title: How to regenerate configure file using autoconf?
body: <p>I use autoconf to regenerate the configure file, it works. But when I execute the generated configure file by <code>./configure</code>, there are some error messages like</p>
  
  <pre><code>./configure: line 3713: syntax error near unexpected token `blas'
  ./configure: line 3713: `  withval=$with_blas; R_ARG_USE(blas)'
  </code></pre>
  
  <p>I googled and found that <code>blas</code> is a library, but it still gives the error messages after installing. I have the autoconf with version "<code>autoconf (GNU Autoconf) 2.69</code>" installed on my Mac, and what I am trying to compile is the R source <code>https://svn.r-project.org/R/</code>.</p>
  
  <hr>
  
  <p>I have run both autoconf -f and autoreconf -f to try to regenerate configure file which has been generated successfully. But, when I run <code>./configure</code> the error happens again.</p>
  
  <p>The error messages say <code>syntax error near unexpected token blas</code> and <code>withval=$with_blas; R_ARG_USE(blas)</code>. I think the problem maybe the unknown function <code>R_ARG_USE</code>. I grep <code>R_ARG_USE</code> in the code base and find that it is defined in the file m4/R.m4:</p>
  
  <pre><code>AC_DEFUN([R_ARG_USE],
  [if test "${withval}" = no; then
    use_$1=no
  else
    use_$1=yes
  fi
  ])# R_ARG_USE
  </code></pre>
  
  <p>Does that mean when I am running autoconf or autoreconf I miss something to let it know the existence of m4/R.m4 ?</p>
  
  <p>I have been stuck here for almost three days, any helps will be appreciated. Thanks a lot.</p>