1 files changed, 36 insertions, 49 deletions

diff --git a/zen/com_error.h b/zen/com_error.h
index 0e0448a7..5eb7611d 100644
--- a/zen/com_error.h
+++ b/zen/com_error.h
@@ -4,31 +4,19 @@
 // * Copyright (C) Zenju (zenju AT gmx DOT de) - All Rights Reserved        *
 // **************************************************************************
 
-#ifndef COM_ERROR_HEADER
-#define COM_ERROR_HEADER
+#ifndef COM_ERROR_HEADER_88425703425254
+#define COM_ERROR_HEADER_88425703425254
 
-#include <string>
 #include <cstdio>
-#include "win.h" //includes "windows.h"
+#include "sys_error.h"
 
 namespace zen
 {
-std::wstring generateErrorMsg(const std::wstring& input, HRESULT hr);
-std::wstring formatWin32Msg(DWORD dwMessageId); //return empty string on error
-
-class ComError
-{
-public:
-    explicit ComError(const std::wstring& msg, HRESULT hr = S_OK) : msg_(hr == S_OK ? msg : generateErrorMsg(msg, hr)) {}
-    const std::wstring& toString() const { return msg_; }
-
-private:
-    std::wstring msg_;
-};
+std::wstring formatComError(const std::wstring& msg, HRESULT hr);
 
 //Convenience Macros checking for COM errors:
 
-#define ZEN_COM_CHECK(func) ZEN_COM_CHECK_IMPL(func, #func) //throw ComError
+#define ZEN_COM_CHECK(func) ZEN_COM_CHECK_IMPL(func, #func) //throw SysError
 /*
 Example: ZEN_COM_CHECK(backupComp->InitializeForBackup());
 
@@ -36,17 +24,17 @@ Equivalent to:
 {
     HRESULT hrInternal = backupComp->InitializeForBackup();
     if (FAILED(hrInternal))
-        throw ComError(L"Error calling \"backupComp->InitializeForBackup()\".", hrInternal);
+        throw SysError(formatComError(L"Error calling \"backupComp->InitializeForBackup()\".", hrInternal));
 }
 */
 
-#define ZEN_COM_ASSERT(obj) ZEN_COM_ASSERT_IMPL(obj, #obj) //throw ComError
+#define ZEN_COM_ASSERT(obj) ZEN_COM_ASSERT_IMPL(obj, #obj) //throw SysError
 /*
 Example: ZEN_COM_ASSERT(obj);
 
 Equivalent to:
     if (!obj)
-		throw ComError(L"Assertion failed: \"obj\".", E_FAIL);
+		throw SysError(formatComError(L"Assertion failed: \"obj\".", E_FAIL));
 */
 
 
@@ -54,32 +42,35 @@ Equivalent to:
 
 
 
-
-
-
-
-
-
-
 //################# implementation #####################
-std::wstring formatWin32Msg(DWORD dwMessageId) //return empty string on error
+namespace impl
+{
+inline
+std::wstring formatWin32Message(DWORD dwMessageId) //return empty string on error
 {
-    std::wstring output;
     LPWSTR buffer = nullptr;
     if (::FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM    |
                         FORMAT_MESSAGE_MAX_WIDTH_MASK |
                         FORMAT_MESSAGE_IGNORE_INSERTS | //important: without this flag ::FormatMessage() will fail if message contains placeholders
                         FORMAT_MESSAGE_ALLOCATE_BUFFER, nullptr, dwMessageId, 0, reinterpret_cast<LPWSTR>(&buffer), 0, nullptr) != 0)
-    {
         if (buffer) //just to be sure
         {
-            output = buffer;
-            ::LocalFree(buffer);
+            ZEN_ON_SCOPE_EXIT(::LocalFree(buffer));
+            return buffer;
         }
-    }
-    return output;
+    return std::wstring();
+}
+
+
+inline
+std::wstring numberToHexString(long number)
+{
+    wchar_t buffer[100] = {};
+    const int charsWritten = ::swprintf(buffer, 100, L"0x%08x", static_cast<int>(number));
+    return charsWritten > 0 ? std::wstring(buffer, charsWritten) : std::wstring();
 }
 
+
 namespace
 {
 std::wstring formatFacility(HRESULT hr)
@@ -199,28 +190,24 @@ std::wstring formatFacility(HRESULT hr)
     }
 }
 }
-
-inline
-std::wstring numberToHexString(long number)
-{
-    wchar_t result[100];
-    ::swprintf(result, 100, L"0x%08x", static_cast<int>(number));
-    return std::wstring(result);
 }
 
 
+std::wstring formatComError(const std::wstring& msg, long long hr); //not implemented! intentional overload ambiguity to catch usage errors with HRESULT!
+
+
 inline
-std::wstring generateErrorMsg(const std::wstring& input, HRESULT hr)
+std::wstring formatComError(const std::wstring& msg, HRESULT hr)
 {
-    std::wstring output(input);
+    std::wstring output(msg);
     output += L"\n";
 
     //don't use _com_error(hr).ErrorMessage(): internally this is nothing more than a call to ::FormatMessage()
-    std::wstring win32Msg = formatWin32Msg(hr);
+    std::wstring win32Msg = impl::formatWin32Message(hr);
     if (!win32Msg.empty())  //empty string on error
-        output += win32Msg + L"\n" + L"HRESULT: " + numberToHexString(hr);
+        output += win32Msg + L"\n" + L"HRESULT: " + impl::numberToHexString(hr);
     else
-        output += L"HRESULT: " + numberToHexString(hr) + L", " + L"Facility: " + formatFacility(hr);
+        output += L"HRESULT: " + impl::numberToHexString(hr) + L", " + L"Facility: " + impl::formatFacility(hr);
     //don't bluntly interpret as Win32 error code HRESULT_CODE(hr), too often misleading!
     //http://blogs.msdn.com/b/oldnewthing/archive/2006/11/03/942851.aspx
 
@@ -232,9 +219,9 @@ std::wstring generateErrorMsg(const std::wstring& input, HRESULT hr)
     {                                 \
         HRESULT hrInternal = func;    \
         if (FAILED(hrInternal))		  \
-            throw zen::ComError(std::wstring(L"Error calling \"") + L ## txt + L"\".", hrInternal); \
+            throw zen::SysError(formatComError(std::wstring(L"Error calling \"") + L ## txt + L"\".", hrInternal)); \
     }
 
-#define ZEN_COM_ASSERT_IMPL(obj, txt) if (!(obj)) throw zen::ComError(std::wstring(L"Assertion failed: \"") + L ## txt + L"\".", E_FAIL);
+#define ZEN_COM_ASSERT_IMPL(obj, txt) if (!(obj)) throw zen::SysError(formatComError(std::wstring(L"Assertion failed: \"") + L ## txt + L"\".", E_FAIL));
 }
-#endif //COM_ERROR_HEADER
+#endif //COM_ERROR_HEADER_88425703425254