Compiler Warning (level 1) C4794
Collapse the table of content
Expand the table of content
The document is archived and information here might be outdated

Compiler Warning (level 1) C4794

Error Message

segment of thread local storage variable 'variable' changed from 'section name' to '.tls$'

You used #pragma data_seg to put a tls variable in a section not starting with .tls$.

The .tls$x section will exist in the object file where __declspec(thread) variables are defined. A .tls section in the EXE or DLL will result from these sections.


The following sample generates C4794:

// C4794.cpp
// compile with: /W1 /c
#pragma data_seg(".someseg")
__declspec(thread) int i;   // C4794

// OK
#pragma data_seg(".tls$9")
__declspec(thread) int j;
© 2016 Microsoft