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From: Laurent Vivier <laurent@vivier.eu>
To: qemu-devel@nongnu.org
Cc: "Peter Maydell" <peter.maydell@linaro.org>,
	"Thomas Huth" <thuth@redhat.com>,
	qemu-trivial@nongnu.org, "Martin Liška" <mliska@suse.cz>,
	"Michael Tokarev" <mjt@tls.msk.ru>,
	"Laurent Vivier" <laurent@vivier.eu>,
	"Stafford Horne" <shorne@gmail.com>,
	"Richard Henderson" <richard.henderson@linaro.org>,
	"Philippe Mathieu-Daudé" <philmd@redhat.com>
Subject: [PULL v2 15/16] hw/openrisc/openrisc_sim: Add assertion to silence GCC warning
Date: Wed, 10 Jun 2020 15:10:10 +0200	[thread overview]
Message-ID: <20200610131011.1941209-16-laurent@vivier.eu> (raw)
In-Reply-To: <20200610131011.1941209-1-laurent@vivier.eu>

From: Philippe Mathieu-Daudé <philmd@redhat.com>

When compiling with GCC 10 (Fedora 32) using CFLAGS=-O2 we get:

    CC      or1k-softmmu/hw/openrisc/openrisc_sim.o
  hw/openrisc/openrisc_sim.c: In function ‘openrisc_sim_init’:
  hw/openrisc/openrisc_sim.c:87:42: error: ‘cpu_irqs[0]’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
     87 |         sysbus_connect_irq(s, i, cpu_irqs[i][irq_pin]);
        |                                  ~~~~~~~~^~~

While humans can tell smp_cpus will always be in the [1, 2] range,
(openrisc_sim_machine_init sets mc->max_cpus = 2), the compiler
can't.

Add an assertion to give the compiler a hint there's no use of
uninitialized data.

Buglink: https://bugs.launchpad.net/qemu/+bug/1874073
Reported-by: Martin Liška <mliska@suse.cz>
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Tested-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Stafford Horne <shorne@gmail.com>
Message-Id: <20200608160611.16966-1-philmd@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
 hw/openrisc/openrisc_sim.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/openrisc/openrisc_sim.c b/hw/openrisc/openrisc_sim.c
index d08ce6181199..02f5259e5e33 100644
--- a/hw/openrisc/openrisc_sim.c
+++ b/hw/openrisc/openrisc_sim.c
@@ -134,6 +134,7 @@ static void openrisc_sim_init(MachineState *machine)
     int n;
     unsigned int smp_cpus = machine->smp.cpus;
 
+    assert(smp_cpus >= 1 && smp_cpus <= 2);
     for (n = 0; n < smp_cpus; n++) {
         cpu = OPENRISC_CPU(cpu_create(machine->cpu_type));
         if (cpu == NULL) {
-- 
2.26.2



  parent reply	other threads:[~2020-06-10 13:23 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-10 13:09 [PULL v2 00/16] Trivial branch for 5.1 patches Laurent Vivier
2020-06-10 13:09 ` [PULL v2 01/16] Fix parameter type in vhost migration log path Laurent Vivier
2020-06-10 13:09 ` [PULL v2 02/16] net: Do not include a newline in the id of -nic devices Laurent Vivier
2020-06-10 13:09 ` [PULL v2 03/16] .mailmap: Update Fred Konrad email address Laurent Vivier
2020-06-10 13:09 ` [PULL v2 04/16] hw/unicore32/puv3: Use qemu_log_mask(ERROR) instead of debug printf() Laurent Vivier
2020-06-10 13:10 ` [PULL v2 05/16] hw/isa/apm: Convert debug printf()s to trace events Laurent Vivier
2020-06-10 13:10 ` [PULL v2 06/16] hw/misc/auxbus: Use qemu_log_mask(UNIMP) instead of debug printf Laurent Vivier
2020-06-10 13:10 ` [PULL v2 07/16] qemu-img: Fix doc typo for 'bitmap' subcommand Laurent Vivier
2020-06-10 13:10 ` [PULL v2 08/16] hw/arm/aspeed: Correct DRAM container region size Laurent Vivier
2020-06-10 13:10 ` [PULL v2 09/16] hw/hppa/dino: Use the IEC binary prefix definitions Laurent Vivier
2020-06-10 13:10 ` [PULL v2 10/16] hw/i386/xen/xen-hvm: " Laurent Vivier
2020-06-10 13:10 ` [PULL v2 11/16] target/i386/cpu: " Laurent Vivier
2020-06-10 13:10 ` [PULL v2 12/16] target/unicore32: Remove unused headers Laurent Vivier
2020-06-10 13:10 ` [PULL v2 13/16] target/unicore32: Replace DPRINTF() by qemu_log_mask(GUEST_ERROR) Laurent Vivier
2020-06-10 13:10 ` [PULL v2 14/16] target/unicore32: Prefer qemu_semihosting_log_out() over curses Laurent Vivier
2020-06-10 13:10 ` Laurent Vivier [this message]
2020-06-10 13:10 ` [PULL v2 16/16] semihosting: remove the pthread include which seems unused Laurent Vivier
2020-06-11 20:19 ` [PULL v2 00/16] Trivial branch for 5.1 patches Peter Maydell

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