PRB: Error L2028: Automatic Data Segment Plus Heap Exceed 64K

The information in this article applies to:

• Microsoft Windows Software Development Kit (SDK) for Windows versions 3.0 and 3.1

SYMPTOMS

The following error is received during linking:

   L2028: Automatic data segment plus heap exceeds 64K

CAUSE

The LINK error L2028 is caused when the data segment required by the application exceeds 64K. This can be calculated by adding the HEAPSIZE and STACKSIZE portions of the .DEF file, plus the global data and static data. These two numbers of the .DEF file plus the size of the global and static data need to be under 65536 bytes. The global data refers to global variables in an application, not the global heap.

RESOLUTION

The solution is to reduce the amount of the HEAPSIZE, STACKSIZE, global data, or static data. If the application utilizes large amounts of global data, some of this data should be moved into the memory covered by Windows [e.g. utilizing GlobalAlloc()]. If the data consists of constants, such as string tables, these can be moved into Windows resources using the RC compiler.

This problem may also be resolved by using the /Gt compile option which is available beginning with the Microsoft C/C++ 7.0 compiler. Using the /Gt switch, you can specify the size a static object and allocate the static object its own data segment. If need be the threshold value can be adjusted to ensure some of the data objects are allocated in an additional data segment, outside of the default data segment. The default threshold value when the /Gt option is not specified will be 32767 bytes.