[ovs-dev] [shadow 2/2] Avoid shadowing local variable names.

Ben Pfaff blp at nicira.com
Thu Sep 2 17:12:33 UTC 2010


All of these changes avoid using the same name for two local variables
within a same function.  None of them are actual bugs as far as I can tell,
but any of them could be confusing to the casual reader.

The one in lib/ovsdb-idl.c is particularly brilliant: inner and outer
loops both using (different) variables named 'i'.

Found with GCC -Wshadow.
---
 lib/dpif-netdev.c          |    1 -
 lib/dynamic-string.c       |    2 --
 lib/json.c                 |    1 -
 lib/learning-switch.c      |    6 +++---
 lib/netdev-linux.c         |    6 +++---
 lib/netlink.c              |   10 +++++-----
 lib/ofp-parse.c            |    6 +++---
 lib/ovsdb-idl.c            |    8 ++++----
 lib/process.c              |    2 +-
 lib/stream-fd.c            |    2 +-
 lib/stream-ssl.c           |    6 +++---
 ofproto/ofproto.c          |    2 --
 ovsdb/execution.c          |    2 --
 tests/test-csum.c          |    3 +--
 tests/test-ovsdb.c         |    6 ++++--
 utilities/ovs-controller.c |    6 ++----
 utilities/ovs-openflowd.c  |    4 ----
 utilities/ovs-vsctl.c      |   24 +++++++++++-------------
 vswitchd/bridge.c          |    4 ----
 19 files changed, 41 insertions(+), 60 deletions(-)

diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index 323f364..3975b5a 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -1104,7 +1104,6 @@ dp_netdev_modify_vlan_tci(struct ofpbuf *packet, uint16_t tci, uint16_t mask)
         veh->veth_tci |= htons(tci);
     } else {
         /* Insert new 802.1Q header. */
-        struct eth_header *eh = packet->l2;
         struct vlan_eth_header tmp;
         memcpy(tmp.veth_dst, eh->eth_dst, ETH_ADDR_LEN);
         memcpy(tmp.veth_src, eh->eth_src, ETH_ADDR_LEN);
diff --git a/lib/dynamic-string.c b/lib/dynamic-string.c
index 5f8054a..3af7fc9 100644
--- a/lib/dynamic-string.c
+++ b/lib/dynamic-string.c
@@ -147,8 +147,6 @@ ds_put_format_valist(struct ds *ds, const char *format, va_list args_)
     if (needed < available) {
         ds->length += needed;
     } else {
-        size_t available;
-
         ds_reserve(ds, ds->length + needed);
 
         va_copy(args, args_);
diff --git a/lib/json.c b/lib/json.c
index 3b70e6b..5887f67 100644
--- a/lib/json.c
+++ b/lib/json.c
@@ -705,7 +705,6 @@ json_lex_number(struct json_parser *p)
      *
      * We suppress negative zeros as a matter of policy. */
     if (!significand) {
-        struct json_token token;
         token.type = T_INTEGER;
         token.u.integer = 0;
         json_parser_input(p, &token);
diff --git a/lib/learning-switch.c b/lib/learning-switch.c
index e189f1e..4e7645d 100644
--- a/lib/learning-switch.c
+++ b/lib/learning-switch.c
@@ -220,10 +220,10 @@ lswitch_process_packet(struct lswitch *sw, struct rconn *rconn,
         }
     }
     if (VLOG_IS_DBG_ENABLED()) {
-        char *p = ofp_to_string(msg->data, msg->size, 2);
+        char *s = ofp_to_string(msg->data, msg->size, 2);
         VLOG_DBG_RL(&rl, "%016llx: OpenFlow packet ignored: %s",
-                    sw->datapath_id, p);
-        free(p);
+                    sw->datapath_id, s);
+        free(s);
     }
 }
 
diff --git a/lib/netdev-linux.c b/lib/netdev-linux.c
index e6036bf..7227f5d 100644
--- a/lib/netdev-linux.c
+++ b/lib/netdev-linux.c
@@ -1779,12 +1779,12 @@ netdev_linux_get_in6(const struct netdev *netdev_, struct in6_addr *in6)
         if (file != NULL) {
             const char *name = netdev_get_name(netdev_);
             while (fgets(line, sizeof line, file)) {
-                struct in6_addr in6;
+                struct in6_addr in6_tmp;
                 char ifname[16 + 1];
-                if (parse_if_inet6_line(line, &in6, ifname)
+                if (parse_if_inet6_line(line, &in6_tmp, ifname)
                     && !strcmp(name, ifname))
                 {
-                    netdev_dev->in6 = in6;
+                    netdev_dev->in6 = in6_tmp;
                     break;
                 }
             }
diff --git a/lib/netlink.c b/lib/netlink.c
index 4e83747..66c27b1 100644
--- a/lib/netlink.c
+++ b/lib/netlink.c
@@ -1036,19 +1036,19 @@ nl_policy_parse(const struct ofpbuf *msg, size_t nla_offset,
 
         type = nla->nla_type;
         if (type < n_attrs && policy[type].type != NL_A_NO_ATTR) {
-            const struct nl_policy *p = &policy[type];
+            const struct nl_policy *e = &policy[type];
             size_t min_len, max_len;
 
             /* Validate length and content. */
-            min_len = p->min_len ? p->min_len : attr_len_range[p->type][0];
-            max_len = p->max_len ? p->max_len : attr_len_range[p->type][1];
+            min_len = e->min_len ? e->min_len : attr_len_range[e->type][0];
+            max_len = e->max_len ? e->max_len : attr_len_range[e->type][1];
             if (len < min_len || len > max_len) {
                 VLOG_DBG_RL(&rl, "%zu: attr %"PRIu16" length %zu not in "
                             "allowed range %zu...%zu",
                             offset, type, len, min_len, max_len);
                 return false;
             }
-            if (p->type == NL_A_STRING) {
+            if (e->type == NL_A_STRING) {
                 if (((char *) nla)[nla->nla_len - 1]) {
                     VLOG_DBG_RL(&rl, "%zu: attr %"PRIu16" lacks null at end",
                                 offset, type);
@@ -1060,7 +1060,7 @@ nl_policy_parse(const struct ofpbuf *msg, size_t nla_offset,
                     return false;
                 }
             }
-            if (!p->optional && attrs[type] == NULL) {
+            if (!e->optional && attrs[type] == NULL) {
                 assert(n_required > 0);
                 --n_required;
             }
diff --git a/lib/ofp-parse.c b/lib/ofp-parse.c
index cc1419a..e649d17 100644
--- a/lib/ofp-parse.c
+++ b/lib/ofp-parse.c
@@ -267,12 +267,12 @@ str_to_action(char *str, struct ofpbuf *b)
             put_output_action(b, str_to_u32(arg));
         } else if (!strcasecmp(act, "enqueue")) {
             char *sp = NULL;
-            char *port = strtok_r(arg, ":q", &sp);
+            char *port_s = strtok_r(arg, ":q", &sp);
             char *queue = strtok_r(NULL, "", &sp);
-            if (port == NULL || queue == NULL) {
+            if (port_s == NULL || queue == NULL) {
                 ovs_fatal(0, "\"enqueue\" syntax is \"enqueue:PORT:QUEUE\"");
             }
-            put_enqueue_action(b, str_to_u32(port), str_to_u32(queue));
+            put_enqueue_action(b, str_to_u32(port_s), str_to_u32(queue));
         } else if (!strcasecmp(act, "drop")) {
             /* A drop action in OpenFlow occurs by just not setting
              * an action. */
diff --git a/lib/ovsdb-idl.c b/lib/ovsdb-idl.c
index 2132f9f..43ff947 100644
--- a/lib/ovsdb-idl.c
+++ b/lib/ovsdb-idl.c
@@ -433,13 +433,13 @@ ovsdb_idl_send_monitor_request(struct ovsdb_idl *idl)
         const struct ovsdb_idl_table *table = &idl->tables[i];
         const struct ovsdb_idl_table_class *tc = table->class;
         struct json *monitor_request, *columns;
-        size_t i;
+        size_t j;
 
         monitor_request = json_object_create();
         columns = json_array_create_empty();
-        for (i = 0; i < tc->n_columns; i++) {
-            const struct ovsdb_idl_column *column = &tc->columns[i];
-            if (table->modes[i] != OVSDB_IDL_MODE_NONE) {
+        for (j = 0; j < tc->n_columns; j++) {
+            const struct ovsdb_idl_column *column = &tc->columns[j];
+            if (table->modes[j] != OVSDB_IDL_MODE_NONE) {
                 json_array_add(columns, json_string_create(column->name));
             }
         }
diff --git a/lib/process.c b/lib/process.c
index a201a88..377c396 100644
--- a/lib/process.c
+++ b/lib/process.c
@@ -517,7 +517,7 @@ process_run_capture(char **argv, char **stdout_log, char **stderr_log,
     block_sigchld(&oldsigs);
     pid = fork();
     if (pid < 0) {
-        int error = errno;
+        error = errno;
 
         unblock_sigchld(&oldsigs);
         VLOG_WARN("fork failed: %s", strerror(error));
diff --git a/lib/stream-fd.c b/lib/stream-fd.c
index 9410009..ef4dc8d 100644
--- a/lib/stream-fd.c
+++ b/lib/stream-fd.c
@@ -214,7 +214,7 @@ pfd_accept(struct pstream *pstream, struct stream **new_streamp)
 
     new_fd = accept(ps->fd, (struct sockaddr *) &ss, &ss_len);
     if (new_fd < 0) {
-        int retval = errno;
+        retval = errno;
         if (retval != EAGAIN) {
             VLOG_DBG_RL(&rl, "accept: %s", strerror(retval));
         }
diff --git a/lib/stream-ssl.c b/lib/stream-ssl.c
index 70b15f0..9c7533d 100644
--- a/lib/stream-ssl.c
+++ b/lib/stream-ssl.c
@@ -385,7 +385,7 @@ do_ca_cert_bootstrap(struct stream *stream)
 
     file = fdopen(fd, "w");
     if (!file) {
-        int error = errno;
+        error = errno;
         VLOG_ERR("could not bootstrap CA cert: fdopen failed: %s",
                  strerror(error));
         unlink(ca_cert.file_name);
@@ -402,7 +402,7 @@ do_ca_cert_bootstrap(struct stream *stream)
     }
 
     if (fclose(file)) {
-        int error = errno;
+        error = errno;
         VLOG_ERR("could not bootstrap CA cert: writing %s failed: %s",
                  ca_cert.file_name, strerror(error));
         unlink(ca_cert.file_name);
@@ -921,7 +921,7 @@ pssl_accept(struct pstream *pstream, struct stream **new_streamp)
 
     new_fd = accept(pssl->fd, &sin, &sin_len);
     if (new_fd < 0) {
-        int error = errno;
+        error = errno;
         if (error != EAGAIN) {
             VLOG_DBG_RL(&rl, "accept: %s", strerror(error));
         }
diff --git a/ofproto/ofproto.c b/ofproto/ofproto.c
index 844083d..e571bd4 100644
--- a/ofproto/ofproto.c
+++ b/ofproto/ofproto.c
@@ -1071,7 +1071,6 @@ ofproto_run1(struct ofproto *p)
 
     for (i = 0; i < 50; i++) {
         struct ofpbuf *buf;
-        int error;
 
         error = dpif_recv(p->dpif, &buf);
         if (error) {
@@ -1122,7 +1121,6 @@ ofproto_run1(struct ofproto *p)
 
         retval = pvconn_accept(ofservice->pvconn, OFP_VERSION, &vconn);
         if (!retval) {
-            struct ofconn *ofconn;
             struct rconn *rconn;
             char *name;
 
diff --git a/ovsdb/execution.c b/ovsdb/execution.c
index 7ce9a3f..a96abfc 100644
--- a/ovsdb/execution.c
+++ b/ovsdb/execution.c
@@ -103,8 +103,6 @@ ovsdb_execute(struct ovsdb *db, const struct json *params,
         || !params->u.array.n
         || params->u.array.elems[0]->type != JSON_STRING
         || strcmp(params->u.array.elems[0]->u.string, db->schema->name)) {
-        struct ovsdb_error *error;
-
         if (params->type != JSON_ARRAY) {
             error = ovsdb_syntax_error(params, NULL, "array expected");
         } else {
diff --git a/tests/test-csum.c b/tests/test-csum.c
index 8c85458..eebc880 100644
--- a/tests/test-csum.c
+++ b/tests/test-csum.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009 Nicira Networks.
+ * Copyright (c) 2009, 2010 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -134,7 +134,6 @@ main(void)
         const uint16_t *data16 = (const uint16_t *) tc->data;
         const uint32_t *data32 = (const uint32_t *) tc->data;
         uint32_t partial;
-        size_t i;
 
         /* Test csum(). */
         assert(ntohs(csum(tc->data, tc->size)) == tc->csum);
diff --git a/tests/test-ovsdb.c b/tests/test-ovsdb.c
index 18784a5..04db654 100644
--- a/tests/test-ovsdb.c
+++ b/tests/test-ovsdb.c
@@ -1095,7 +1095,7 @@ do_query_distinct(int argc OVS_UNUSED, char *argv[])
     size_t n_classes;
     struct json *json;
     int exit_code = 0;
-    size_t i, j, k;
+    size_t i;
 
     /* Parse table schema, create table. */
     json = unbox_json(parse_json(argv[1]));
@@ -1161,6 +1161,7 @@ do_query_distinct(int argc OVS_UNUSED, char *argv[])
     for (i = 0; i < json->u.array.n; i++) {
         struct ovsdb_row_set results;
         struct ovsdb_condition cnd;
+        size_t j;
 
         check_ovsdb_error(ovsdb_condition_from_json(ts, json->u.array.elems[i],
                                                     NULL, &cnd));
@@ -1171,6 +1172,8 @@ do_query_distinct(int argc OVS_UNUSED, char *argv[])
         ovsdb_row_set_init(&results);
         ovsdb_query_distinct(table, &cnd, &columns, &results);
         for (j = 0; j < results.n_rows; j++) {
+            size_t k;
+
             for (k = 0; k < n_rows; k++) {
                 if (uuid_equals(ovsdb_row_get_uuid(results.rows[j]),
                                 &rows[k].uuid)) {
@@ -1833,7 +1836,6 @@ do_idl(int argc, char *argv[])
     for (i = 2; i < argc; i++) {
         char *arg = argv[i];
         struct jsonrpc_msg *request, *reply;
-        int error;
 
         if (*arg == '+') {
             /* The previous transaction didn't change anything. */
diff --git a/utilities/ovs-controller.c b/utilities/ovs-controller.c
index b18959a..40e2a80 100644
--- a/utilities/ovs-controller.c
+++ b/utilities/ovs-controller.c
@@ -107,7 +107,6 @@ main(int argc, char *argv[])
     for (i = optind; i < argc; i++) {
         const char *name = argv[i];
         struct vconn *vconn;
-        int retval;
 
         retval = vconn_open(name, OFP_VERSION, &vconn);
         if (!retval) {
@@ -146,12 +145,10 @@ main(int argc, char *argv[])
 
     while (n_switches > 0 || n_listeners > 0) {
         int iteration;
-        int i;
 
         /* Accept connections on listening vconns. */
         for (i = 0; i < n_listeners && n_switches < MAX_SWITCHES; ) {
             struct vconn *new_vconn;
-            int retval;
 
             retval = pvconn_accept(listeners[i], OFP_VERSION, &new_vconn);
             if (!retval || retval == EAGAIN) {
@@ -171,7 +168,8 @@ main(int argc, char *argv[])
             bool progress = false;
             for (i = 0; i < n_switches; ) {
                 struct switch_ *this = &switches[i];
-                int retval = do_switching(this);
+
+                retval = do_switching(this);
                 if (!retval || retval == EAGAIN) {
                     if (!retval) {
                         progress = true;
diff --git a/utilities/ovs-openflowd.c b/utilities/ovs-openflowd.c
index 8cb50e4..945b11d 100644
--- a/utilities/ovs-openflowd.c
+++ b/utilities/ovs-openflowd.c
@@ -458,8 +458,6 @@ parse_options(int argc, char *argv[], struct ofsettings *s)
     s->n_controllers = controllers.n;
     s->controllers = xmalloc(s->n_controllers * sizeof *s->controllers);
     if (argc > 1) {
-        size_t i;
-
         for (i = 0; i < s->n_controllers; i++) {
             s->controllers[i] = controller_opts;
             s->controllers[i].target = controllers.names[i];
@@ -468,8 +466,6 @@ parse_options(int argc, char *argv[], struct ofsettings *s)
 
     /* Sanity check. */
     if (controller_opts.band == OFPROTO_OUT_OF_BAND) {
-        size_t i;
-
         for (i = 0; i < s->n_controllers; i++) {
             if (!strcmp(s->controllers[i].target, "discover")) {
                 ovs_fatal(0, "Cannot perform discovery with out-of-band "
diff --git a/utilities/ovs-vsctl.c b/utilities/ovs-vsctl.c
index 4d50194..41ccf28 100644
--- a/utilities/ovs-vsctl.c
+++ b/utilities/ovs-vsctl.c
@@ -1305,12 +1305,11 @@ add_port(struct vsctl_context *ctx,
 
     get_info(ctx->ovs, &info);
     if (may_exist) {
-        struct vsctl_port *port;
+        struct vsctl_port *vsctl_port;
 
-        port = find_port(&info, port_name, false);
-        if (port) {
+        vsctl_port = find_port(&info, port_name, false);
+        if (vsctl_port) {
             struct svec want_names, have_names;
-            size_t i;
 
             svec_init(&want_names);
             for (i = 0; i < n_ifaces; i++) {
@@ -1319,15 +1318,16 @@ add_port(struct vsctl_context *ctx,
             svec_sort(&want_names);
 
             svec_init(&have_names);
-            for (i = 0; i < port->port_cfg->n_interfaces; i++) {
-                svec_add(&have_names, port->port_cfg->interfaces[i]->name);
+            for (i = 0; i < vsctl_port->port_cfg->n_interfaces; i++) {
+                svec_add(&have_names,
+                         vsctl_port->port_cfg->interfaces[i]->name);
             }
             svec_sort(&have_names);
 
-            if (strcmp(port->bridge->name, br_name)) {
+            if (strcmp(vsctl_port->bridge->name, br_name)) {
                 char *command = vsctl_context_to_string(ctx);
                 vsctl_fatal("\"%s\" but %s is actually attached to bridge %s",
-                            command, port_name, port->bridge->name);
+                            command, port_name, vsctl_port->bridge->name);
             }
 
             if (!svec_equal(&want_names, &have_names)) {
@@ -2767,8 +2767,8 @@ do_vsctl(const char *args, struct vsctl_command *commands, size_t n_commands,
 
             ds_chomp(ds, '\n');
             for (j = 0; j < ds->length; j++) {
-                int c = ds->string[j];
-                switch (c) {
+                int ch = ds->string[j];
+                switch (ch) {
                 case '\n':
                     fputs("\\n", stdout);
                     break;
@@ -2778,7 +2778,7 @@ do_vsctl(const char *args, struct vsctl_command *commands, size_t n_commands,
                     break;
 
                 default:
-                    putchar(c);
+                    putchar(ch);
                 }
             }
             putchar('\n');
@@ -2796,8 +2796,6 @@ do_vsctl(const char *args, struct vsctl_command *commands, size_t n_commands,
 
     if (wait_for_reload && status != TXN_UNCHANGED) {
         for (;;) {
-            const struct ovsrec_open_vswitch *ovs;
-
             ovsdb_idl_run(idl);
             OVSREC_OPEN_VSWITCH_FOR_EACH (ovs, idl) {
                 if (ovs->cur_cfg >= next_cfg) {
diff --git a/vswitchd/bridge.c b/vswitchd/bridge.c
index 598b001..3f5e3d4 100644
--- a/vswitchd/bridge.c
+++ b/vswitchd/bridge.c
@@ -632,7 +632,6 @@ bridge_reconfigure(const struct ovsrec_open_vswitch *ovs_cfg)
         struct odp_port *dpif_ports;
         size_t n_dpif_ports;
         struct shash cur_ifaces, want_ifaces;
-        struct shash_node *node;
 
         /* Get the set of interfaces currently in this datapath. */
         dpif_port_list(br->dpif, &dpif_ports, &n_dpif_ports);
@@ -765,7 +764,6 @@ bridge_reconfigure(const struct ovsrec_open_vswitch *ovs_cfg)
             struct ovsrec_controller **controllers;
             struct ofproto_sflow_options oso;
             size_t n_controllers;
-            size_t i;
 
             memset(&oso, 0, sizeof oso);
 
@@ -2822,7 +2820,6 @@ bond_rebalance_port(struct port *port)
              * smallest hashes instead of the biggest ones.  There is little
              * reason behind this decision; we could use the opposite sort
              * order to shift away big hashes ahead of small ones. */
-            size_t i;
             bool order_swapped;
 
             for (i = 0; i < from->n_hashes; i++) {
@@ -3407,7 +3404,6 @@ port_reconfigure(struct port *port, const struct ovsrec_port *cfg)
     trunks = NULL;
     if (vlan < 0 && cfg->n_trunks) {
         size_t n_errors;
-        size_t i;
 
         trunks = bitmap_allocate(4096);
         n_errors = 0;
-- 
1.7.1





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