const_seg pragma

Specifies the section (segment) where const variables are stored in the object (.obj) file.

Syntax

#pragma const_seg( [ "section-name" [ , "section-class" ] ] )
#pragma const_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 const 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, the directive pops records off the internal stack until identifier is removed. If identifier isn't found on the internal stack, nothing is popped.

"section-name"
(Optional) The name of a section. When used with pop, the stack is popped and section-name becomes the active const 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 const section is a section that contains constant data. In this article, the terms segment and section have the same meaning.

The const_seg pragma directive tells the compiler to put all constant data items from the translation unit into a const section named section-name. The default section in the object file for const variables is .rdata. Some const variables, such as scalars, are automatically inlined into the code stream. Inlined code doesn't appear in .rdata. A const_seg pragma directive without a section-name parameter resets the section name for the subsequent const data items to .rdata.

If you define an object that requires dynamic initialization in a const_seg, the result is undefined behavior.

For a list of names that shouldn't be used to create a section, see /SECTION.

You can also specify sections for initialized data (data_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_const_seg.cpp
// compile with: /EHsc
#include <iostream>

const int i = 7;               // inlined, not stored in .rdata
const char sz1[]= "test1";     // stored in .rdata

#pragma const_seg(".my_data1")
const char sz2[]= "test2";     // stored in .my_data1

#pragma const_seg(push, stack1, ".my_data2")
const char sz3[]= "test3";     // stored in .my_data2

#pragma const_seg(pop, stack1) // pop stack1 from stack
const char sz4[]= "test4";     // stored in .my_data1

int main() {
    using namespace std;
   // const data must be referenced to be put in .obj
   cout << sz1 << endl;
   cout << sz2 << endl;
   cout << sz3 << endl;
   cout << sz4 << endl;
}

test1
test2
test3
test4

See also

Pragma directives and the __pragma and _Pragma keywords