[SOLVED] Where is memset()

CollieJim · 03-05-2015, 03:44 AM

I'm compiling software to support my Logitech G510s keyboard. It is obtained from
http://sourceforge.net/projects/g15daemon/

It has a C++ program that uses memset() and memcpy() which is giving me 'not in scope' errors. I have tried

Code:

#include <string>    //  original code - see below
          and
#include <string.h>        // more errors than <string>
          and
#include <cstring>         // same again

In /usr/include/string.h, memset() and memcpy() are declared:

Code:

__BEGIN_NAMESPACE_STD
/* Copy N bytes of SRC to DEST.  */
extern void *memcpy (void *__restrict __dest, const void *__restrict __src,
		     size_t __n) __THROW __nonnull ((1, 2));
/* Copy N bytes of SRC to DEST, guaranteeing
   correct behavior for overlapping strings.  */
extern void *memmove (void *__dest, const void *__src, size_t __n)
     __THROW __nonnull ((1, 2));
__END_NAMESPACE_STD

__BEGIN_NAMESPACE_STD
/* Set N bytes of S to C.  */
extern void *memset (void *__s, int __c, size_t __n) __THROW __nonnull ((1));

Code snippets:

Code:

/*
    This file is part of g15lcd.

    g15lcd is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.
...
*/

#include <iostream>
#include <cstdlib>
#include <usb.h>
#include <string>
#include <fstream>
#include <vector>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
...
void processInputLine(unsigned char *buffer, pthread_mutex_t *mutex, int *changed, string const &line)
{
   if (line.length() < 3)
   {
      cout << "How about passing useful data into this program?" << endl;
      return;
   }
   
   unsigned char buf[0x03e0];
   memset(buf,0,0x03e0);
   buf[0] = 0x03;
   
   if (line[0] == 'T')
   {
      handleTextCommand(buf,line);
   }
   else if (line[0] == 'P')
   {
      handlePixelCommand(buf,line);
   }
   
   pthread_mutex_lock(mutex);
      memcpy(buffer, buf, 0x03e0);
      *changed = 1;
   pthread_mutex_unlock(mutex);
}

Code:

$ make
g++ -O2 -Wall -pedantic -c font_8x8.cpp
g++ -O2 -Wall -pedantic -c font_7x5.cpp
g++ -O2 -Wall -pedantic -c font_6x4.cpp
g++ -O2 -Wall -pedantic -c lcd.cpp
lcd.cpp: In function ‘void processInputLine(unsigned char*, pthread_mutex_t*, int*, const string&)’:
lcd.cpp:234:23: error: ‘memset’ was not declared in this scope
    memset(buf,0,0x03e0);
                       ^
lcd.cpp:247:33: error: ‘memcpy’ was not declared in this scope
       memcpy(buffer, buf, 0x03e0);
                                 ^
Makefile:18: recipe for target 'all' failed
make: *** [all] Error 1

In C++ I understand that functions can have a variable number of arguments as long as there are appropriate declarations, and that a 'not in scope' error is given if the wrong number of arguments is used. Is that the case here?

NevemTeve · 03-05-2015, 03:49 AM

Do these steps:

1. 'man memcpy' -> you find out it is in <string.h>
2. beacuse it is C++, change it to <cstring>
3. so put this into your code:

Code:

#include <cstring>

Edit: my g++ version is: g++ (Debian 4.4.5-8) 4.4.5

veerain · 03-05-2015, 04:13 AM

Quote:

Originally Posted by NevemTeve

Do these steps:

1. 'man memcpy' -> you find out it is in <string.h>
2. beacuse it is C++, change it to <cstring>
3. so put this into your code:

Code:

#include <cstring>

Edit: my g++ version is: g++ (Debian 4.4.5-8) 4.4.5

But OP says he has tried this already.

NevemTeve · 03-05-2015, 04:23 AM

Off: I learned from experience that OP's aren't always reliable... for example, they tend not to give compiler-version-numbers, the complete source, the specification of the platform, etc

CollieJim · 03-05-2015, 04:58 AM

Unreliable is right! When I initially substituted cstring I failed to notice that the larger batch of errors I got was for a different file...

It also needed cstring, and all is well now.

Thanks for the help.