编译器警告(等级 1)C4378

必须获得函数指针才能运行初始值设定项;请考虑使用 System::ModuleHandle::ResolveMethodHandle

在 /clr 下,初始化表达式符号包含函数标记,而不是函数指针。 你需要使用 ResolveMethodHandle 将标记转换为指针。

示例

下面的示例生成 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();
}

以下示例演示如何解决 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();
}