data_seg pragma
Specifies the data section (segment) where initialized variables are stored in the object (.obj) file.
Syntax
#pragma data_seg([ "section-name" [,"section-class" ] ])
#pragma data_seg({push|pop} [,identifier ] [,"section-name" [,"section-class" ] ])
Parameters
push
(Optional) Puts a record on the internal compiler stack. A push can have an identifier and section-name.
pop
(Optional) Removes a record from the top of the internal compiler stack. A pop can have an identifier and section-name. You can pop multiple records using just one pop command by using the identifier. The section-name becomes the active data section name after the pop.
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 isn't found on the internal stack, nothing is popped.
identifier enables multiple records to be popped with a single pop command.
"section-name"
(Optional) The name of a section. When used with pop, the stack is popped and section-name becomes the active data section name.
"section-class"
(Optional) Ignored, but included for compatibility with versions of Microsoft C++ earlier than version 2.0.
Remarks
A section in an object file is a named block of data that's loaded into memory as a unit. A data section is a section that contains initialized data. In this article, the terms segment and section have the same meaning.
The default section in the .obj file for initialized variables is .data. Variables that are uninitialized are considered to be initialized to zero and are stored in .bss.
The data_seg pragma directive tells the compiler to put all initialized data items from the translation unit into a data section named section-name. By default, the data section used for initialized data in an object file is named .data. Variables that are uninitialized are considered to be initialized to zero, and are stored in .bss. A data_seg pragma directive without a section-name parameter resets the data section name for the subsequent initialized data items to .data.
Data allocated using data_seg doesn't retain any information about its location.
For a list of names that shouldn't be used to create a section, see /SECTION.
You can also specify sections for const variables (const_seg), uninitialized data (bss_seg), and functions (code_seg).
You can use the DUMPBIN.EXE application to view object files. Versions of DUMPBIN for each supported target architecture are included with Visual Studio.
Example
// 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 .my_data1
int main() {
}