"struct has no member named" error with gcc on dev machine - gcc

#include <stdio.h>
#include <stdlib.h>
#include "ReadMethods.h"
int main(int argc,char * argv[])
{
DPDA WordChecker;
DPDA * WordCheckerPointer=&WordChecker;
WordChecker.DPDAFilename=(char*)malloc(25*sizeof(char));
WordChecker.DPDAInputFilename=(char*)malloc(25*sizeof(char));
WordChecker.DPDAOutputFilename=(char*)malloc(25*sizeof(char));
strcpy( WordChecker.DPDAFilename,argv[1]);
strcpy( WordChecker.DPDAInputFilename,argv[2]);
strcpy( WordChecker.DPDAOutputFilename,argv[3]);
readDPDA(argv[1],WordCheckerPointer);
readInputLines(argv[2],WordCheckerPointer,argv[3]);
return 0;
}
This is my code that gives error from mallocs until last strcpy() ,total 6 lines.The error is "DPDA has no member named DPDAFilename" and same for other fields for every malloc and strcpy linesthat i work on.Here is the part of header file.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct tagRule{
char *startingState;
char symbolToPop;
char expectedInput;
char *endingState;
char symbolToPush;
}Rule;
typedef struct tagStackDPDA{
char * arrayOfSymbols;
int stackElementCount;
char * currentState;
}stackDPDA;
typedef struct tagDPDA{
char * alphabet;
char * stackSymbols;
char ** states;
char *startingState;
char **finalStates;
int finalStatesAmount;
Rule * ruleList;
stackDPDA stackOfDPDA;
int sizeArray[4];//This array holds amount values of states,alphabet symbols,stack symbols and transition rules
char *DPDAFilename;
char *DPDAInputFilename;
char *DPDAOutputFilename;
}DPDA;
The code works fine in codeblocks environment but in gcc (-Wall -ansi).Those filenames come from input text files yet i am not sure it can cause this error.
Edit:By the way I am using this command line to compile;
gcc -Wall -ansi main.c ReadMethods.h -o WordChecker

May be if you compile in C mode, you have to use C-style comments in header?
/**/ instead of //

Related

#including <alsa/asoundlib.h> and <sys/time.h> results in multiple definition conflict

Here is the minimal C program to reproduce:
#include <alsa/asoundlib.h>
#include <sys/time.h>
int main( void )
{
}
This will compile with gcc -c -o timealsa.o timealsa.c, but if you include the -std=c99 switch, you get a redefinition error:
In file included from /usr/include/sys/time.h:28:0,
from timealsa.c:3:
/usr/include/bits/time.h:30:8: error: redefinition of ‘struct timeval’
struct timeval
^
In file included from /usr/include/alsa/asoundlib.h:49:0,
from timealsa.c:2:
/usr/include/alsa/global.h:138:8: note: originally defined here
struct timeval {
^
How can I resolve this conflict while still using -std=c99?
Since your question suggests you are using GLIBC's time.h there is a way to avoid this by telling it not to define timeval. Include asoundlib.h first then define _STRUCT_TIMEVAL. The one defined in asoundlib.h will be the one that gets used.
#include <alsa/asoundlib.h>
#ifndef _STRUCT_TIMEVAL
# define _STRUCT_TIMEVAL
#endif
#include <sys/time.h>
int main( void )
{
}
With C99 and later you can't have duplicate definitions of the same struct. The problem is that alsa/asoundlib.h includes alsa/global.h which contains this code:
/* for timeval and timespec */
#include <time.h>
...
#ifdef __GLIBC__
#if !defined(_POSIX_C_SOURCE) && !defined(_POSIX_SOURCE)
struct timeval {
time_t tv_sec; /* seconds */
long tv_usec; /* microseconds */
};
struct timespec {
time_t tv_sec; /* seconds */
long tv_nsec; /* nanoseconds */
};
#endif
#endif
So the Michael Petch's solution won't work - by the time you've included alsa/asoundlib.h it is already too late. The proper solution is to define _POSIX_C_SOURCE (_POSIX_SOURCE is obsolete). There's more information about these macros here and here.
For example you could try -D_POSIX_C_SOURCE=200809L. However, if you do that you'll get errors like this:
/usr/include/arm-linux-gnueabihf/sys/time.h:110:20: error: field ‘it_interval’ has incomplete type
struct timeval it_interval;
^
/usr/include/arm-linux-gnueabihf/sys/time.h:112:20: error: field ‘it_value’ has incomplete type
struct timeval it_value;
^
/usr/include/arm-linux-gnueabihf/sys/time.h:138:61: error: array type has incomplete element type
extern int utimes (const char *__file, const struct timeval __tvp[2])
^
This is all a big mess of old C code and macro madness. The only way I got it to work was to give up and use -std=gnu11.

char * variable declaration

I just want to verify I got this right.
The copy from sr to ds2 gives an error. Is this because ds2 is considered "const"??
Thanks and hope this isn't a bore.
#include <stdio.h>
#include <string.h>
#include <malloc.h>
int main(void)
{
char *sr = "Hello World";
char *ds1 = (char*)malloc(100 * sizeof(char));
char *ds2 = "12345678901234567890";
// This statement works just fine
printf("%s\n", strcpy(ds1, sr));
// This gives error
strcpy(ds2, sr);
printf("%s\n", ds2);
return 0;
}
Here is a similar post
difference between char* and char[] with strcpy()
When you do this
char *ds2 = "12345678901234567890";
the compiler leaves the pointer pointing to a non-writable memory region.
With this line
// This gives error
strcpy(ds2, sr);
You are trying to do an strcpy into the non-writable memory.
You should also have a free for each malloc as you are allocating memory but not de-allocating it.

insmod module param : invalid parameters

I'm developping sample kernel module driver.ko. I want to specify the block size of data_node structure with module parameter BlockSize. when I run insmod driver.ko alone, it works, but when I specify BlockSize insmod driver.ko BlockSize = 10 I get this eror :
Error: could not insert module driver.ko: Invalid parameters
modinfo -p ./driver.ko command give me this :
BlockSize: size of buffer (int)
driver.c
#include <linux/init.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/cdev.h>
#include <linux/kdev_t.h>
#include <linux/fs.h>
#include <asm/uaccess.h>
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/slab.h>
/* parametter */
static int BlockNumber = 8;
static int BlockSize = 512;
module_param( variable name, type, permission); */
module_param(BlockSize, int, S_IRUGO);
MODULE_PARM_DESC(BlockSize , " size of buffer");
/* using 'k' as magic number */
#define SAMPLE_IOC_MAGIC 'k'
#define SAMPLE_IOCRESET _IOWR(SAMPLE_IOC_MAGIC, 0, int)
#define SAMPLE_IOC_MAXNR 0
struct cdev* my_cdev;
dev_t dev;
static int size_to_read;
/* Macro used to compute the minimum */
#define MIN(a,b) (((a) < (b)) ? (a) : (b))
/* data buffer structure */
typedef struct dnode
{
int bufSize;
char *buffer;
struct dnode *next;
} data_node;
/* liste stucture */
typedef struct lnode
{
data_node *head;
data_node *cur_write_node;
data_node *cur_read_node;
int cur_read_offset;
int cur_write_offset;
}liste;
code ..........................
..
It appears that module parameters should be passed without a space between the name and value, ie you should use:
insmod driver.ko BlockSize=10
This makes some sense, as in the command line to insmod itself "BlockSize=10" is a single entry in *argv[] which can be handed off to the kernel as a chunk, while "BlockSize = 10" would be three distinct entries ("BlockSize", "=", "10") which someone would have to write code to re-join.

Xcode, Instruments, Allocations, Command Line App, not registering free()

I have a very simple Command Line Tool in Xcode:
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
int main(int argc, const char * argv[])
{
void *p = calloc(32, 1);
assert(p);
free(p);
return 0;
}
When I run Instruments->Allocations it shows one living block. The free seems to be ignored.
In the olden days, I remember that you could actually still use the last free'ed block. So I tried this:
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
int main(int argc, const char * argv[])
{
void *p = calloc(32, 1);
assert(p);
free(p);
void *q = calloc(32, 1);
assert(q);
free(q);
return 0;
}
Now, Instruments->Allocations shows no living blocks. This seems correct.
Can anyone explain or reproduce the problem I am seeing in the first program?
I'm using Xcode 4.1.1
Thanks.
Let me rephrase the comments above.
Apple LLVM in Xcode 5 resolved the alloc / free behavior so that no blocks allocated now, thus the free() method runs as expected.

Can't Build a simple Cuda Program using Xcode !

I'm using Xcode 3.2 on Mac OS 10.6 to build a very simple HelloWorld program for CUDA
but it fails to build .. any ideas !!!
this is the code :
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <CUDA/CUDA.h>
__device__ char napis_device[14];
__global__ void helloWorldOnDevice(void){
napis_device[0]='H';
napis_device[1]='e';
napis_device[2]='l';
napis_device[3]='l';
napis_device[4]='o';
napis_device[5]=' ';
napis_device[6]='W';
napis_device[7]='o';
napis_device[8]='r';
napis_device[9]='l';
napis_device[10]='d';
napis_device[11]='\n';
}
int main (int argc, char * const argv[]) {
helloWorldOnDevice<<<1,1>>> ();
cudaThreadSynchronize();
char napis_host[14];
const char *symbol="napis device";
cudaMemcpyFromSymbol (napis_host, symbol, sizeof(char)*13, 0, cudaMemcpyDeviceToHost);
return 0;
}
The error appears at this line
helloWorldOnDevice<<<1,1>>> ();
Expected primary-expression before '<' token !!!!!!
You're compiling your program with gcc coming with Xcode. Should use nvcc compiler instead to compile CUDA code. Normally I would use a Makefile to tell that *.cu to be compiled by nvcc and *.cpp by gcc, then link produced objects to an executable.

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