Cache copy of library on first symbol/signature lookup (#1642)

Always perform signature searches on an unaltered copy of the binary. This avoids signature mismatches if the same function is detoured twice and thus the first bytes of the function were replaced by the detour.

core/logic/MemoryUtils.h

@@ -32,6 +32,8 @@
 
 #include "common_logic.h"
 #include <IMemoryUtils.h>
+#include <am-hashmap.h>
+#include <memory>
 #if defined PLATFORM_LINUX || defined PLATFORM_APPLE
 #include <sh_vector.h>
 #include "sm_symtable.h"
@@ -49,6 +51,7 @@ struct DynLibInfo
 {
 	void *baseAddress;
 	size_t memorySize;
+	std::unique_ptr<char[]> originalCopy;
 };
 
 #if defined PLATFORM_LINUX || defined PLATFORM_APPLE
@@ -73,7 +76,7 @@ public: // IMemoryUtils
 	void *FindPattern(const void *libPtr, const char *pattern, size_t len);
 	void *ResolveSymbol(void *handle, const char *symbol);
 public:
-	bool GetLibraryInfo(const void *libPtr, DynLibInfo &lib);
+	const DynLibInfo *GetLibraryInfo(const void *libPtr);
 #if defined PLATFORM_LINUX || defined PLATFORM_APPLE
 private:
 	CVector<LibSymbolTable *> m_SymTables;
@@ -83,6 +86,8 @@ private:
 	SInt32 m_OSXMinor;
 #endif
 #endif
+	typedef ke::HashMap<void *, DynLibInfo, ke::PointerPolicy<void> > LibraryInfoMap;
+	LibraryInfoMap m_InfoMap;
 };
 
 extern MemoryUtils g_MemUtils;