From: Andrew Burgess <aburgess@redhat.com>
To: gdb-patches@sourceware.org
Subject: [PATCH 1/5] sim/cgen: mask uninitialized variable warning in cgen-run.c
Date: Wed, 12 Oct 2022 13:38:31 +0100 [thread overview]
Message-ID: <aab2ea3326ddac9c919045fd90c54085b1ce4811.1665578246.git.aburgess@redhat.com> (raw)
In-Reply-To: <cover.1665578246.git.aburgess@redhat.com>
I see an uninitialized variable warning (with gcc 9.3.1) from
cgen-run.c, like this:
/tmp/build/sim/../../src/sim/cris/../common/cgen-run.c: In function ‘sim_resume’:
/tmp/build/sim/../../src/sim/cris/../common/cgen-run.c:259:5: warning: ‘engine_fns$’ may be used uninitialized in this function [-Wmaybe-uninitialized]
259 | (* engine_fns[next_cpu_nr]) (cpu);
| ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/tmp/build/sim/../../src/sim/cris/../common/cgen-run.c:232:14: note: ‘engine_fns$’ was declared here
232 | ENGINE_FN *engine_fns[MAX_NR_PROCESSORS];
| ^~~~~~~~~~
This is a false positive - we over allocate engine_fn, and then only
initialize the nr_cpus entries which we will later go on to use.
However, we can easily silence this warning by initializing the unused
entries in engine_fns to NULL, this might also help if anyone ever
looks at engine_fns in a debugger, it should now be obvious which
entries are in use, and which are not.
With this change the warning is gone.
There should be no change in behaviour with this commit.
---
sim/common/cgen-run.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/sim/common/cgen-run.c b/sim/common/cgen-run.c
index 9a13b0ca416..a9a493c01b9 100644
--- a/sim/common/cgen-run.c
+++ b/sim/common/cgen-run.c
@@ -242,6 +242,11 @@ engine_run_n (SIM_DESC sd, int next_cpu_nr, int nr_cpus, int max_insns, int fast
prime_cpu (cpu, max_insns);
}
+ /* Ensure the remaining engine_fns slots are initialized, this silences a
+ compiler warning when engine_fns is used below. */
+ for (i = nr_cpus; i < MAX_NR_PROCESSORS; ++i)
+ engine_fns[i] = NULL;
+
while (1)
{
SIM_ENGINE_PREFIX_HOOK (sd);
--
2.25.4
next prev parent reply other threads:[~2022-10-12 12:38 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-12 12:38 [PATCH 0/5] Silence some build warnings in various simulators Andrew Burgess
2022-10-12 12:38 ` Andrew Burgess [this message]
2022-10-23 12:30 ` [PATCH 1/5] sim/cgen: mask uninitialized variable warning in cgen-run.c Mike Frysinger
2022-10-24 15:57 ` Andrew Burgess
2022-10-24 15:59 ` Mike Frysinger
2022-10-27 15:53 ` Andrew Burgess
2022-10-12 12:38 ` [PATCH 2/5] sim/ppc: fix warnings related to printf format strings Andrew Burgess
2022-10-12 12:46 ` Tsukasa OI
2022-10-12 13:50 ` Andrew Burgess
2022-10-23 12:20 ` Mike Frysinger
2022-10-24 15:41 ` Andrew Burgess
2022-10-12 12:38 ` [PATCH 3/5] sim/ppc: mark device_error function as ATTRIBUTE_NORETURN Andrew Burgess
2022-10-12 12:38 ` [PATCH 4/5] sim/erc32: avoid dereferencing type-punned pointer warnings Andrew Burgess
2022-10-12 14:11 ` Pedro Alves
2022-10-12 17:02 ` Lancelot SIX
2022-10-13 10:35 ` Andrew Burgess
2022-10-13 10:49 ` Pedro Alves
2022-10-23 12:34 ` Mike Frysinger
2022-10-24 15:42 ` Andrew Burgess
2022-10-12 12:38 ` [PATCH 5/5] sim/iq2000: silence pointer-sign warnings Andrew Burgess
2022-10-23 12:32 ` Mike Frysinger
2022-10-24 15:45 ` Andrew Burgess
2022-10-26 8:51 ` Mike Frysinger
2022-10-14 17:50 ` [PATCH 0/5] Silence some build warnings in various simulators Tom Tromey
2022-10-19 13:34 ` Andrew Burgess
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=aab2ea3326ddac9c919045fd90c54085b1ce4811.1665578246.git.aburgess@redhat.com \
--to=aburgess@redhat.com \
--cc=gdb-patches@sourceware.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).