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Just installed Visual Studio and I'm at a roadblock trying to compile a C program. The help files are all about C++, so I'm not sure how to continue.
I have a hashTable.h and hashTable.c file, and then my main.c file.
When I try to compile, it says "undeclared" blah blah because it's not seeing the .h/.c files. How do I properly set up my project?
Create the Project:
File->New->Project
Select "General" and "Empty Project".
Change the Project Settings:
In the Solution Explorer, right-click your new project and click Properties.
Change the Configuration pull down to "All Configurations".
Go to C/C++ -> General.
Change to Warning Level 4, and Treat Warnings As Errors = Yes.
Go to C/C++ -> Advanded.
Change to "Compile As C".
Click Apply & OK.
Add existing files to the project:
In the Solution Explorer, right-click on the Header Files or Source Files folder under your project and click Add->Existing Item.
Choose your file and add it.
Add new files to the project:
In the Solution Explorer, right-click on the Header Files or Source Files folder under your project and click Add->New Item.
Choose "Header File (.h)" or "C++ File (.cpp)", give it a name (with a .h or .c extension) & click OK.
Sweet.Quote:
Originally Posted by cpjust
Now I'm at the compile step.
I can compile hashTable.c separately, by right clicking the file -> selecting compile. That's works ok.
But I can't compile main.c (or build the whole project). It gives errors because main.c is not recognizing hashTable.h or hashTable.c. It's acting like they're not even there.
Any ideas on what I'm doing wrong here?
Ahhh, this is ridiculous. I've been through every option in Visual Studio, why the heck doesn't this crap work.
Perhaps this is not correct?
#include <stdio.h>
#include <string.h>
#include "hashTable.c"
#include "hashTable.h"
But putting it in <> gives an error that the hashTable.c file doesn't exist.
Post the exact errors you're getting, and the code (or relevant parts if it's big).
One thing that might be part of the problem would be if you didn't install the Platform SDK.
You'll need it eventually, so even if it's not the problem, you might as well install it...
Oh, and one other thing that might be the cause - In the Project Properties, in C/C++ -> General, make sure you have the path to your .h files in the "Additional Include Directories" if they aren't in the same directory as the VC++ project.
Sure. It's pretty big though. Let me see if I can comment out a lot of crap and still get the relevant error to appear.Quote:
Originally Posted by cpjust
Don't #include .c files.Quote:
Originally Posted by Paul22000
Why not? Works fine in Unix?Quote:
Originally Posted by robwhit
It's not the way to do multi-file projects. Usually you compile each source file separately. That way, you can use a makefile or an IDE, so that you don't have to compile as much each time you recompile if you are fixing something in one file.
hashTable.h:
-----Code:#ifndef HASHTABLE_H
#define HASHTABLE_H
struct wordCount
{
char *word;
int count;
};
typedef struct wordCount HT_Element;
typedef struct wordCount *HT_Element_Ptr;
// Paul22000: Removed A LOT of comments for each method below for simplicity:
extern void HT_initialize(int n);
extern void HT_cleanup();
extern HT_Element_Ptr HT_lookup(char *s);
extern HT_Element_Ptr HT_install (char *word);
extern int HT_getNrOfSlots();
extern int HT_getNrOfElements();
extern HT_Element HT_getFirstElement();
extern HT_Element HT_getNextElement();
#endif
main.c:
(Literally commented everything out for this post, to show errors)
-----Code:#include <stdio.h>
#include <string.h>
#include "hashTable.c"
int main()
{
// commented everything out, still get errors
return 0;
}
The Errors:
Code:1>------ Build started: Project: Project2, Configuration: Debug Win32 ------
1>Linking...
1>countWords.obj : error LNK2005: _HT_initialize already defined in hashTable.obj
1>countWords.obj : error LNK2005: _HT_lookup already defined in hashTable.obj
1>countWords.obj : error LNK2005: _hash already defined in hashTable.obj
1>C:\Documents and Settings\Paul\My Documents\Visual Studio 2008\Projects\countWords\Debug\Project2.exe : fatal error LNK1169: one or more multiply defined symbols found
1>Build log was saved at "file://c:\Documents and Settings\Paul\My Documents\Visual Studio 2008\Projects\countWords\countWords\Debug\BuildLog.htm"
1>Project2 - 4 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
And here's hashTable.c, it doesn't really help, which is why I put it last in the post, so feel free to ignore this completely.
(Ignore all the crap going on in the functions, I'm in the middle of implementing them but having quit a lot of trouble)
Code:#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#ifndef HASHTABLE_H
#define HASHTABLE_H
#define HASHSIZE 50000
/* =================================
* Type Declarations:
*/
unsigned hash(char *s);
struct wordCount
{
char *word;
int count;
};
typedef struct wordCount HT_Element;
typedef struct wordCount *HT_Element_Ptr;
struct llistelem
{
HT_Element hte;
struct llistelem *next;
};
typedef struct llistelem LL_Element;
LL_Element *myhashtable;
/* ==============================================================
* Function Declarations:
*/
void HT_initialize(int n)
{
myhashtable = (LL_Element *)calloc(n, sizeof(LL_Element));
}
extern void HT_cleanup();
/////////////////////////////////////////////////////////////////////
// Ignore all this crap, I'm in the middle of implementing these functions, and have no idea how to do it
HT_Element_Ptr HT_lookup(char *s)
{
//np = &myhashtable[0];
//printf("test1: %s\n", np->hte.word);
LL_Element *np = (LL_Element *)calloc(1, sizeof(LL_Element));
int x = 0;
for (np = &myhashtable[hash(s)]; np != NULL; np = np->next)
{
printf("%s\n", np->hte.word);
x++;
}
//if (strcmp(s, np->hte.word) == 0)
//return NULL;//&np; /* found */
return NULL; /* not found */
}
extern HT_Element_Ptr HT_install (char *word);
extern int HT_getNrOfSlots();
extern int HT_getNrOfElements();
extern HT_Element HT_getFirstElement();
extern HT_Element HT_getNextElement();
unsigned hash(char *s)
{
unsigned hashval;
for (hashval = 0; *s != '\0'; s++)
hashval = *s + 31 * hashval;
return hashval % HASHSIZE;
}
#endif /* HASHTABLE_H */
How do you do this? Compiling each separately etcQuote:
Originally Posted by robwhit
Yeah, I was using a makefile when I was doing it in Putty/Unix.
Anywho, I posted my code. Mind taking a look at the errors and seeing what I'm doing wrong?
Funny, so far hours wasted at this, and I'm not even working on the project. :( Maybe it's just not worth it? Putty is a pain in the ass but at least it works :(
If you added it to the VC++ Project and it shows up in the "Source Files" folder, it will be compiled into a .obj file when you click the build button, then all those .obj files are linked together into a .exe. There's not much you need to do other than make sure it's included in the project.Quote:
Originally Posted by Paul22000
Remove this line and see if it compiles.Code:#include "hashTable.c"
Never #include source files - only header files.
hashTables.c will get compiled into hashTables.obj and main.c will compile into main.obj. It's the linkers job to combine those two .obj files together, which is why you don't #include source files.
Ok, I changed it from .c to .hQuote:
Originally Posted by cpjust
(I still don't understand why this works fine in Putty/Unix but not in Visual Studio)
Here's my main now:
And the errors changed, now it's undeclared identifiers again. This was happening before I commented out *everything* in my main.c, but for different variables.Code:#include <stdio.h>
#include <string.h>
#include "hashTable.h"
int main()
{
LL_Element head;
return 0;
}
What does it mean? Why is this happening??
Code:1>------ Build started: Project: Project2, Configuration: Debug Win32 ------
1>Compiling...
1>countWords.c
1>c:\documents and settings\paul\my documents\visual studio 2008\projects\countwords\countwords\countwords.c(65) : error C2065: 'LL_Element' : undeclared identifier
1>c:\documents and settings\paul\my documents\visual studio 2008\projects\countwords\countwords\countwords.c(65) : error C2146: syntax error : missing ';' before identifier 'head'
1>c:\documents and settings\paul\my documents\visual studio 2008\projects\countwords\countwords\countwords.c(65) : error C2065: 'head' : undeclared identifier
1>Build log was saved at "file://c:\Documents and Settings\Paul\My Documents\Visual Studio 2008\Projects\countWords\countWords\Debug\BuildLog.htm"
1>Project2 - 3 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
Did you #include "hashtable.h" in countwords.c?
Function prototypes are automatically extern. You don't need to put the extern there.
Yes, check out my code above. I still don't understand the "undeclared identifiers" though?Quote:
Originally Posted by robwhit
Aw, screw it
Nevermind
Thanks for the help guys but this project is due in 2 days. I really don't have time to be debugging something that already works fine when I use Putty, especially since they'll be testing it in Unix anyway. Again, thanks the help
Undeclared identifiers means you didn't tell the compiler yet what some variable or function was. You might have told it later, or in a different file, but not that the compiler could see yet.Quote:
Originally Posted by Paul22000
I couldn't find countwords.c anywhere in this thread. Maybe it's somewhere in your project and you forgot about it?
Oh, countWords.c is what I've been referring to "main.c" in this thread (for simplicity)Quote:
Originally Posted by robwhit
You appear to define LL_Element in hashTable.c. You need to do that in hashTable.h or it will not be visible outside of the hashTable.c file.
I think this was the problem, putting this in my hashTable.c:
#ifndef HASHTABLE_H
#define HASHTABLE_H
Oops?
I'm on campus right now so can't test it, but a buddy of mine did the same, ouch. Maybe there is hope for Visual Studio after all!
Except that link error was pretty useless, gave no hints as to the above problem...
Yeah, link errors are a big pain in the ass since they don't give you the line number of where the problem is the way compile errors do, but once you see enough of them, you'll start to understand the most likely causes for them.Quote:
Originally Posted by Paul22000
Yeah, the line number would have been VERY helpful...Quote:
Originally Posted by cpjust
Hate it when the errors are so simple like that, makes me want to pull my hair out!
Remember: Visual Studio is not at fault here; your other compiler/IDE is. Including other source files is a big no-no.
Now TWO files will have the same source - so there's bound to be more than one symbol with the same name which is not allowed.
As for your error... LL_Element must be declared/defined somewhere, right? Probably in that .c file. Declarations for structs and such should be in headers. And all source files that needs to use them includes that header. Simple.
You'll see that it should compile then.
I'm guessing the reason it compiled on UNIX is that he probably wasn't linking both hashTable.obj & main.obj in the makefile, so the multiple definition problem wouldn't have appeared.
Maybe Unix is more forgiving with these types of errors? If it finds a way to still compile and run, then it will just go ahead (even if it's not what you want to do)?Quote:
Originally Posted by cpjust
Can't tell unless you post the entire source and the makefile/build process.