Compiler Warning (level 1) C4378
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Compiler Warning (level 1) C4378

Error Message

Must obtain function pointers to run initializers; consider System::ModuleHandle::ResolveMethodHandle

Under /clr, initializer symbols contain function tokens, not functions pointers. You need to convert tokens to pointers using ResolveMethodHandle.

Example

The following sample generates C4378.

// C4378.cpp
// compile with: /W1 /clr /c
typedef void (__cdecl *PF)(void);
int cxpf = 0;   // number of destructors to call
PF pfx[200];   // ptrs to those dtors, watch for overflow

int myexit (PF pf) {
   pfx[cxpf++] = pf;
   return 0;
}

struct A {
   A() {}
   ~A() {}
};

A aaaa; 

#pragma data_seg(".mine$a")
PF InitSegStart = (PF)1;
#pragma data_seg(".mine$z")
PF InitSegEnd = (PF)1;
#pragma data_seg()

void InitializeObjects () {
   PF *x = &InitSegStart;
   for (++x ; x < &InitSegEnd ; ++x)
      if (*x)
         (*x)();
}

#pragma init_seg(".mine$m",myexit)   // C4378
A bbbb;   // crash

int main () {
   InitializeObjects();
}

The following sample shows how to resolve C4378.

// C4378_b.cpp
// compile with: /clr
#pragma warning(disable:4378)
using namespace System;
typedef void (__cdecl *PF)(void);
typedef void (__clrcall * CLRPF)(void);

int cxpf = 0;  // number of destructors we need to call
PF pfx[200];   // ptrs to those dtors. Watch out for overflow!

ref class TypeClassHolder {
public:
   static TypeClassHolder ^typeClass = gcnew TypeClassHolder();
};

CLRPF FuncTokenToFuncPtr(PF tknFunc) {
   ModuleHandle type = 
      Type::GetTypeFromHandle(Type::GetTypeHandle(TypeClassHolder::typeClass))->Module->ModuleHandle;
   return (CLRPF)type.ResolveMethodHandle((int)(size_t)(tknFunc)).GetFunctionPointer().ToPointer();
}

int myexit (PF pf) {
   pfx[cxpf++] = pf;
   return 0;
}

struct A {
   A() {}
   ~A() {}
};

A aaaa; 

#pragma data_seg(".mine$a")
PF InitSegStart = (PF)1;
#pragma data_seg(".mine$z")
PF InitSegEnd = (PF)1;
#pragma data_seg()

void InitializeObjects () {
   PF *x = &InitSegStart;
   for (++x ; x < &InitSegEnd ; ++x)
      if(*x) {
         CLRPF realppfunc;
         realppfunc = FuncTokenToFuncPtr(*x);
         (realppfunc)();
      }
}

#pragma init_seg(".mine$m",myexit)
A bbbb; // constructor call succeeds

int main () {
   InitializeObjects();
}
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