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Last Updated: 11/22/2016

warning C28741: Unannotated buffer in the function

This warning indicates that a buffer passed as a function parameter or returned by a function should be annotated with the Microsoft Source Code Annotation language (SAL). Static analysis tools can use such annotations to detect buffer overruns.

Currently, only non-constant string buffers are diagnosed with this warning. Ideally, all buffers passed as function parameters or returned by functions should be annotated. Arrays of wchar_t or char are candidates for this warning. Unsigned chars currently are not.


The code following example generates this warning.

  int foo( LPTSTR buffer, size_t cch );

The following code example avoids this warning by using the SAL annotation _Out_writes_ to specify that the called function writes to the buffer and that the buffer cannot be NULL. The annotation indicates that the buffer is of cch elements.

    int foo(_Out_writes_(cch) LPTSTR buffer, size_t cch );

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