Codechange: [WIN32] Add a wrapper around GetProcAddress()

4 files changed, 61 insertions, 50 deletions

diff --git a/src/os/windows/crashlog_win.cpp b/src/os/windows/crashlog_win.cpp
index 1d3ed5193..5ce04e52e 100644
--- a/src/os/windows/crashlog_win.cpp
+++ b/src/os/windows/crashlog_win.cpp
@@ -368,22 +368,7 @@ static const uint MAX_FRAMES     = 64;
 
 char *CrashLogWindows::AppendDecodedStacktrace(char *buffer, const char *last) const
 {
-#define M(x) x "\0"
-	static const char dbg_import[] =
-		M("dbghelp.dll")
-		M("SymInitialize")
-		M("SymSetOptions")
-		M("SymCleanup")
-		M("StackWalk64")
-		M("SymFunctionTableAccess64")
-		M("SymGetModuleBase64")
-		M("SymGetModuleInfo64")
-		M("SymGetSymFromAddr64")
-		M("SymGetLineFromAddr64")
-		M("")
-		;
-#undef M
-
+	DllLoader dbghelp(L"dbghelp.dll");
 	struct ProcPtrs {
 		BOOL (WINAPI * pSymInitialize)(HANDLE, PCSTR, BOOL);
 		BOOL (WINAPI * pSymSetOptions)(DWORD);
@@ -394,12 +379,22 @@ char *CrashLogWindows::AppendDecodedStacktrace(char *buffer, const char *last) c
 		BOOL (WINAPI * pSymGetModuleInfo64)(HANDLE, DWORD64, PIMAGEHLP_MODULE64);
 		BOOL (WINAPI * pSymGetSymFromAddr64)(HANDLE, DWORD64, PDWORD64, PIMAGEHLP_SYMBOL64);
 		BOOL (WINAPI * pSymGetLineFromAddr64)(HANDLE, DWORD64, PDWORD, PIMAGEHLP_LINE64);
-	} proc;
+	} proc = {
+		dbghelp.GetProcAddress("SymInitialize"),
+		dbghelp.GetProcAddress("SymSetOptions"),
+		dbghelp.GetProcAddress("SymCleanup"),
+		dbghelp.GetProcAddress("StackWalk64"),
+		dbghelp.GetProcAddress("SymFunctionTableAccess64"),
+		dbghelp.GetProcAddress("SymGetModuleBase64"),
+		dbghelp.GetProcAddress("SymGetModuleInfo64"),
+		dbghelp.GetProcAddress("SymGetSymFromAddr64"),
+		dbghelp.GetProcAddress("SymGetLineFromAddr64"),
+	};
 
 	buffer += seprintf(buffer, last, "\nDecoded stack trace:\n");
 
 	/* Try to load the functions from the DLL, if that fails because of a too old dbghelp.dll, just skip it. */
-	if (LoadLibraryList((Function*)&proc, dbg_import)) {
+	if (dbghelp.Success()) {
 		/* Initialize symbol handler. */
 		HANDLE hCur = GetCurrentProcess();
 		proc.pSymInitialize(hCur, nullptr, TRUE);
@@ -486,14 +481,14 @@ char *CrashLogWindows::AppendDecodedStacktrace(char *buffer, const char *last) c
 /* virtual */ int CrashLogWindows::WriteCrashDump(char *filename, const char *filename_last) const
 {
 	int ret = 0;
-	HMODULE dbghelp = LoadLibrary(L"dbghelp.dll");
-	if (dbghelp != nullptr) {
+	DllLoader dbghelp(L"dbghelp.dll");
+	if (dbghelp.Success()) {
 		typedef BOOL (WINAPI *MiniDumpWriteDump_t)(HANDLE, DWORD, HANDLE,
 				MINIDUMP_TYPE,
 				CONST PMINIDUMP_EXCEPTION_INFORMATION,
 				CONST PMINIDUMP_USER_STREAM_INFORMATION,
 				CONST PMINIDUMP_CALLBACK_INFORMATION);
-		MiniDumpWriteDump_t funcMiniDumpWriteDump = (MiniDumpWriteDump_t)GetProcAddress(dbghelp, "MiniDumpWriteDump");
+		MiniDumpWriteDump_t funcMiniDumpWriteDump = dbghelp.GetProcAddress("MiniDumpWriteDump");
 		if (funcMiniDumpWriteDump != nullptr) {
 			seprintf(filename, filename_last, "%scrash.dmp", _personal_dir.c_str());
 			HANDLE file  = CreateFile(OTTD2FS(filename).c_str(), GENERIC_WRITE, 0, nullptr, CREATE_ALWAYS, 0, 0);
@@ -519,7 +514,6 @@ char *CrashLogWindows::AppendDecodedStacktrace(char *buffer, const char *last) c
 		} else {
 			ret = -1;
 		}
-		FreeLibrary(dbghelp);
 	}
 	return ret;
 }
diff --git a/src/os/windows/font_win32.cpp b/src/os/windows/font_win32.cpp
index 6c4e67deb..956e4a85c 100644
--- a/src/os/windows/font_win32.cpp
+++ b/src/os/windows/font_win32.cpp
@@ -620,8 +620,9 @@ void LoadWin32Font(FontSize fs)
 			if (AddFontResourceEx(fontPath, FR_PRIVATE, 0) != 0) {
 				/* Try a nice little undocumented function first for getting the internal font name.
 				 * Some documentation is found at: http://www.undocprint.org/winspool/getfontresourceinfo */
+				static DllLoader _gdi32(L"gdi32.dll");
 				typedef BOOL(WINAPI *PFNGETFONTRESOURCEINFO)(LPCTSTR, LPDWORD, LPVOID, DWORD);
-				static PFNGETFONTRESOURCEINFO GetFontResourceInfo = (PFNGETFONTRESOURCEINFO)GetProcAddress(GetModuleHandle(L"Gdi32"), "GetFontResourceInfoW");
+				static PFNGETFONTRESOURCEINFO GetFontResourceInfo = _gdi32.GetProcAddress("GetFontResourceInfoW");
 
 				if (GetFontResourceInfo != nullptr) {
 					/* Try to query an array of LOGFONTs that describe the file. */
diff --git a/src/os/windows/win32.cpp b/src/os/windows/win32.cpp
index 4478caa65..788021008 100644
--- a/src/os/windows/win32.cpp
+++ b/src/os/windows/win32.cpp
@@ -50,30 +50,6 @@ bool MyShowCursor(bool show, bool toggle)
 	return !show;
 }
 
-/**
- * Helper function needed by dynamically loading libraries
- */
-bool LoadLibraryList(Function proc[], const char *dll)
-{
-	while (*dll != '\0') {
-		HMODULE lib;
-		lib = LoadLibrary(OTTD2FS(dll).c_str());
-
-		if (lib == nullptr) return false;
-		for (;;) {
-			FARPROC p;
-
-			while (*dll++ != '\0') { /* Nothing */ }
-			if (*dll == '\0') break;
-			p = GetProcAddress(lib, dll);
-			if (p == nullptr) return false;
-			*proc++ = (Function)p;
-		}
-		dll++;
-	}
-	return true;
-}
-
 void ShowOSErrorBox(const char *buf, bool system)
 {
 	MyShowCursor(true);
@@ -679,7 +655,8 @@ int OTTDStringCompare(const char *s1, const char *s2)
 #endif
 
 	if (first_time) {
-		_CompareStringEx = (PFNCOMPARESTRINGEX)GetProcAddress(GetModuleHandle(L"Kernel32"), "CompareStringEx");
+		static DllLoader _kernel32(L"Kernel32.dll");
+		_CompareStringEx = _kernel32.GetProcAddress("CompareStringEx");
 		first_time = false;
 	}
 
diff --git a/src/os/windows/win32.h b/src/os/windows/win32.h
index bf88e312a..1d3127330 100644
--- a/src/os/windows/win32.h
+++ b/src/os/windows/win32.h
@@ -13,8 +13,47 @@
 #include <windows.h>
 bool MyShowCursor(bool show, bool toggle = false);
 
-typedef void (*Function)(int);
-bool LoadLibraryList(Function proc[], const char *dll);
+class DllLoader {
+public:
+	explicit DllLoader(LPCTSTR filename)
+	{
+		this->hmodule = ::LoadLibrary(filename);
+		if (this->hmodule == nullptr) this->success = false;
+	}
+
+
+	~DllLoader()
+	{
+		::FreeLibrary(this->hmodule);
+	}
+
+	bool Success() { return this->success; }
+
+	class ProcAddress {
+	public:
+		explicit ProcAddress(void *p) : p(p) {}
+
+		template <typename T, typename = std::enable_if_t<std::is_function_v<T>>>
+		operator T *() const
+		{
+			return reinterpret_cast<T *>(this->p);
+		}
+
+	private:
+		void *p;
+	};
+
+	ProcAddress GetProcAddress(const char *proc_name)
+	{
+		void *p = reinterpret_cast<void *>(::GetProcAddress(this->hmodule, proc_name));
+		if (p == nullptr) this->success = false;
+		return ProcAddress(p);
+	}
+
+private:
+	HMODULE hmodule = nullptr;
+	bool success = true;
+};
 
 char *convert_from_fs(const wchar_t *name, char *utf8_buf, size_t buflen);
 wchar_t *convert_to_fs(const char *name, wchar_t *utf16_buf, size_t buflen);