From: Szabolcs Nagy <szabolcs.nagy@arm.com>
To: David Malcolm <dmalcolm@redhat.com>
Cc: Florian Weimer <fweimer@redhat.com>,
Szabolcs Nagy via Gcc <gcc@gcc.gnu.org>,
libc-alpha@sourceware.org, Mir Immad <mirimnan017@gmail.com>
Subject: Re: Adding file descriptor attribute(s) to gcc and glibc
Date: Thu, 14 Jul 2022 09:30:32 +0100 [thread overview]
Message-ID: <Ys/UKN3/TBGM/M73@arm.com> (raw)
In-Reply-To: <71f2ff67c5e81ab98860d28232cba74a96c1f441.camel@redhat.com>
The 07/13/2022 12:55, David Malcolm wrote:
> On Wed, 2022-07-13 at 16:01 +0200, Florian Weimer wrote:
> > * David Malcolm:
> GCC trunk's -fanalyzer implements the new warnings via a state machine
> for file-descriptor values; it currently has rules for handling "open",
> "close", "read", and "write", and these functions are currently hard-
> coded inside the analyzer.
>
> Here are some examples on Compiler Explorer of what it can/cannot
> detect:
> https://godbolt.org/z/nqPadvM4f
>
> Probably the most important one IMHO is the leak detection.
nice.
> Would it be helpful to have some kind of attribute for "returns a new
> open FD"? Are there other ways to close a FD other than calling
> "close" on it? (Would converting that to some kind of "closes"
> attribute be a good idea?)
dup2(oldfd, newfd)
dup3(oldfd, newfd, flags)
closes newfd (and also opens it to be a dup of oldfd)
unless the call fails.
close_range(first, last, flags)
fclose(fdopen(fd, mode))
but users can write all sorts of wrappers around close too.
>
> Are there any other "magic" values for file-descriptors we should be
> aware of?
>
mmap may require fd==-1 for anonymous maps.
next prev parent reply other threads:[~2022-07-14 8:31 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-12 17:31 [PATCH] filedescriptor attribute Immad Mir
2022-07-12 17:33 ` Mir Immad
2022-07-12 22:16 ` Adding file descriptor attribute(s) to gcc and glibc David Malcolm
2022-07-12 22:25 ` David Malcolm
2022-07-13 8:37 ` Szabolcs Nagy
2022-07-13 8:46 ` Andreas Schwab
2022-07-13 12:05 ` Florian Weimer
2022-07-13 13:33 ` David Malcolm
2022-07-13 14:01 ` Florian Weimer
2022-07-13 16:55 ` David Malcolm
2022-07-14 8:30 ` Szabolcs Nagy [this message]
2022-07-14 15:22 ` David Malcolm
2022-07-14 17:07 ` Paul Eggert
2022-07-13 16:56 ` Mir Immad
2022-07-13 19:29 ` David Malcolm
2022-07-13 12:57 ` David Malcolm
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