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Subject: Re: [PATCH v2] PCI: rpaphp: Avoid a sometimes-uninitialized warning
To:     Nathan Chancellor <natechancellor@gmail.com>,
        Tyrel Datwyler <tyreld@linux.ibm.com>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>
Cc:     Bjorn Helgaas <bhelgaas@google.com>, linux-pci@vger.kernel.org,
        linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
        clang-built-linux@googlegroups.com,
        Nick Desaulniers <ndesaulniers@google.com>
References: <20190603174323.48251-1-natechancellor@gmail.com>
 <20190603221157.58502-1-natechancellor@gmail.com>
From:   Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Message-ID: <78f5a331-6158-0ef5-0476-b976c8e71a68@linux.vnet.ibm.com>
Date:   Mon, 3 Jun 2019 17:03:09 -0700
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On 06/03/2019 03:11 PM, Nathan Chancellor wrote:
> When building with -Wsometimes-uninitialized, clang warns:
> 
> drivers/pci/hotplug/rpaphp_core.c:243:14: warning: variable 'fndit' is
> used uninitialized whenever 'for' loop exits because its condition is
> false [-Wsometimes-uninitialized]
>         for (j = 0; j < entries; j++) {
>                     ^~~~~~~~~~~
> drivers/pci/hotplug/rpaphp_core.c:256:6: note: uninitialized use occurs
> here
>         if (fndit)
>             ^~~~~
> drivers/pci/hotplug/rpaphp_core.c:243:14: note: remove the condition if
> it is always true
>         for (j = 0; j < entries; j++) {
>                     ^~~~~~~~~~~
> drivers/pci/hotplug/rpaphp_core.c:233:14: note: initialize the variable
> 'fndit' to silence this warning
>         int j, fndit;
>                     ^
>                      = 0
> 
> fndit is only used to gate a sprintf call, which can be moved into the
> loop to simplify the code and eliminate the local variable, which will
> fix this warning.
> 
> Link: https://github.com/ClangBuiltLinux/linux/issues/504
> Fixes: 2fcf3ae508c2 ("hotplug/drc-info: Add code to search ibm,drc-info property")
> Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

Acked-by: Tyrel Datwyler <tyreld@linux.ibm.com>