Example: initial heap storage map

The three map sections in the listing, INITIAL HEAP STORAGE MAP, WORKING-STORAGE MAP, and BELOW THE LINE STORAGE MAP are collectively called the initial heap storage maps of a program. The storage for these areas is allocated at the start of the program and persists until the end of the run unit or until the program is canceled.

The layouts of these three map sections are similar:
  • The first column shows the offset of the item from a block of storage allocated by the compiler.
  • The second column is the size of the symbol, including all of its sublevel members.
  • The third column is the name of the area being described.
See the following INITIAL HEAP STORAGE MAP as an example of the layout. If the NORENT compiler option is in effect, the WORKING-STORAGE data items are mapped in the INITIAL HEAP STORAGE MAP section. For COBOL data items, the offset is the offset to the start of the level-01 data item from the block of storage allocated by the compiler. The starting address of this block resides in the Constant Area.

* * * * *   I N I T I A L     H E A P     S T O R A G E     M A P   * * * * *

     OFFSET (HEX)   LENGTH (HEX)   NAME

            0              4       BLL_Ptrs
            4              C       BLT_Ptrs
           10             60       GPCB
           70              4       WS-BASE-ADDRESS
           74              8       TS2=6

If the RENT and DATA(31) compiler options are in effect, the WORKING-STORAGE data items are shown under the WORKING-STORAGE MAP. If the RENT and DATA(24) options are in effect, the WORKING-STORAGE data items are shown under the BELOW THE LINE STORAGE MAP. An INITIAL HEAP STORAGE MAP section is also shown where compiler generated internal data items and locators are mapped.


* * * * *   B E L O W     T H E     L I N E     S T O R A G E     M A P   * * * * *

      OFFSET (HEX)   LENGTH (HEX)   NAME

            0              4       JNIENVPTR
            8              2       RETURN-CODE
           10              2       SORT-RETURN
           18              8       SORT-CONTROL
           20              4       SORT-CORE-SIZE
           28              4       SORT-FILE-SIZE
           30              4       SORT-MODE-SIZE
           38              8       SORT-MESSAGE
           40              4       TALLY
           48              1       SHIFT-OUT
           50              1       SHIFT-IN
           58              4       XML-CODE
           60             1E       XML-EVENT
           80              4       XML-INFORMATION
           88             50       COMMUTER-FILE
           D8             50       COMMUTER-FILE-MST
          128             7A       PRINT-FILE
          1A8              1       WORKING-STORAGE-FOR-IGYCARA
          1B0              2       COMP-CODE
          1B8              3       WS-TYPE
          1C0              2       I-F-STATUS-AREA
          1C8              8       STATUS-AREA
          1D0              2       UPDATE-FILE-STATUS