HLASM: V1R6 Language Ref

CSECT instructionCSECT instructionThe CSECT instruction initiates an executable control section or indicates thecontinuation of an executable control section.►►symbolCSECT►◄symbolis one of the following:v An ordinary symbolv A variable symbol that has been assigned a character string with a value thatis valid for an ordinary symbolv A sequence symbolThe CSECT instruction can be used anywhere in a source module after any ICTLor *PROCESS statements. If it is used to initiate the first executable control section,it must not be preceded by any instruction that affects the location counter andthereby causes a control section to be initiated.If symbol denotes an ordinary symbol, the ordinary symbol identifies the controlsection. If several CSECT instructions within a source module have the samesymbol in the name field, the first occurrence initiates the control section and therest indicate the continuation of the control section. The ordinary symbol denotedby symbol represents the address of the first byte in the control section, and has alength attribute value of 1.If symbol is not specified, or if name is a sequence symbol, the CSECT instructioninitiates, or indicates the continuation of the unnamed control section.If the first control section is initiated by a START instruction, the CSECTinstruction which continues the section must have the same name as the STARTinstruction.z/VM and z/OSWhen the GOFF option is not specified a control section is initiated or resumed bythe CSECT, RSECT, and COM statements. Any machine language text created bystatements that follow such control section declarations belongs to the controlsection, and is manipulated during program linking and binding as an indivisibleunit.When the GOFF option is specified, the behavior of CSECT, RSECT, and COMstatements is somewhat different. By default, the assembler creates a definition of atext class named B_TEXT, to which subsequent machine language text belongs ifno other classes are declared. If you specify other class names using the CATTRstatement, machine language text following such CATTR statements belongs to thatclass.The combination of a section name and a class name defines an element, which isthe indivisible unit manipulated during linking and binding. All elements with the122 HLASM: V1R6 Language Ref