release function name by the symbol table search means and starts the memory release function. Set a breakpoint at the address. When the program is executed with the breakpoints set as above and a break occurs at the start address of the memory allocation function, the breakpoint control means stores the memory such as the function name, line number, memory size that called the memory allocation function. The secured trace information is collected and stored in the memory secured state table by the memory secured trace means. When a break occurs at the start address of the memory release function, the breakpoint control means collects memory release trace information such as the function name and line number that called the memory release function, and stores it in the memory allocation state table by the memory release trace means. After that, when a command requesting display of the memory allocation status is input from the user input / output device, the memory allocation status display means reads the memory allocation trace information and the memory allocation trace information stored in the memory allocation status table. Output to user input / output device.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings.

Referring to FIG. 1, a memory allocation tracing device 1 according to an embodiment of the present invention includes a main control unit 2, a command input unit 3, a display output unit 4, a symbol table search unit 5, a breakpoint control unit 6, and a break control unit 6. It has a memory allocation trace unit 7, a memory release trace unit 8 and a memory allocation status display unit 9, and is connected to a load module file 12, a terminal device 13 which is a user input / output device, a memory allocation status table 10 and a memory 11. There is. Such a memory allocation tracing device 1 is incorporated in the information processing device as a part of the debugger.

The memory 11 is a main memory of the information processing apparatus, and 14 of the memory is a program to be debugged. The program 14 is, for example, a C language program and is composed of a plurality of functions (modules). In particular, the memory reservation function 15 and the memory release function 16 are used to dynamically secure and release the memory in the memory 11. The processing proceeds while performing. The purpose of the memory allocation tracing device 1 is to check whether the memory of which size and memory address is secured and released at which line number of which function of the program 14 is used.

The load module file 12 is a load module file corresponding to the program 14, and the program 14 is loaded from the load module file 12 into the memory 11 when it is executed. The load module file 12 has a symbol table 17.
The symbol table 17 holds a function name forming a source program of the program 14, a line number on the source program, an address on the memory 11 into which a machine language instruction corresponding to each source line is loaded. .

The memory allocation status table 10 includes a memory allocation traced by the memory allocation tracing device 1.
It is a table that stores trace information about release.
For example, it is constructed on the main memory of the information processing apparatus. As shown in FIG. 2, for example, the memory reservation state table 10 is composed of a reservation column 101 for storing memory reservation trace information and a release column 102 for storing memory release trace information. Entries E11 to E1
n, E21 to E2n.

Both the reservation column 101 and the release column 102 are used in order from the first entry E11, E21.
One entry of the reservation column 101 stores the name of the function requesting the memory reservation, the line number in the source program, the memory size to be reserved, and the reserved memory address. Further, in one entry of the release column 102, the function name requesting the release of the memory, the line number on the source program, and the released memory address are stored.

3 and 4 are flowcharts showing an example of the processing of the breakpoint control unit 6 in the memory allocation tracing device 1. Hereinafter, detailed functions of each unit in the memory allocation tracing device 1 will be described through the entire operation with reference to the drawings.

In the state where the control is transferred to the memory allocation tracing device 1, the main control part 2 is waiting for a command input from the terminal device 13 in the command input part 3. In this state, when the user inputs a command requesting a memory allocation trace from the terminal device 13, the command is accepted by the command input unit 3 and passed to the main control unit 2.

When the main control unit 2 recognizes that the input command is a command requesting a memory reservation trace, it requests the breakpoint control unit 6 for a memory reservation trace.

The break point control unit 6 includes a main control unit 2
When a memory reservation trace or a memory release trace is requested by the process, the process shown in FIG. 3 is performed. Then, when it is recognized that the memory allocation trace is requested in the process S1 of FIG. 3, the symbol table search unit 5 is used to search the symbol table 17 by the function name of the memory allocation function, and the memory allocation function on the memory 11 is searched. To obtain the address (S2). Then, the code at the start address of the memory allocation function 15 is replaced with an interrupt instruction code, the start address of the memory allocation function 15 and the original code are stored inside (S3), and control is passed to the main control unit 2 (S6). .

When control is returned from the break point control unit 6, the main control unit 2 waits for a command to be input in the command input unit 3.

When the user inputs a command instructing the execution of the program from the terminal device 13 in this state, the main control section 2 causes the execution of the program 14.

When the execution of the program 14 is started, a memory reservation function 15 is called by a certain function in the program 14, and control is transferred to the start address of the memory reservation function 15, an interrupt instruction code existing there causes an interrupt. Occurrence occurs, and control is transferred to the breakpoint control unit 6 of the memory allocation tracing device 1.

The breakpoint control unit 6 performs the processing shown in FIG. 4 when an interrupt occurs. First, by comparing the interrupted memory address with the address stored internally, whether the interrupt occurred at the start address of the memory allocation function or whether the interrupt occurred at the return address from the memory allocation function as described later. It is then determined whether or not an interrupt has occurred at the start address of the memory release function (S11).

In this case, since it is recognized that an interrupt has occurred at the start address of the memory allocation function, the breakpoint control unit 6 uses the return address from the memory allocation function stacked in the stack (not shown) to determine the memory allocation function. By recognizing the memory address that called, and using the symbol table search unit 5 to search the symbol table 17 with this memory address, the function name and line number that called the memory securing function are obtained (S12). Further, the requested memory size is acquired from the parameter used in the call of the memory securing function this time (S13). Then, the obtained contents are passed to the memory reservation trace unit 7 as memory reservation trace information to request storage (S14).

The memory allocation trace unit 7 stores the function name, line number, and memory size in the memory allocation trace information passed from the breakpoint control unit 6 in the allocation column 101 of the memory allocation state table 10 shown in FIG. The entry E11 at the head is stored in order. Now, assuming that all the entries E11 to E1n in the reservation column 101 are empty, first the entry E1
1, the function name func1, the line number 100, and the memory size 20 are stored in the entry E11 as shown in FIG. After that, the memory allocation tracing unit 7 returns the control to the breakpoint control unit 6.

When the control returns, the breakpoint control unit 6 obtains again the memory address that called the memory allocation function from the return address on the stack, replaces the code of the memory address with the code of the interrupt instruction, and returns the return address. And the original code is stored internally (S15). Then, the code of the interrupt instruction this time (the code set in the head address of the memory securing function) is replaced with the original code (S16), and the control is passed to the main control unit 2 (S17).

When control is returned from the break point control unit 6, the main control unit 2 waits for a command to be input in the command input unit 3.

In this state, when the user inputs a command from the terminal device 13 to restart the execution of the program,
The main control unit 2 restarts the execution of the program 14 from the interrupted address. As a result, the memory reservation function 15 is executed and the memory is reserved.

When the execution of the memory allocation function 15 is completed and control is returned to the calling source, an interrupt is generated again by the interrupt instruction code existing there, and control is transferred to the breakpoint control section 6.

In step S11 of FIG. 4, the breakpoint control unit 6 recognizes that an interrupt has occurred at the return address from the memory securing function by comparing the interrupted memory address with the internally stored address. Then, the memory address secured this time is obtained from the return value of the memory securing function (S18), the obtained memory address is passed to the memory securing trace unit 7 as additional memory securing trace information, and storage is requested (S19). .

The memory allocation trace unit 7 stores the memory address in the additional memory allocation trace information passed from the breakpoint control unit 6 into the memory allocation state table 10.
It is stored in the entry used immediately before in the reservation field 101 of.
As a result, as shown in FIG. 2, in addition to the function name, line number, and memory size, the memory address (for example, 1234) is stored in the previously used entry E11.

When control is returned from the memory allocation tracing section 7 to the breakpoint control section 6, the code of the interrupt instruction at this time (the code set in the return address of the memory allocation function) is replaced with the original code (S16), Control is passed to the main control unit 2 (S17).

When the control is returned from the break point control unit 6, the main control unit 2 waits again for command input.

In this state, when the user inputs a command from the terminal device 13 to restart the execution of the program,
The main control unit 2 restarts the execution of the program 14 from the interrupted address. As a result, the execution of the program 14 is restarted.

When the user inputs a command requesting a memory release trace from the terminal device 13 while the memory allocation tracing device 1 is in a command input waiting state, the command is accepted by the command input unit 3. And passed to the main controller 2.

When the main control unit 2 recognizes that the input command is a command requesting a memory release trace, it requests the breakpoint control unit 6 for a memory release trace.

When the breakpoint control unit 6 recognizes the memory release trace request in the process S1 of FIG. 3, it searches the symbol table 17 with the function name of the memory release function using the symbol table search unit 5, and releases the memory. The address of the function on the memory 11 is obtained (S4). Then, the code at the start address of the memory release function 16 is replaced with the interrupt instruction code, the start address of the memory release function 16 and its original code are stored inside (S5), and control is passed to the main control unit 2 (S6). .

When the control is returned from the breakpoint control unit 6, the main control unit 2 waits again for command input, and when a command for restarting program execution is input from the terminal device 13, execution of the program 14 is restarted. .

When the execution of the program 14 progresses and a memory release function 16 is called by a certain function in the program 14 and control is transferred to the start address of the memory release function 16, an interrupt is generated by an interrupt instruction code existing there. Then, the control is transferred to the breakpoint control unit 6.

In step S11 of FIG. 4, the breakpoint control unit 6 recognizes that an interrupt has occurred at the start address of the memory release function by comparing the interrupted memory address with the internally stored address. , The name of the function that called the memory release function by recognizing the memory address that called the memory release function from the return address on the stack and searching the symbol table 17 using the symbol table search unit 5 with this memory address, The line number is obtained (S20). Further, the memory address requested to be released is acquired from the parameter used in the call of the memory release function this time (S2
1). Then, the acquired function name, line number, and memory address are passed to the memory release trace unit 8 as memory release trace information to request storage (S22).

The memory release trace unit 8 stores the function name, line number, and memory address in the memory release trace information passed from the breakpoint control unit 6 in the release column 102 of the memory allocation state table 10 shown in FIG. The entry E21 at the beginning is stored in order. Now, assuming that all the entries E21 to E2n in the release column 102 are empty, the entry E
21 is used and its entry E21 as shown in FIG.
For example, the function name func1, the line number 200, and the memory address 1234 are stored. After that, the memory release tracing unit 8 returns the control to the breakpoint control unit 6.

In this embodiment, it is possible to instruct the memory release trace unit 8 to check the release address when the memory allocation trace device 1 is activated. When such an instruction has been given in advance, the memory release tracing unit 8 checks whether or not there is a memory address matching the memory address released this time in the reservation column 101, and if there is no matching memory address. The display output unit 4 is used to output a message to the effect that an unauthorized memory address release is requested and the content of the memory release trace information of this time to the terminal device 13.

When control is returned from the memory release trace unit 8 to the breakpoint control unit 6, the code of the current interrupt instruction (the code set at the start address of the memory release function) is replaced with the original code (S16). ), And passes control to the main control unit 2 (S17).

When the control is returned from the break point control unit 6 to the main control unit 2, the command input unit 3 waits for a command input.

In this state, when the user inputs a command from the terminal device 13 to restart the execution of the program,
The main control unit 2 restarts the execution of the program 14 from the interrupted address. As a result, the memory release function 16 is executed, and the memory is released.

Next, when the user inputs a command requesting the display of the memory reserved state from the terminal device 13 in the state of waiting for the input of the command, the main control section 2 which recognizes this command causes the memory reserved state display section 9 to display. to start.

The memory reservation state display unit 9 reads the contents of the entries in the reservation column 101 and the release column 102 of the memory reservation state table 10 and stores the function name, line number, memory size, and memory number stored in each entry of the reservation column 101. The memory address and the function name, line number, and memory address stored in each entry of the release column 102 are edited so that each line fits in one line, and the display output unit 4 is used to display each on the display surface of the terminal device 13. The entries are displayed in the order of the columns 101 and 102. As a result, the user can recognize which function of the program 14, which line number, what size and memory address the memory has been secured and released.
In addition, since the display order is secured and secured for each release and released, the order of memory securement and release can be known.

[0047]

According to the memory allocation trace device of the present invention described above, the following effects can be obtained.

By inputting a command for requesting a memory allocation trace and a memory allocation status display command, it is possible to determine what size and memory address of the memory is secured in which source line of which function in the program to be debugged. Can be investigated.

It is possible to investigate which memory address and what memory address is released in which source line of which function in the program to be debugged by simply inputting a command for requesting memory release trace and a memory allocation status display command. can do.

Therefore, even a user who does not have abundant experience or specialized knowledge can secure the memory for the program to be debugged.
It is possible to investigate the operation related to release, and it is effective in shortening the work time for investigating problems related to memory while debugging a program.

When an illegal memory address in which the memory address to be released does not match the already secured memory address is released, a message to that effect is output, and the work of extracting the problematic part is facilitated.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of a memory allocation tracing device of the present invention.

FIG. 2 is a diagram showing an example of contents of a memory reservation state table.

FIG. 3 is a flowchart showing an example of processing performed by a breakpoint control unit when a memory allocation trace request command and a memory release trace request command are input.

FIG. 4 is a flowchart showing an example of processing performed by a breakpoint control unit at the time of a break due to a breakpoint.

[Explanation of symbols]

 1 ... Memory allocation tracing device 2 ... Main control unit 3 ... Command input unit 4 ... Display output unit 5 ... Symbol table search unit 6 ... Breakpoint control unit 7 ... Memory reservation trace unit 8 ... Memory release trace unit 9 ... Memory reservation state Display unit 10 ... Memory reservation state table 11 ... Memory 12 ... Load module file 13 ... Terminal device 14 ... Debug target program 15 ... Memory reservation function 16 ... Memory release function 17 ... Symbol table

Claims (7)

[Claims] 1. In an information processing device for executing a program for executing a process while dynamically allocating a memory by calling a memory allocating function, a memory allocating state table and collected memory allocating trace information are stored in the memory allocating state table. And a symbol table search unit for searching a symbol table in the load module file of the program, a user I / O device, and a command requesting a memory reservation trace from the user I / O device. By inputting, a breakpoint is set at the start address of the memory securing function obtained by searching the symbol table with the memory securing function name by the symbol table searching means, and memory securing trace information at the time of a break by the breakpoint. Collect the above The memory reservation trace means stores the memory reservation state table in the memory reservation state table, and the user input / output device inputs a command requesting the display of the memory reservation state to store the memory reservation state table in the memory reservation state table. And a memory allocation status display means for reading the memory allocation trace information and outputting it to the user input / output device. 2. The breakpoint control means searches the symbol table with the memory address of the breakpoint through the symbol table search means to obtain the function name and line number that called the memory allocation function, and 2. The memory allocation trace device according to claim 1, wherein a memory size is acquired from a call parameter of the memory allocation function, and these are stored in the memory allocation state table as the memory allocation trace information by the memory allocation trace means. 3. The breakpoint control means sets a breakpoint at a return address from the memory securing function at the time of the break, and a memory secured from the return value of the memory securing function at the time of the break by the set breakpoint. 3. The memory allocation tracing device according to claim 2, wherein an address is acquired and the acquired memory address is registered in the memory allocation state table by the memory allocation tracing means as additional memory allocation trace information. 4. An information processing apparatus that executes a program that advances a process while dynamically allocating and releasing memory by calling a memory allocating function and a memory allocating function, and a memory allocating state table and collected memory allocating trace information. Memory allocation trace means for storing the memory allocation status table in the memory allocation status table, memory allocation tracing means for storing the collected memory allocation trace information in the memory allocation status table, and searching the symbol table in the load module file of the program. A symbol table search means, a user input / output device, and a command requesting a memory reservation trace are input from the user input / output device, whereby the symbol table search means searches the symbol table with a memory reservation function name. Of the memory allocation function obtained by A breakpoint is set at the head address, memory reservation trace information is collected at the time of a break due to the breakpoint, stored in the memory reservation state table by the memory reservation trace means, and the memory is released from the user input / output device. When a command requesting a trace is input, a breakpoint is set at the start address of the memory release function obtained by searching the symbol table with the memory release function name by the symbol table search means, and Break point control means for collecting memory release trace information at the time of break and storing it in the memory secured state table by the memory released trace means, and a command for requesting display of the memory secured state from the user input / output device are input. Especially And a memory allocation status display means for reading the memory allocation trace information and the memory allocation trace information stored in the memory allocation status table and outputting them to the user input / output device. . 5. The break point control means searches the symbol table with the memory address of the breakpoint at the time of the break due to the break point at the start address of the memory securing function, and calls the memory securing function, The memory size is acquired from the call parameter of the memory allocation function, the line size is acquired, the memory size is stored in the memory allocation state table as the memory allocation trace information by the memory allocation trace means, and the memory release function is also acquired. At the time of a break due to a breakpoint at the start address of the memory release function, the symbol table is searched with the memory address of the breakpoint to obtain the function name and line number that called the memory release function, and a memo from the call parameter of the memory release function. 5. The memory allocation trace device according to claim 4, wherein re-addresses are acquired and stored as the memory release trace information in the memory allocation state table by the memory release trace means. 6. The memory release trace means does not store a memory address matching the memory address in the memory release trace information passed from the breakpoint control means as memory reserve trace information in the memory reserve state table. The memory allocation trace device according to claim 5, wherein a message to that effect is output to the user input / output device. 7. The break point control means sets a break point at a return address from the memory reservation function at the time of a break at the start address of the memory reservation function, and sets the break point at the set break point. 7. The memory allocation trace device according to claim 6, wherein a reserved memory address is acquired from a return value of the memory reservation function, and the acquired memory address is registered in the memory reservation state table by the memory reservation trace means. .