On Mon, Feb 25, 2019 at 9:39 PM Nathan Chancellor
<natechancel...@gmail.com> wrote:
>
> When building with -Wsometimes-uninitialized, Clang warns:
>
> arch/powerpc/xmon/ppc-dis.c:157:7: warning: variable 'opcode' is used
> uninitialized whenever 'if' condition is false
> [-Wsometimes-uninitialized]
> if (cpu_has_feature(CPU_FTRS_POWER9))
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> arch/powerpc/xmon/ppc-dis.c:167:7: note: uninitialized use occurs here
> if (opcode == NULL)
> ^~~~~~
> arch/powerpc/xmon/ppc-dis.c:157:3: note: remove the 'if' if its
> condition is always true
> if (cpu_has_feature(CPU_FTRS_POWER9))
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> arch/powerpc/xmon/ppc-dis.c:132:38: note: initialize the variable
> 'opcode' to silence this warning
> const struct powerpc_opcode *opcode;
> ^
> = NULL
> 1 warning generated.
>
> This warning seems to make no sense on the surface because opcode is set
> to NULL right below this statement. However, there is a comma instead of
> semicolon to end the dialect assignment, meaning that the opcode
> assignment only happens in the if statement. Properly terminate that
> line so that Clang no longer warns.
>
> Fixes: 5b102782c7f4 ("powerpc/xmon: Enable disassembly files (compilation
> changes)")
> Link: https://github.com/ClangBuiltLinux/linux/issues/390
> Signed-off-by: Nathan Chancellor <natechancel...@gmail.com>
haha! (shows office mates). Nice find, and fix!
Reviewed-by: Nick Desaulniers <ndesaulni...@google.com>
> ---
> arch/powerpc/xmon/ppc-dis.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/xmon/ppc-dis.c b/arch/powerpc/xmon/ppc-dis.c
> index 9deea5ee13f6..27f1e6415036 100644
> --- a/arch/powerpc/xmon/ppc-dis.c
> +++ b/arch/powerpc/xmon/ppc-dis.c
> @@ -158,7 +158,7 @@ int print_insn_powerpc (unsigned long insn, unsigned long
> memaddr)
> dialect |= (PPC_OPCODE_POWER5 | PPC_OPCODE_POWER6 | PPC_OPCODE_POWER7
> | PPC_OPCODE_POWER8 | PPC_OPCODE_POWER9 | PPC_OPCODE_HTM
> | PPC_OPCODE_ALTIVEC | PPC_OPCODE_ALTIVEC2
> - | PPC_OPCODE_VSX | PPC_OPCODE_VSX3),
> + | PPC_OPCODE_VSX | PPC_OPCODE_VSX3);
>
> /* Get the major opcode of the insn. */
> opcode = NULL;
> --
> 2.21.0
>
--
Thanks,
~Nick Desaulniers
