c - 尝试实现一个从用户那里获取功能的通用链表

Question

这个程序的基本思想是实现一个通用的排序链表，它从用户那里获取函数(我有一个主文件，其中包含这两个文件但什么都不做)。编辑:问题是我的声明是在结构之前声明的。

我的标题:

#ifndef GADT_H
#define GADT_H
#include <stdio.h>
//typedef declaration
typedef void* ELM;
typedef void* SLN;
typedef void* HEAD;
typedef enum { success, outOfMem, badArgs, failure} RESULT;

HEAD SLCreate(ELM head_val, ELM(*create_elm)(), void(*cpy_elm)(ELM, ELM),
int(*cmp_elm)( ELM, ELM), void(*free_elm)(ELM),
void(*print_elm)( ELM), ELM(*add_elm_to_elm)(ELM, ELM));
void SLDestroy(HEAD head);
RESULT SLAddListElement(HEAD* head, ELM node);
RESULT SLRemoveElement(HEAD* head, ELM node);
SLN SLFindElement(HEAD head, ELM node);
void SLAddToElement(HEAD* head, ELM toEl, ELM addEl);
void SLPrintElements(HEAD head);
#endif

我的c文件:

#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
#include "gadt.h"
//static funcs:
static void sortLinkedList(HEAD* head); 
static void nodeDataSwap(Node* nodeOne, Node* nodeTwo);
typedef struct Node{
    ELM data;
    struct Node * next;
    //Functions associated with the struct.
    ELM(*create_elm)();
    void(*cpy_elm)(ELM, ELM);
    int(*cmp_elm)( ELM, ELM);
    void(*free_elm)(ELM);
    void(*print_elm)( ELM);
    ELM(*add_elm_to_elm)(ELM, ELM);
}Node;
/************************************************************************
* function name: SLCreate
* The input: a pointer to a value(void*), pointers to functions
  that are associated with the struct.
* The output: void*
* the operation: creates the a pointer to a new linked list
 and initializes its functions.
*************************************************************************/
extern HEAD SLCreate(ELM head_val, ELM(*create_elm)(), void(*cpy_elm)(ELM, ELM),
int(*cmp_elm)( ELM, ELM), void(*free_elm)(ELM),
void(*print_elm)( ELM), ELM(*add_elm_to_elm)(ELM, ELM)){
    HEAD head;
    Node* pToFirstNode=(Node*)malloc(sizeof(Node));
    if (pToFirstNode!=NULL){ //if the allocation hasn't failed
        pToFirstNode->data=(ELM)create_elm();
        cpy_elm(pToFirstNode->data, head_val);
        pToFirstNode->next=NULL;
        //initializing functions assosiated with Head.
        pToFirstNode->cpy_elm=cpy_elm;
        pToFirstNode->create_elm=create_elm;
        pToFirstNode->cmp_elm=cmp_elm;
        pToFirstNode->free_elm=free_elm;
        pToFirstNode->print_elm=print_elm;
        pToFirstNode->add_elm_to_elm=add_elm_to_elm;
        head=pToFirstNode; //so both of them point ot the same place
        return head;
    }
    return;
}
/************************************************************************
* function name: SLAddListElement
* The input: the head of the list and the node to be created
* The output: integer-RESULT (outOfMem, Succes)
* the operation:goes to the end of the linked list, allocates memory at the end
and copies node to it.
*************************************************************************/
extern RESULT SLAddListElement(HEAD* head, ELM node){
    Node* currNode=(Node*)(*head);
    Node* lastNode=(Node*)(*head);
    while(currNode->next!=NULL){
        lastNode=currNode;
        currNode=currNode->next;
    }
    currNode=(Node*)malloc(sizeof(Node));
    if(currNode==NULL){
        return outOfMem;
    }
    //inserting functions into currNode
    currNode->add_elm_to_elm=lastNode->add_elm_to_elm;
    currNode->cpy_elm=lastNode->cpy_elm;
    currNode->create_elm=lastNode->create_elm;
    currNode->free_elm=lastNode->free_elm;
    currNode->print_elm=lastNode->print_elm;
    currNode->cmp_elm=lastNode->cmp_elm;
    //inserting data into currNode
    currNode->cpy_elm(currNode->data,node);//calls the function from head.
    currNode->next=NULL;
    //sort the list
    sortLinkedList(head);

    return success;
}

extern void SLDestroy(HEAD head){
    Node* currNode=(Node*)head;
    Node* subsequentNode=(Node*)head; //next node after previous
    //need two pointers because after i free the first one 
    //i dont have access to the next node.
    while(currNode->next!=NULL){
        subsequentNode=subsequentNode->next;
        currNode->free_elm(currNode->data);
        free(currNode);
        currNode=subsequentNode;
    }
}
static void sortLinkedList(HEAD* head){
    Node* currNode=(Node*)(*head);
    while(currNode->next=NULL);
    if(currNode->cmp_elm(currNode->data,currNode->next->data) > 0){
        nodeDataSwap(currNode,currNode->next);
    }
}
static void nodeDataSwap(Node* nodeOne, Node* nodeTwo){
    void * temp;
    temp=nodeOne->data;
    nodeOne->data=nodeTwo->data;
    nodeTwo->data=temp;
}

extern void SLPrintElements(HEAD head){
    Node* nodePointer=(Node*)head;
    nodePointer->print_elm(nodePointer->data);
    while (nodePointer=NULL){
        printf("\n\t");
        nodePointer->print_elm(nodePointer->data);
    }
}

这些是我得到的错误:PICTURE

我觉得问题与我的结构定义有关，但我不确定，希望得到一些帮助

Answer 1

您的类型定义有问题。永远不要在 typedef 类型中隐藏指针!

typedef void* HEAD;  // DANGER!! DANGER!! DANGER!!

...

extern RESULT SLAddListElement(HEAD* head, ELM node){
    Node* currNode=(Node*)head;  // <= BOOM

HEAD* 表示 void ** 最后。您将 head 将他指向某物的指针转换为 Node* 这是指向结构的指针。这很可能是间接级别的不匹配。

即使您的文本编辑器中没有出现红色小东西，Visual Studio 的错误消息也应该包含一些文本和一些行信息。您应该始终在问题中包含错误消息，以便更好地进行分析。

编辑:缺少 header 也可能是一个问题:

#include "Gadf.h"  <== Probably you want gadt.h