| description | title | ms.date | f1_keywords | helpviewer_keywords | ms.assetid | ||
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Learn more about: Compiler Warning (level 3) C4398 |
Compiler Warning (level 3) C4398 |
11/04/2016 |
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b6221432-9fed-4272-a547-a73f587904e6 |
'variable' : per-process global object might not work correctly with multiple appdomains; consider using __declspec(appdomain)
A virtual function with __clrcall calling convention in a native type causes the creation of a per application domain vtable. Such a variable may not correct correctly when used in multiple application domains.
You can resolve this warning by explicitly marking the variable __declspec(appdomain). In versions of Visual Studio before Visual Studio 2017, you can resolve this warning by compiling with /clr:pure, which makes global variables per appdomain by default. The /clr:pure compiler option is deprecated in Visual Studio 2015 and unsupported in Visual Studio 2017.
For more information, see appdomain and Application Domains and Visual C++.
The following sample generates C4398.
// C4398.cpp
// compile with: /clr /W3 /c
struct S {
virtual void f( System::String ^ ); // String^ parameter makes function __clrcall
};
S glob_s; // C4398
__declspec(appdomain) S glob_s2; // OK