Demonstrate a Static Initialization problem in Visual C++ 2015

example/DllLoader/DllLoader.cpp

@@ -9,7 +9,7 @@
 
 typedef int (*addNumberProc)(int, int);
 
-#define DLL_FILE TEXT("..\\SampleDLL\\SampleDLL.dll")
+#define DLL_FILE TEXT("..\\SampleDLL\\Debug\\SampleDLL.dll")
 
 void LoadFromFile(void)
 {
@@ -100,8 +100,12 @@ void LoadFromMemory(void)
 
 int main(int argc, char* argv[])
 {
- LoadFromFile();
+ // Oddly, doing this first seems to make the load from memory work
+ //OutputDebugString("Loading from File\n");
+ //--> LoadFromFile();
+
  printf("\n\n");
+ OutputDebugString("Loading from Memory\n");
  LoadFromMemory();
  return 0;
 }

example/SampleDLL/SampleDLL.cpp

@@ -1,9 +1,67 @@
 #include "SampleDLL.h"
+#include <windows.h>
+
+
+#include <string>
+#include <sstream>
+#include <unordered_map>
+using namespace std;
+
+
+// adding this class to track instantiations
+class FunnBall{
+public:
+ FunnBall(const char* ident)
+ : _ident(ident){
+ ostringstream msg;
+ msg << "Hi, I'm in the constructor for FB ident: " << _ident << endl;
+ OutputDebugString(msg.str().c_str());
+ }
+ const string& ident() const{return _ident}
+private:
+ string _ident;
+};
+
+// module static, this always seems to work.
+// they end up happening in the c++ runtime as part of DllMain
+static FunnBall fb1("This is the module static");
+
+// make a function that has static objects inside it
+static void havefun(){
+
+ // these guys are required to be initialized before first use by c++
+ // They fail to properly initialize with MemoryLoader
+ // Looking (with very rusty eyes) at the assembler, it appears that VC
+ // is trying to do this trick by writing a conditional so that it can test
+ // if it is the first-time through the function, and then doing the initialization
+ // only once. It works with LoadLibrary, but not MemoryLoader.
+ // the thing being examined (if you look at the assembler) is a location that
+ // is initialized with DD dup(?), which makes no immediate sense. So I'm guessing
+ // that something else in the load process is initializing this DWORD in the LoadLibrary
+ // case.
+ static FunnBall fb2("This is the static in the function");
+ static unordered_map<string, string> damap ={
+{"one", "wun"},
+{"two", "too"}
+ };
+
+ ostringstream msg;
+ msg << "idents in play: fb1=" << fb1.ident() << ", fb2=" << fb2.ident()
+ << ", map has " << damap.size() << endl;
+ OutputDebugString(msg.str().c_str());
+
+ if (damap.size() != 2){
+ OutputDebugString("============== FAIL ==============\n");
+ }
+}
+
 
 extern "C"{
 
 SAMPLEDLL_API int addNumbers(int a, int b)
 {
+ // force our test function to run.
+ havefun();
  return a + b;
 }