HLASM: V1R6 Language Ref

CSECT instructionsame section name are “owned” by that section, and binding actions (such assection replacement) act on all elements owned by a section.When the GOFF option is specified, and if no CATTR statements are present, thenall machine language text is placed in the default class B_TEXT, and the behaviorof the elements in the bound module is essentially the same as the behavior ofcontrol sections when the OBJECT option is specified. However, if additionalclasses are declared, a section name can best be thought of as a “handle” by whichelements within declared classes are owned.End of z/VM and z/OSThe beginning of a control section is aligned on a boundary determined by theSECTALGN option. However, when an interrupted control section is continuedusing the CSECT instruction, the location counter last specified in that controlsection is continued. Consider the coding in Figure 17:ALPHA START ┐ ┌───────────────────────┐BALR 12,0 ├───────────────────────────►│ ALPHA │USING │ ┌────────────────────────►│ │. │ │ │ │. ┘ │ │ │NEWCSECT CSECT ┐ │ ├ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ┤. ├──┼────────────────────────►│ NEWCSECT │. │ │ │ │. ┘ │ │ │ALPHA CSECT ┐ │ │ │. ├──┘ │ │. │ │ │. ┘ │ │Figure 17. How the location counter worksThe source statements following a CSECT instruction that either initiate or indicatethe continuation of a control section are assembled into the object code of thecontrol section identified by that CSECT instruction.The end of a control section or portion of a control section is marked by:v Any instruction that defines a new or continued control sectionv The END instructionThe CSECT instruction may interact with any LOCTR instructions that are present.For more information about this interaction, see “LOCTR instruction” on page 190.CXDinstructionThe CXD instruction reserves a fullword area in storage. The linker or loaderinserts into this area the total length of all external dummy sections specified in thesource modules that are assembled and linked into one program. If a controlsection has not previously been established, CXD will initiate an unnamed(private) control section.Chapter 5. Assembler instruction statements 123