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C51: STDDEF.H CREATES WARNING


Information in this knowledgebase article applies to:

  • C51 Compiler Version 8.17

SYMPTOM

When compiling an application using the C51 Compiler Version 8.17 the following warning is created by the file stddef.h.

compiling main.c...
C:\KEIL\C51\INC\STDDEF.H(21): warning C322: unknown identifier

CAUSE

The check for a preprocessor symbol __CX2__ has been incorrectly implemented. It should be #ifdef __CX2__ instead of just #if __CX2__.

RESOLUTION

Download the attached version of the STDDEF.H file and copy it to the folder C:\KEIL\C51\INC.

STATUS

The problem only occurs in C51 Version 8.17. It does not occur in any other version of the toolchain.

ATTACHED FILES

Request the files attached to this knowledgebase article.

Last Reviewed: Friday, January 16, 2009


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