错误：在C中，得到错误“解除引用指针为不完整类型”在结构指针中 [英] Error: In C, got the error "dereferencing pointer to incomplete type" in a struct pointer

问题描述

Hello Everybody！

我在尝试测试游戏Clever Frog的代码时遇到以下错误：
错误：解除引用指向不完整类型的指针

'完整代码'位于pastebin.com - 这里 （不会过期）。但我认为，有了下面的解释，任何人都可以理解。注意：我还没有实现将擦除分配的内存和其他东西的函数。

我在1.c文件中定义了一个结构：

  #include1.h
 ... 
 struct test {
 int a; 
}; 
 ... 
  

我有一个1.h wicth有typedef使用它：

  ... 
 typedef struct test testT; 
 ... 
  

然后我有一个函数，其中有一个参数取决于testT ，在2.c中：

  ... 
 void funcTest（testT ** t，int * size ，...）{
 / *另一个在上面创建mem.space/alocate基于内存的输入代码的函数* / 
 createMem（t，* size）; / * void createMem（testT ** t，int size）; * / 
 
 t [0]  - > a = 0; / *错误在这里* / 
 / * ...更多代码... * / 
} 
 ... 
  

2.h文件如下所示：

  ... 
 void funcTest（testT ** t，int * size，..）; 
 ... 
  

我会传递一个 testT * var 如下所示，在主程序中：

  ... 
 testT * varTest; int size; 
 
 funcTest（& varTest，& size）; 
 ... 
  

奇怪的是，当我使用结构测试在1.h文件（从1.c删除 struct test - 这是错误的）。但是，当运行已编译的程序时，错误发生的位置就是 t [0] - > a 的位置。

'一切'但没有任何工作:(我有信心，这是非常愚蠢的东西，所以如果有人知道的东西，请告诉我：D
谢谢！

当您尝试访问 t [0] 结构体的 a 成员时<解决方案编译器需要知道这个结构是怎么样的（例如，看看是否有任何 a 成员），因为你没有把<$ c $编译器在编译 2.c 时可以看到它的任何地方，你会得到一个错误。编译器不知道什么是 struct test 包含。

如果将 struct test 在 1.h 中，编译器会看到这个类型是怎么样的，并且可以使用这个struct成员。

只需放入完整的类型定义即可 1.h ，这就是它应该是的地方。

Hello Everybody!

I got the following error, while trying to test a code for the game Clever Frog: error: dereferencing pointer to incomplete type

The 'full code' is at pastebin.com - here (won't expire). But I think that with the explanation below, anybody can understands. Note: I haven't implemented yet the function that will erase the allocated memory and other things.

I have a struct defined in a 1.c file:

#include "1.h"
...
struct test {
   int a;
   };
...

I have a 1.h wicth have the typedef using it:

...
typedef struct test testT;
...

Then I have a function that has a parameter in it depending on testT, wich is in 2.c:

...
void funcTest(testT **t, int *size, ..){
   /* another function that creates mem.space/alocate memory based enter code here`on the need of size above */
   createMem(t,*size); /* void createMem(testT **t, int size); */

   t[0]->a = 0; /*ERROR HERE*/
   /* ... more code ... */
}
...

The 2.h file is like this:

...
void funcTest(testT **t, int *size, ..);
...

I will pass a testT *var as the way below, at the main programam:

...
testT *varTest; int size;

funcTest(&varTest, &size);
...

The bizarre thing is that the code compile when I use struct test at 1.h file (removing struct test from 1.c - which is wrong). But, when running the compiled program, exactly where the error occurs is the place of t[0]->a.

I already tried 'everything' but nothing worked :( I have faith that is something very stupid, so if anybody knows something, please tell me :D Thanks!

解决方案

When you try to access the a member of the t[0] struct the compiler needs to know how this struct looks like (for example to see if there even is any a member in it). Since you didn't put the struct test type definition anywhere where the compiler can see it when compiling 2.c, you get an error. The compiler doesn't know what a struct test contains.

If you put the definition of the struct test in 1.h, the compiler sees how that type looks like and can use the struct members.

Just put the complete type definition in 1.h, that's where it's supposed to be.

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