未能将c代码链接到lapack：未定义的引用 [英] Failing to link c code to lapack: undefined reference

问题描述

我试图从C中使用lapack函数。

以下是一些测试代码，从这个问题

  #include  
 #include< stdio.h> 
 #include< time.h> 
 #includeclapack.h
 #includecblas.h
 
 void invertMatrix（float * a，unsigned int height）{
 int info，ipiv [高度]; 
 info = clapack_sgetrf（CblasColMajor，height，height，a，height，ipiv）; 
 info = clapack_sgetri（CblasColMajor，height，a，height，ipiv）; 
} 
 
 void displayMatrix（float * a，unsigned int height，unsigned int width）
 {
 int i，j;对于（j = 0; j <宽度; j ++）
 {
 printf（％1.3f），
为（i = 0; i } 
 printf（\\\
）; 
} 
 printf（\\\
）; 
 
 
 $ b int main（int argc，char * argv []）
 {
 int i; 
 float a [9]，b [9]，c [9]; 
 srand（time（NULL））; （i = 0; i <9; i ++）
 {
 a [i] = 1.0f * rand（）/ RAND_MAX; 
 b [i] = a [i]; 
} 
 displayMatrix（a，3，3）; 
返回0; 
} 
  

我使用gcc进行编译：

  gcc -o test test.c \ 
 -lblas -llapack -lf2c 
  

nb：我试过了各种命令库，我也尝试过其他库，如latlas，lcblas，lgfortran等。

错误信息是：
$ b $ pre $ /tmp//cc8JMnRT.o：函数`inverseMatrix'：
test.c :(。text + 0x94）：对`clapack_sgetrf'的未定义引用
test.c :(。text + 0xb4）：未定义对`clapack_sgetri'的引用
collect2：错误：ld返回1退出状态


找到并包含clapack.h（作为图集的一部分安装）。 clapack.h包含有问题的函数---所以不能找到它们？

符号实际上在库libalapack中（使用字符串）。但是，向gcc命令添加-lalapack似乎需要添加-lcblas（大量未定义的cblas_ *引用）。安装cblas会自动卸载地图集，这会删除clapack.h。

所以，这种感觉就像某种依赖性地狱。

我使用的是FreeBSD 10 amd64，所有相关的库似乎都已安装，并且路径正确。

任何帮助都非常感谢。

谢谢 $ b Ivan

解决方案

我卸载了所有与远程相关的东西--- blas，cblas，lapack，atlas等---然后单独重新安装atlas（从端口），然后是lapack和blas包。

这一次，/ usr / local / lib包含一个新的lib文件：libcblas.so ---之前的随机安装必须已经删除它。

现在编译的gcc代码如下：

  gcc -o test test.c \ 
 -llapack -lblas -lalapack -lcblas 
  

更改-l参数的顺序似乎没有任何区别。 p>

I am trying to use lapack functions from C.

Here is some test code, copied from this question

#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include "clapack.h"
#include "cblas.h"

void invertMatrix(float *a, unsigned int height){
  int info, ipiv[height];
  info = clapack_sgetrf(CblasColMajor, height, height, a, height, ipiv);
  info = clapack_sgetri(CblasColMajor, height, a, height, ipiv);
}

void displayMatrix(float *a, unsigned int height, unsigned int width)
{
  int i, j;
  for(i = 0; i < height; i++){
    for(j = 0; j < width; j++)
      {
        printf("%1.3f ", a[height*j + i]);
      }
    printf("\n");
  }
  printf("\n");
}


int main(int argc, char *argv[])
{
  int i;
  float a[9], b[9], c[9];
  srand(time(NULL));
  for(i = 0; i < 9; i++)
    {
      a[i] = 1.0f*rand()/RAND_MAX;
      b[i] = a[i];
    }
  displayMatrix(a, 3, 3);
  return 0;
}

I compile this with gcc:

gcc -o test test.c  \
    -lblas -llapack -lf2c

n.b.: I've tried those libraries in various orders, I've also tried others libs like latlas, lcblas, lgfortran, etc.

The error message is:

/tmp//cc8JMnRT.o: In function `invertMatrix':
test.c:(.text+0x94): undefined reference to `clapack_sgetrf'
test.c:(.text+0xb4): undefined reference to `clapack_sgetri'
collect2: error: ld returned 1 exit status

clapack.h is found and included (installed as part of atlas). clapack.h includes the offending functions --- so how can they not be found?

The symbols are actually in the library libalapack (found using strings). However, adding -lalapack to the gcc command seems to require adding -lcblas (lots of undefined cblas_* references). Installing cblas automatically uninstalls atlas, which removes clapack.h.

So, this feels like some kind of dependency hell.

I am on FreeBSD 10 amd64, all the relevant libraries seem to be installed and on the right paths.

Any help much appreciated.

Thanks

Ivan

解决方案

I uninstalled everything remotely relevant --- blas, cblas, lapack, atlas, etc. --- then reinstalled atlas (from ports) alone, and then the lapack and blas packages.

This time around, /usr/local/lib contained a new lib file: libcblas.so --- previous random installations must have deleted it.

The gcc line that compiles is now:

gcc -o test test.c  \
-llapack -lblas -lalapack -lcblas

Changing the order of the -l arguments doesn't seem to make any difference.

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