RSECT instruction

The RSECT instruction initiates a read-only executable control section or indicates the continuation of a read-only executable control section.

Read syntax diagramSkip visual syntax diagram>>-+--------+--RSECT-------------------------------------------><
   '-symbol-'         
 
symbol
is one of the following:

When an executable control section is initiated by the RSECT instruction, the assembler automatically checks the control section for possible coding violations of program reenterability, regardless of the setting of the RENT assembler option. As the assembler cannot check program logic, the checking is not exhaustive. Non-reentrant code is diagnosed by a warning message.

The RSECT instruction can be used anywhere in a source module after the ICTL instruction. If it is used to initiate the first executable control section, it must not be preceded by any instruction that affects the location counter and thereby causes the first control section to be initiated.

If symbol denotes an ordinary symbol, the ordinary symbol identifies the control section. If several RSECT instructions within a source module have the same symbol in the name field, the first occurrence initiates the control section and the rest indicate the continuation of the control section. The ordinary symbol denoted by symbol represents the address of the first byte in the control section, and has a length attribute value of 1.

If symbol is not specified, or if name is a sequence symbol, the RSECT instruction initiates or indicates the continuation of the unnamed control section.

See CSECT instruction for a discussion on the interaction between RSECT and the GOFF assembler option.

The beginning of a control section is aligned on a boundary determined by the SECTALGN option. However, when an interrupted control section is continued using the RSECT instruction, the location counter last specified in that control section is continued.

The source statements following a RSECT instruction that either initiate or indicate the continuation of a control section are assembled into the object code of the control section identified by that RSECT instruction.

Notes:
  1. The assembler indicates that a control section is read-only by setting the read-only attribute in the object module.
  2. The end of a control section or portion of a control section is marked by (a) any instruction that defines a new or continued control section, or (b) the END instruction.

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