JPH02201541A - Compiling system - Google Patents

Abstract

PURPOSE:To reduce the capacity of an object program to reduce the storage cost by discriminating whether data definition description preliminarily has a data substance or not and setting its area information at the time when it has not any data substance. CONSTITUTION:A filing device 2 includes a source program 21, and a filing device 3 includes an intermediate text file 31, and a filing device 4 includes a program control information part 42, a data part 43, and a code part 44. A compiler 1 consists of a front end part 11 including a discriminating means 12 and a back end part 13 having a data part generating means 14. When the discriminating means 12 discriminates that data definition description in the source program 21 does not preliminarily include any data substance, the data part generating means 14 sets information indicating the area of data definition description to the program control information part 42. Thus, the capacity of the object program is reduced to reduce the storage cost.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a compilation method for generating a target program from a source program, and particularly relates to a compilation method that can reduce the capacity of the data section of the target program (conventional). (Technology) A source program generally consists of an instruction part and a data description definition, and is compiled by a compiler to generate a target program that can be executed by a computer and includes a data part, a code part, and control information to manage these parts, and is written in a file. is stored in.

Each data description definition in a source program generally includes actual data (data entity) in advance, and other cases do not include actual data and only secure an area, but in both cases, the compiler uses the data description The area specified by the definition is generated in the data section of the target program.

(Problem to be Solved by the Invention) As mentioned above, even if the data description definition does not contain actual data and allocates an area, conventional compilers do not allocate the area of the data description definition in the data section of the target program. , the target program becomes large and storage costs such as file capacity increase.As described above, conventional compilation methods have problems that need to be solved.

The present invention has been made in view of the above circumstances, and its purpose is to avoid generating data in the data section of the target program for data description definitions that do not include actual data in advance. The purpose of the present invention is to provide a compilation method that can reduce program capacity and storage costs.

(Means for Solving the Problems) In order to achieve the above object, the compilation method of the present invention provides an object program that includes a code section, a data section, and control information for managing the code section and the data section from a source program. A compiler that generates a compiler, comprising: a determining means for determining whether or not a data definition description in the source program includes a data entity in advance; and a determining means that determines that the data definition description does not include a data entity. and data section generation means for setting information indicating the area of the data definition description in the program control information.

(Operation) In the compilation method of the present invention, when the determination means determines that the data definition description in the source program does not include a data entity in advance, the data part generation means adds the area of the data definition description to the program control information. Set the information to be displayed.

(Example) Next, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a configuration diagram of an embodiment of the present invention, in which 1 is a compiler, 2, 3.4 are file devices connected to the compiler 1, and the file device 2 stores a source program 21.
The file device 3 stores the intermediate text file 31 as a file! 4 includes a program control information section 42, a data section 43, and a code section 44, respectively.The compiler 1 is composed of a front end section 11 including a determining means 12 and a back end section 13 having a data section generating means 14. There is. Further, the data portion generating means 14 includes a buffer α.

FIG. 2 shows the format of the intermediate text of the data description definition. The initial text 51 in FIG. 2(a) shows the format of the intermediate text when the data description definition already contains actual data, and the length of the data entity C (actual data) and the data entity C ( For example, the length B is a byte length), and the data address A is the address at which the data entity C is stored. Figure 2 (b
) shows the format of the text 52 without an initial value, which is the same as the initial value text 51 in FIG. 5(a) with the data entity C removed. Note that in the text 52 without initial values, the data entity C is generated by the program when the program is executed, or input from the outside.

FIG. 3 is a flowchart showing an example of processing by the data section generating means 13.

Next, the operation of the embodiment of the present invention will be explained with reference to each figure. When the compiler 1 is started from the outside, each means starts operating. First, the front end section 11 starts the file device 2.
The source program 21 is input, the source program 21 is searched to find a data description definition, and the determining means 12 is activated each time a data definition description is found. The activated determining means 12 determines whether this data definition description has a data entity.

If the data entity is present, the initial value text 51 shown in FIG. 2(a) is generated, and if the data entity is not present, the initial value text 52 shown in FIG. is output to an intermediate text file 31. Such processing is performed on all the data description definitions in the source program 21. In addition, for example, the instruction part other than the data description definitions, the same processing as conventional is performed, and the processing results are output to the intermediate text file 31.

Next, the back end unit 13 inputs the intermediate text file 31 in the file device 3 and stores the initial value text 51 and the text without initial value 52 in a predetermined area.

Then, the data part generation means 14 is activated. As shown in FIG. 3, the activated data part generation means 14 takes out one intermediate text (initial value text 51 and no initial value text 52) from the area stored by the back end part 13 in step S1, and It is determined whether the intermediate text extracted in step S2 is the initial value text 51 or not.

When the text 52 has no initial value (No in step S2)
), in step S7, text 5 with no initial value is stored in buffer α.
2 is stored. If the text 52 without an initial value is not stored in the buffer α (No in step S7), the text 52 without an initial value retrieved in step S9 is stored in the buffer α, and step 310
Proceed to 0 Conversely, buffer α has no initial value text 52
is stored (YES in step S7), the text 52 without initial value stored in the buffer α is updated in step S8. That is, the following processing is performed using the data address A and length B of the text 52 without an initial value stored in the buffer α and the text 52 without an initial value just taken out.

■If the data addresses are consecutive The value obtained by adding the length B to the data address A of the text 52 without an initial value stored in the buffer α and the value of the data address A of the text 52 without an initial value extracted this time are If it is continuous, the length B stored in buffer α
Add the length B of the text 52 without an initial value to be extracted this time.

■When the data addresses are not consecutive As in ■, when the value of data address A plus length B is not consecutive with the value of address A of text 52 with no initial value retrieved this time, the buffer α is The stored length B is the address A and length B of the text 52 with no initial value extracted this time.
and add.

When it is determined in step S2 that the initial value address is 51,
In step S3, the target program 41 in the file device 4
Generate data for the data section of.

Then, in step S4, it is determined whether or not the text 52 without an initial value is stored in the buffer α, and if it is not stored, the process advances to step S10.

On the other hand, when the text 52 without an initial value is stored in the buffer α, the text 52 without an initial value in the buffer α is
Set area (for example, address and length) information in the program control information section 42 based on , clear the buffer α, and proceed to step 910. It is determined whether or not the processing has been completed, and if there is text that has not been processed yet, the above-mentioned processing is repeated, and when there is no more text 52 to be processed (YES in step S10).
Text 52 with no initial value in buffer α in step Sll
is stored in the buffer α, and if it is not stored in the buffer α, the process ends. On the other hand, when the text 52 without an initial value is stored in the buffer α, the program control information section 4 performs the same process as step S5.
2, and complete the process. Note that the instruction part is processed and stored in the code part 44 in the same manner as before.

(Effects of the Invention) As explained above, the compilation method of the present invention determines whether or not a data description definition has a data entity in advance, and when the data entity does not exist, the area information (address and length) is determined. By setting the size of the target program, the capacity of the target program can be reduced, and storage costs such as file capacity can be significantly reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a diagram showing an example of the structure of intermediate text, and FIG. 3 is a flowchart showing an example of processing by the data section generating means 13. 1... Compiler, 2.3.4... File device,
11... Front end section, 12... Judgment means, 1
3... Back end section, 14... Data section generation means, 21... Source program, 31... Intermediate text file, 42... Program control information section, 43.
...Data section, 44...Code section.

Claims (1)

[Claims] In a compiler that generates a target program including a code section, a data section, and control information for managing the code section and the data section from a source program, a data definition description in the source program defines a data entity. determining means for determining in advance whether or not the data definition description includes the data entity; and when the determining means determines that the data definition description does not include the data entity, setting information indicating the area of the data definition description in the program control information. A compilation method characterized by comprising a data part generation means.