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Chapter 18: Compiler-directing Statements

During the creation of your source program, you may wish to include some of the optional Compiler-directing statements. These are found in the library module,

the Basis mechanism, the ++INCLUDE/ -INC mechanisms,

conditional compilation

, and the listing control statements.

The USE, NOTE and ENTER statements are described in the chapter Program Definition. They determine how your source program will be created from a set of source files, by allowing text from other files to be included in your source file during the compile process.

18.1 The Library Module

The library module allows you to specify text that is to be copied from a source user-library. This is usually created using any suitable source text editor.

It also allows you to replace text in the source program.

COBOL libraries consist of files that contain source to be made available to the COBOL system. The effect of the interpretation of the COPY statement is to insert text into the source program, where it will be treated by the COBOL system as part of the source program. All occurrences of a given literal, identifier, word or group of words in the library text can be replaced with alternative text during the copy process. The library module also allows you to access more than one COBOL library at the time the object code is created.

The effect of the REPLACE statement is to substitute new text for text appearing in the source program and have the new text treated by your COBOL system as part of the source program.

18.2 The BASIS Mechanism

The Basis mechanism provides support to allow an entire COBOL program source file to be noninteractively edited (temporarily) and the result of this edit to be submitted to your COBOL system. The COBOL program source file referenced as the source of the temporary edit (the "subject-program") remains unchanged, and there is no record of the result of the edit other than the files output by your COBOL system (listing, and so on). The resulting code file cannot be animated since there is no source file for reference.

The BASIS mechanism is valid for fixed format source only.

The program submitted to your COBOL system consists of two files: an edit control file (containing the BASIS statement and editing information) and the COBOL source file (the "subject program" as described above).

Three special statements are associated with the BASIS mechanism:

  1. BASIS

  2. INSERT

  3. DELETE.

These special statements are not part of the COBOL language. They must, in their entirety, be contained on a single line and must be in upper case.

If you modify the COBOL source program provided by a BASIS statement with INSERT or DELETE statements, the sequence field of the COBOL source program must contain numeric sequence numbers in ascending order.

General Notes on Basis Mechanism Statements

  1. DELETE statements wholly within area B of the source-program line, not followed by a valid subject-sequence or subject-sequence-range, will be treated as a COBOL DELETE statement by your COBOL system.

  2. Within the Basis mechanism DELETE statement, all subject-sequence and subject-sequence-range numbers must be in ascending numeric order.

  3. Within the edit control file, all subject-sequence and subject-sequence-range numbers must be in ascending numeric order.

18.3 The ++INCLUDE and -INC Mechanisms

The ++INCLUDE and -INC mechanisms provide another (IBM-mainframe compatible) means whereby a COBOL program source file or portion of source code can be included in a file to be compiled.

These special statements are not part of the COBOL language. They must, in their entirety, be contained on a single line and must be in upper case.

18.4 Conditional Compilation

The COBOL system provides a mechanism for selectively compiling part or all of the COBOL source. To benefit fully from the advantages of conditional compilation the use of level 78's (see the chapter Program Definition) and the CONSTANT Compiler directive is recommended. Conditional compilation is controlled by $IF, $ELSE, $END constructs. It behaves in a similar way to the COBOL IF construct.

General Notes on all Conditional Compilation Statements

  1. Conditional compilation statements are indicated by a dollar ($) in column 7 in fixed format source, or column 1 in free format source of the COBOL source line followed by one of the key words IF, ELSE, END.

  2. Conditional compilation should not be used to split a COBOL character string; that is, continuation lines should not be split by conditional compilation controls.

18.5 The Listing Control Statements

The listing control statements provide a control for producing output file listings during the compile process.

Three statements are associated with the listing control statements:

  1. EJECT

  2. SKIP1, SKIP2 AND SKIP3

  3. TITLE.

18.6 The Statements

18.6.1 The BASIS Statement

Function

The BASIS statement identifies that the program (the edit control file and the COBOL source file) is to be submitted to your COBOL system under the BASIS mechanism rules.

General Format

Syntax Rules

  1. The BASIS statement must be the first line of the edit control file.

  2. The BASIS reserved word can commence anywhere between columns 1 and 66 of the statement line.

  3. Sequence numbers can be included anywhere in columns 1 through 6 of the statement and must be followed by a space.

  4. Text-name defines a unique external file-name which conforms to the rules for user defined words (note lower case is translated into upper case). External-file-name-literal is an alphanumeric literal enclosed in quotation marks, which conforms to the operating system rules for file-names.

General Rules

  1. Text-name or external-file-name-literal determines the COBOL source file to be edited by the control file.

  2. The editing of the COBOL source file is determined by the INSERT and DELETE statements in the edit control file.

18.6.2 The COPY Statement

Function

The COPY statement incorporates text into a COBOL source program.

Examples

  1. An example of using the OLDCOPY Compiler directive to achieve ANSI'68 or LANGLVL(1) behavior is provided in the Examples chapter in your Language Reference - Additional Topics.

  2. An example of using the COPY statement with partial word replacement supported by ANSI'85 rules is provided in the Examples chapter in your Language Reference - Additonal Topics.

General Format

Directives

  1. In addition to Compiler directives which provide flagging and modify the reserved word list, the following directives may impact either the syntax or semantics described in this section.

Syntax Rules

  1. If more than one COBOL library is available while the source is passed through the COBOL system, text-name must be qualified by the library-name identifying the COBOL library in which the text associated with text-name resides. See your COBOL system documentation for details of libraries.

    This restriction is removed.

  2. The COPY statement must be preceded by a space and terminated by the separator period.

  3. Pseudo-text-1 must not be null, nor can it consist solely of either the character space(s) or comment lines.

  4. Pseudo-text-2 can be null.

  5. Character-strings within pseudo-text-1 and pseudo-text-2 can be continued. However, both characters of a pseudo-text delimiter must be on the same line. (See the section Continuation of Lines in the chapter Concepts of a COBOL Program.)

  6. Word-1 or word-2 can be any single COBOL word.

  7. A COPY statement can occur in the source program anywhere a character-string or a separator can occur except that a COPY statement must not occur within another COPY statement.

  8. Text-name defines a unique external file-name which conforms to the rules for user defined words.

    External-file-name-literal is an alphanumeric literal that conforms to the operating system rules for file-names. It can be specified with or without enclosing quotation marks.

    Text-names and unquoted external-file-name-literals are always converted to uppercase.

  9. Library-name-literal is an alphanumeric literal that conforms either to the operating system rules for file-names or to the operating system rules for device identifiers. It can be specified with or without enclosing quotation marks.

    Unquoted library-name-literals are always converted to uppercase.

  10. The SUPPRESS phrase is used to suppress printing the contents of the copy member on the source listing.

  11. If the word COPY appears in a comment-entry or in the place where a comment entry can appear, it is considered part of the comment-entry.

    A COPY statement that appears in a comment-entry is processed.

  12. External-file-name-literal and library-name-literal, when enclosed in quotation marks, may contain the $, #, and @ characters.

General Rules

  1. The compilation of a source program containing COPY statements is logically equivalent to processing all COPY statements prior to the processing of the resulting source program.

  2. The effect of processing a COPY statement is that the library text associated with text-name is copied into the source program, logically replacing the entire COPY statement, beginning with the reserved word COPY and ending with the punctuation character period, inclusive.

  3. If the REPLACING phrase is not specified, the library text is copied unchanged.

    If the REPLACING phrase is specified, the library text is copied and each properly matched occurrence of pseudo-text-1, identifier-1, literal-1 and word-1 in the library text is replaced by the corresponding pseudo-text-2, identifier-2, literal-2 or word-2.

  4. For purposes of matching, identifier-1, literal-1 and word-1 are treated as pseudo-text containing only identifier-1, literal-1 or word-1, respectively.

  5. The comparison operation to determine text replacement occurs in the following manner:

    1. The leftmost library text word which is not a separator comma or a separator semicolon is the first text word used for comparison. Any text word or space preceding this text word is copied into the source program. Starting with the first text word for comparison and first pseudo-text-1, identifier-1, word-1, or literal-1 that was specified in the REPLACING phrase, the entire REPLACING phrase operand that precedes the reserved word BY is compared to an equivalent number of contiguous library text words.

    2. Pseudo-text-1, identifier-1, word-1, or literal-1 match the library text if, and only if, the ordered sequence of text words that forms pseudo text-1, identifier-1, word-1, or literal-1 is equal, character for character, to the ordered sequence of library text words. For purposes of matching, each occurrence of a separator comma, semicolon, or space in pseudo-text-1 or in the library text is considered to be a single space. Each sequence of one or more space separators is considered to be a single space.

      Each lowercase letter is equivalent to the corresponding uppercase letter as specified for the COBOL character set.

    3. If no match occurs, the comparison is repeated with each next successive pseudo-text-1, identifier-1, word-1, or literal-1, if any, in the REPLACING phrase until either a match is found or there is no next successive REPLACING operand.

    4. When all the REPLACING phrase operands have been compared and no match has occurred, the leftmost library text word is copied into the source program. The next successive library text word is then considered as the leftmost library text word, and the comparison cycle starts again with the first pseudo-text-1, identifier-1, word-1, or literal-1 specified in the REPLACING phrase.

    5. Whenever a match occurs between pseudo-text-1, identifier-1, word-1, or literal-1 and the library text, the corresponding pseudo-text-2, identifier-2, word-2, or literal-2 is placed into the source program. The library text word immediately following the rightmost text word that participated in the match is then considered as the leftmost text word. The comparison cycle starts again with the first pseudo-text-1, identifier-1, word-1, or literal-1 specified in the REPLACING phrase.

    6. The comparison operation continues until the rightmost text word in the library text has either participated in a match or been considered as a leftmost library text word and participated in a complete comparison cycle.

  6. A comment line occurring in either the library text or pseudo-text-1 is interpreted, for purposes of matching, as a single space. Comment lines appearing in either pseudo-text-2 or library text are copied into the source program unchanged.

  7. Debugging lines are permitted within library text and pseudo-text-2. Debugging lines are not permitted within pseudo-text-1; text-words within a debugging line participate in the matching rules as if the "D" did not appear in the indicator area.

    A debugging line is specified within pseudo-text if the debugging line begins in the source program after the opening pseudo-text delimiter but before the matching closing pseudo-text delimiter.

  8. The text produced as a result of the complete processing of a COPY statement must not contain a COPY statement.

    This text can contain a COPY statement provided neither this contained COPY nor the already expanded COPY includes the REPLACING phrase. However, recursive COPY statements (where a library-text is referred to by a COPY statement within it) are not allowed.

    COPY statements may be nested in this way to any level. One of the COPY statements in this structure may include the REPLACING phrase, and the replacements specified will be in effect for all subsidiary COPYs.

  9. The syntactic correctness of the library text cannot be independently determined.

    Except for COPY statements,

    the syntactic correctness of the entire COBOL source program cannot be determined until all COPY statements have been completely processed.

  10. Each text word copied from the library but not replaced is copied so as to start in the same area of the line in the resultant program as it begins in the line within the library. However, if a text word copied from the library begins in area A but follows another text word, which also begins in area A of the same line, and if replacement of a preceding text word in the line by replacement text of greater length occurs, the following text word begins in area B if it cannot begin in area A. Each text word in pseudo-text-2 that is to be placed into the resultant program begins in the same area of the resultant program as it appears in pseudo-text-2. Each identifier-2, literal-2, and word-2 that is to be placed into the resultant program begins in the same area of the resultant program as the leftmost library text word that participated in the match would appear if it had not been replaced.

    Library text must conform to the rules for COBOL reference format.

    If additional lines are introduced into the source program as a result of a COPY statement, each text word introduced appears on a debugging line if the copy statement begins on a debugging line, or if the text word being introduced appears on a debugging line in library text. When a text word specified in the BY phrase is introduced, it appears on a debugging line if the first library text word being replaced is specified on a debugging line. Except in the preceding cases, only those text words that are specified on debugging lines where the debugging line is within pseudo-text-2 appear on debugging lines in the resultant program. If any literal specified as literal-2 or within pseudo-text-2 or library text is of too great a length to be accommodated on a single line without continuation to another line in the resultant program and the literal is not being placed on a debugging line, additional continuation lines are introduced which contain the remainder of the literal. If replacement requires that the continued literal be continued on a debugging line, the program is in error.

  11. For purposes of compilation, text-words after replacement are placed in the source program according to the rules for reference format as described in the chapter Concepts of a COBOL Program.

  12. If the unit identifier is not explicitly specified, the default drive will be used. (The default is operating system-dependent.)

  13. The OLDCOPY Compiler directive causes the entire entry to be replaced by the information identified by text-name, except that the data-name preceding the COPY statement replaces the corresponding data-name in the text-name.

  14. If certain conventions are followed in library text, parts of names, for example the prefix portion of data-names, can be changed with the REPLACING phrase.

    To use this type of "partial word replacement" the portion of the words to be modified must be enclosed as follows:

    1. In pairs of left and right parentheses. For example, (ABC)

    2. Within colons. For example :XYZ: is a valid candidate.

18.6.3 The DELETE Statement - Basis Control

Function

The DELETE statement (under the Basis mechanism) identifies lines of the COBOL source file to be ignored by your COBOL system. Any COBOL statements that follow the DELETE statement (up to the next Basis-mechanism INSERT or DELETE statement in the edit control file) are included.

General Format

Syntax Rules

  1. The DELETE reserved word can commence anywhere between columns 1 and 66 of the statement line.

  2. Sequence numbers can be included anywhere in columns 1 through 6 of the statement and must be followed by a space.

  3. Subject-sequence-1, subject-sequence-2, and so on, must be unquoted 6-digit positive integers (following the rules for integer numeric-literals).

  4. Subject-sequence-range-1, subject-sequence-range-2, and so on, must consist of two subject-sequence numbers (as above) separated by a hyphen (-).

  5. The comma between subject-sequences and/or subject-sequence ranges is mandatory.

General Rules

  1. Subject-sequence-1, subject-sequence-2, and so on, refer to sequence numbers of those statements within the COBOL source file which are to be ignored by your COBOL system.

  2. Subject-sequence-range-1, subject-sequence-range-2, and so on, refer to inclusive ranges of statement sequence numbers within the COBOL source file, all of which statements are to be ignored when the intermediate code is produced.

  3. Any COBOL statements following the DELETE statement in the edit control file up to the next BASIS-mechanism DELETE or INSERT statement will be included in the source submitted to your COBOL system. These COBOL source statements are inserted in place of the last statement omitted by this Basis-mechanism DELETE statement.

18.6.4 $DISPLAY Statement with Conditional Compilation

Function

If a $DISPLAY statement is encountered while source lines are actively being processed (not in source lines which are conditionally excluded), the text-data will be displayed on the standard output device.

General Format

Syntax Rules

  1. The whole statement must appear on a single line.

18.6.5 The EJECT Statement

Function

The EJECT statement tells your COBOL system to print the next line of source code at the top of the next page.

General Format

Syntax Rules

  1. EJECT may begin either in area A or in area B, must be the only statement on the line and may optionally be followed by a period.

General Rules

  1. The EJECT statement itself is not printed.

18.6.6 $ELSE Statement with Conditional Compilation

Function

The most recent $IF condition is reversed. If the now active $IF condition is true, the source lines following the $ELSE statement are processed. If the $IF condition is false, COBOL source lines are ignored until the next conditional compilation line is encountered.

General Format

Syntax Rules

  1. The whole statement must appear on a single line.

18.6.7 $END Statement with Conditional Compilation

Function

The innermost $IF condition is terminated. The now active $IF condition is considered. If the active condition is true the source lines following the $END are processed. If the condition is false, COBOL source lines are ignored until the next conditional compilation line is encountered.

General Format

Syntax Rules

  1. The whole statement must appear on a single line.

18.6.8 $IF Statement with Conditional Compilation

Function

A $IF statement provides the means whereby selected parts of the source text are not included in the compilation.

Examples

  1. An example of using conditional compilation is provided in the Examples chapter in your Language Reference - Additonal Topics.

General Formats

Format 1

Format 2

Syntax Rules

  1. Constant-name-1 is defined by a level 78 entry or a CONSTANT Compiler directive.

  2. If literal-1 is numeric, it must be zero or a positive integer.

  3. The whole statement must appear on a single line.

  4. $IF can be nested within another $IF.

General Rules

  1. Constant-name-2 is DEFINED if it is the subject of a level 78 entry or a CONSTANT Compiler directive, otherwise it is NOT DEFINED.

  2. If the condition evaluates true the source lines following the $IF statement are processed. If the condition evaluates false, COBOL source lines are ignored until the next conditional compilation line is encountered.

18.6.9 The -INC Statement

Function

The -INC statement is used to include all of the data records of one source file in another source file at compilation time.

General Format

Directives and Run-time Switches

  1. In addition to Compiler directives which provide flagging and modify the reserved word list, the following directive may impact either the syntax or semantics described in this section.

Syntax Rules

  1. -INC must begin in column 1 and be followed by one or more spaces.

  2. Text-name defines a unique external file-name which conforms to the rules for user defined words.

  3. These special statements are not part of the COBOL language. They must, in their entirety, be contained on a single line and must be in upper case.

General Rules

  1. Text-name determines the COBOL source file to be included at this specific place in the source code.

  2. Any other text appearing on the line is treated as a comment.

18.6.10 The ++INCLUDE Statement

Function

The ++INCLUDE statement is used to include all of the data records of one source file in another source file at compilation time.

General Format

Directives and Run-time Switches

  1. In addition to Compiler directives which provide flagging and modify the reserved word list, the following directive may impact either the syntax or semantics described in this section.

Syntax Rules

  1. ++INCLUDE must begin in column 8, must be in uppercase and must be followed by one or more spaces.

  2. Text-name defines a unique external file-name which conforms to the rules for user defined words.

  3. These special statements are not part of the COBOL language. They must, in their entirety, be contained on a single line and must be in upper case.

General Rules

  1. Text-name determines the COBOL source file to be included at this place in the source code.

  2. Any other text appearing on the line is treated as a comment.

18.6.11 The INSERT Statement - Basis Control

Function

The INSERT statement (under the Basis mechanism) lists lines of COBOL source to be included in the program submitted to your COBOL system.

General Format

Syntax Rules

  1. The INSERT reserved word can commence anywhere between columns 1 and 66 of the statement line.

  2. Subject-sequence must be an unquoted positive numeric integer (following the rules for integer numeric literals).

General Rules

  1. Subject-sequence refers to that statement within the COBOL source file after which the COBOL statement(s) is to be included.

  2. All those COBOL statements following the INSERT statement in the edit control file up to the next Basis-mechanism DELETE or INSERT statement will be included in the source submitted to your COBOL system. At least one COBOL statement must immediately follow the Basis-mechanism INSERT statement.

18.6.12 The REPLACE Statement

Function

The REPLACE statement is used to replace source program text.

General Formats

Format 1

Format 2

Syntax Rules

  1. A REPLACE statement can occur wherever a character-string can occur in the source program. It must be preceded by a separator period except when it is the first statement in a separate program.

  2. A REPLACE statement must be terminated by a separator period.

  3. Pseudo-text-1 must contain one or more text words.

  4. Pseudo-text-2 can contain zero, one, or more text words.

  5. Character-strings within pseudo-text-1 and pseudo-text-2 can be continued.

  6. A text word within pseudo-text must be between 1 and 322 characters long.

  7. Pseudo-text-1 must not consist entirely of a separator comma or a separator semicolon.

  8. If the word REPLACE appears in a comment-entry or in the place where a comment-entry can appear, it is considered part of the comment-entry.

General Rules

  1. The Format 1 REPLACE statement specifies the text of the source program to be replaced by the corresponding text. Each matched occurrence of pseudo-text-1 in the source program is replaced by the corresponding pseudo-text-2.

  2. The Format 2 REPLACE statement specifies that any text replacement currently in effect is discontinued.

  3. A given occurrence of the REPLACE statement is in effect from the point at which it is specified until the next occurrence of the statement or the end of the separate program, respectively.

  4. Where both REPLACE and COPY statements are contained in a source program, any COPY statements are processed first.

  5. The text produced as a result of the processing of a REPLACE statement must contain neither a COPY statement nor a REPLACE statement.

  6. The comparison operation to determine text replacement occurs in the following manner:

    1. Starting with the leftmost source program text word and the first pseudo-text-1, pseudo-text-1 is compared to an equivalent number of contiguous source program text words.

    2. Pseudo-text-1 matches the source program text if, and only if, the order sequence of text words that forms pseudo-text-1 is equal, character for character, to the ordered sequence of source program text words. For purposes of matching, each occurrence of a separator comma, semicolon, or space in pseudo-text-1 or in the source program text is considered to be a single space. Each sequence of one or more space separators is considered to be a single space.

      Each lowercase letter is equivalent to the corresponding uppercase letter as specified for the COBOL character set.

    3. If no match occurs, the comparison is repeated with each next successive occurrence of pseudo-text-1, until either a match is found or there is no next successive occurrence of pseudo-text-1.

    4. Whenever a match occurs between pseudo-text-1 and the source program text, the correponding pseudo-text-2 replaces the matched text in the source program. The source program text word immediately following the rightmost text word that participated in the match is then considered as the leftmost source program text word. The comparison cycle starts again with the first occurrence of pseudo-text-1.

    5. The comparison operation continues until the rightmost text word in the source program text which is within the scope of the REP LACE statement has either participated in a match or been considered as a leftmost source program text word and participated in a complete comparison cycle.

  7. Comment lines or blank lines occurring in either the source program text or pseudo-text-1 are ignored for purposes of matching; and the sequence of text words in the source program text and in pseudo-text-1 is determined by the rules for reference format. See the section Reference Format Representation in the chapter Concepts of a COBOL Program. Comment lines or blank lines in pseudo-text-2 are placed into the resultant program unchanged whenever pseudo-text-2 is placed into the source program as a result of text replacement. A comment line or blank line in source program text is not placed into the resultant program if that comment line or blank line appears within the sequence of text words that match pseudo-text-1.

  8. Debugging lines are permitted in pseudo-text. Text words within a debugging line participate in the matching rules as if the "D" did not appear in the indicator area.

  9. Only after all COPY and REPLACE statements have been completely processed, can the syntactical correctness of the rest of the source code be determined.

  10. Text words inserted into the source program as a result of processing a REPLACE statement are placed in the source program according to the rules for reference format. See the section Reference Format in the chapter Concepts of a COBOL Program. When inserting text words of pseudo-text-2 into the source program, additional spaces can be introduced only between text words where a space (including the assumed space between source lines) already exists.

  11. If additional lines are introduced into the source program as a result of the processing of REPLACE statements, the indicator area of the introduced lines contains the same character as the line on which the text being replaced begins, unless that line contains a hyphen, in which case the introduced line contains a space.

    If any literal within pseudo-text-2 is of a length too great to be accommodated on a single line without continuation to another line in the resultant program and the literal is not being placed on a debugging line, additional continuation lines are introduced to contain the remainder of the literal. If replacement requires the continued literal to be continued on a debugging line, the program is in error.

18.6.13 The SKIP1, SKIP2 and SKIP3 Statements

Function

The SKIP1, SKIP2 and SKIP3 statements control the vertical spacing of the so urce code listing produced by your COBOL system. They specify the lines to be skipped in the source code listing.

General Format

Syntax Rules

  1. These statements can begin in area A or in area B, must be the only statement on the line

    and can optionally be followed by a period.

General Rules

  1. SKIP1 tells your COBOL system to skip one line (double spacing). SKIP2 tells your COBOL system to skip two lines (triple spacing). SKIP3 tells your COBOL system to skip three lines (quadruple spacing).

  2. The SKIP statement itself is not printed.

18.6.14 The TITLE Statement

Function

The TITLE statement tells your COBOL system what title to print on the first line of all subsequent pages of the program listing.

General Format

Syntax Rules

  1. Literal-1 must be nonnumeric and can be followed by a period. It cannot be a figurative constant.

  2. The word TITLE can begin either in Area A or Area B and must be the only statement on the line.

  3. The TITLE statement can appear anywhere in the source program.

General Rules

  1. Literal-1 will be used as a title on all subsequent pages of the program listing. The default title, which is used until a TITLE directive is encountered, identifies your COBOL system and its current release level.

  2. The chosen or default title occupies the left-hand side of the first line of each page. The remainder of the line gives the date and time the intermediate code is produced and a page number.

  3. A second title line is also output containing the name of the main source file and of the current COPY-file.

  4. The TITLE statement causes an immediate new page.

  5. The TITLE statement itself is not printed.


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