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Re: Analysis of clang results against the nmap-npingchanges branch for nping directory only.
From: James Rogers <jamesmrogers () gmail com>
Date: Tue, 19 Jun 2012 11:20:25 -0400
I added the no return attribute to several function definitions in
nmap-npingchanges/nping/output.h. Then ran the clang analyzer against
nmap-npingchanges and got a report with many less bugs.
This totally eliminated the rest of the clang bug reports for
I've attached a diff to this email, please review and see if you want
me to check these changes in.
I had never used an __attribute__ before, seems like something
interesting to learn about sometime soon.
On Wed, Jun 13, 2012 at 3:06 PM, James Rogers <jamesmrogers () gmail com> wrote:
On Wed, Jun 13, 2012 at 2:09 PM, David Fifield <david () bamsoftware com> wrote:
On Wed, Jun 13, 2012 at 02:05:55PM -0400, James Rogers wrote:
Only found two real issues:
API Argument with 'nonnull' attribute passed null nping
/common_modified.cc 490 20
490 s = strchr(addy[i],',');
20 Null pointer passed as an argument to a 'nonnull' parameter
Is a bug. hostexp is never checked to make sure it is not NULL.
371 char *hostexp = strdup(target_expr);
386 addy = addy = addy = addy = addy = NULL;
387 addy = r = hostexp;
Dead store Dead assignment nping /EchoServer.cc 1507 1
1507 loopret=nsock_loop(nsp, 1000);
Value stored to 'loopret' is never read
This is a bug. Easy to fix.
There were a lot more references to loopret that have been removed in
this branch, this looks like the last one remaining.
The rest of the bugs were generated by clang not recognizing that
nping_fatal() and fatal() do not return.
Is there a way to annotate these functions so that Clang can know they
don't return? In nmap_error.h we have for example,
void fatal(const char *fmt, ...)
But that's missing in nping/output.h. If you add it, do those spurious
warnings go away?
The documentation talked about ways to mark things in general, but I
didn't see any detailed explanation of how to do that.
I'll add that attribute to the nmap-npingchanges version I have and
see if it stops these bugs from being reported when I run the tool
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