diff mbox

[1/2] iproute2: tc/m_pedit.c - remove dead code

Message ID 1435222983-14661-1-git-send-email-zenczykowski@gmail.com
State Accepted, archived
Delegated to: stephen hemminger
Headers show

Commit Message

Maciej Żenczykowski June 25, 2015, 9:03 a.m. UTC 
From: Maciej Żenczykowski <maze@google.com>

The initializers are simply not needed.

These if-blocks are outright dead code, because '0 > unsigned' is always
false, so only else clause triggers and regardless of which clause triggers
it only updates 'ind' which is later unconditionally written to before
being used anyway.

Otherwise we get errors from clang:

  m_pedit.c:166:8: error: comparison of 0 > unsigned expression is always false [-Werror,-Wtautological-compare]
    if (0 > tkey->off) {
        ~ ^ ~~~~~~~~~
  m_pedit.c:209:8: error: comparison of 0 > unsigned expression is always false [-Werror,-Wtautological-compare]
    if (0 > tkey->off) {
        ~ ^ ~~~~~~~~~
  2 errors generated.

Change-Id: I3c9e9092915088fc56f992e5df736851541a4458
---
 tc/m_pedit.c | 32 ++++++++------------------------
 1 file changed, 8 insertions(+), 24 deletions(-)

Comments

stephen hemminger June 25, 2015, 12:54 p.m. UTC | #1 
On Thu, 25 Jun 2015 02:03:02 -0700
Maciej Żenczykowski <zenczykowski@gmail.com> wrote:

> From: Maciej Żenczykowski <maze@google.com>
> 
> The initializers are simply not needed.
> 
> These if-blocks are outright dead code, because '0 > unsigned' is always
> false, so only else clause triggers and regardless of which clause triggers
> it only updates 'ind' which is later unconditionally written to before
> being used anyway.
> 
> Otherwise we get errors from clang:
> 
>   m_pedit.c:166:8: error: comparison of 0 > unsigned expression is always false [-Werror,-Wtautological-compare]
>     if (0 > tkey->off) {
>         ~ ^ ~~~~~~~~~
>   m_pedit.c:209:8: error: comparison of 0 > unsigned expression is always false [-Werror,-Wtautological-compare]
>     if (0 > tkey->off) {
>         ~ ^ ~~~~~~~~~
>   2 errors generated.
> 
> Change-Id: I3c9e9092915088fc56f992e5df736851541a4458
> ---
>  tc/m_pedit.c | 32 ++++++++------------------------
>  1 file changed, 8 insertions(+), 24 deletions(-)

Both applied
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diff mbox

Patch

diff --git a/tc/m_pedit.c b/tc/m_pedit.c
index dfe9b2ebd6e0..4fdd189d7d9c 100644
--- a/tc/m_pedit.c
+++ b/tc/m_pedit.c
@@ -160,17 +160,9 @@  pack_key32(__u32 retain,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey)
 int
 pack_key16(__u32 retain,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey)
 {
-	int ind = 0, stride = 0;
+	int ind, stride;
 	__u32 m[4] = {0xFFFF0000,0xFF0000FF,0x0000FFFF};
 
-	if (0 > tkey->off) {
-		ind = tkey->off + 1;
-		if (0 > ind)
-			ind = -1*ind;
-	} else {
-		ind = tkey->off;
-	}
-
 	if (tkey->val > 0xFFFF || tkey->mask > 0xFFFF) {
 		fprintf(stderr, "pack_key16 bad value\n");
 		return -1;
@@ -178,18 +170,16 @@  pack_key16(__u32 retain,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey)
 
 	ind = tkey->off & 3;
 
-	if (0 > ind || 2 < ind) {
+	if (ind == 3) {
 		fprintf(stderr, "pack_key16 bad index value %d\n",ind);
 		return -1;
 	}
 
 	stride = 8 * ind;
 	tkey->val = htons(tkey->val);
-	if (stride > 0) {
-		tkey->val <<= stride;
-		tkey->mask <<= stride;
-		retain <<= stride;
-	}
+	tkey->val <<= stride;
+	tkey->mask <<= stride;
+	retain <<= stride;
 	tkey->mask = retain|m[ind];
 
 	tkey->off &= ~3;
@@ -203,28 +193,22 @@  pack_key16(__u32 retain,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey)
 int
 pack_key8(__u32 retain,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey)
 {
-	int ind = 0, stride = 0;
+	int ind, stride;
 	__u32 m[4] = {0xFFFFFF00,0xFFFF00FF,0xFF00FFFF,0x00FFFFFF};
 
-	if (0 > tkey->off) {
-		ind = tkey->off + 1;
-		if (0 > ind)
-			ind = -1*ind;
-	} else {
-		ind = tkey->off;
-	}
-
 	if (tkey->val > 0xFF || tkey->mask > 0xFF) {
 		fprintf(stderr, "pack_key8 bad value (val %x mask %x\n", tkey->val, tkey->mask);
 		return -1;
 	}
 
 	ind = tkey->off & 3;
+
 	stride = 8 * ind;
 	tkey->val <<= stride;
 	tkey->mask <<= stride;
 	retain <<= stride;
 	tkey->mask = retain|m[ind];
+
 	tkey->off &= ~3;
 
 	if (pedit_debug)