The meaning of the terms segment and section are interchangeable in this topic.

OBJ files can be viewed with the dumpbin application. The default segment in the .obj file for initialized variables is .data. Variables initialized to zero are considered uninitialized and are stored in .bss.

data_seg with no parameters resets the segment to .data.

push(optional)

Puts a record on the internal compiler stack. A push can have an identifier and segment-name.

pop (optional)

Removes a record from the top of the internal compiler stack.

identifier (optional)

When used with push, assigns a name to the record on the internal compiler stack. When used with pop, pops records off the internal stack until identifier is removed; if identifier is not found on the internal stack, nothing is popped.

identifier enables multiple records to be popped with a single pop command.

"segment-name"(optional)

The name of a segment. When used with pop, the stack is popped and segment-name becomes the active segment name.

"segment-class" (optional)

Included for compatibility with C++ prior to version 2.0. It is ignored.

// pragma_directive_data_seg.cpp
int h = 1;                     // stored in .data
int i = 0;                     // stored in .bss
#pragma data_seg(".my_data1")
int j = 1;                     // stored in "my_data1"

#pragma data_seg(push, stack1, ".my_data2")   
int l = 2;                     // stored in "my_data2"

#pragma data_seg(pop, stack1)   // pop stack1 off the stack
int m = 3;                     // stored in "stack_data1"

int main() {
}

Data allocated using data_seg does not retain any information about its location.

See /SECTION for a list of names you should not use when creating a section.

You can also specify sections for const variables (const_seg), uninitialized data (bss_seg), and functions (code_seg).

Reference