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

From: Tianjia Zhang
Date: Fri Sep 25 2020 - 10:01:26 EST


Hi Herbert,

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

Tested-by: Tianjia Zhang <tianjia.zhang@xxxxxxxxxxxxxxxxx>

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 <tianjia.zhang@xxxxxxxxxxxxxxxxx>
Tested-by: Xufeng Zhang <yunbo.xufeng@xxxxxxxxxxxxxxxxx>

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 <herbert@xxxxxxxxxxxxxxxxxxx>

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;