问题描述
我正在尝试使用“iso_c_binding”将一个字符串数组从 C 返回到 Fortran。该程序编译,但给出一个运行时错误。 我的 C 程序:
#include <stdio.h>
void ret_array(int * numStrings,char **arr2 ) {
int dim1=5;
char *arr1[5]={"name1","name2","name3","name4","name5"};
arr2 = &arr1;
printf("%s\n",arr2[0]);
printf("%s\n",arr2[1]);
printf("%s\n",arr2[2]);
printf("%s\n",arr2[3]);
printf("%s\n",arr2[4]);
numStrings = &dim1;
printf("%s","Ending interface :");
fflush(stdout);
}
我调用的 Fortran 程序
program main
implicit none
CHaraCTER(LEN = 255),dimension(:),allocatable:: str2
integer(kind = 4):: istr
call get_arr(istr,str2)
PRINT *,str2(1)
contains
subroutine get_arr(n,str1)
use iso_c_binding
implicit none
INTEGER(KIND = 4):: n
CHaraCTER(LEN = 255),ALLOCATABLE:: str1
character(kind = c_char),pointer:: fptr(:)
TYPE(C_PTR),DIMENSION(:),allocatable:: cptr
integer:: len1,ii
interface
subroutine ret_array(dim_len,str_arr1) bind(c)
use iso_c_binding
integer(c_int),INTENT(OUT):: dim_len
TYPE(C_PTR),DIMENSION(:,:),intent(out):: str_arr1
end subroutine
end interface
call ret_array(n,cptr)
PRINT *,"Number :",n
allocate(str1(n))
do ii = 1,n
call c_f_pointer(cptr(ii),fptr,[ 255 ])
len1 = index(fptr(ii),C_NULL_CHAR)
PRINT *,len1
str1(ii) = TRANSFER(fptr(1:len1-1),str1(ii))
end do
end subroutine
end program
当我运行它时,出现以下错误。
name1
name2
name3
name4
name5
Ending interface :
Program received signal SIGFPE: Floating-point exception - erroneous arithmetic operation.
Backtrace for this error:
#0 0x7f9e86776d01 in ???
#1 0x7f9e86775ed5 in ???
#2 0x7f9e865aa20f in ???
#3 0x7f9e869aa077 in ???
#4 0x55e9a5195350 in get_arr
at /home/test/fort_code/ret_arr.f90:27
#5 0x55e9a5195984 in MAIN__
at /home/test/fort_code/ret_arr.f90:6
#6 0x55e9a5195a37 in main
at /home/test/fort_code/ret_arr.f90:7
make: *** [Makefile:3: run] Floating point exception (core dumped)
我是在 iso_c_binding 中使用指针的新手。你能指出为什么指针没有被返回给 Fortran 程序吗? 预先感谢您的帮助
解决方法
您正在更改 arr2
以指向本地数组 arr1
,然后返回本地数组的地址。
那行不通。 arr1
在函数返回后无效。