JPH09179753A - Stack information collecting system using timing of return processing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to collect program stacking information to which reference is usually disabled due to overwriting caused by the repetition of function calls and returns by integrating a storing function inside by using the timing of a return at the time of compiling. SOLUTION: When a source 11 is compiled by a compiler 12, a stack information processing routine is integrated in a text part of an object 10. The routine is read out from each function immediately before a return instruction to transfer stack information to a stack information storing area 6. When the area 6 is filled with the stored stack information or a program 1 has ended, the stack information stored in the area 6 is outputted to an output device 9. Since stack information to be communicated with respective functions can be referred to at the occurance of a fault in the program 1, the program 1 can easily be analyzed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to collection of stack information of a program, and more particularly, it is triggered by return processing that collects stack information of a program that is overwritten due to repeated function calls and returns and becomes unreferenceable, and makes it available for reference. Regarding the stack information collection method.

[0002]

2. Description of the Related Art When collecting stack information of a conventional program, when referring to the stack for the purpose of program analysis, etc., refer to a running program by using a debugger or add a logic for collecting information to the source. Was going by.

[0003]

When referring to the stack in the above-mentioned conventional system, there is a drawback in that the source program must be recompiled by incorporating the logic for debugging.

An object of the present invention is to provide a stack information collecting method which is an extended function of a return instruction and which is triggered by a return process of collecting stack information used by a function at the time of returning to an output device.

[0005]

A stack information collection method triggered by a return process of the first invention is a main storage device for collecting stack information, and an auxiliary storage for storing a source program and an object program. A device, a compiler having a function of incorporating a stack information processing routine at the time of compiling a source program, an input device for a user to specify the collection of the stack information to the system, and a specification of the collection input from the input device System setting recognizing means for recognizing the setting information, a system setting information table in which the setting information is set through the system setting recognizing means, a stack information storage area for storing the stack information, and the stack information. The storage area management table that manages the storage location of the storage area and the stack information An output device for pay, and is configured with the stack information stored in the stack information storage area provided with a data output means for outputting to the output device.

Further, the stack information collection method triggered by the return process of the second invention is the stack information in the first invention, which is a factor to the function and a call address of the function when the function call process is executed. It is configured to include internal variables, return values, register information at the time of exception processing, and the like.

Further, in the stack information collecting method triggered by the return process of the third invention, in the first invention, the system setting recognizing means judges and collects the designation of collecting the stack information of the system user. It is configured to set the collection mode in the system setting information table when specified.

Further, in the stack information collecting method triggered by the return process of the fourth invention, in the first invention, the storage area management table has a start address indicating the top position of the stack information storage area and the stack information. And an end address indicating the storage end position of

Further, the stack information collecting method triggered by the return process of the fifth invention is configured such that the initial value of the end address is the same value as the start address in the fourth invention.

Further, in the stack information collecting method triggered by the return process of the sixth invention, in the first invention, the stack information storage area includes a next area pointer indicating a storage start position of the stack information and an information storage area. A stopper storing a prescribed character is provided at the position indicated by the next area pointer.

[0011]

Next, an embodiment of the present invention will be described with reference to the drawings.

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

In this embodiment, a stack information processing routine is incorporated in the text portion of the object 10 when the source 11 is compiled by the compiler 12 as shown in FIG. The compiler 12 creates the object 10 so that the stack information processing routine is called immediately before each return instruction of the source 11.

When the object 10 is activated, the auxiliary storage device 14 loads the program 1 into the main storage device 13 and allocates the stack area 5.

The program 1 checks the system setting information table by the stack information processing routine to determine whether to collect the stack information of the used stack area 5. (The collection or non-collection of stack information is designated by the user of the system from the input device 8 before the program 1 is started, and the setting information of the collecting mode or the non-collecting mode is set by the system setting recognizing means 3. (Set in the information table 2) When the system setting information table 2 is in the non-collection mode, it immediately returns, and when in the collection mode, the end address 42 of the storage area management table 4 is acquired and the stack of the stack area 5 is followed according to this address The information is transferred to the stack information storage area 6.

The stack information in the stack information storage area 6 is output to the output device 9 via the data output means 7.

Next, an execution example of the stack information collection processing routine will be described.

The program 1 has a stack pointer for each function as a pointer for accessing the stack area 5. When a function is called, the stack pointer moves according to the number of local variables and factors used, and the stack is allocated to the called function. The stack size for each function can be calculated by taking the difference from the stack pointer value of the adjacent function.

Next, the operation of the function flow shown in FIG. 2A will be described with reference to FIGS. 2B, 2C and 2D.

In FIG. 2A, the main function calls the a function during its processing, and the a function calls the a1 function and returns from the a1 function to the a function (return 1), and the a function becomes the main function. Return (return 2).

Next, the main function calls the b function,
In this example, the b function returns to the main function (return 3) and the stack information of the returns 1, 2, and 3 is collected.

In FIG. 2B, the main function calls the a function during its processing, the a function calls the a1 function, and when the a1 function returns to the a function (return 1), information is collected from the input device. The system setting information table 2 which manages whether the mode is designated is checked. In this example, since the mode is the collection mode, the storage area management table 4 that manages the write address of the stack information storage area 6 is referred to, and the end address 42 indicating the address to be written next and the stack information written before is acquired. . The initial value of the end address 42 is ptr of the start address 41.
Since the same value as 0 is set, the end address 42 of the storage area management table 4 acquires the initial value ptr0 here.

Next, the size of the stack information (stk-a1) used by the a1 function is set to the end address 42 (ptr).
0) to obtain the end address (ptr1),
If tr1 exceeds the range of the stack information storage area 6, the stack information area is insufficient, so the previously written stack information is output to the output device 9.

Since it has not exceeded here, after setting ptr1 to the next area pointer indicating the position to write the next stack information at the write start address ptr0 of the stack information storage area 6, after setting ptr1 to the address ptr1 indicated by the next area pointer. After setting the prescribed character as the stopper, the stack information (stk-a1) used by the a1 function is transferred immediately after the next area pointer of the end address (initial value ptr0) of the storage area management table 4 is stored. Next, the end address 42 (initial value ptr0) of the storage area management table 4 is set to ptr1.
To update.

In FIG. 2 (c), a function to main
When returning to the function (return 2), as in the case of return 1, the system setting information table 2 that manages whether the collection mode is designated by the input device is checked. In this example, since it is the collection mode, the end address 42 (ptr1) is acquired by referring to the storage area management table 4 that manages the write address of the stack information storage area 6.

Next, the stack information (s
The size of tk-a) is added to the end address 42 (ptr1) to obtain the end address (ptr2), and this ptr2
If the stack information storage area 6 exceeds the stack information storage area 6, the stack information area is insufficient and the previously written stack information is output to the output device 9.

Here, it is assumed that it has not exceeded, after setting ptr2 to the next area pointer indicating the position to write the next stack information in the write address ptr1 of the stack information storage area 6, as a stopper at the address ptr2 indicated by the next area pointer. After setting the prescribed character, the stack information (stk-a) used by the a function is transferred immediately after the next area pointer of the end address 42 (ptr1) of the storage area management table 4 is stored. Next, the end address 42 (ptr1) of the storage area management table 4 is updated to ptr2.

In FIG. 2D, the main function calls the b function during its processing, and when the b function returns from the input function 8 to the main function (return 3), the input mode is collected from the input device 8 as in the case of the return 2. Check the system setting information table 2 which manages whether or not is specified. In this example, since it is the collection mode, the end address 42 (ptr2) is acquired by referring to the storage area management table 4 that manages the write address of the stack information storage area 6.

Next, the size of the stack information (stk-b) used by the b function is set to the end address 42 (ptr).
2) is added to obtain the end address (ptr3), and this p
If tr3 exceeds the range of the stack information storage area 6, the stack information area is insufficient, so the previously written stack information is output to the output device.

Here, it is assumed that it has not exceeded, and after setting ptr3 to the next area pointer indicating the position to write the next stack information in the write address ptr2 of the stack information storage area 6, as a stopper at the address ptr3 indicated by the next area pointer. After storing the specified character, the stack information (stk-b) used by the b function is transferred immediately after the next area pointer of the end address 42 (ptr2) of the storage area management table 4 is stored. Next, the end address 42 (ptr2) of the storage area management table 4 is updated to ptr3.

Next, the operation during the return process will be described with reference to the flowchart of FIG.

Step 1 refers to the system setting information table 2 to determine whether the collecting mode or the non-collecting mode for collecting the stack information used in this function when the processing of the called function is completed and the process returns to the calling source. The processing of step 2 is performed in the collection mode, and the processing of step 11 is performed in the non-collection mode.

In step 2, the storage area management table 4 is referenced to obtain the address (end address 42) for writing the stack information into the stack information storage area 6, and the processing of step 3 is performed.

In step 3, the used size of the stack information stored in the stack area 5 is added to the obtained end address 42, and it is checked whether or not it exceeds the range of the stack information storage area 6, and when there is no free space, step 4 Process is performed, and if there is a space, the process of step 5 is performed.

In step 4, after the stack information stored in the stack information storage area 6 up to the end address 42 obtained in step 2 is output to the output device 9, the end address 42 is reset to the initial value and the process of step 5 is performed. .

In step 5, the end address 4 is set to the next area pointer of the stack information storage area 6 indicated by the end address 42.
An address obtained by adding the used size of the stack information to 2 is set, and the process of step 6 is performed.

In step 6, the specified character of the stopper is set at the position indicated by the next area pointer set in step 5, and the process of step 7 is performed.

In step 7, the stack information of the stack area 5 is transferred immediately after the next area pointer of the end address 42 of the storage area management table 4 is stored, and the processing of step 8 is performed.

In step 8, the address of the next area pointer set in step 5 is set in the end address 42 and the processing in step 9 is performed.

In step 9, it is checked whether the stack information in the stack area 5 is the final stack information, and when it is the final stack information, the processing in step 10 is performed. If the final stack information has not been reached, the process of step 11 is performed.

In step 10, after the stack information stored in the stack information storage area 6 up to the end address 42 is output to the output device 9, the end address 42 is reset to the initial value and the process of step 11 is performed.

Step 11 executes the return instruction and returns to the caller.

[0043]

As described above, in the stack information collecting method of the present invention triggered by the return processing, the data written in the stack is saved, so that the details of the execution history of the program and the already completed function are Since the stack information used in the above can be referred to, it has the effect of debugging the program and the effect that the information can be collected at an arbitrary timing according to the setting of the system user and the overhead at the information unnecessary portion is small.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a stack information collection method triggered by return processing of the present invention.

FIG. 2 shows an example of an operation in this embodiment.
FIG. 2A is a diagram showing a transition of a function, and FIG.
FIG. 2C and FIG. 2D are diagrams showing the state of data at the time of returning each function.

3 is a flowchart showing an example of the operation of a stack information collection processing routine in the program of FIG. 1 according to the present embodiment.

[Explanation of symbols]

 1 Program 2 System Setting Information Table 3 System Setting Recognition Means 4 Storage Area Management Table 5 Stack Area 6 Stack Information Storage Area 7 Data Output Means 8 Input Device 9 Output Device 10 Objects 11 Source 12 Copiler 13 Main Storage Device 14 Auxiliary Storage Device 41 Start address 42 End address

Claims (6)

[Claims] 1. A stack information collection method triggered by a return process of collecting stack information when a program calls a function and returns from the function, a main storage device for collecting stack information, a source program, and An auxiliary storage device in which an object program is stored, a compiler having a function of incorporating a stack information processing routine at the time of compiling a source program, an input device for a user to give the system a designation to collect the stack information, and the input A system setting recognition unit for recognizing collection-specified setting information input from the device, a system setting information table in which the setting information is set via the system setting recognition unit, and a stack for storing the stack information. Information storage area and the stack information storage area A storage area management table for managing storage locations; an output device for storing the stack information; and a data output means for outputting the stack information stored in the stack information storage area to the output device. A stack information collection method triggered by the return process. 2. The stack information includes a factor to the function when the function is called, a call address of the function, an internal variable, a return value, register information at the time of exception processing, and the like. A stack information collection method triggered by the return processing described in item 1. 3. The system setting recognizing means judges the designation of collecting the stack information of a system user and sets a collection mode in the system setting information table when the collection is designated. Stack information collection method triggered by the described return processing. 4. The storage area management table is composed of a start address indicating the top position of the stack information storage area and an end address indicating the storage end position of the stack information. Stack information collection method triggered by the described return processing. 5. The stack information collection method triggered by return processing according to claim 4, wherein the initial value of the end address is the same value as the start address. 6. The stack information storage area comprises a next area pointer indicating a storage start position of the stack information, an information storage area, and a stopper storing a prescribed character at a position indicated by the next area pointer. The stack information collection method triggered by the return process according to claim 1.