JPH0981411A - Compiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate an object program inspecting the citing of a data area without depending on the specification of a source program, regarding a compiler. SOLUTION: In a compiler 2 generating an object program 11 of an executable form on the basis of a source program 1, a program analysis part 2' analyzing the source program 1 and generating the set of intermediate codes and an object program generation part 6 coupling the intermediate codes and generating the object program 11 are provided. The object program generation part 6 has a constitution that the generated intermediate codes are retrieved, based on the citing of the data area included in the set of the intermediate codes and the intermediate code calling the inspection program inspecting the justification of the citing of a definition based on the intermediate code is incorporated into the set of the intermediate codes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compiler for checking the validity of data area quoting. A high-level language program for a computer needs to translate a source program into an object program in a form executable by a compiler. If the source program created in such a high-level language contains an error such as quoting an area outside the definition of the data area, the object program will not operate properly. Therefore, it is necessary to point out and display the error when translating it into an object program by the compiler.

[0002]

2. Description of the Related Art A source program is composed of declarative statements (definition of a data area) relating to a data area and execution statements that cite them. Also, when an object program is generated and executed by the compiler, the correctness of the quotation of the data area is checked (when a value indicating the position of the data area is obtained during the execution of the program, that value is the range of the definition It is possible to specify whether or not to perform inspection such as (inspection of whether or not it is inside). When the inspection is specified, for example, when the validity of the citation of the data area is inspected, the information about the data area and the inspection program are provided separately from the object program when the inspection is not performed. The object program containing the intermediate code that calls is generated, and the inspection program is called at the time of execution for inspection.

FIG. 9 shows a conventional compiler. In FIG. 9, 110 is a source program.

Reference numeral 111 is a definition of a data area (declaration statement). For example, an array, a character string, or a structure (the definition A includes the elements b and c). Reference numeral 111 ′ is a quoted sentence of the data area (execution sentence of the program, which includes a value indicating the position of the data area, or whose value is obtained as a calculation result).

Reference numeral 112 is a compiler. Reference numeral 114 denotes a source analysis unit, which analyzes a source program. A semantic analysis unit 115 analyzes the meaning of the source program.

Reference numeral 116 is an intermediate code generation unit which generates an intermediate code which is a language close to a machine language based on the result of semantic analysis of the source program. An optimization processing unit 117 optimizes the program by, for example, deleting intermediate codes that are not required to execute the program, such as unquoted mathematical formulas.

Reference numeral 118 is an object program generation unit, which generates an object program based on a set of intermediate codes. 120 is an object program execution unit.

Reference numeral 121 is an execution result output unit. Reference numeral 125 is an inspection program library, which is a library provided with various inspection programs.

FIG. 10 is a flowchart of a conventional compiler. The operation of the conventional compiler shown in FIG. 9 will be described with reference to FIG. If there is no check specification in compilation.

The S1 compiler 112 inputs the source program 110. S2 Determine whether or not to check the validity of the citation in the data area. In this case, there is no inspection specified, so S3
Proceed to. If the inspection is designated, the process proceeds to S10.

The S3 source analysis unit 114 performs syntax analysis such as extracting a program sentence from the input character string of the program. S4 The semantic analysis unit 115 analyzes the meaning of the program statement obtained by source analysis.

The intermediate code generator S5 generates an intermediate code based on the result of the semantic analysis. S6 The optimization processing unit 117 performs optimization processing on the intermediate code group of the source program 110 so that the program can be optimally executed without waste.

S7 object program generator 11
Reference numeral 8 generates an object program by combining (linking) each intermediate code of the intermediate code group. The S8 object program execution unit 120 executes the generated object program.

The execution result output section 121 outputs the execution result. When there is a check specification in compilation. The S1 compiler 112 inputs the source program 110.

S2: It is judged whether or not there is an inspection designation. In this case, since the inspection is designated, the process proceeds to S11. The S11 source analysis unit 114 performs source analysis on the input source program 110.

S12 The semantic analysis unit 115 performs semantic analysis on the program statement obtained by the source analysis. S13 The intermediate code generation unit 116 generates an intermediate code based on the semantic analysis result.

S14: Since there is an inspection designation, an intermediate code relating to information to be inspected such as a data area is generated based on the source analysis result and the semantic analysis result. For example, in the case of checking the validity of quoting the data area, an intermediate code representing the start address of the data area, the size of the data area, the address where the data is arranged, the size of the data, etc. is generated.

S15 An intermediate code for calling the target inspection program is generated. S6 The optimization processing unit 117 performs optimization processing on the intermediate code group of the source program 110 so that the program can be executed optimally without waste.

S7 object program generator 11
8 engages the intermediate code to generate an object program. At this time, the intermediate codes for inspection generated in S14 and S15 are combined so as to be inserted into the intermediate code group generated in S13.

S8 object program execution unit 12
0 executes the object program containing the intermediate code that calls the check program. During execution, an inspection program specified by the inspection program library 125 is called by an intermediate code that calls the inspection program, and it is checked whether or not the data area quoted by the quoted text of the data area is within a defined range. .

S9 The execution result output unit 121 outputs the execution result.

[0022]

As described above, when the source program is compiled by designating the data area check, the check program performs each check based on the declaration statement of the data area definition of the source program. The intermediate code to call is generated and inserted into the translated object program of the source program. Then, the routine of the inspection program is called when the program is executed, and the inspection program verifies the validity of the citation of the data area. Therefore, in the conventional compiler, the checking depends on the specification of the programming language, and it is necessary to change the compiler or the checking program every time the language specification is changed or extended.

In addition, when the check is specified by the conventional compiler, a mechanism for checking the correctness of the data area quoting, in addition to the original object code corresponding to the definition (declaration statement) of the source program and the execution statement (Intermediate code) is generated in the object program. Therefore, for example, the intermediate code group that calculates the address of the data area is included in both the original object code and the object code for inspection, and the processing is duplicated such that the address calculation is performed by both of them, which reduces the execution time. Had lowered.

Further, the conventional compiler requires the translation system of two systems, that is, the case where the checking is performed and the case where the checking is not performed in the compiler. It is an object of the present invention to provide a compiler that can check the validity of a data area reference without depending on changes or extensions of language specifications, and that can be executed at high speed even when a check is specified. And

[0025]

An executable object program obtained by translating a source program refers to elements in aggregate data such as array elements, character string elements, and structure elements. In this case, the address of the target element is obtained by adding the transition from the start address of the set data. The citation of these data has a special structure represented by a base (start address of set data) and an index (shift from start address of set data) in the operand of the intermediate code.

The intermediate code group is a set of information in which the description content of the source program is converted in a format close to the machine language of the computer, and this information is finally converted into an object program. Each intermediate code is composed of one operand and a plurality of operands that point to the definition and data area information to be quoted.

Here, in the case of checking the validity of the citation of the data area, attention is paid to the intermediate code that cites the data area using the base and the index from the sequence of the intermediate codes. Detect everything you do. With this intermediate code, the start address of the data area to be quoted, the size of the entire data area, and the length of the data to be quoted can be obtained from the data area information specified in the operand of the corresponding intermediate code. These pieces of information are necessary for executing the program, and are always present in the data area information.

Since this intermediate code search method does not directly refer to the information of the source program, the target intermediate code can be searched without depending on the language specifications. Based on the information obtained as a result of the above, an intermediate code having a function of calling an instruction sequence to be inspected or an inspection procedure is inserted immediately before each corresponding intermediate code.

Then, the inspection is performed as follows and the result is output. If the addition result of the base, index, and the length of the data to be quoted is larger than the addition result of the start address of the data area and the size of the entire data area, it means that the data area is unequally quoted. Notify the user.

If the addition result of the base and the index is larger than the addition result of the start address of the data area and the size of the entire data area, it is an unequal reference to the data area, and the user is notified of that fact. .

If the addition result of the base and the index is smaller than the start address of the data area, it is an unequal citation of the data area, and the user is notified to that effect. In these checks, the execution performance can be improved by sharing the addition result of the base value and the index value with the calculation result for quoting the corresponding data.

The compiler is generally composed of a source analysis unit, a semantic analysis unit, an intermediate code generation unit, an intermediate code optimization unit and an object program generation unit, and they operate in this order. According to the present invention, the intermediate code for calling the inspection program is created in the object program generation unit. Therefore, the format of the intermediate code can be made common to the instruction sequence for checking the validity of the citation of the data area when the instruction sequence is generated and when it is not generated.

Therefore, the present invention combines an intermediate code with a program analysis unit that analyzes the source program and generates a set of intermediate codes in a compiler that generates an executable object program based on the source program. And an object program generation unit that generates an object program by means of the object program generation unit, the object program generation unit searches for an intermediate code generated based on a citation of a data area included in a set of intermediate codes, and based on the intermediate code, The intermediate code for calling a check program for checking the correctness of the definition citation is incorporated in the set of the intermediate code.

FIG. 1 shows the basic configuration of the present invention. In FIG. 1, 1 is a source program.

Reference numeral 2 is a compiler. Reference numeral 2'denotes a program analysis unit, which performs syntax analysis of the source program 1, semantic analysis of program statements obtained by the syntax analysis, and generation of intermediate code groups.

Reference numeral 3 denotes a source analysis unit for performing syntax analysis of the source program 1 (processing such as analyzing a character string to obtain a program statement). Reference numeral 4 denotes a semantic analysis unit that analyzes the meaning of the program statement obtained as a result of the syntax analysis.

An intermediate code generator 5 generates an intermediate code based on the result of the semantic analysis. 6
Is an object program generation unit, which combines a set of intermediate codes (intermediate code group) generated by the program analysis unit 2'to generate an executable program. At that time, the object program generator 6
If the compiler specifies to inspect, the intermediate code group generated by the program analysis unit 2'is analyzed to obtain information necessary for inspection, and the intermediate code and the inspection program for the information are analyzed. The intermediate code to be called is generated and inserted into the intermediate code group generated by the program analysis unit 2 '. If an inspection is specified,
In this way, the inspection information and the intermediate code for calling the inspection program are combined with the intermediate code group of the executable statement to create an executable program.

Reference numeral 7 is a process for determining whether or not to inspect. Reference numeral 8 is a process for retrieving information necessary for checking the validity of the citation of the data area and generating an intermediate code thereof.

Reference numeral 9 is for generating an intermediate code for calling a program for checking the validity of quoting the data area. 1
0 is a process for generating an object program,
This is a process of combining each intermediate code of the intermediate code group to create an executable program.

Reference numeral 11 is an executable object program. An inspection program library 12 includes various inspection programs.

FIG. 2 is an explanatory diagram of the basic configuration of the present invention.
In FIG. 2, 1 is a source program.

Reference numeral 11 'is a data area definition (declaration statement). 12 'is a sentence that cites the data area. An executable statement that contains the value defined in the data area definition statement,
Alternatively, the value defined by the operation can be obtained. A sentence including a value indicating the position of the data area, or a value indicating the position of the data area is obtained by calculation.

Reference numerals 13 and 13 'denote intermediate code groups (intermediate code sets). The intermediate code group 13 'does not include an intermediate code for inspection. Reference numeral 14 is an intermediate code based on the citation of the data area.

In the intermediate code group 13 ', 15 is an intermediate code of information necessary for checking the validity of the citation of the data area. Reference numeral 16 is an intermediate code for calling a check program for checking the validity of the citation of the data area.

Reference numeral 14 is an intermediate code based on the citation of the data area (same as the intermediate code based on the citation of the data area of the intermediate code group 13). The basic configuration of the present invention shown in FIG. 1 will be described with reference to FIG.

The compiler 2 inputs the source program 1. The source analysis unit 3 analyzes the syntax of the source program 1. Then, the semantic analysis unit 4 performs semantic analysis on the program statement obtained by the syntactic analysis, and the intermediate code generation unit 5 generates the intermediate code.

The object program generator 6 determines whether or not there is an inspection instruction. If there is no instruction to check the validity of quoting the data area, the intermediate code group 13 created by the program analysis unit 2'is combined to generate an object program. Alternatively, if the inspection instruction is given, the intermediate code of the intermediate code group 13 is analyzed to search for the presence or absence of the intermediate code 14 based on the citation of the data area. Then, if the intermediate code 14 exists, an intermediate code 15 of information (arguments etc.) necessary for the validity check of the definition citation is created based on the intermediate code 14. Further, the intermediate code 16 for calling the inspection program for the inspection is generated, and the intermediate code group 13 'is obtained.

Then, the intermediate codes of the intermediate code group 13 'are combined so that the intermediate codes 15 and 16 are inserted before the intermediate code 14 based on the reference of the data area, and the object program 11 of the execution format is formed. create. When the object program 11 is executed, the object program that calls the inspection program calls the inspection program from the inspection program library 12 to inspect the validity of the citation of the data area.

According to the present invention, the intermediate code necessary for checking the validity of the citation of the data area is generated from the set of intermediate codes (intermediate code group) generated based on the source program. The intermediate code generation process of does not depend on the specifications of the source program. Therefore, even if the language specification is changed or expanded, it is possible to compile without changing the compiler and the inspection program library.

Further, in the present invention, in the object program, a part of the instruction sequence corresponding to the definition (declaration statement) and the execution statement of the source program and the instruction sequence for checking the correctness of the data area are commonly used. Therefore, the time from compiling to obtaining the execution result is shortened. For example, for quoting a data area, the address of the area is calculated when the program is executed. In the present invention, the calculation result is also used for checking the validity of quoting the data area. Therefore, according to the present invention, the program execution time can be shortened even when the validity check of the data area citation is performed.

Further, according to the present invention, since the intermediate code necessary for checking the validity of the definition citation is generated in the object program generating section which is the end section of the compiler, the internal interface of the compiler in the program analyzing section before that is generated. However, according to the present invention, the load on the compiler for realizing the functions required for the check is small because the check is common to the case where it is not checked.

[0052]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 shows the configuration of an embodiment of the present invention. In FIG. 3, 1 is a source program.

Reference numeral 2 is a compiler. Reference numeral 21 denotes a program analysis unit, which includes a source analysis unit, a semantic analysis unit, and an intermediate code generation unit as part names, and converts the description of the source program into an intermediate code.

Reference numerals 22, 22 ′ and 22 ″ are intermediate code groups. Intermediate code group 22 ′ has been subjected to optimization processing. Intermediate code group 22 ″ has been inserted with intermediate code that cites a check program. belongs to.

Reference numeral 23 denotes an optimizing unit which has an intermediate code optimizing unit as the name of the unit and improves the performance of the program by deleting unnecessary descriptions (such as unused arithmetic expressions).

Reference numeral 25 denotes an object program generating section having a code generating section as a section name. The object program generation unit 25 extracts the element reference part of the aggregate data (array, character string, structure) from the intermediate code group, inserts the intermediate code that calls the data area reference validity check program, It is a process for generating an object program from a code group.

26 is an object program. FIG. 4 shows an example of the defined data area.
This is a data area defined by "ERA (10), ISUB".

Reference numeral 30 is a defined data area. A
(1), A (2), ..., A (10) are array elements. ad2 is the start address of the defined data area.
The width of one data area of the array element is 4, and the total width of the data area is 40. ad2 + t2 is a shift from the head address and is a quoted address of the array element A (3) (t2 = 8 in the case of FIG. 4).

If a check (translation option DEBUG (RAGE)) is specified when the compiler is activated, the following operation is performed. Object program generator 25 in the compiler
Performs the following operations when this translation option is specified to be valid.

(1) Each intermediate code is sequentially searched from the beginning, and in each operand of the intermediate code, the intermediate code (intermediate code of the aggregate) that refers to the data area in the format of base + index is searched.

(2) Immediately before the intermediate code, the intermediate code having the function of calling the library with the following information as an argument is inserted. (a) Quoted address of data area (base (starting address) + index) (b) Start address of referenced data area (base) (c) Total size of data area (d) Length of quoted data (e) Data name These pieces of information are acquired from the data area information specified by the operand of the intermediate code currently being processed. In the case of the example in FIG. 4, (a) the quoted address of the data area is ad2 + t
2. (b) The start address of the data area quoted is a
d2. (c) The size of the entire data area is 40. (d) The length of the data quoted is 4. (E)
The data name is A.

(3) The above operation is repeated until the intermediate code ends. The object program generated through these processes calls a library for checking the validity of the data area reference at execution time. The called library performs the following checks based on the information given in the argument.

If the addition result of the base, the index, and the length of the data to be quoted is larger than the addition result of the start address of the data area and the size of the entire data area,
Since it is an unequal citation of the data area, notify the user accordingly.

If the addition result of the base and the index is larger than the addition result of the start address of the data area and the size of the entire data area, it is an unequal citation of the data area, and the user is notified to that effect. .

If the addition result of the base and the index is smaller than the start address of the data area, it is an unequal citation of the data area, and the user is notified to that effect. Next, the operation of the configuration of FIG. 3 will be described in detail.

FIG. 5 shows an embodiment of the intermediate code of the present invention (before inserting the intermediate code for calling the inspection program). In FIG. 5, 1 is a source program.

Reference numeral 22 is an intermediate code group. The source program 1 defines an array A having 10 elements. The meaning of "INTEGER A (10), ISUB" indicates that the data is an integer type, the array name is A, and the number of elements is 10. ISUB is an integer parameter.

Substitute 3 for ISUB when ISUB = 3 (this line is not subject to the validity check of the data area). A
(ISUB) = 3 means that A (ISUB = 3) = 3. This line is the subject of validity checking for citation in the data area. The quoted address of A (ISUB) is the start address (base) of A + (ISUB-1) × 4.

The intermediate code group 22 is an intermediate code obtained by compiling the source program 1. "MOVE ISU
"B, CC3" represents an operation for substituting CC3 (a constant and value 3) of the second operand into ISUB of the first operand.

"SUB t1, ISUB, CC1" is
It represents an operation of subtracting CC1 (a constant and a value of 1) from ISUB and holding it in the register t1. "MULT t2,
t1, CC4 "is CC4 at t1 (constant and value 4)
Is multiplied and the result is held in the register t2.

"ST bxop, CC3" is CC3 (=
3) is stored in bxop. b
xop is a value obtained by adding the value held in the register t2 to ad2 (the head address of A), and A (ISUB)
Is the address of. That is, it indicates that CC3 = 3 is substituted into the address of A (3), and indicates that A (3) = 3.

In the data area information, ISUB is a user-defined variable whose head address is ad1 and whose data size is 4 (unit is byte. The same applies hereinafter).

A is a user-defined variable whose head address is ad2 and whose data size is 40. CC1 is a constant whose head address is ad3 and whose data size is 4.

CC3 is a constant whose head address is ad4 and whose data size is 4. CC4 has a head address of ad
5, the data size is a constant of 4. t1 is a temporary name with no head address and a data size of 4.

T2 is a temporary name with no head address and a data size of 4. bxop is the base (A) (A
Of the set data (array, character string, structure) that is (the start address of the) + index (t2) (refers to the address of A (ISUB)).

FIG. 6 shows an embodiment of the intermediate code of the present invention, in which the intermediate code for calling the inspection program is inserted. Reference numeral 22 'denotes an intermediate code group, which is a state after the intermediate code for calling the inspection program is inserted.

"CALL 0, lib, arg" is an intermediate code for calling the validity checking program for the data area. arg is an intermediate code b based on the definition of the data area
It is generated based on xop.

In the lib, the head address is ad6 and the data size is 4. ad6 is the start address of the data area validity checking program. The head address of arg is ad7 and the data size is 20. The contents of arg are the sequence of actual arguments (bxop, ad2, 40, 4,
A).

Here, bxop refers to the element of the above-mentioned aggregate and is an address (size 4). a
d2 is the head address of the array A (size 4), and 40 represents the width of the area of the array A (10 4 bytes) (size 4). 4 is the size of one element, and A is for displaying that there is an error in array A when displaying an error message.

"CALL 0, l of the intermediate code group 22"
ib, arg ”(0 indicates that there is no data in the first operand), the array of actual arguments of arg (bxop,
The inspection program (library) of ad6 is called by using ad2, 40, 4, A) as an argument. And the inspection program is arg (bxop, ad2, 40, 4,
According to A), it is determined whether or not the calculation result of "ST bxop, CC3" is within the range of the defined data area.

7 and 8 are flowcharts of the compiler of the present invention. The operation of the embodiment of the present invention shown in FIG. 3 will be described with reference to FIGS. 7 and 8 (refer to FIGS. 5 and 6 as necessary).

S1 The compiler 2 is the source program 1
Enter The S2 source analysis unit analyzes the syntax of the source program 1. S3 The semantic analysis unit analyzes the semantics of the program sentence obtained by the syntax analysis.

S4 The intermediate code generating section generates an intermediate code according to the result of the semantic analysis. Then, the intermediate code group 22 composed of the intermediate codes of all the programs is obtained. The intermediate code group 22 is optimized by the S5 optimizing unit 23 (obtaining the intermediate code group 22 'in FIG. 3).

S6, S7 The object program generator 25 inputs one intermediate code. If there is an intermediate code, the process proceeds to S8, and if not, the process proceeds to S12. In S8, it is determined whether or not there is a designation of the validity check of the citation of the data area, and if there is the designation of the check, the process proceeds to S9.

S9 The intermediate code determines whether or not the set data is quoted (for example, b
Judgment based on the presence or absence of the description of xop). If quoted, S1
The process proceeds to 0, and if not quoted, the processes from S6 are repeated.

S10 A sequence of actual arguments for checking the validity of data citation is created. In the case of the embodiment of the intermediate code of FIG. 6, the sequence of actual arguments of the inspection program (bxop, a
Create d2, 40, 4, A).

S11 Immediately before the intermediate code (bxop or the like) for quoting the set data, an intermediate code for calling the data citation validity checking program is inserted. For example, in the case of the embodiment of the intermediate code of FIG. 6, “CALL 0, lib, a
rg "is created. After that, the processing from S6 is repeated.

S8 The above processing is performed for each intermediate code, and when all the intermediate codes are searched, the obtained intermediate code group is subjected to the combining processing (link), and the object program in the execution format is generated by the processing from S12. .

S12, S13 It is judged whether or not the data citation validity checking program is called. If not, the process proceeds to S15. If there is, an object for referring to the data citation validity checking program is generated (S14). Generate an object program that combines the intermediate code inserted for inspection with the executable program).

S15 All intermediate codes are converted into machine language. S16 The execution format program (object program) is executed. In the execution of the object program, if the addition result of the base, index, and the length of the data to be quoted is larger than the addition result of the start address of the data area and the size of the entire data area, the data area is unequally quoted. Since there is, notify the user to that effect.

If the addition result of the base and the index is larger than the addition result of the start address of the data area and the size of the entire data area, it is an unequal reference to the data area, and the user is notified of that fact. .

If the addition result of the base and the index is smaller than the start address of the data area, it indicates that the data area is unequal, and the user is notified to that effect.

[0093]

According to the present invention, the intermediate code for checking the validity of the citation of the data area is extracted from the set of intermediate code generated based on the source program, without depending on the specifications of the source program. Can be generated. Therefore, even if the language specifications are changed or expanded, the compiler,
There is no need to change the inspection program library, greatly improving the efficiency of program development.

Further, in the present invention, in the object program, a part of the instruction sequence for the definition (declaration statement) and the execution statement of the source program and the instruction sequence for checking the validity of the citation of the data area are commonly used. Therefore, the execution time of the compile for checking the validity of the citation of the data area is shortened.

Further, according to the present invention, since the intermediate code necessary for checking the validity of the citation of the data area is performed in the object program generation unit which is the end portion of the compiler,
The internal interface of the compiler in the program analysis unit before that can be made common in the case of checking and the case of not checking. Therefore, according to the present invention, the load on the compiler for realizing the functions required for the inspection is small.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic configuration of the present invention.

FIG. 2 is an explanatory diagram of a basic configuration of the present invention.

FIG. 3 is a diagram showing a configuration of an embodiment of the present invention.

FIG. 4 is a diagram showing an example of a defined data area.

FIG. 5 is a diagram showing an embodiment of an intermediate code of the present invention.

FIG. 6 is a diagram showing an embodiment of an intermediate code of the present invention.

FIG. 7 is a diagram showing a flowchart of a compiler of the present invention.

FIG. 8 is a diagram showing a flowchart of a compiler of the present invention.

FIG. 9 is a diagram showing a conventional compiler.

FIG. 10 is a diagram showing a flowchart of a conventional compiler.

[Explanation of symbols]

1: Source program 2: Compiler 2 ': Program analysis unit 3: Source analysis unit 4: Semantic analysis unit 5: Intermediate code generation unit 6: Object program generation unit 7: Whether or not the validity check of the data area citation is specified Judgment process 8: Process for retrieving information necessary for checking validity of data area citation and generating intermediate code thereof 9: Process for generating intermediate code for calling data area citation validity checking program 10: Process for generating object program 11: Object program 12: Inspection program library

Claims (4)

[Claims] 1. A compiler for generating an executable object program based on a source program, a program analysis unit for analyzing a source program to generate a set of intermediate code, and an object program by combining the intermediate code. And an object program generation unit for generating, wherein the object program generation unit searches for an intermediate code generated based on a reference of a data area included in a set of intermediate codes, and based on the intermediate code, searches for the reference of the definition. A compiler characterized by incorporating intermediate code for calling a check program for checking correctness into a set of the intermediate code. 2. A data area definition is an array, a character string, or a structure definition.
Compiler as described in. 3. The compiler according to claim 1, wherein the intermediate code for calling the inspection program with the definition information of the data area as an argument is incorporated immediately before the intermediate code to be inspected. 4. The validity check of the citation of the definition is to check whether or not the value representing the position of the quoted data area is within a defined range. Alternatively, the compiler described in 2.