Sorry to occupy your precious time.
Recently,I have a project carrying out the program of FMM on DSP.But when I
use the CCS 2.20 to carry out the simple C code such as hello.c ,it can't
build.Compiling window demonstrate the following :
Error, Don't know how to build file "D:\ccs-test\examples\hello
world\main.c"
Compile Complete,
  1 Errors, 0 Warnings, 0 Remarks.
But when compiling and building the complicated program,it's strange to
pass. 
Why??