lclint-interest message 61

From eric@rrinc.com Sun Mar 24 13:33:43 1996
Sender: eric@access.rrinc.com
Date: Fri, 22 Mar 1996 20:32:57 -0500
From: Eric Bloodworth 
Organization: Recognition Research, Inc
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To: lclint_sig 
Subject: can lclint detect this leak? 
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Here is a simplified example of the kind of memory allocation that is quite 
common in our company's code.  I can't seem to make lclint 
detect this very simple leak....
Comments included where I haven't been 
able to figure out an anotation that will do what I want. 

Also, is it possible to annotate particular fields of a structure 
passed into a function?  It doesn't appear to be...  


---- Eric 

#include 
#include 

typedef struct {
	int foo; 
	char *bar; 
} booga_s; 

extern int frob(/*@out@*/ booga_s *stuff); 
extern void free_booga_s(/*@in@*/ booga_s * stuff); 

int frob(booga_s *stuff)
{
	
	/* 
		How do I say storage->bar isn't allocated after the 	
		memset? 
	*/
 	(void)memset(stuff, 0, sizeof(*stuff));  
	stuff->bar = malloc(100); 
	if (NULL != stuff->bar) {
		stuff->foo = 100; 
		return 0; 
	}
	return -1; 

}

void free_booga_s(booga_s *stuff)
{
	free(stuff->bar); 
	(void)memset(stuff, 0, sizeof(*stuff)); 
}

/* 
	here I'm returning without freeing leaker.
	How do I tell lclint that leaker must be freed
	by calling free_booga_s?  Or is there something 
	I must say about frob which says storage is allocated? 
*/

void leaker(void)
{
	booga_s leaker; 
	if (0 == frob(&leaker)) {
		printf("frobnicated\n"); 

	}

}
int main(
	/*@unused@*/ int argc, 
	/*@unused@*/ char *argv[])
{
	leaker(); 

	exit(0); 
}


-- Eric