Segmentation fault with GMP - c++

Question

I have a program that reads a matrix from a file and stores it in the variable basis_MP, which is an instance variable. Since the values read from the files are very big (don't fit in native datatypes), I use GMP for a higher precision. I print the values of the matrix where the file is stored and they are correct.
After reading the file, I also initialize some other auxiliary variables that also use GMP. I declared them as instance variables, because I don't want to allocate and free them on each call to other methods. As soon as the line of code that initializes the first of them is executed, I get a segmentation fault.
basis.h:
#ifndef BASIS_H
#define BASIS_H
#include <math.h>
#include <gmp.h>
using namespace std;
class Basis {
private:
int rank; //No. vectors in the basis (also called n)
int dimension; //Dimension of each vector in the basis (also called m)
mpz_t **basis_MP; //Matrix containing all the vectors in the basis
mpf_t aux_MP_f0;
mpf_t aux_MP_f1;
mpf_t aux_MP_f2;
public:
Basis(); //Empty constructor
Basis(char *filename); //Constructor from file
}
basis_MP is the variable where the matrix is sotred, while aux_MP_f0, aux_MP_f1, aux_MP_f2 are the 3 auxiliary variables. All of them use GMP for a higher precision. In the constructor Basis(char *filename) all of these variables are initialized and the matrix is read.
basis.cpp:
#include "basis.h"
Basis::Basis() // Empty constructor
{
}
Basis::Basis(char* filename) // Constructor from file
{
char delim[] = " \n[]";
ifstream stream;
stream.open(filename);
if(!stream) cerr << "File was not read" << endl;
stream.seekg (0, stream.end);
int length = stream.tellg();
stream.seekg (0, stream.beg);
char * buffer = new char [length];
char * number = new char [length];
std::cout << "Reading " << length << " characters... " << endl;
stream.read (buffer,length);
int count = 0;
for (int i = 0; i < length; i++){
if (buffer[i] == '\n') {
count++;
break;
}
if (buffer[i] == ' ') {
count++;
}
}
dimension = count;
rank = count;
basis_MP = (mpz_t**)malloc(rank*sizeof(mpz_t*));
for (int i = 0; i < rank; i++)
basis_MP[i] = (mpz_t*)malloc(dimension*sizeof(mpz_t));
number = strtok(buffer, delim);
for (int i = 0; i < rank; i++) {
for (int j = 0; j < dimension; j++) {
mpz_init_set_str(basis_MP[i][j], number, 10);
number = strtok(NULL, delim);
}
}
stream.close();
mpf_init2(aux_MP_f0, mpz_sizeinbase(basis_MP[0][0], 2));
mpf_init2(aux_MP_f1, mpz_sizeinbase(basis_MP[0][0], 2));
mpf_init2(aux_MP_f2, mpz_sizeinbase(basis_MP[0][0], 2));
delete buffer;
delete number;
}
The auxiliary variables are initialized with the precision of the first vector of the matrix. The segmentation fault occurs on this line: mpf_init2(aux_MP_f0, mpz_sizeinbase(basis_MP[0][0], 2));
main.cpp:
#include "basis.h"
int main (int argc, char **argv) {
Basis *b = new Basis(argv[1]);
}
The error I get is the following:
Program received signal SIGSEGV, Segmentation fault.
_int_malloc (av=0x7ffff7114760 <main_arena>, bytes=144) at malloc.c:3489
3489 malloc.c: No such file or directory.
Output of the backtrace from gdb:
(gdb) bt
#0 _int_malloc (av=0x7ffff7114760 <main_arena>, bytes=144) at malloc.c:3489
#1 0x00007ffff6dd92f0 in __GI___libc_malloc (bytes=144) at malloc.c:2891
#2 0x00007ffff7b71829 in __gmp_default_allocate () from /home/fcorreia/install/gmpxx/lib/libgmp.so.10
#3 0x00007ffff7b721db in __gmpf_init2 () from /home/fcorreia/install/gmpxx/lib/libgmp.so.10
#4 0x000000000040208f in Basis::Basis (this=0x607010, filename=0x7fffffffea8c "/home/project/dim10.txt") at src/basis.cpp:55
#5 0x000000000040517b in main (argc=2, argv=0x7fffffffe818) at src/main.cpp:4
I also tried replacing mpf_init2 by mpf_init and got the following error:
*** Error in `/home/project/a.out': malloc(): memory corruption: 0x0000000000608080 ***
Program received signal SIGABRT, Aborted.
0x00007ffff6d8ce37 in __GI_raise (sig=sig#entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
56 ../nptl/sysdeps/unix/sysv/linux/raise.c: No such file or directory.
And the corresponding backtrace:
(gdb) bt
#0 0x00007ffff6d8ce37 in __GI_raise (sig=sig#entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
#1 0x00007ffff6d8e528 in __GI_abort () at abort.c:89
#2 0x00007ffff6dceb04 in __libc_message (do_abort=1, fmt=fmt#entry=0x7ffff6ed7a80 "*** Error in `%s': %s: 0x%s ***\n") at ../sysdeps/posix/libc_fatal.c:175
#3 0x00007ffff6dd829b in malloc_printerr (ptr=0x608080, str=0x7ffff6ed3bda "malloc(): memory corruption", action=<optimized out>) at malloc.c:4996
#4 _int_malloc (av=0x7ffff7114760 <main_arena>, bytes=24) at malloc.c:3447
#5 0x00007ffff6dd92f0 in __GI___libc_malloc (bytes=24) at malloc.c:2891
#6 0x00007ffff7b71829 in __gmp_default_allocate () from /home/install/gmpxx/lib/libgmp.so.10
#7 0x00007ffff7b72190 in __gmpf_init () from /home/install/gmpxx/lib/libgmp.so.10
#8 0x00000000004020fc in Basis::Basis (this=0x608010, filename=0x7fffffffea8c "/home/project/dim10.txt") at src/basis.cpp:55
#9 0x0000000000405219 in main (argc=2, argv=0x7fffffffe818) at src/main.cpp:4
Somewhere the memory is being corrupted and I can't figure out where. Probably, I'm not using gmp correct. Does anyone have some hints?
Thanks