const_seg
The latest version of this topic can be found at const_seg. Specifies the segment where const variables are stored in the .obj file.
Syntax
#pragma const_seg ( [ [ { push | pop}, ] [ identifier, ] ] [ "segment-name" [, "segment-class" ] )
Remarks
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 const
variables is .rdata. Some const
variables, such as scalars, are automatically inlined into the code stream. Inlined code will not appear in .rdata.
Defining an object requiring dynamic initialization in a const_seg
results in undefined behavior.
#pragma const_seg
with no parameters resets the segment to .rdata.
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.
Using 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.
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
Comments
See /SECTION for a list of names you should not use when creating a section.
You can also specify sections for initialized data (data_seg), uninitialized data (bss_seg), and functions (code_seg).