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From: storm@cs.mcgill.ca (Marc WANDSCHNEIDER)
Newsgroups: comp.lang.c
Subject: Problems with malloc()
Message-ID: <1991Apr1.171908.2198@cs.mcgill.ca>
Date: 1 Apr 91 17:19:08 GMT
Sender: news@cs.mcgill.ca (Netnews Administrator)
Organization: SOCS, McGill University, Montreal, Canada
Lines: 60


I have written a program in an attempt to impliment queues in ANSI C.  How-
ever, I have run into a few problems.  My compiler at home (TC++ 1.0)
behaves INCREDIBLY strangely with the following pieces of code:

m,m1...m5 are all pointers to a struct of type Message (ie, they're type Link)
msgalloc() returns a type Link, and is sort of taken from the prototype given
on page 146 of K & R 2nd ed.

	m1 = msgalloc();
	messagemakenull(m1);
	m1->source = 7;
	m1->dest = 1;
	m1->sent = 1.0;

	m2 = msgalloc();
	messagemakenull(m2);
	m2->source = 6;
	m2->dest = 2;
	m2->sent = 2.0;
etc...

	m4 = msgallloc();   /* <--- WARNING 1 (see below) */
	messagemakenull(m4);
	m4->source = 4;
	m4->dest = 8;
	m4->sent = 4.0;

Link msgalloc(void)
{
	return (Message *) malloc(sizeof(Message));
}

void messagemakenull(Link makemenull)
{
	makemenull->next = NULL;
	makemenull->source = 0;
	makemenull->dest = 0;
	makemenull->sent = 0;
}

Now, the problem is, TC++ 1.0 will compile this when I run it from the  DOS
prompt, but will give me the warning NON-PORTABLE FUNCTION CONVERSION IN
MAIN at the line m4 = msgalloc(); as indicated above.

However, when I choose BUILD ALL it under the IDE of TC, it SOMETIMES
 generates the same line as an ERROR, but it always generates a LINK ERROR
which states UNDEFINED SYMBOL _MSGALLOC IN MODULE QUEUES.C.

Can somebody please tell me what the *%*&^ is going on.  All I really want
to do is something similar to the NEW(pointer to type X) in PASCAL....

Any help would save my hair.

./*-
-- 
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storm@cs.mcgill.ca         McGill University           It's 11pm, do YOU
Marc Wandschneider         Montreal, CANADA            know what time it is?
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