Question

从未见过这个Seg错误，帮助你可以帮助我。在GDB中我得到了这个：

Program received signal SIGSEGV, Segmentation fault.
#0  0x0000000000401c08 in InvLib::pinv_jazz (
    this=<error reading variable: Cannot access memory at address 0x7fffff766188>, 
    r=<error reading variable: Cannot access memory at address 0x7fffff766184>, 
    co=<error reading variable: Cannot access memory at address 0x7fffff766180>, 
    A=<error reading variable: Cannot access memory at address 0x7fffff766178>,  
    Ai=<error reading variable: Cannot access memory at address 0x7fffff766170>)  
    at ../eigen/../inc/InvLib.h:288  
288       void pinv_jazz(const int r, const int co, double *A, double *Ai)  {
#1  0x00000000004022de in init_Ai (this=<optimized out>) at ../eigen/../inc/InvLib.h:624
#2  InvLib::test_col_updating () at ../eigen/../inc/InvLib.h:918   
#3  0x000000000040fb2a in InvLib::test_lib () at ../eigen/../inc/InvLib.h:1140  
#4  0x0000000000400c88 in main (argc=1, argv=0x7fffffffe758) at til.cc:6

据我所知，InvLib :: pinv_jazz所取的所有值都是无效的，这很奇怪。请让我首先提供init_Ai和pinv_jazz的定义：

class InvLib {
      ...

// initialize Ai to be pinv(A) using SVD   
inline __attribute__((always_inline))   
  void init_Ai()  {   
  printf ("%p\n", this);   
  printf ("%d %d\n", m_r, m_co);  
  printf ("%p %p\n", m_A, m_Ai); 
  pinv_jazz(m_r, m_co, m_A, m_Ai); 
}  

// compute SVD-inv on a mat_t matrix  
void pinv_jazz(const int r, const int co, double *A, double *Ai)  {   
  static CoeffMat eA, eAi;  
  static int i, j;     
  static double *A_, *Ai_;  
  assert(r <= MAXSIZE); 
  assert(co <= MAXSIZE); 

  printf ("my %p %p\n", A, Ai);    

  eA.resize(r, co);    
  A_ = A;  
  for (i = 0; i < r; i++)      {   
      for (j = 0; j < co; j++)      {    
          eA(i, j) = Complex(*A_, *(A_+1));   
          A_ += 2;     
        }  
    }  
  //eAi = eigen_pinv(&eA);    

  {   
    Eigen::JacobiSVD<CoeffMat> svdx(eA,   Eigen::ComputeThinU      
                                        | Eigen::ComputeThinV); 
    Eigen::MatrixXf Ss;      
    int n = svdx.singularValues().asDiagonal().rows();  
    printf ("%d\n", n);               
    Ss.resize(n, 1);      
    int i;  
    for (i = 0; i < n; i++)      {             
      Ss(i) = svdx.singularValues()(i);  
    } 
    CoeffMat S;     
    S.resize(n, 1);    
    for (i = 0; i < n; ++i)       {    
      if ( Ss(i) > TOLE_PINV )   
        { S(i)=1.0/Ss(i); }     
      else   
        { S(i)=0; }      
    } 
    eAi = svdx.matrixV() * S.asDiagonal() * svdx.matrixU().adjoint();   
  }
} 

} //InvLib

首先我不明白为什么pinv_jazz在GDB的输出中被编写为InvLib :: pinv_jazz而init_Ai被写为init_Ai？它们都是非静态函数！

其次，GDB抱怨它无法访问0x7fffff766188等内存，但是在init_Ai中，在调用pinv_jazz之前，我打印了要放入pinv_jazz的m_A和m_Ai的值，并且它们不是由GDB抱怨的0x7fffff766178或0x7fffff766170 。我想知道GDB在哪里获得地址0x7fffff766178和0x7fffff766170？

第三个奇怪的是，如果我删除了这条线 eAi = svdx.matrixV（）* S.asDiagonal（）* svdx.matrixU（）。adjoint（）; 然后它运行顺利，没有错误。但我无法弄清楚为什么这条线会导致上述错误。

使用GCC 4.6.3和-O0编译代码。请帮帮我!!

基于特征的伪逆Lib的奇怪段错误

0 个答案: