JPS6224323A - Link system - Google Patents

Abstract

PURPOSE:To recover an abnormal end to continue a program by producing a load module so as to execute again a module having the same function and stored in another library in case an instruction is received to give an abnormal end to the program. CONSTITUTION:A linker 3 detects a CALL-ABORT instruction out of a loaded library 1 and loads a module 201 having the same function as a module 502 including the CALL-ABORT instruction through another library 2. Then this instruction is replaced with a branch instruction to the entrance address of a module 503 loaded later. Thus a load module is produced so as to execute again the module having the same function and stored in another library in case an instruction is received to give an abnormal end to a program. Therefore a module can be executed again before revision when the program has an abnormal end state owing to the bug mixed by the revision in case the libraries 1 and 2 are defines as those set after and before revision of the program respectively.

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a linking method, and particularly to an executable program (
This invention relates to a linking method for creating a load module (hereinafter referred to as a load module).

PRIOR ART Conventionally, this type of linking method has been used to link an object module A specified by link specification 4 as shown in FIG.
, B (101, 102) in object library 1
An instruction (“CALL ABOIIT” in the example of FIG. 4) that loads the program from the loaded object module (501, 502) and causes the program to terminate abnormally.
If there is a branch instruction to the abnormal termination processing routine of O8 (operating system) ('
BRANCII(abt)'').

In the figure, 3 is the main body of the linker, and 5 is the load module library.

In the conventional linking method using a linker, when an abnormality occurs in a program, control is passed directly to the abnormality handling routine of O8, which not only makes it impossible to recover from the abnormality of the program itself, but also prevents the program from continuing. There are drawbacks.

An object of the present invention is to provide a linking method that, when there is an instruction to abnormally terminate a program, can recover from the abnormal termination and allow the program to continue.

Structure of the Invention The linking method according to the present invention is a linking method in which separately compiled object modules are combined to create a load module, and the linking method combines at least two libraries containing object modules with the same function, and this library. means for detecting the presence of an instruction for abnormally terminating a program in an object module loaded from one of the libraries, and loading an object module having the same function from another library, and later loading the instruction for abnormally terminating the program. The feature is that the branch instruction is changed to the module entry address.

Example Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a functional block diagram of an embodiment of the present invention, in which a main routine 11. Link specification reading routine 12. Object library, Library 1 reading routine 13. Other object library 2 loading routine 14. 15. Linkage symbol holding routine that stores linkage symbols used for reference relationships between modules; 15. Linkage symbol search routine that resolves linkage symbol references by converting them into real addresses; 16. “CALL ABORT” determination routine to find “CALL ABORT” command 17. It consists of an address relocation routine 18 which converts each instruction compiled as a relative address into an absolute address, and an output module write routine 19.

The second factor is a schematic diagram showing the processing functions of the linker using the blocks in FIG. 1 in a manner similar to that in FIG. 4, and parts equivalent to those in FIG. 1 are designated by the same reference numerals. Object library 1 contains object modules A and B (
101, 102), and is the library from which the module to be linked is first selected. Object library 2 has the same function (same name) module B' (
201) is the library selected for the second time. The link result is placed in the load module library 5 as one module (501 to 503).

FIG. 3 is an operational flow diagram of the embodiment shown in FIGS.
This routine is characterized by the detection of the "CALL ABORT" command (routine 17 in FIG. 1) and the processing therefor.

That is, the program creator normally places a so-called "CALL ABORT" command for passing control to the abnormality processing routine of O8 in the part of the program that corresponds to the abnormality. Therefore, in the linking method according to the present invention, in one loaded library 1, this 'CALL ABORT'
When a command is detected, a module 20 having the same function as the module 502 containing the "CALL ABORT" command
1 from another library 2, and the previously detected C
ALL^BORT'' instruction is replaced with a branch instruction to the entrance address of the module 503 loaded later.

By doing this, when there is an instruction to abnormally terminate Progera, a load module is created so that a module with the same function in another library is executed again. Therefore, for example, if the first library 1 is the library after the program revision and the second library 2 is the library before the program revision, when the program ends abnormally due to a bug introduced by the program revision, , it becomes possible to re-execute the module from before the program was revised.

Effects of the Invention As described above, according to the present invention, when there is an instruction to abnormally terminate a program, an O-to module is generated so that the same functional module in another library is executed again. This has the effect of recovering from abnormal program termination and allowing the program to continue.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram of a linker according to an embodiment of the present invention, FIG. 2 is a diagram schematically showing the processing functions of the linker in FIG. 1, and FIG. 3 is an operation of an embodiment of the present invention. The flowchart, FIG. 4, is a diagram schematically showing the processing functions of a conventional linker. Explanation of codes of main parts 1.2...Object library 3...
・・Linker

Claims (1)

[Claims] A linking method that creates a load module by combining separately compiled object modules, the linking method comprising at least two libraries containing object modules with the same functionality and an object module loaded from one of the libraries. means for detecting the presence of an instruction that causes the program to terminate abnormally and loading an object module with the same function from another library, and changing the instruction that causes the abnormal termination to a branch instruction to the entrance address of the module that is subsequently loaded. A link method characterized by the following.