来自AC_CHECK_FUNCS的结果不一致(Inconsistent results from AC_CHECK_FUNCS)

 我遇到一个配置脚本验证是否存在某些基本功能的问题， 
 
AC_CHECK_FUNCS([floor gettimeofday memset pow sqrt sin exp])
 
 在某些标准下，结果是预期的（ checking for x... yes ）。 否则，声称未定义上述数学函数。 不同之处在于首先要验证一些lapack例程。 它们由AC_CHECK_LIB([lapack],[dsyev_],...检查。如果先不进行这些检查，则上述数学函数无法检查（最终编译工作）。 
 
 我已将配置脚本缩减为以下重新创建问题， 
 
AC_INIT([TEST], [0.0], [none@none.com])
#AC_CHECK_LIB([lapack],[dsyev_], , AC_MSG_FAILURE([Missing lapack]))
AC_CHECK_FUNCS([floor gettimeofday memset pow sqrt sin exp])
 
 取消注释第二行会产生适当的视觉效果。 我想，由于某种原因，不包括或检查数学库。 实际上， AC_CHECK_LIB([m],[exp])工作正常。 
 
 造成这种情况的原因是什么，使用该指令的正确方法是什么？ 我应该注意哪种x平台注意事项？ 

I am having a problem with a configure script verifying the presence of some basic functions, 
 
AC_CHECK_FUNCS([floor gettimeofday memset pow sqrt sin exp])
 
Under certain criteria, the results are expected (checking for x... yes). Otherwise the math functions above are claimed to be not defined. The difference is a call to verify some lapack routines first. These are checked by, AC_CHECK_LIB([lapack],[dsyev_],.... If these checks are not done first, then the above math functions fail to check (final compilation works).
 
I've reduced the configure script to the following that recreates the issue,
 
AC_INIT([TEST], [0.0], [none@none.com])
#AC_CHECK_LIB([lapack],[dsyev_], , AC_MSG_FAILURE([Missing lapack]))
AC_CHECK_FUNCS([floor gettimeofday memset pow sqrt sin exp])
 
Uncommenting the second line results in proper visual results. I imagine that the math library isn't included or checked for some reason. In fact, AC_CHECK_LIB([m],[exp]) works fine.
 
What's the cause of this, and what is the proper way to use this directive? What kind of x-platform considerations should I observe?

原文：https://stackoverflow.com/questions/4749615