Problem defining structure

Printable View

09-08-2009
MTK

Problem defining structure

I am trying to compile a program but GCC shows an error in it. I looked around and the code looks perfectly valid to me. Can you tell what's wrong?

Code:

/* Linked List of Text Lines For Use with Text Editors */ #include <stdio.h> //For File I/O #include <stdlib.h> //For malloc(), etc. #include <string.h> //Array Manipulation Functions struct linked_line { // Linked Line Structure char* text = NULL; unsigned long alloc = 0; unsigned long len = 0; struct linked_line* prev = NULL; struct linked_line* next = NULL; }; typedef struct linked_line LINKED_LINE; #define LL_ALLOC_STEP 1024 //Line memory allocation step LINKED_LINE* ll_new(); //Create new blank line LINKED_LINE* ll_new(FILE* file); //Create new list of lines from file void ll_realloc(LINKED_LINE* ll, unsigned long num_chars); //Reallocate in steps void ll_squash(LINKED_LINE* ll); //Reallocate to just enough room unsigned long ll_get_line_num(LINKED_LINE* ll); //Get number of line unsigned long ll_get_line_count(LINKED_LINE* ll); //Get amount of lines void ll_ins_char(LINKED_LINE* ll, char c, unsigned long col; //Insert character void ll_ins_line(LINKED_LINE* ll); //Insert line void ll_ins_str(LINKED_LINE* ll, char* str, unsigned long col); //Insert string void ll_merge_lines(LINKED_LINE *ll); //Merge lines void ll_split_line(LINKED_LINE *ll, unsigned long col); //Split line

Error Message:

Code:

$ gcc editor2.c linked-line.c -lncurses In file included from editor2.c:2: linked-line.h:10: error: expected ‘:’, ‘,’, ‘;’, ‘}’ or ‘__attribute__’ before ‘=’ token editor2.c:4: error: expected declaration specifiers or ‘...’ before ‘wprint_ll’ In file included from linked-line.c:1: linked-line.h:10: error: expected ‘:’, ‘,’, ‘;’, ‘}’ or ‘__attribute__’ before ‘=’ token linked-line.c:4: error: expected ‘;’, ‘,’ or ‘)’ before ‘{’ token
09-08-2009
bithub

Code:

void ll_ins_char(LINKED_LINE* ll, char c, unsigned long col; //Insert character

Something's missing from this line :)

EDIT: Also noticed that the structure is trying to initialize its members which is a bit no-no.
09-08-2009
MTK

I corrected that, but still the same error.

Now it is even has pages and pages of stuff that looks like this, too:

Code:

linked-line.c:120: error: ‘LINKED_LINE’ has no member named ‘len’ linked-line.c:121: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:122: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:122: error: ‘LINKED_LINE’ has no member named ‘text’ linked-line.c:122: error: ‘LINKED_LINE’ has no member named ‘len’
09-08-2009
bithub

In that case, I would need to see some of the code in the .c file to see what is generating the error.

This compiles just fine on my machine (gcc 4.01):

Code:

#include <stdio.h> //For File I/O #include <stdlib.h> //For malloc(), etc. #include <string.h> //Array Manipulation Functions struct linked_line { // Linked Line Structure char* text; unsigned long alloc; unsigned long len; struct linked_line* prev; struct linked_line* next; }; typedef struct linked_line LINKED_LINE; #define LL_ALLOC_STEP 1024 //Line memory allocation step LINKED_LINE* ll_new(); //Create new blank line LINKED_LINE* ll_new(FILE* file); //Create new list of lines from file void ll_realloc(LINKED_LINE* ll, unsigned long num_chars); //Reallocate in steps void ll_squash(LINKED_LINE* ll); //Reallocate to just enough room unsigned long ll_get_line_num(LINKED_LINE* ll); //Get number of line unsigned long ll_get_line_count(LINKED_LINE* ll); //Get amount of lines void ll_ins_char(LINKED_LINE* ll, char c, unsigned long col); //Insert character void ll_ins_line(LINKED_LINE* ll); //Insert line void ll_ins_str(LINKED_LINE* ll, char* str, unsigned long col); //Insert string void ll_merge_lines(LINKED_LINE *ll); //Merge lines void ll_split_line(LINKED_LINE *ll, unsigned long col); //Split line int main(void) { LINKED_LINE line; line.text = NULL; line.alloc = 0; line.len = 0; line.prev = NULL; line.next = NULL; return 0; }
09-08-2009
MTK

Here are the three source files:
09-08-2009
bithub

Well, one problem is that the ll_new() function is overloaded. While this is perfectly valid C++, it is illegal in C.

Also, the ll_new() function is returning a reference to a local variable, so that will crash when the application is run.
09-08-2009
MTK

Quote:

Originally Posted by bithub

Well, one problem is that the ll_new() function is overloaded. While this is perfectly valid C++, it is illegal in C.

I named the one that takes a FILE ll_file().

Quote:

Originally Posted by bithub

Also, the ll_new() function is returning a reference to a local variable, so that will crash when the application is run.

I made it to create a pointer and return it, instead of creating a LINKED_LINE and returning its address.

But it still produces errors!

Code:

$ gcc editor2.c linked-line.c -lncurses editor2.c:4: error: expected declaration specifiers or ‘...’ before ‘LINKED_LINE’ editor2.c: In function ‘wprint_ll’: editor2.c:6: error: ‘LINKED_LINE’ undeclared (first use in this function) editor2.c:6: error: (Each undeclared identifier is reported only once editor2.c:6: error: for each function it appears in.) editor2.c:6: error: ‘temp’ undeclared (first use in this function) editor2.c:6: error: ‘ll’ undeclared (first use in this function) editor2.c:9: warning: passing argument 1 of ‘wprintw’ from incompatible pointer type /usr/include/ncurses.h:771: note: expected ‘struct WINDOW *’ but argument is of type ‘char *’ editor2.c: In function ‘main’: editor2.c:40: error: ‘LINKED_LINE’ undeclared (first use in this function) editor2.c:40: error: ‘line’ undeclared (first use in this function) editor2.c:51: error: ‘ll’ undeclared (first use in this function) editor2.c:55: error: invalid type argument of ‘->’ (have ‘long unsigned int’) editor2.c:63: error: ‘text’ undeclared (first use in this function) In file included from linked-line.c:1: linked-line.h:10: error: expected ‘:’, ‘,’, ‘;’, ‘}’ or ‘__attribute__’ before ‘=’ token linked-line.c: In function ‘ll_new’: linked-line.c:6: error: ‘LINKED_LINE’ has no member named ‘text’ linked-line.c:7: error: ‘LINKED_LINE’ has no member named ‘text’ linked-line.c:8: error: ‘LINKED_LINE’ has no member named ‘prev’ linked-line.c:9: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:10: error: ‘LINKED_LINE’ has no member named ‘alloc’ linked-line.c:11: error: ‘LINKED_LINE’ has no member named ‘len’ linked-line.c: In function ‘ll_file’: linked-line.c:21: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:22: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:24: error: ‘LINKED_LINE’ has no member named ‘len’ linked-line.c:25: error: ‘LINKED_LINE’ has no member named ‘len’ linked-line.c:28: error: ‘LINKED_LINE’ has no member named ‘prev’ linked-line.c:29: error: ‘LINKED_LINE’ has no member named ‘prev’ linked-line.c: In function ‘ll_realloc’: linked-line.c:38: error: ‘LINKED_LINE’ has no member named ‘alloc’ linked-line.c:39: error: ‘LINKED_LINE’ has no member named ‘text’ linked-line.c:39: error: ‘LINKED_LINE’ has no member named ‘text’ linked-line.c:40: error: ‘LINKED_LINE’ has no member named ‘alloc’ linked-line.c: In function ‘ll_squash’: linked-line.c:46: error: ‘LINKED_LINE’ has no member named ‘alloc’ linked-line.c:46: error: ‘LINKED_LINE’ has no member named ‘len’ linked-line.c:47: error: ‘LINKED_LINE’ has no member named ‘text’ linked-line.c:47: error: ‘LINKED_LINE’ has no member named ‘text’ linked-line.c:47: error: ‘LINKED_LINE’ has no member named ‘len’ linked-line.c: In function ‘ll_get_line_num’: linked-line.c:55: error: ‘LINKED_LINE’ has no member named ‘prev’ linked-line.c:56: error: ‘LINKED_LINE’ has no member named ‘prev’ linked-line.c: In function ‘ll_get_line_count’: linked-line.c:66: error: ‘LINKED_LINE’ has no member named ‘prev’ linked-line.c:67: error: ‘LINKED_LINE’ has no member named ‘prev’ linked-line.c:71: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:72: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c: In function ‘ll_ins_char’: linked-line.c:80: error: ‘LINKED_LINE’ has no member named ‘len’ linked-line.c:81: error: ‘LINKED_LINE’ has no member named ‘text’ linked-line.c:81: error: ‘LINKED_LINE’ has no member named ‘text’ linked-line.c:81: error: ‘LINKED_LINE’ has no member named ‘len’ linked-line.c:82: error: ‘LINKED_LINE’ has no member named ‘text’ linked-line.c:83: error: ‘LINKED_LINE’ has no member named ‘len’ linked-line.c: In function ‘ll_ins_line’: linked-line.c:88: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:89: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:90: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:92: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:93: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:94: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:95: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:96: error: ‘LINKED_LINE’ has no member named ‘prev’ linked-line.c:96: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c: In function ‘ll_ins_str’: linked-line.c:103: error: ‘LINKED_LINE’ has no member named ‘len’ linked-line.c:104: error: ‘LINKED_LINE’ has no member named ‘text’ linked-line.c:104: error: ‘LINKED_LINE’ has no member named ‘text’ linked-line.c:104: error: ‘LINKED_LINE’ has no member named ‘len’ linked-line.c:105: error: ‘LINKED_LINE’ has no member named ‘text’ linked-line.c:106: error: ‘LINKED_LINE’ has no member named ‘len’ linked-line.c: In function ‘ll_merge_lines’: linked-line.c:111: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:111: error: ‘LINKED_LINE’ has no member named ‘len’ linked-line.c:112: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:112: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:113: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:114: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c: In function ‘ll_split_line’: linked-line.c:120: error: ‘LINKED_LINE’ has no member named ‘len’ linked-line.c:121: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:122: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:122: error: ‘LINKED_LINE’ has no member named ‘text’ linked-line.c:122: error: ‘LINKED_LINE’ has no member named ‘len’ linked-line.c:123: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:124: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:124: error: ‘LINKED_LINE’ has no member named ‘next’ linked-line.c:125: error: ‘LINKED_LINE’ has no member named ‘text’ linked-line.c:126: error: ‘LINKED_LINE’ has no member named ‘len’
09-08-2009
bithub

Code:

int main() { // ... LINKED_LINE* line; unsigned long line = 0, col = 0;

In the above code, you have 2 variables declared right next to each other. Both variables are named line. Also, your editor.c file is not including linked-line.h.
09-08-2009
MTK

Quote:

Originally Posted by bithub

Code:

int main() { // ... LINKED_LINE* line; unsigned long line = 0, col = 0;

In the above code, you have 2 variables declared right next to each other. Both variables are named line. Also, your editor.c file is not including linked-line.h.

Didn't help.
09-08-2009
dwks

Well, keep posting your error messages. Did you fix this?

Quote:

Also, your editor.c file is not including linked-line.h.

You also have some invalid code here:

Code:

struct linked_line { // Linked Line Structure char* text = NULL; unsigned long alloc = 0; unsigned long len = 0; struct linked_line* prev = NULL; struct linked_line* next = NULL; };

You can't initialize members of structures like that; that's just a structure declaration, it doesn't create an instance of it at all.
09-08-2009
MTK

That fixed it. I didn't know that you can't initialize members of a struct like that.

Of course at the first character I typed I got a seg fault :mad:, but I will work on that.
09-08-2009
MTK

Now it's working.
09-08-2009
bithub

Quote:

That fixed it. I didn't know that you can't initialize members of a struct like that.

Could have saved you (and me) a lot of time if you had just read my first post in this thread...