lclint-interest message 104

From kir@iitb.fhg.de Tue Sep 17 08:47:01 1996
X-Env: (fhg.de) kir@iitb.fhg.de -> lclint-interest@larch.lcs.mit.EDU.VIA-SMTP
Date: Tue, 17 Sep 1996 09:35:33 +0200
From: kir@iitb.fhg.de (Harald Kirsch)
To: lclint-interest@larch.lcs.mit.edu
Subject: (Known?) Bugs? of LCLint and questions


1) Running the program
------------------------------------------------------------------------
#include 
#include 

int
main(int argc, char **argv)
{
  char bla[10];
  char *s = malloc(10);
  if( !s ) {
    free(s);
  }

  s = bla;
  printf("%d, %s\n", argc, argv[0]);
  return 0;
}
------------------------------------------------------------------------
results in the message:

------------------------------------------------------------------------
LCLint 2.1a --- 23 Apr 96

x.c: (in function main)
x.c:11,3: Variable s is released in true branch, but live in continuation.
  The state of a variable is different depending on which branch is taken. This
  means no annotation can sensibly be applied to the storage. Use -branchstate
  to suppress message.
   x.c:10,10: Storage s is released

Finished LCLint checking --- 1 code error found
------------------------------------------------------------------------

Isn't it possible for LCLint to find out that s need not be freed in the
contination, since it was never allocated?



2) Handling of realloc is obviously a problem, in particular the case
were it does not succeed. How would I write a wrapper around realloc
that can be fully specified with LCLint annotations?


3) In 2.1a somethings seems to go wrong with #includes and #defines. In
two libraries I introduced something like

#ifndef __bool__
typdef int bool
 ...
#endif

and wherever both .h-files are included I get messages about double
defined types. Is +allmacros probably the reason?


4) I've got a program that creates code for a command line parser from a
simple specification file. The command line parser puts all its findings
into a static struct, and returns the address of this structure to the
calling main. 

How do I have to annotate the parser function and/or the static struct
to make LCLint a believer?


Regards,
	Harald.

-------------------------------------------------+------------------
Harald Kirsch, kir@iitb.fhg.de, +49 721 6091 384 | This  message is
FhG/IITB,      Fraunhoferstr.1, 76131 Karlsruhe  | subject oriented.