X-Authentication-Warning:	delorie.com: mail set sender to djgpp-bounces using -f
From:	"K.J.Williams" <lordwilliams1972 AT gmail DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Upgrading from a bad C compiler
Date:	Thu, 19 Jul 2012 19:16:06 -0700 (PDT)
Organization:	http://groups.google.com
Lines:	101
Message-ID:	<17d4b525-2c31-4c20-b3c5-a7118343e9a5@googlegroups.com>
NNTP-Posting-Host:	67.5.176.227
Mime-Version:	1.0
X-Trace:	posting.google.com 1342750566 1635 127.0.0.1 (20 Jul 2012 02:16:06 GMT)
X-Complaints-To:	groups-abuse AT google DOT com
NNTP-Posting-Date:	Fri, 20 Jul 2012 02:16:06 +0000 (UTC)
Complaints-To:	groups-abuse AT google DOT com
Injection-Info:	glegroupsg2000goo.googlegroups.com; posting-host=67.5.176.227; posting-account=jrLHRgkAAABPV01ZW_RN_U6Tm5UnYNUx
User-Agent:	G2/1.0
X-Received-Bytes:	3712
Bytes:	3812
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp
X-MIME-Autoconverted:	from quoted-printable to 8bit by delorie.com id q6K2U2o5013726
Reply-To:	djgpp AT delorie DOT com

I recently upgraded, and imported some source code from a non-standard ANSI C compliant compiler (Borland Turbo C++ 3.0 for DOS) to DJGPP because of the memory limitation and the fact that TC++ far invention for accessing memory does not work. Now I am using DJGPP via RHIDE get over this disadvantage of memory, and I am running into a lot of compiler (syntax) errors because the old compiler I used was not compliant. The only difference between RHIDE and Turbo C++ that I have noticed, is that there is no verbose explanation of the errors - which I could access in TC++. Is there a documentation where I can find out more in depth what these errors mean? 

3 examples of errors - simplified (2 of which I solved)- things that I could do in C in TC++ that DJGPP compiler nails me on : 

#1 

//in myfile1.c

short int myfunc(char x)
{
  char w[0] = x;// legal in TC++ - but illegal in DJGPP, to assign the address
                // of x to w[0] in this manner  
  ....
  ....
  return 0;
}

the fix: 

char w[0] = &x;

#2 

#define WIDGETS 200

//in myfile2.c - a global struct  

struct mystuff
{
   ....
   ....
};

struct mystuff *mything = NULL; //for use with malloc() & free() 

short int badstuff = 0;

short int myfunc(void)
{
   short unsigned int x; 
   ....
   x = sizeof(mystuff)*WIDGETS; //legal in TC++ but illegal in DJGPP 
   ....
   return 0;
}


the fix:  

x = sizeof(mything)*WIDGETS; // I don't understand why "mystuff" 

//doesn't work instead of using mything... 
                              
#3

//in myfile3.c , declares two extern of two variables in myfile2.c outside before any function //bodies  

// first extern:

extern short int badstuff = 0;//legal in TC++ but illegal in DJGPP 

// the fix is : extern short int badstuff;// but I dont understand why

// second extern: 

extern struct mystuff *mything;//legal in TC++ but illegal in DJGPP 

extern mystuff *mything;//doesnt work becuase the compiler doesn't know what mystuff is
extern struct mystuff;//doesnt work becuase mystuff is a struct template, not a instantiation 
extern mything;//doesnt work becuase it doesnt know what type mything is, and even so... 

//... mything is a variable not a pointer to a struct of mystuff which is what I am trying to 
//get recognized in myfile3.c

//THIS IS WHERE I AM STUCK

//please note on some download sites, TC++ is available - even though its obsolete and 
//non-standard ANSI compliant, it should never be used. I have it as the product that 
//came in a box with the books and etc. mediums to install it. 


Thanks In Advance, 

KJ

- Raw text -