Q40376: Warning C4051 Generated by Clock Function in C

Article: Q40376
Product(s): See article
Version(s): 5.10   | 5.10
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | s_QuickC docerr | mspl13_c
Last Modified: 16-MAY-1989

The example on Page 167 of the "Microsoft C 5.1 Optimizing Compiler
Run-Time Library Reference" that shows how to use the run-time library
function clock produces a warning C4051 : data conversion. The warning
is generated because the variable tm is defined as an integer while
clock_t is defined as a long in the include file time.h.

As a result, warning C4051 is generated on the following line:

   if ((tm=clock()) != (clock_t)-1)

To eliminate this warning, declare variable tm as a long.

Also, if you want to see the elapsed time as real numbers, the
following line should be changed:

   printf("Processor time equals %d second\n", tm/CLK_TCK)

The line above should be changed to the following:

   printf("Processor time equals %fsecond\n",tm/(float)CLK_TCK)

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 1986-2002.