Clang static code analyzer show warning:
target/arm/translate-a64.c:8635:14: warning: Value stored to 'tcg_rn' during its
 initialization is never read
    TCGv_i64 tcg_rn = new_tmp_a64(s);
             ^~~~~~   ~~~~~~~~~~~~~~
target/arm/translate-a64.c:8636:14: warning: Value stored to 'tcg_rd' during its
 initialization is never read
    TCGv_i64 tcg_rd = new_tmp_a64(s);
             ^~~~~~   ~~~~~~~~~~~~~~

There is a memory leak for the variable new_tmp_a64 "s".
We should delete the assignment.

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
---
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: qemu-arm@nongnu.org
---
 target/arm/translate-a64.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 534c3ff5f3..c83bb85e4e 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -8632,8 +8632,8 @@ static void handle_scalar_simd_shli(DisasContext *s, bool insert,
     int size = 32 - clz32(immh) - 1;
     int immhb = immh << 3 | immb;
     int shift = immhb - (8 << size);
-    TCGv_i64 tcg_rn = new_tmp_a64(s);
-    TCGv_i64 tcg_rd = new_tmp_a64(s);
+    TCGv_i64 tcg_rn;
+    TCGv_i64 tcg_rd;
 
     if (!extract32(immh, 3, 1)) {
         unallocated_encoding(s);
-- 
2.23.0

On Tue, 25 Aug 2020 at 12:26, Chen Qun <kuhn.chenqun@huawei.com> wrote:
>
> Clang static code analyzer show warning:
> target/arm/translate-a64.c:8635:14: warning: Value stored to 'tcg_rn' during its
>  initialization is never read
>     TCGv_i64 tcg_rn = new_tmp_a64(s);
>              ^~~~~~   ~~~~~~~~~~~~~~
> target/arm/translate-a64.c:8636:14: warning: Value stored to 'tcg_rd' during its
>  initialization is never read
>     TCGv_i64 tcg_rd = new_tmp_a64(s);
>              ^~~~~~   ~~~~~~~~~~~~~~
>
> There is a memory leak for the variable new_tmp_a64 "s".

There is not, because TCG temps allocated via new_tmp_a64()
are all freed via free_tmp_a64() at the end of disas_a64_insn().

> We should delete the assignment.

But yes, the assignments are unused and should be deleted.

If you fix the commit message, then
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM

> On Tue, 25 Aug 2020 at 12:26, Chen Qun <kuhn.chenqun@huawei.com> wrote:
> >
> > Clang static code analyzer show warning:
> > target/arm/translate-a64.c:8635:14: warning: Value stored to 'tcg_rn'
> > during its  initialization is never read
> >     TCGv_i64 tcg_rn = new_tmp_a64(s);
> >              ^~~~~~   ~~~~~~~~~~~~~~
> > target/arm/translate-a64.c:8636:14: warning: Value stored to 'tcg_rd'
> > during its  initialization is never read
> >     TCGv_i64 tcg_rd = new_tmp_a64(s);
> >              ^~~~~~   ~~~~~~~~~~~~~~
> >
> > There is a memory leak for the variable new_tmp_a64 "s".
> 
> There is not, because TCG temps allocated via new_tmp_a64() are all freed via
> free_tmp_a64() at the end of disas_a64_insn().
> 
OK, I'll delete that description later.

Thanks,
ChenQun