2020-09-25 14:02:56

by Tianjia Zhang

[permalink] [raw]
Subject: Re: [PATCH] lib/mpi: Fix unused variable warnings

Hi Herbert,

Thanks for your patch, The changes look good.
I have tested this patch, so,

Tested-by: Tianjia Zhang <[email protected]>

Best regards,
Tianjia

On 9/25/20 4:19 PM, Herbert Xu wrote:
> On Mon, Sep 21, 2020 at 12:20:55AM +0800, Tianjia Zhang wrote:
>> Expand the mpi library based on libgcrypt, and the ECC algorithm of
>> mpi based on libgcrypt requires these functions.
>> Some other algorithms will be developed based on mpi ecc, such as SM2.
>>
>> Signed-off-by: Tianjia Zhang <[email protected]>
>> Tested-by: Xufeng Zhang <[email protected]>
>
> This creates some compiler warnings.
>
> ---8<---
> This patch removes a number of unused variables and marks others
> as unused in order to silence compiler warnings about them.
>
> Fixes: a8ea8bdd9df9 ("lib/mpi: Extend the MPI library")
> Signed-off-by: Herbert Xu <[email protected]>
>
> diff --git a/lib/mpi/mpi-div.c b/lib/mpi/mpi-div.c
> index 21332dab97d4..45beab8b9e9e 100644
> --- a/lib/mpi/mpi-div.c
> +++ b/lib/mpi/mpi-div.c
> @@ -92,7 +92,6 @@ void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den)
> unsigned int normalization_steps;
> mpi_limb_t q_limb;
> mpi_ptr_t marker[5];
> - unsigned int marker_nlimbs[5];
> int markidx = 0;
>
> /* Ensure space is enough for quotient and remainder.
> @@ -152,7 +151,6 @@ void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den)
> * numerator would be gradually overwritten by the quotient limbs.
> */
> if (qp == np) { /* Copy NP object to temporary space. */
> - marker_nlimbs[markidx] = nsize;
> np = marker[markidx++] = mpi_alloc_limb_space(nsize);
> MPN_COPY(np, qp, nsize);
> }
> @@ -173,7 +171,6 @@ void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den)
> * the most significant word. Use temporary storage not to clobber
> * the original contents of the denominator.
> */
> - marker_nlimbs[markidx] = dsize;
> tp = marker[markidx++] = mpi_alloc_limb_space(dsize);
> mpihelp_lshift(tp, dp, dsize, normalization_steps);
> dp = tp;
> @@ -195,7 +192,6 @@ void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den)
> if (dp == rp || (quot && (dp == qp))) {
> mpi_ptr_t tp;
>
> - marker_nlimbs[markidx] = dsize;
> tp = marker[markidx++] = mpi_alloc_limb_space(dsize);
> MPN_COPY(tp, dp, dsize);
> dp = tp;
> diff --git a/lib/mpi/mpi-internal.h b/lib/mpi/mpi-internal.h
> index d29c4537c3a3..554002182db1 100644
> --- a/lib/mpi/mpi-internal.h
> +++ b/lib/mpi/mpi-internal.h
> @@ -114,7 +114,7 @@ typedef int mpi_size_t; /* (must be a signed type) */
> */
> #define UDIV_QRNND_PREINV(q, r, nh, nl, d, di) \
> do { \
> - mpi_limb_t _ql; \
> + mpi_limb_t _ql __maybe_unused; \
> mpi_limb_t _q, _r; \
> mpi_limb_t _xh, _xl; \
> umul_ppmm(_q, _ql, (nh), (di)); \
> diff --git a/lib/mpi/mpi-mul.c b/lib/mpi/mpi-mul.c
> index 587e6335cc12..8f5fa200f297 100644
> --- a/lib/mpi/mpi-mul.c
> +++ b/lib/mpi/mpi-mul.c
> @@ -21,7 +21,6 @@ void mpi_mul(MPI w, MPI u, MPI v)
> int usign, vsign, sign_product;
> int assign_wp = 0;
> mpi_ptr_t tmp_limb = NULL;
> - unsigned int tmp_limb_nlimbs = 0;
>
> if (u->nlimbs < v->nlimbs) {
> /* Swap U and V. */
> @@ -55,7 +54,6 @@ void mpi_mul(MPI w, MPI u, MPI v)
> } else { /* Make U and V not overlap with W. */
> if (wp == up) {
> /* W and U are identical. Allocate temporary space for U. */
> - tmp_limb_nlimbs = usize;
> up = tmp_limb = mpi_alloc_limb_space(usize);
> /* Is V identical too? Keep it identical with U. */
> if (wp == vp)
> @@ -64,7 +62,6 @@ void mpi_mul(MPI w, MPI u, MPI v)
> MPN_COPY(up, wp, usize);
> } else if (wp == vp) {
> /* W and V are identical. Allocate temporary space for V. */
> - tmp_limb_nlimbs = vsize;
> vp = tmp_limb = mpi_alloc_limb_space(vsize);
> /* Copy to the temporary space. */
> MPN_COPY(vp, wp, vsize);
> diff --git a/lib/mpi/mpih-div.c b/lib/mpi/mpih-div.c
> index 182a656a1ba0..be70ee2e42d3 100644
> --- a/lib/mpi/mpih-div.c
> +++ b/lib/mpi/mpih-div.c
> @@ -31,7 +31,7 @@ mpihelp_mod_1(mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
> {
> mpi_size_t i;
> mpi_limb_t n1, n0, r;
> - mpi_limb_t dummy;
> + mpi_limb_t dummy __maybe_unused;
>
> /* Botch: Should this be handled at all? Rely on callers? */
> if (!dividend_size)
> @@ -382,7 +382,7 @@ mpihelp_divmod_1(mpi_ptr_t quot_ptr,
> {
> mpi_size_t i;
> mpi_limb_t n1, n0, r;
> - mpi_limb_t dummy;
> + mpi_limb_t dummy __maybe_unused;
>
> if (!dividend_size)
> return 0;
>