从C传递数组到Fortran

pasuka

问题：
从C传递数组到Fortran，分别通过interface定义了subroutine和function的形式，前者未起作用，而后者却可以
编译器：gcc/gfortran 4.7&4.8
fortran代码：

[Fortran] 纯文本查看 复制代码

module dynamic
use,intrinsic::iso_c_binding
implicit none
interface
	! Method 1: pass array via subroutine
	subroutine dynamic_array(length,a,n)bind(c,name='dynamic_array')
	import
	implicit none
	integer(c_int),intent(in),value::length
	integer(c_int),intent(out)::n
	type(c_ptr),intent(out)::a
	end subroutine
	! Mehtod 2: pass array via funciton
	type(c_ptr) function dynamic_array2(length,n)bind(c,name='d_array')
	import
	implicit none
	integer(c_int),intent(in),value::length
	integer(c_int),intent(out)::n
	end function
end interface
end module
program test
use dynamic
implicit none
real,pointer::array(:)
type(c_ptr)::c_array
real(c_float),allocatable::array2(:)
integer::i,j
! Initialize pointer
nullify(array)
c_array=c_null_ptr

i=10
j=0
! Method 1
! not worked
call dynamic_array(i,c_array,j)

call c_f_pointer(c_array,array,[j])
write(*,'(A)')"Pass by subroutine"
write(*,'(A,i4)')"Len of array:",j
write(*,'(A)')"Array values:"
write(*,*)array
c_array=c_null_ptr
array=>null()

i = 10
j = 0
! Method2
! worked
c_array = dynamic_array2(i,j)
call c_f_pointer(c_array,array,[j])
write(*,'(A)')"Pass by function"
write(*,'(A,i4)')"Len of array:",j
write(*,'(A)')"Array values:"
write(*,*)array
c_array=c_null_ptr
array=>null()

end program 

C代码：

[C] 纯文本查看 复制代码

#include <stdlib.h>
#include <stdio.h>
/* float array printing function */ 
void print_float_array(float *array, int len) 
{ 
    int i;
    for(i=0; i<len; i++) 
        printf("%f | ", array[i]);
    putchar('\n');
}

void dynamic_array(int n1,float *a,int *n2)
{
	int i;
	// allocate array
	a = (float*)malloc(n1*2*sizeof(float));
	// set values of array
	for(i=0;i<n1*2;i++){a[i] = (float)i*i+1.0;}
	//print_float_array(a,n1*2);
	// set length of array
	*n2 = 20;
}

float* d_array(int n1,int *n2)
{
	int i;
	float *a;
	// allocate array
	a = (float*)malloc(n1*2*sizeof(float));
	// set value
	for(i=0;i<n1*2;i++){a[i] = (float)i*i+1.0;}
	//print_float_array(a,n1*2);
	// set len of array
	*n2 = 20;
	return a;
}

pasuka

chuxf 发表于 2014-3-13 00:43
我把 float *a 改成 float **a 以后就可以正常运行了。

因为平时用 Binding 模块少，不太清楚具体如何规定 ...

多谢达人
终于搞明白这个问题了