Merge pull request #4438 from MugBergerFries/patch-6

Updated C6276

Author: LJSpiller

docs/code-quality/c6276.md

@@ -1,59 +1,50 @@
 ---
 description: "Learn more about: C6276"
 title: C6276
-ms.date: 11/04/2016
+ms.date: 09/28/2022
 ms.topic: reference
-f1_keywords: ["C6276"]
+f1_keywords: ["C6276", "CHAR_TO_WCHAR_CAST", "__WARNING_CHAR_TO_WCHAR_CAST"]
 helpviewer_keywords: ["C6276"]
 ms.assetid: 88f288da-da81-4d32-ab0f-be9d01a2606a
 ---
-# C6276
+# Warning C6276
 
-> warning C6276: Cast between semantically different string types: char* to wchar_t\*. Use of invalid string can lead to undefined behavior
+> Cast between semantically different string types. Use of invalid string can lead to undefined behavior.
 
-This warning indicates a potentially incorrect cast from an ANSI string (`char_t*`) to a UNICODE string (`wchar_t *`). Because UNICODE strings have a character size of 2 bytes, this cast might yield strings that are not correctly terminated. Using such strings with the wcs* library of functions could cause buffer overruns and access violations.
+This warning indicates a potentially incorrect cast from a narrow character string (`char*`) to a wide character string (`wchar_t*`).
 
-## Example
-
-The following code generates this warning:
+## Remarks
 
-```cpp
-#include <windows.h>
-VOID f()
-{
-   WCHAR szBuffer[8];
-   LPWSTR pSrc;
+Because the Microsoft compiler implements wide strings with a character size of 2 bytes, casting from a narrow string might produce strings that aren't correctly terminated. If you use such strings with the `wcs*` functions in the runtime library, they could cause buffer overruns and access violations.
+ 
+Code analysis name: CHAR_TO_WCHAR_CAST
 
-   pSrc = (LPWSTR)"a";
-   wcscpy(szBuffer, pSrc);
-}
-```
+## Example
 
-The following code corrects this warning by appending the letter L to represent the ASCII character as a wide character:
+The following code generates warning C6276. It's caused by an improper cast of the narrow string "a" (2 bytes, one for the 'a' and one for the null terminator) to a wide string (a 2-byte wide character 'a' with no null terminator):
 
 ```cpp
 #include <windows.h>
 
-VOID f()
+void f()
 {
-   WCHAR szBuffer[8];
-   LPWSTR pSrc;
-
-   pSrc = L"a";
-   wcscpy(szBuffer, pSrc);
+    WCHAR szBuffer[8];
+    LPWSTR pSrc;
+    pSrc = (LPWSTR)"a";
+    wcscpy_s(szBuffer, pSrc);
 }
 ```
 
-The following code uses the safe string manipulation function, `wcscpy_s`, to correct this warning:
+The following code corrects this warning. It removes the problem cast and adds an `L` prefix to the string to define it as a properly terminated wide character string:
 
 ```cpp
 #include <windows.h>
 
-VOID f()
+void f()
 {
-   WCHAR szBuffer[8];
-   LPWSTR pSrc;
-   pSrc = L"a";
-   wcscpy_s(szBuffer,8,pSrc);
+    WCHAR szBuffer[8];
+    LPWSTR pSrc;
+    pSrc = L"a";
+    wcscpy_s(szBuffer, pSrc);
 }
 ```