[PATCH] lib/mpi: Fix unused variable warnings

[Herbert Xu]

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;
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt