Revert "Add Type Checking On Channel Args"

23 files changed, 211 insertions, 134 deletions

diff --git a/src/core/ext/filters/client_channel/client_channel.cc b/src/core/ext/filters/client_channel/client_channel.cc
index f141aabe70..ea6775a8d8 100644
--- a/src/core/ext/filters/client_channel/client_channel.cc
+++ b/src/core/ext/filters/client_channel/client_channel.cc
@@ -327,14 +327,16 @@ static void on_resolver_result_changed_locked(void* arg, grpc_error* error) {
   if (chand->resolver_result != nullptr) {
     if (chand->resolver != nullptr) {
       // Find LB policy name.
-      const char* lb_policy_name = grpc_channel_args_get_string(
+      const grpc_arg* channel_arg = grpc_channel_args_find(
           chand->resolver_result, GRPC_ARG_LB_POLICY_NAME);
+      const char* lb_policy_name = grpc_channel_arg_get_string(channel_arg);
       // Special case: If at least one balancer address is present, we use
       // the grpclb policy, regardless of what the resolver actually specified.
-      grpc_lb_addresses* addresses =
-          grpc_channel_args_get_pointer<grpc_lb_addresses>(
-              chand->resolver_result, GRPC_ARG_LB_ADDRESSES);
-      if (addresses != nullptr) {
+      channel_arg =
+          grpc_channel_args_find(chand->resolver_result, GRPC_ARG_LB_ADDRESSES);
+      if (channel_arg != nullptr && channel_arg->type == GRPC_ARG_POINTER) {
+        grpc_lb_addresses* addresses =
+            static_cast<grpc_lb_addresses*>(channel_arg->value.pointer.p);
         bool found_balancer_address = false;
         for (size_t i = 0; i < addresses->num_addresses; ++i) {
           if (addresses->addresses[i].is_balancer) {
@@ -398,15 +400,18 @@ static void on_resolver_result_changed_locked(void* arg, grpc_error* error) {
       // The copy will be saved in chand->lb_policy_name below.
       lb_policy_name_dup = gpr_strdup(lb_policy_name);
       // Find service config.
-      service_config_json = gpr_strdup(grpc_channel_args_get_string(
-          chand->resolver_result, GRPC_ARG_SERVICE_CONFIG));
+      channel_arg = grpc_channel_args_find(chand->resolver_result,
+                                           GRPC_ARG_SERVICE_CONFIG);
+      service_config_json =
+          gpr_strdup(grpc_channel_arg_get_string(channel_arg));
       if (service_config_json != nullptr) {
         grpc_core::UniquePtr<grpc_core::ServiceConfig> service_config =
             grpc_core::ServiceConfig::Create(service_config_json);
         if (service_config != nullptr) {
           if (chand->enable_retries) {
-            const char* server_uri = grpc_channel_args_get_string(
-                chand->resolver_result, GRPC_ARG_SERVER_URI);
+            channel_arg = grpc_channel_args_find(chand->resolver_result,
+                                                 GRPC_ARG_SERVER_URI);
+            const char* server_uri = grpc_channel_arg_get_string(channel_arg);
             GPR_ASSERT(server_uri != nullptr);
             grpc_uri* uri = grpc_uri_parse(server_uri, true);
             GPR_ASSERT(uri->path[0] != '\0');
@@ -643,37 +648,45 @@ static grpc_error* cc_init_channel_elem(grpc_channel_element* elem,
                                "client_channel");
   grpc_client_channel_start_backup_polling(chand->interested_parties);
   // Record max per-RPC retry buffer size.
-  chand->per_rpc_retry_buffer_size = (size_t)grpc_channel_args_get_integer(
-      args->channel_args, GRPC_ARG_PER_RPC_RETRY_BUFFER_SIZE,
-      {DEFAULT_PER_RPC_RETRY_BUFFER_SIZE, 0, INT_MAX});
+  const grpc_arg* arg = grpc_channel_args_find(
+      args->channel_args, GRPC_ARG_PER_RPC_RETRY_BUFFER_SIZE);
+  chand->per_rpc_retry_buffer_size = (size_t)grpc_channel_arg_get_integer(
+      arg, {DEFAULT_PER_RPC_RETRY_BUFFER_SIZE, 0, INT_MAX});
   // Record enable_retries.
-  chand->enable_retries = grpc_channel_args_get_bool(
-      args->channel_args, GRPC_ARG_ENABLE_RETRIES, true);
+  arg = grpc_channel_args_find(args->channel_args, GRPC_ARG_ENABLE_RETRIES);
+  chand->enable_retries = grpc_channel_arg_get_bool(arg, true);
   // Record client channel factory.
-  grpc_client_channel_factory* client_channel_factory =
-      grpc_channel_args_get_pointer<grpc_client_channel_factory>(
-          args->channel_args, GRPC_ARG_CLIENT_CHANNEL_FACTORY);
-  if (client_channel_factory == nullptr) {
+  arg = grpc_channel_args_find(args->channel_args,
+                               GRPC_ARG_CLIENT_CHANNEL_FACTORY);
+  if (arg == nullptr) {
     return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
-        "Missing or malformed client channel factory in args for client "
-        "channel filter");
+        "Missing client channel factory in args for client channel filter");
   }
-  grpc_client_channel_factory_ref(client_channel_factory);
-  chand->client_channel_factory = client_channel_factory;
+  if (arg->type != GRPC_ARG_POINTER) {
+    return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+        "client channel factory arg must be a pointer");
+  }
+  grpc_client_channel_factory_ref(
+      static_cast<grpc_client_channel_factory*>(arg->value.pointer.p));
+  chand->client_channel_factory =
+      static_cast<grpc_client_channel_factory*>(arg->value.pointer.p);
   // Get server name to resolve, using proxy mapper if needed.
-  char* server_uri =
-      grpc_channel_args_get_string(args->channel_args, GRPC_ARG_SERVER_URI);
-  if (server_uri == nullptr) {
+  arg = grpc_channel_args_find(args->channel_args, GRPC_ARG_SERVER_URI);
+  if (arg == nullptr) {
+    return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+        "Missing server uri in args for client channel filter");
+  }
+  if (arg->type != GRPC_ARG_STRING) {
     return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
-        "Missing or malformed server uri in args for client channel filter");
+        "server uri arg must be a string");
   }
   char* proxy_name = nullptr;
   grpc_channel_args* new_args = nullptr;
-  grpc_proxy_mappers_map_name(server_uri, args->channel_args, &proxy_name,
-                              &new_args);
+  grpc_proxy_mappers_map_name(arg->value.string, args->channel_args,
+                              &proxy_name, &new_args);
   // Instantiate resolver.
   chand->resolver = grpc_core::ResolverRegistry::CreateResolver(
-      proxy_name != nullptr ? proxy_name : server_uri,
+      proxy_name != nullptr ? proxy_name : arg->value.string,
       new_args != nullptr ? new_args : args->channel_args,
       chand->interested_parties, chand->combiner);
   if (proxy_name != nullptr) gpr_free(proxy_name);
diff --git a/src/core/ext/filters/client_channel/http_connect_handshaker.cc b/src/core/ext/filters/client_channel/http_connect_handshaker.cc
index 58f059829c..4e8b8b71db 100644
--- a/src/core/ext/filters/client_channel/http_connect_handshaker.cc
+++ b/src/core/ext/filters/client_channel/http_connect_handshaker.cc
@@ -254,8 +254,9 @@ static void http_connect_handshaker_do_handshake(
       reinterpret_cast<http_connect_handshaker*>(handshaker_in);
   // Check for HTTP CONNECT channel arg.
   // If not found, invoke on_handshake_done without doing anything.
-  char* server_name =
-      grpc_channel_args_get_string(args->args, GRPC_ARG_HTTP_CONNECT_SERVER);
+  const grpc_arg* arg =
+      grpc_channel_args_find(args->args, GRPC_ARG_HTTP_CONNECT_SERVER);
+  char* server_name = grpc_channel_arg_get_string(arg);
   if (server_name == nullptr) {
     // Set shutdown to true so that subsequent calls to
     // http_connect_handshaker_shutdown() do nothing.
@@ -266,8 +267,8 @@ static void http_connect_handshaker_do_handshake(
     return;
   }
   // Get headers from channel args.
-  char* arg_header_string =
-      grpc_channel_args_get_string(args->args, GRPC_ARG_HTTP_CONNECT_HEADERS);
+  arg = grpc_channel_args_find(args->args, GRPC_ARG_HTTP_CONNECT_HEADERS);
+  char* arg_header_string = grpc_channel_arg_get_string(arg);
   grpc_http_header* headers = nullptr;
   size_t num_headers = 0;
   char** header_strings = nullptr;
diff --git a/src/core/ext/filters/client_channel/http_proxy.cc b/src/core/ext/filters/client_channel/http_proxy.cc
index e21de35a7d..9baccd8628 100644
--- a/src/core/ext/filters/client_channel/http_proxy.cc
+++ b/src/core/ext/filters/client_channel/http_proxy.cc
@@ -88,7 +88,9 @@ done:
  * should be used.
  */
 bool http_proxy_enabled(const grpc_channel_args* args) {
-  return grpc_channel_args_get_bool(args, GRPC_ARG_ENABLE_HTTP_PROXY, true);
+  const grpc_arg* arg =
+      grpc_channel_args_find(args, GRPC_ARG_ENABLE_HTTP_PROXY);
+  return grpc_channel_arg_get_bool(arg, true);
 }
 
 static bool proxy_mapper_map_name(grpc_proxy_mapper* mapper,
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
index 0ee4958f3d..263b51ae89 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
@@ -1045,8 +1045,8 @@ GrpcLb::GrpcLb(const grpc_lb_addresses* addresses,
                     grpc_combiner_scheduler(args.combiner));
   grpc_connectivity_state_init(&state_tracker_, GRPC_CHANNEL_IDLE, "grpclb");
   // Record server name.
-  const char* server_uri =
-      grpc_channel_args_get_string(args.args, GRPC_ARG_SERVER_URI);
+  const grpc_arg* arg = grpc_channel_args_find(args.args, GRPC_ARG_SERVER_URI);
+  const char* server_uri = grpc_channel_arg_get_string(arg);
   GPR_ASSERT(server_uri != nullptr);
   grpc_uri* uri = grpc_uri_parse(server_uri, true);
   GPR_ASSERT(uri->path[0] != '\0');
@@ -1058,12 +1058,12 @@ GrpcLb::GrpcLb(const grpc_lb_addresses* addresses,
   }
   grpc_uri_destroy(uri);
   // Record LB call timeout.
-  lb_call_timeout_ms_ = grpc_channel_args_get_integer(
-      args.args, GRPC_ARG_GRPCLB_CALL_TIMEOUT_MS, {0, 0, INT_MAX});
+  arg = grpc_channel_args_find(args.args, GRPC_ARG_GRPCLB_CALL_TIMEOUT_MS);
+  lb_call_timeout_ms_ = grpc_channel_arg_get_integer(arg, {0, 0, INT_MAX});
   // Record fallback timeout.
-  lb_fallback_timeout_ms_ = grpc_channel_args_get_integer(
-      args.args, GRPC_ARG_GRPCLB_FALLBACK_TIMEOUT_MS,
-      {GRPC_GRPCLB_DEFAULT_FALLBACK_TIMEOUT_MS, 0, INT_MAX});
+  arg = grpc_channel_args_find(args.args, GRPC_ARG_GRPCLB_FALLBACK_TIMEOUT_MS);
+  lb_fallback_timeout_ms_ = grpc_channel_arg_get_integer(
+      arg, {GRPC_GRPCLB_DEFAULT_FALLBACK_TIMEOUT_MS, 0, INT_MAX});
   // Process channel args.
   ProcessChannelArgsLocked(*args.args);
 }
@@ -1284,10 +1284,8 @@ void GrpcLb::NotifyOnStateChangeLocked(grpc_connectivity_state* current,
 }
 
 void GrpcLb::ProcessChannelArgsLocked(const grpc_channel_args& args) {
-  const grpc_lb_addresses* addresses =
-      grpc_channel_args_get_pointer<grpc_lb_addresses>(&args,
-                                                       GRPC_ARG_LB_ADDRESSES);
-  if (GPR_UNLIKELY(addresses == nullptr)) {
+  const grpc_arg* arg = grpc_channel_args_find(&args, GRPC_ARG_LB_ADDRESSES);
+  if (GPR_UNLIKELY(arg == nullptr || arg->type != GRPC_ARG_POINTER)) {
     // Ignore this update.
     gpr_log(
         GPR_ERROR,
@@ -1295,6 +1293,8 @@ void GrpcLb::ProcessChannelArgsLocked(const grpc_channel_args& args) {
         this);
     return;
   }
+  const grpc_lb_addresses* addresses =
+      static_cast<const grpc_lb_addresses*>(arg->value.pointer.p);
   // Update fallback address list.
   if (fallback_backend_addresses_ != nullptr) {
     grpc_lb_addresses_destroy(fallback_backend_addresses_);
@@ -1860,12 +1860,13 @@ class GrpcLbFactory : public LoadBalancingPolicyFactory {
   OrphanablePtr<LoadBalancingPolicy> CreateLoadBalancingPolicy(
       const LoadBalancingPolicy::Args& args) const override {
     /* Count the number of gRPC-LB addresses. There must be at least one. */
-    grpc_lb_addresses* addresses =
-        grpc_channel_args_get_pointer<grpc_lb_addresses>(args.args,
-                                                         GRPC_ARG_LB_ADDRESSES);
-    if (addresses == nullptr) {
+    const grpc_arg* arg =
+        grpc_channel_args_find(args.args, GRPC_ARG_LB_ADDRESSES);
+    if (arg == nullptr || arg->type != GRPC_ARG_POINTER) {
       return nullptr;
     }
+    grpc_lb_addresses* addresses =
+        static_cast<grpc_lb_addresses*>(arg->value.pointer.p);
     size_t num_grpclb_addrs = 0;
     for (size_t i = 0; i < addresses->num_addresses; ++i) {
       if (addresses->addresses[i].is_balancer) ++num_grpclb_addrs;
@@ -1892,9 +1893,10 @@ bool maybe_add_client_load_reporting_filter(grpc_channel_stack_builder* builder,
                                             void* arg) {
   const grpc_channel_args* args =
       grpc_channel_stack_builder_get_channel_arguments(builder);
-  const char* lb_policy =
-      grpc_channel_args_get_string(args, GRPC_ARG_LB_POLICY_NAME);
-  if (lb_policy != nullptr && strcmp(lb_policy, "grpclb") == 0) {
+  const grpc_arg* channel_arg =
+      grpc_channel_args_find(args, GRPC_ARG_LB_POLICY_NAME);
+  if (channel_arg != nullptr && channel_arg->type == GRPC_ARG_STRING &&
+      strcmp(channel_arg->value.string, "grpclb") == 0) {
     return grpc_channel_stack_builder_append_filter(
         builder, (const grpc_channel_filter*)arg, nullptr, nullptr);
   }
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel_secure.cc b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel_secure.cc
index 972bdd40d5..441efd5e23 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel_secure.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel_secure.cc
@@ -72,10 +72,11 @@ grpc_channel_args* grpc_lb_policy_grpclb_modify_lb_channel_args(
   grpc_arg args_to_add[2];
   size_t num_args_to_add = 0;
   // Add arg for targets info table.
+  const grpc_arg* arg = grpc_channel_args_find(args, GRPC_ARG_LB_ADDRESSES);
+  GPR_ASSERT(arg != nullptr);
+  GPR_ASSERT(arg->type == GRPC_ARG_POINTER);
   grpc_lb_addresses* addresses =
-      grpc_channel_args_get_pointer<grpc_lb_addresses>(args,
-                                                       GRPC_ARG_LB_ADDRESSES);
-  GPR_ASSERT(addresses != nullptr);
+      static_cast<grpc_lb_addresses*>(arg->value.pointer.p);
   grpc_core::RefCountedPtr<grpc_core::TargetAuthorityTable>
       target_authority_table = grpc_core::CreateTargetAuthorityTable(addresses);
   args_to_add[num_args_to_add++] =
diff --git a/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc
index 70220e28d3..ff2140e628 100644
--- a/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc
@@ -281,10 +281,8 @@ void PickFirst::PingOneLocked(grpc_closure* on_initiate, grpc_closure* on_ack) {
 }
 
 void PickFirst::UpdateLocked(const grpc_channel_args& args) {
-  const grpc_lb_addresses* addresses =
-      grpc_channel_args_get_pointer<const grpc_lb_addresses>(
-          &args, GRPC_ARG_LB_ADDRESSES);
-  if (addresses == nullptr) {
+  const grpc_arg* arg = grpc_channel_args_find(&args, GRPC_ARG_LB_ADDRESSES);
+  if (arg == nullptr || arg->type != GRPC_ARG_POINTER) {
     if (subchannel_list_ == nullptr) {
       // If we don't have a current subchannel list, go into TRANSIENT FAILURE.
       grpc_connectivity_state_set(
@@ -300,6 +298,8 @@ void PickFirst::UpdateLocked(const grpc_channel_args& args) {
     }
     return;
   }
+  const grpc_lb_addresses* addresses =
+      static_cast<const grpc_lb_addresses*>(arg->value.pointer.p);
   if (grpc_lb_pick_first_trace.enabled()) {
     gpr_log(GPR_INFO,
             "Pick First %p received update with %" PRIuPTR " addresses", this,
diff --git a/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc
index 066f6ef7a6..b177385065 100644
--- a/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc
@@ -607,10 +607,8 @@ void RoundRobin::PingOneLocked(grpc_closure* on_initiate,
 }
 
 void RoundRobin::UpdateLocked(const grpc_channel_args& args) {
-  grpc_lb_addresses* addresses =
-      grpc_channel_args_get_pointer<grpc_lb_addresses>(&args,
-                                                       GRPC_ARG_LB_ADDRESSES);
-  if (GPR_UNLIKELY(addresses == nullptr)) {
+  const grpc_arg* arg = grpc_channel_args_find(&args, GRPC_ARG_LB_ADDRESSES);
+  if (GPR_UNLIKELY(arg == nullptr || arg->type != GRPC_ARG_POINTER)) {
     gpr_log(GPR_ERROR, "[RR %p] update provided no addresses; ignoring", this);
     // If we don't have a current subchannel list, go into TRANSIENT_FAILURE.
     // Otherwise, keep using the current subchannel list (ignore this update).
@@ -622,6 +620,8 @@ void RoundRobin::UpdateLocked(const grpc_channel_args& args) {
     }
     return;
   }
+  grpc_lb_addresses* addresses =
+      static_cast<grpc_lb_addresses*>(arg->value.pointer.p);
   if (grpc_lb_round_robin_trace.enabled()) {
     gpr_log(GPR_INFO, "[RR %p] received update with %" PRIuPTR " addresses",
             this, addresses->num_addresses);
diff --git a/src/core/ext/filters/client_channel/lb_policy_factory.cc b/src/core/ext/filters/client_channel/lb_policy_factory.cc
index 93dae753bf..7c8cba55b7 100644
--- a/src/core/ext/filters/client_channel/lb_policy_factory.cc
+++ b/src/core/ext/filters/client_channel/lb_policy_factory.cc
@@ -147,6 +147,9 @@ grpc_arg grpc_lb_addresses_create_channel_arg(
 
 grpc_lb_addresses* grpc_lb_addresses_find_channel_arg(
     const grpc_channel_args* channel_args) {
-  return grpc_channel_args_get_pointer<grpc_lb_addresses>(
-      channel_args, GRPC_ARG_LB_ADDRESSES);
+  const grpc_arg* lb_addresses_arg =
+      grpc_channel_args_find(channel_args, GRPC_ARG_LB_ADDRESSES);
+  if (lb_addresses_arg == nullptr || lb_addresses_arg->type != GRPC_ARG_POINTER)
+    return nullptr;
+  return static_cast<grpc_lb_addresses*>(lb_addresses_arg->value.pointer.p);
 }
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
index 01156b1e40..f4f6444c5f 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
@@ -140,11 +140,14 @@ AresDnsResolver::AresDnsResolver(const ResolverArgs& args)
     dns_server_ = gpr_strdup(args.uri->authority);
   }
   channel_args_ = grpc_channel_args_copy(args.args);
-  request_service_config_ = !grpc_channel_args_get_bool(
-      channel_args_, GRPC_ARG_SERVICE_CONFIG_DISABLE_RESOLUTION, false);
-  min_time_between_resolutions_ = grpc_channel_args_get_integer(
-      channel_args_, GRPC_ARG_DNS_MIN_TIME_BETWEEN_RESOLUTIONS_MS,
-      {1000, 0, INT_MAX});
+  const grpc_arg* arg = grpc_channel_args_find(
+      channel_args_, GRPC_ARG_SERVICE_CONFIG_DISABLE_RESOLUTION);
+  request_service_config_ = !grpc_channel_arg_get_integer(
+      arg, (grpc_integer_options){false, false, true});
+  arg = grpc_channel_args_find(channel_args_,
+                               GRPC_ARG_DNS_MIN_TIME_BETWEEN_RESOLUTIONS_MS);
+  min_time_between_resolutions_ =
+      grpc_channel_arg_get_integer(arg, {1000, 0, INT_MAX});
   interested_parties_ = grpc_pollset_set_create();
   if (args.pollset_set != nullptr) {
     grpc_pollset_set_add_pollset_set(interested_parties_, args.pollset_set);
diff --git a/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc b/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
index 25e92a078d..fae4c33a17 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
+++ b/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
@@ -116,9 +116,10 @@ NativeDnsResolver::NativeDnsResolver(const ResolverArgs& args)
   if (path[0] == '/') ++path;
   name_to_resolve_ = gpr_strdup(path);
   channel_args_ = grpc_channel_args_copy(args.args);
-  min_time_between_resolutions_ = grpc_channel_args_get_integer(
-      args.args, GRPC_ARG_DNS_MIN_TIME_BETWEEN_RESOLUTIONS_MS,
-      {1000, 0, INT_MAX});
+  const grpc_arg* arg = grpc_channel_args_find(
+      args.args, GRPC_ARG_DNS_MIN_TIME_BETWEEN_RESOLUTIONS_MS);
+  min_time_between_resolutions_ =
+      grpc_channel_arg_get_integer(arg, {1000, 0, INT_MAX});
   interested_parties_ = grpc_pollset_set_create();
   if (args.pollset_set != nullptr) {
     grpc_pollset_set_add_pollset_set(interested_parties_, args.pollset_set);
diff --git a/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc b/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc
index 9250dbd6b3..99a33f2277 100644
--- a/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc
+++ b/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc
@@ -252,15 +252,20 @@ static const grpc_arg_pointer_vtable response_generator_arg_vtable = {
 
 grpc_arg FakeResolverResponseGenerator::MakeChannelArg(
     FakeResolverResponseGenerator* generator) {
-  return grpc_channel_arg_pointer_create(
-      const_cast<char*>(GRPC_ARG_FAKE_RESOLVER_RESPONSE_GENERATOR), generator,
-      &response_generator_arg_vtable);
+  grpc_arg arg;
+  arg.type = GRPC_ARG_POINTER;
+  arg.key = (char*)GRPC_ARG_FAKE_RESOLVER_RESPONSE_GENERATOR;
+  arg.value.pointer.p = generator;
+  arg.value.pointer.vtable = &response_generator_arg_vtable;
+  return arg;
 }
 
 FakeResolverResponseGenerator* FakeResolverResponseGenerator::GetFromArgs(
     const grpc_channel_args* args) {
-  return grpc_channel_args_get_pointer<FakeResolverResponseGenerator>(
-      args, GRPC_ARG_FAKE_RESOLVER_RESPONSE_GENERATOR);
+  const grpc_arg* arg =
+      grpc_channel_args_find(args, GRPC_ARG_FAKE_RESOLVER_RESPONSE_GENERATOR);
+  if (arg == nullptr || arg->type != GRPC_ARG_POINTER) return nullptr;
+  return static_cast<FakeResolverResponseGenerator*>(arg->value.pointer.p);
 }
 
 //
diff --git a/src/core/ext/filters/client_channel/subchannel.cc b/src/core/ext/filters/client_channel/subchannel.cc
index 5db5d1f6c0..f010002ab9 100644
--- a/src/core/ext/filters/client_channel/subchannel.cc
+++ b/src/core/ext/filters/client_channel/subchannel.cc
@@ -736,8 +736,9 @@ void grpc_get_subchannel_address_arg(const grpc_channel_args* args,
 }
 
 const char* grpc_get_subchannel_address_uri_arg(const grpc_channel_args* args) {
-  const char* addr_str =
-      grpc_channel_args_get_string(args, GRPC_ARG_SUBCHANNEL_ADDRESS);
+  const grpc_arg* addr_arg =
+      grpc_channel_args_find(args, GRPC_ARG_SUBCHANNEL_ADDRESS);
+  const char* addr_str = grpc_channel_arg_get_string(addr_arg);
   GPR_ASSERT(addr_str != nullptr);  // Should have been set by LB policy.
   return addr_str;
 }
diff --git a/src/core/ext/filters/deadline/deadline_filter.cc b/src/core/ext/filters/deadline/deadline_filter.cc
index caa547204b..e0a41a3637 100644
--- a/src/core/ext/filters/deadline/deadline_filter.cc
+++ b/src/core/ext/filters/deadline/deadline_filter.cc
@@ -358,8 +358,8 @@ const grpc_channel_filter grpc_server_deadline_filter = {
 };
 
 bool grpc_deadline_checking_enabled(const grpc_channel_args* channel_args) {
-  return grpc_channel_args_get_bool(
-      channel_args, GRPC_ARG_ENABLE_DEADLINE_CHECKS,
+  return grpc_channel_arg_get_bool(
+      grpc_channel_args_find(channel_args, GRPC_ARG_ENABLE_DEADLINE_CHECKS),
       !grpc_channel_args_want_minimal_stack(channel_args));
 }
 
diff --git a/src/core/ext/filters/http/client/http_client_filter.cc b/src/core/ext/filters/http/client/http_client_filter.cc
index fe7f2ba705..ae94ce47b9 100644
--- a/src/core/ext/filters/http/client/http_client_filter.cc
+++ b/src/core/ext/filters/http/client/http_client_filter.cc
@@ -23,7 +23,6 @@
 #include <stdint.h>
 #include <string.h>
 #include "src/core/ext/filters/http/client/http_client_filter.h"
-#include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gprpp/manual_constructor.h"
 #include "src/core/lib/profiling/timers.h"
@@ -436,43 +435,64 @@ static void destroy_call_elem(grpc_call_element* elem,
                               const grpc_call_final_info* final_info,
                               grpc_closure* ignored) {}
 
-static grpc_mdelem scheme_from_args(const grpc_channel_args* channel_args) {
+static grpc_mdelem scheme_from_args(const grpc_channel_args* args) {
+  unsigned i;
+  size_t j;
   grpc_mdelem valid_schemes[] = {GRPC_MDELEM_SCHEME_HTTP,
                                  GRPC_MDELEM_SCHEME_HTTPS};
-  char* scheme =
-      grpc_channel_args_get_string(channel_args, GRPC_ARG_HTTP2_SCHEME);
-  if (scheme != nullptr) {
-    for (size_t i = 0; i < GPR_ARRAY_SIZE(valid_schemes); i++) {
-      if (0 == grpc_slice_str_cmp(GRPC_MDVALUE(valid_schemes[i]), scheme)) {
-        return valid_schemes[i];
+  if (args != nullptr) {
+    for (i = 0; i < args->num_args; ++i) {
+      if (args->args[i].type == GRPC_ARG_STRING &&
+          strcmp(args->args[i].key, GRPC_ARG_HTTP2_SCHEME) == 0) {
+        for (j = 0; j < GPR_ARRAY_SIZE(valid_schemes); j++) {
+          if (0 == grpc_slice_str_cmp(GRPC_MDVALUE(valid_schemes[j]),
+                                      args->args[i].value.string)) {
+            return valid_schemes[j];
+          }
+        }
       }
     }
   }
   return GRPC_MDELEM_SCHEME_HTTP;
 }
 
-static size_t max_payload_size_from_args(
-    const grpc_channel_args* channel_args) {
-  return grpc_channel_args_get_integer(
-      channel_args, GRPC_ARG_MAX_PAYLOAD_SIZE_FOR_GET,
-      {kMaxPayloadSizeForGet, 0, kMaxPayloadSizeForGet});
+static size_t max_payload_size_from_args(const grpc_channel_args* args) {
+  if (args != nullptr) {
+    for (size_t i = 0; i < args->num_args; ++i) {
+      if (0 == strcmp(args->args[i].key, GRPC_ARG_MAX_PAYLOAD_SIZE_FOR_GET)) {
+        if (args->args[i].type != GRPC_ARG_INTEGER) {
+          gpr_log(GPR_ERROR, "%s: must be an integer",
+                  GRPC_ARG_MAX_PAYLOAD_SIZE_FOR_GET);
+        } else {
+          return static_cast<size_t>(args->args[i].value.integer);
+        }
+      }
+    }
+  }
+  return kMaxPayloadSizeForGet;
 }
 
 static grpc_slice user_agent_from_args(const grpc_channel_args* args,
                                        const char* transport_name) {
   gpr_strvec v;
+  size_t i;
   int is_first = 1;
   char* tmp;
   grpc_slice result;
 
   gpr_strvec_init(&v);
 
-  char* user_agent_str =
-      grpc_channel_args_get_string(args, GRPC_ARG_PRIMARY_USER_AGENT_STRING);
-  if (user_agent_str != nullptr) {
-    if (!is_first) gpr_strvec_add(&v, gpr_strdup(" "));
-    is_first = 0;
-    gpr_strvec_add(&v, gpr_strdup(user_agent_str));
+  for (i = 0; args && i < args->num_args; i++) {
+    if (0 == strcmp(args->args[i].key, GRPC_ARG_PRIMARY_USER_AGENT_STRING)) {
+      if (args->args[i].type != GRPC_ARG_STRING) {
+        gpr_log(GPR_ERROR, "Channel argument '%s' should be a string",
+                GRPC_ARG_PRIMARY_USER_AGENT_STRING);
+      } else {
+        if (!is_first) gpr_strvec_add(&v, gpr_strdup(" "));
+        is_first = 0;
+        gpr_strvec_add(&v, gpr_strdup(args->args[i].value.string));
+      }
+    }
   }
 
   gpr_asprintf(&tmp, "%sgrpc-c/%s (%s; %s; %s)", is_first ? "" : " ",
@@ -481,11 +501,17 @@ static grpc_slice user_agent_from_args(const grpc_channel_args* args,
   is_first = 0;
   gpr_strvec_add(&v, tmp);
 
-  user_agent_str =
-      grpc_channel_args_get_string(args, GRPC_ARG_SECONDARY_USER_AGENT_STRING);
-  if (user_agent_str != nullptr) {
-    gpr_strvec_add(&v, gpr_strdup(" "));
-    gpr_strvec_add(&v, gpr_strdup(user_agent_str));
+  for (i = 0; args && i < args->num_args; i++) {
+    if (0 == strcmp(args->args[i].key, GRPC_ARG_SECONDARY_USER_AGENT_STRING)) {
+      if (args->args[i].type != GRPC_ARG_STRING) {
+        gpr_log(GPR_ERROR, "Channel argument '%s' should be a string",
+                GRPC_ARG_SECONDARY_USER_AGENT_STRING);
+      } else {
+        if (!is_first) gpr_strvec_add(&v, gpr_strdup(" "));
+        is_first = 0;
+        gpr_strvec_add(&v, gpr_strdup(args->args[i].value.string));
+      }
+    }
   }
 
   tmp = gpr_strvec_flatten(&v, nullptr);
diff --git a/src/core/ext/filters/http/http_filters_plugin.cc b/src/core/ext/filters/http/http_filters_plugin.cc
index d3cbe50016..f03fa0141d 100644
--- a/src/core/ext/filters/http/http_filters_plugin.cc
+++ b/src/core/ext/filters/http/http_filters_plugin.cc
@@ -48,8 +48,8 @@ static bool maybe_add_optional_filter(grpc_channel_stack_builder* builder,
   optional_filter* filtarg = static_cast<optional_filter*>(arg);
   const grpc_channel_args* channel_args =
       grpc_channel_stack_builder_get_channel_arguments(builder);
-  bool enable = grpc_channel_args_get_bool(
-      channel_args, filtarg->control_channel_arg,
+  bool enable = grpc_channel_arg_get_bool(
+      grpc_channel_args_find(channel_args, filtarg->control_channel_arg),
       !grpc_channel_args_want_minimal_stack(channel_args));
   return enable ? grpc_channel_stack_builder_prepend_filter(
                       builder, filtarg->filter, nullptr, nullptr)
diff --git a/src/core/ext/filters/load_reporting/server_load_reporting_plugin.cc b/src/core/ext/filters/load_reporting/server_load_reporting_plugin.cc
index 73bcf242d8..667c0c56ef 100644
--- a/src/core/ext/filters/load_reporting/server_load_reporting_plugin.cc
+++ b/src/core/ext/filters/load_reporting/server_load_reporting_plugin.cc
@@ -33,7 +33,8 @@
 #include "src/core/lib/surface/channel_init.h"
 
 static bool is_load_reporting_enabled(const grpc_channel_args* a) {
-  return grpc_channel_args_get_bool(a, GRPC_ARG_ENABLE_LOAD_REPORTING, false);
+  return grpc_channel_arg_get_bool(
+      grpc_channel_args_find(a, GRPC_ARG_ENABLE_LOAD_REPORTING), false);
 }
 
 static bool maybe_add_server_load_reporting_filter(
diff --git a/src/core/ext/filters/max_age/max_age_filter.cc b/src/core/ext/filters/max_age/max_age_filter.cc
index bbe4998f00..1fe8288bd0 100644
--- a/src/core/ext/filters/max_age/max_age_filter.cc
+++ b/src/core/ext/filters/max_age/max_age_filter.cc
@@ -519,12 +519,13 @@ static bool maybe_add_max_age_filter(grpc_channel_stack_builder* builder,
                                      void* arg) {
   const grpc_channel_args* channel_args =
       grpc_channel_stack_builder_get_channel_arguments(builder);
-  bool enable = grpc_channel_args_get_integer(
-                    channel_args, GRPC_ARG_MAX_CONNECTION_AGE_MS,
-                    MAX_CONNECTION_AGE_INTEGER_OPTIONS) != INT_MAX ||
-                grpc_channel_args_get_integer(
-                    channel_args, GRPC_ARG_MAX_CONNECTION_IDLE_MS,
-                    MAX_CONNECTION_IDLE_INTEGER_OPTIONS) != INT_MAX;
+  bool enable =
+      grpc_channel_arg_get_integer(
+          grpc_channel_args_find(channel_args, GRPC_ARG_MAX_CONNECTION_AGE_MS),
+          MAX_CONNECTION_AGE_INTEGER_OPTIONS) != INT_MAX ||
+      grpc_channel_arg_get_integer(
+          grpc_channel_args_find(channel_args, GRPC_ARG_MAX_CONNECTION_IDLE_MS),
+          MAX_CONNECTION_IDLE_INTEGER_OPTIONS) != INT_MAX;
   if (enable) {
     return grpc_channel_stack_builder_prepend_filter(
         builder, &grpc_max_age_filter, nullptr, nullptr);
diff --git a/src/core/ext/filters/message_size/message_size_filter.cc b/src/core/ext/filters/message_size/message_size_filter.cc
index 9815c93145..c7fc3f2e62 100644
--- a/src/core/ext/filters/message_size/message_size_filter.cc
+++ b/src/core/ext/filters/message_size/message_size_filter.cc
@@ -254,8 +254,9 @@ static grpc_error* init_channel_elem(grpc_channel_element* elem,
   channel_data* chand = static_cast<channel_data*>(elem->channel_data);
   chand->limits = get_message_size_limits(args->channel_args);
   // Get method config table from channel args.
-  const char* service_config_str =
-      grpc_channel_args_get_string(args->channel_args, GRPC_ARG_SERVICE_CONFIG);
+  const grpc_arg* channel_arg =
+      grpc_channel_args_find(args->channel_args, GRPC_ARG_SERVICE_CONFIG);
+  const char* service_config_str = grpc_channel_arg_get_string(channel_arg);
   if (service_config_str != nullptr) {
     grpc_core::UniquePtr<grpc_core::ServiceConfig> service_config =
         grpc_core::ServiceConfig::Create(service_config_str);
diff --git a/src/core/ext/transport/chttp2/client/authority.cc b/src/core/ext/transport/chttp2/client/authority.cc
index e3ef47c199..bad3153b01 100644
--- a/src/core/ext/transport/chttp2/client/authority.cc
+++ b/src/core/ext/transport/chttp2/client/authority.cc
@@ -28,8 +28,9 @@ grpc_channel_args* grpc_default_authority_add_if_not_present(
   size_t num_new_args = 0;
   grpc_core::UniquePtr<char> default_authority;
   if (!has_default_authority) {
-    const char* server_uri_str =
-        grpc_channel_args_get_string(args, GRPC_ARG_SERVER_URI);
+    const grpc_arg* server_uri_arg =
+        grpc_channel_args_find(args, GRPC_ARG_SERVER_URI);
+    const char* server_uri_str = grpc_channel_arg_get_string(server_uri_arg);
     GPR_ASSERT(server_uri_str != nullptr);
     default_authority =
         grpc_core::ResolverRegistry::GetDefaultAuthority(server_uri_str);
diff --git a/src/core/ext/transport/chttp2/client/secure/secure_channel_create.cc b/src/core/ext/transport/chttp2/client/secure/secure_channel_create.cc
index f49bd27b6c..5ce73a95d7 100644
--- a/src/core/ext/transport/chttp2/client/secure/secure_channel_create.cc
+++ b/src/core/ext/transport/chttp2/client/secure/secure_channel_create.cc
@@ -64,8 +64,9 @@ static grpc_subchannel_args* get_secure_naming_subchannel_args(
     return nullptr;
   }
   // To which address are we connecting? By default, use the server URI.
-  const char* server_uri_str =
-      grpc_channel_args_get_string(args->args, GRPC_ARG_SERVER_URI);
+  const grpc_arg* server_uri_arg =
+      grpc_channel_args_find(args->args, GRPC_ARG_SERVER_URI);
+  const char* server_uri_str = grpc_channel_arg_get_string(server_uri_arg);
   GPR_ASSERT(server_uri_str != nullptr);
   grpc_uri* server_uri =
       grpc_uri_parse(server_uri_str, true /* supress errors */);
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.cc b/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
index 1a924e66e6..a8090d18a6 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
@@ -447,19 +447,20 @@ static void init_transport(grpc_chttp2_transport* t,
             grpc_channel_arg_get_integer(&channel_args->args[i], {0, 0, 1}));
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_OPTIMIZATION_TARGET)) {
-        char* opt_target_str =
-            grpc_channel_arg_get_string(&channel_args->args[i]);
-        if (opt_target_str == nullptr) {
-          gpr_log(GPR_ERROR, "null/missing value opt target, assuming 'blend'");
-        } else if (0 == strcmp(opt_target_str, "blend")) {
+        if (channel_args->args[i].type != GRPC_ARG_STRING) {
+          gpr_log(GPR_ERROR, "%s should be a string",
+                  GRPC_ARG_OPTIMIZATION_TARGET);
+        } else if (0 == strcmp(channel_args->args[i].value.string, "blend")) {
           t->opt_target = GRPC_CHTTP2_OPTIMIZE_FOR_LATENCY;
-        } else if (0 == strcmp(opt_target_str, "latency")) {
+        } else if (0 == strcmp(channel_args->args[i].value.string, "latency")) {
           t->opt_target = GRPC_CHTTP2_OPTIMIZE_FOR_LATENCY;
-        } else if (0 == strcmp(opt_target_str, "throughput")) {
+        } else if (0 ==
+                   strcmp(channel_args->args[i].value.string, "throughput")) {
           t->opt_target = GRPC_CHTTP2_OPTIMIZE_FOR_THROUGHPUT;
         } else {
           gpr_log(GPR_ERROR, "%s value '%s' unknown, assuming 'blend'",
-                  GRPC_ARG_OPTIMIZATION_TARGET, opt_target_str);
+                  GRPC_ARG_OPTIMIZATION_TARGET,
+                  channel_args->args[i].value.string);
         }
       } else {
         static const struct {
diff --git a/src/core/ext/transport/cronet/transport/cronet_transport.cc b/src/core/ext/transport/cronet/transport/cronet_transport.cc
index 5d614c1d05..420c2d13e1 100644
--- a/src/core/ext/transport/cronet/transport/cronet_transport.cc
+++ b/src/core/ext/transport/cronet/transport/cronet_transport.cc
@@ -1450,8 +1450,20 @@ grpc_transport* grpc_create_cronet_transport(void* engine, const char* target,
   }
   strcpy(ct->host, target);
 
-  ct->use_packet_coalescing = grpc_channel_args_get_bool(
-      args, GRPC_ARG_USE_CRONET_PACKET_COALESCING, true);
+  ct->use_packet_coalescing = true;
+  if (args) {
+    for (size_t i = 0; i < args->num_args; i++) {
+      if (0 ==
+          strcmp(args->args[i].key, GRPC_ARG_USE_CRONET_PACKET_COALESCING)) {
+        if (GPR_UNLIKELY(args->args[i].type != GRPC_ARG_INTEGER)) {
+          gpr_log(GPR_ERROR, "%s ignored: it must be an integer",
+                  GRPC_ARG_USE_CRONET_PACKET_COALESCING);
+        } else {
+          ct->use_packet_coalescing = (args->args[i].value.integer != 0);
+        }
+      }
+    }
+  }
 
   return &ct->base;
 
diff --git a/src/core/ext/transport/inproc/inproc_transport.cc b/src/core/ext/transport/inproc/inproc_transport.cc
index 6e5aa5a46b..2c3bff5c1e 100644
--- a/src/core/ext/transport/inproc/inproc_transport.cc
+++ b/src/core/ext/transport/inproc/inproc_transport.cc
@@ -1204,9 +1204,10 @@ grpc_channel* grpc_inproc_channel_create(grpc_server* server,
 
   // Add a default authority channel argument for the client
 
-  grpc_arg default_authority_arg = grpc_channel_arg_string_create(
-      const_cast<char*>(GRPC_ARG_DEFAULT_AUTHORITY),
-      const_cast<char*>("inproc.authority"));
+  grpc_arg default_authority_arg;
+  default_authority_arg.type = GRPC_ARG_STRING;
+  default_authority_arg.key = (char*)GRPC_ARG_DEFAULT_AUTHORITY;
+  default_authority_arg.value.string = (char*)"inproc.authority";
   grpc_channel_args* client_args =
       grpc_channel_args_copy_and_add(args, &default_authority_arg, 1);