Change destroy_call_elem() to return a grpc_error*.

22 files changed, 133 insertions, 94 deletions

diff --git a/src/core/ext/census/grpc_filter.c b/src/core/ext/census/grpc_filter.c
index 397dbc40a8..c73385f98b 100644
--- a/src/core/ext/census/grpc_filter.c
+++ b/src/core/ext/census/grpc_filter.c
@@ -167,11 +167,12 @@ static void server_destroy_call_elem(grpc_exec_ctx *exec_ctx,
   /* TODO(hongyu): record rpc server stats and census_tracing_end_op here */
 }
 
-static void init_channel_elem(grpc_exec_ctx *exec_ctx,
-                              grpc_channel_element *elem,
-                              grpc_channel_element_args *args) {
+static grpc_error* init_channel_elem(grpc_exec_ctx *exec_ctx,
+                                     grpc_channel_element *elem,
+                                     grpc_channel_element_args *args) {
   channel_data *chand = elem->channel_data;
   GPR_ASSERT(chand != NULL);
+  return GRPC_ERROR_NONE;
 }
 
 static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
diff --git a/src/core/ext/client_channel/client_channel.c b/src/core/ext/client_channel/client_channel.c
index 7df3bca5d8..13d8036b8d 100644
--- a/src/core/ext/client_channel/client_channel.c
+++ b/src/core/ext/client_channel/client_channel.c
@@ -451,9 +451,9 @@ static void cc_get_channel_info(grpc_exec_ctx *exec_ctx,
 }
 
 /* Constructor for channel_data */
-static void cc_init_channel_elem(grpc_exec_ctx *exec_ctx,
-                                 grpc_channel_element *elem,
-                                 grpc_channel_element_args *args) {
+static grpc_error* cc_init_channel_elem(grpc_exec_ctx *exec_ctx,
+                                        grpc_channel_element *elem,
+                                        grpc_channel_element_args *args) {
   channel_data *chand = elem->channel_data;
   memset(chand, 0, sizeof(*chand));
   GPR_ASSERT(args->is_last);
@@ -478,8 +478,10 @@ static void cc_init_channel_elem(grpc_exec_ctx *exec_ctx,
   GPR_ASSERT(arg != NULL);
   GPR_ASSERT(arg->type == GRPC_ARG_STRING);
   chand->resolver = grpc_resolver_create(arg->value.string, args->channel_args);
-// FIXME: return failure instead of asserting
-  GPR_ASSERT(chand->resolver != NULL);
+  if (chand->resolver == NULL) {
+    return GRPC_ERROR_CREATE("resolver creation failed");
+  }
+  return GRPC_ERROR_NONE;
 }
 
 /* Destructor for channel_data */
diff --git a/src/core/ext/client_channel/subchannel.c b/src/core/ext/client_channel/subchannel.c
index a148b2a0e1..f1ed95ba9d 100644
--- a/src/core/ext/client_channel/subchannel.c
+++ b/src/core/ext/client_channel/subchannel.c
@@ -542,14 +542,20 @@ static void publish_transport_locked(grpc_exec_ctx *exec_ctx,
   grpc_channel_stack_builder_set_transport(builder,
                                            c->connecting_result.transport);
 
-  if (grpc_channel_init_create_stack(exec_ctx, builder,
-                                     GRPC_CLIENT_SUBCHANNEL)) {
-    con = grpc_channel_stack_builder_finish(exec_ctx, builder, 0, 1,
-                                            connection_destroy, NULL);
-  } else {
+  if (!grpc_channel_init_create_stack(exec_ctx, builder,
+                                      GRPC_CLIENT_SUBCHANNEL)) {
     grpc_channel_stack_builder_destroy(builder);
     abort(); /* TODO(ctiller): what to do here (previously we just crashed) */
   }
+  grpc_error *error = grpc_channel_stack_builder_finish(
+      exec_ctx, builder, 0, 1, connection_destroy, NULL, (void**)&con);
+  if (error != GRPC_ERROR_NONE) {
+    const char* msg = grpc_error_string(error);
+    gpr_log(GPR_ERROR, "error initializing subchannel stack: %s", msg);
+    grpc_error_free_string(msg);
+    GRPC_ERROR_UNREF(error);
+    abort(); /* TODO(ctiller): what to do here? */
+  }
   stk = CHANNEL_STACK_FROM_CONNECTION(con);
   memset(&c->connecting_result, 0, sizeof(c->connecting_result));
 
diff --git a/src/core/ext/load_reporting/load_reporting_filter.c b/src/core/ext/load_reporting/load_reporting_filter.c
index b810e20bb9..a0feb086c7 100644
--- a/src/core/ext/load_reporting/load_reporting_filter.c
+++ b/src/core/ext/load_reporting/load_reporting_filter.c
@@ -152,9 +152,9 @@ static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
 }
 
 /* Constructor for channel_data */
-static void init_channel_elem(grpc_exec_ctx *exec_ctx,
-                              grpc_channel_element *elem,
-                              grpc_channel_element_args *args) {
+static grpc_error* init_channel_elem(grpc_exec_ctx *exec_ctx,
+                                     grpc_channel_element *elem,
+                                     grpc_channel_element_args *args) {
   GPR_ASSERT(!args->is_last);
 
   channel_data *chand = elem->channel_data;
@@ -171,6 +171,8 @@ static void init_channel_elem(grpc_exec_ctx *exec_ctx,
                                                 NULL,
                                                 NULL};
                                                 */
+
+  return GRPC_ERROR_NONE;
 }
 
 /* Destructor for channel data */
diff --git a/src/core/lib/channel/channel_stack.c b/src/core/lib/channel/channel_stack.c
index 999ad5f507..ab78dfbf3e 100644
--- a/src/core/lib/channel/channel_stack.c
+++ b/src/core/lib/channel/channel_stack.c
@@ -102,13 +102,11 @@ grpc_call_element *grpc_call_stack_element(grpc_call_stack *call_stack,
   return CALL_ELEMS_FROM_STACK(call_stack) + index;
 }
 
-void grpc_channel_stack_init(grpc_exec_ctx *exec_ctx, int initial_refs,
-                             grpc_iomgr_cb_func destroy, void *destroy_arg,
-                             const grpc_channel_filter **filters,
-                             size_t filter_count,
-                             const grpc_channel_args *channel_args,
-                             grpc_transport *optional_transport,
-                             const char *name, grpc_channel_stack *stack) {
+grpc_error* grpc_channel_stack_init(
+    grpc_exec_ctx *exec_ctx, int initial_refs, grpc_iomgr_cb_func destroy,
+    void *destroy_arg, const grpc_channel_filter **filters, size_t filter_count,
+    const grpc_channel_args *channel_args, grpc_transport *optional_transport,
+    const char *name, grpc_channel_stack *stack) {
   size_t call_size =
       ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(grpc_call_stack)) +
       ROUND_UP_TO_ALIGNMENT_SIZE(filter_count * sizeof(grpc_call_element));
@@ -126,6 +124,7 @@ void grpc_channel_stack_init(grpc_exec_ctx *exec_ctx, int initial_refs,
       ROUND_UP_TO_ALIGNMENT_SIZE(filter_count * sizeof(grpc_channel_element));
 
   /* init per-filter data */
+  grpc_error *first_error = GRPC_ERROR_NONE;
   for (i = 0; i < filter_count; i++) {
     args.channel_stack = stack;
     args.channel_args = channel_args;
@@ -134,7 +133,15 @@ void grpc_channel_stack_init(grpc_exec_ctx *exec_ctx, int initial_refs,
     args.is_last = i == (filter_count - 1);
     elems[i].filter = filters[i];
     elems[i].channel_data = user_data;
-    elems[i].filter->init_channel_elem(exec_ctx, &elems[i], &args);
+    grpc_error *error =
+        elems[i].filter->init_channel_elem(exec_ctx, &elems[i], &args);
+    if (error != GRPC_ERROR_NONE) {
+      if (first_error == GRPC_ERROR_NONE) {
+        first_error = error;
+      } else {
+        GRPC_ERROR_UNREF(error);
+      }
+    }
     user_data += ROUND_UP_TO_ALIGNMENT_SIZE(filters[i]->sizeof_channel_data);
     call_size += ROUND_UP_TO_ALIGNMENT_SIZE(filters[i]->sizeof_call_data);
   }
@@ -144,6 +151,7 @@ void grpc_channel_stack_init(grpc_exec_ctx *exec_ctx, int initial_refs,
              grpc_channel_stack_size(filters, filter_count));
 
   stack->call_stack_size = call_size;
+  return first_error;
 }
 
 void grpc_channel_stack_destroy(grpc_exec_ctx *exec_ctx,
diff --git a/src/core/lib/channel/channel_stack.h b/src/core/lib/channel/channel_stack.h
index 004643d45f..9491b9ab1b 100644
--- a/src/core/lib/channel/channel_stack.h
+++ b/src/core/lib/channel/channel_stack.h
@@ -146,8 +146,9 @@ typedef struct {
      is_first, is_last designate this elements position in the stack, and are
      useful for asserting correct configuration by upper layer code.
      The filter does not need to do any chaining */
-  void (*init_channel_elem)(grpc_exec_ctx *exec_ctx, grpc_channel_element *elem,
-                            grpc_channel_element_args *args);
+  grpc_error *(*init_channel_elem)(grpc_exec_ctx *exec_ctx,
+                                   grpc_channel_element *elem,
+                                   grpc_channel_element_args *args);
   /* Destroy per channel data.
      The filter does not need to do any chaining */
   void (*destroy_channel_elem)(grpc_exec_ctx *exec_ctx,
@@ -214,12 +215,12 @@ grpc_call_element *grpc_call_stack_element(grpc_call_stack *stack, size_t i);
 size_t grpc_channel_stack_size(const grpc_channel_filter **filters,
                                size_t filter_count);
 /* Initialize a channel stack given some filters */
-void grpc_channel_stack_init(grpc_exec_ctx *exec_ctx, int initial_refs,
-                             grpc_iomgr_cb_func destroy, void *destroy_arg,
-                             const grpc_channel_filter **filters,
-                             size_t filter_count, const grpc_channel_args *args,
-                             grpc_transport *optional_transport,
-                             const char *name, grpc_channel_stack *stack);
+grpc_error* grpc_channel_stack_init(
+    grpc_exec_ctx *exec_ctx, int initial_refs, grpc_iomgr_cb_func destroy,
+    void *destroy_arg, const grpc_channel_filter **filters,
+    size_t filter_count, const grpc_channel_args *args,
+    grpc_transport *optional_transport, const char *name,
+    grpc_channel_stack *stack);
 /* Destroy a channel stack */
 void grpc_channel_stack_destroy(grpc_exec_ctx *exec_ctx,
                                 grpc_channel_stack *stack);
diff --git a/src/core/lib/channel/channel_stack_builder.c b/src/core/lib/channel/channel_stack_builder.c
index eda4968f48..747db0749e 100644
--- a/src/core/lib/channel/channel_stack_builder.c
+++ b/src/core/lib/channel/channel_stack_builder.c
@@ -227,11 +227,10 @@ void grpc_channel_stack_builder_destroy(grpc_channel_stack_builder *builder) {
   gpr_free(builder);
 }
 
-void *grpc_channel_stack_builder_finish(grpc_exec_ctx *exec_ctx,
-                                        grpc_channel_stack_builder *builder,
-                                        size_t prefix_bytes, int initial_refs,
-                                        grpc_iomgr_cb_func destroy,
-                                        void *destroy_arg) {
+grpc_error *grpc_channel_stack_builder_finish(
+    grpc_exec_ctx *exec_ctx, grpc_channel_stack_builder *builder,
+    size_t prefix_bytes, int initial_refs, grpc_iomgr_cb_func destroy,
+    void *destroy_arg, void **result) {
   // count the number of filters
   size_t num_filters = 0;
   for (filter_node *p = builder->begin.next; p != &builder->end; p = p->next) {
@@ -250,15 +249,15 @@ void *grpc_channel_stack_builder_finish(grpc_exec_ctx *exec_ctx,
   size_t channel_stack_size = grpc_channel_stack_size(filters, num_filters);
 
   // allocate memory, with prefix_bytes followed by channel_stack_size
-  char *result = gpr_malloc(prefix_bytes + channel_stack_size);
+  *result = gpr_malloc(prefix_bytes + channel_stack_size);
   // fetch a pointer to the channel stack
   grpc_channel_stack *channel_stack =
-      (grpc_channel_stack *)(result + prefix_bytes);
+      (grpc_channel_stack *)(*result + prefix_bytes);
   // and initialize it
-  grpc_channel_stack_init(exec_ctx, initial_refs, destroy,
-                          destroy_arg == NULL ? result : destroy_arg, filters,
-                          num_filters, builder->args, builder->transport,
-                          builder->name, channel_stack);
+  grpc_error* error = grpc_channel_stack_init(
+      exec_ctx, initial_refs, destroy,
+      destroy_arg == NULL ? *result : destroy_arg, filters, num_filters,
+      builder->args, builder->transport, builder->name, channel_stack);
 
   // run post-initialization functions
   i = 0;
@@ -273,5 +272,5 @@ void *grpc_channel_stack_builder_finish(grpc_exec_ctx *exec_ctx,
   grpc_channel_stack_builder_destroy(builder);
   gpr_free((grpc_channel_filter **)filters);
 
-  return result;
+  return error;
 }
diff --git a/src/core/lib/channel/channel_stack_builder.h b/src/core/lib/channel/channel_stack_builder.h
index 4a00f7bfdb..65bfebcabc 100644
--- a/src/core/lib/channel/channel_stack_builder.h
+++ b/src/core/lib/channel/channel_stack_builder.h
@@ -146,16 +146,15 @@ bool grpc_channel_stack_builder_append_filter(
 void grpc_channel_stack_builder_iterator_destroy(
     grpc_channel_stack_builder_iterator *iterator);
 
-/// Destroy the builder, return the freshly minted channel stack
+/// Destroy the builder, return the freshly minted channel stack in \a result.
 /// Allocates \a prefix_bytes bytes before the channel stack
 /// Returns the base pointer of the allocated block
 /// \a initial_refs, \a destroy, \a destroy_arg are as per
 /// grpc_channel_stack_init
-void *grpc_channel_stack_builder_finish(grpc_exec_ctx *exec_ctx,
-                                        grpc_channel_stack_builder *builder,
-                                        size_t prefix_bytes, int initial_refs,
-                                        grpc_iomgr_cb_func destroy,
-                                        void *destroy_arg);
+grpc_error *grpc_channel_stack_builder_finish(
+    grpc_exec_ctx *exec_ctx, grpc_channel_stack_builder *builder,
+    size_t prefix_bytes, int initial_refs, grpc_iomgr_cb_func destroy,
+    void *destroy_arg, void **result);
 
 /// Destroy the builder without creating a channel stack
 void grpc_channel_stack_builder_destroy(grpc_channel_stack_builder *builder);
diff --git a/src/core/lib/channel/compress_filter.c b/src/core/lib/channel/compress_filter.c
index 2874d63fc7..2afe28941a 100644
--- a/src/core/lib/channel/compress_filter.c
+++ b/src/core/lib/channel/compress_filter.c
@@ -285,9 +285,9 @@ static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
 }
 
 /* Constructor for channel_data */
-static void init_channel_elem(grpc_exec_ctx *exec_ctx,
-                              grpc_channel_element *elem,
-                              grpc_channel_element_args *args) {
+static grpc_error* init_channel_elem(grpc_exec_ctx *exec_ctx,
+                                     grpc_channel_element *elem,
+                                     grpc_channel_element_args *args) {
   channel_data *channeld = elem->channel_data;
 
   channeld->enabled_algorithms_bitset =
@@ -315,6 +315,7 @@ static void init_channel_elem(grpc_exec_ctx *exec_ctx,
   }
 
   GPR_ASSERT(!args->is_last);
+  return GRPC_ERROR_NONE;
 }
 
 /* Destructor for channel data */
diff --git a/src/core/lib/channel/connected_channel.c b/src/core/lib/channel/connected_channel.c
index 038e819f72..92739f70c7 100644
--- a/src/core/lib/channel/connected_channel.c
+++ b/src/core/lib/channel/connected_channel.c
@@ -114,12 +114,13 @@ static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
 }
 
 /* Constructor for channel_data */
-static void init_channel_elem(grpc_exec_ctx *exec_ctx,
-                              grpc_channel_element *elem,
-                              grpc_channel_element_args *args) {
+static grpc_error* init_channel_elem(grpc_exec_ctx *exec_ctx,
+                                     grpc_channel_element *elem,
+                                     grpc_channel_element_args *args) {
   channel_data *cd = (channel_data *)elem->channel_data;
   GPR_ASSERT(args->is_last);
   cd->transport = NULL;
+  return GRPC_ERROR_NONE;
 }
 
 /* Destructor for channel_data */
diff --git a/src/core/lib/channel/deadline_filter.c b/src/core/lib/channel/deadline_filter.c
index 0e703d8d27..470ccfea57 100644
--- a/src/core/lib/channel/deadline_filter.c
+++ b/src/core/lib/channel/deadline_filter.c
@@ -207,10 +207,11 @@ void grpc_deadline_state_client_start_transport_stream_op(
 //
 
 // Constructor for channel_data.  Used for both client and server filters.
-static void init_channel_elem(grpc_exec_ctx* exec_ctx,
-                              grpc_channel_element* elem,
-                              grpc_channel_element_args* args) {
+static grpc_error* init_channel_elem(grpc_exec_ctx* exec_ctx,
+                                     grpc_channel_element* elem,
+                                     grpc_channel_element_args* args) {
   GPR_ASSERT(!args->is_last);
+  return GRPC_ERROR_NONE;
 }
 
 // Destructor for channel_data.  Used for both client and server filters.
diff --git a/src/core/lib/channel/http_client_filter.c b/src/core/lib/channel/http_client_filter.c
index f57d7c2453..8be9e0a2cb 100644
--- a/src/core/lib/channel/http_client_filter.c
+++ b/src/core/lib/channel/http_client_filter.c
@@ -415,9 +415,9 @@ static grpc_mdstr *user_agent_from_args(const grpc_channel_args *args,
 }
 
 /* Constructor for channel_data */
-static void init_channel_elem(grpc_exec_ctx *exec_ctx,
-                              grpc_channel_element *elem,
-                              grpc_channel_element_args *args) {
+static grpc_error* init_channel_elem(grpc_exec_ctx *exec_ctx,
+                                     grpc_channel_element *elem,
+                                     grpc_channel_element_args *args) {
   channel_data *chand = elem->channel_data;
   GPR_ASSERT(!args->is_last);
   GPR_ASSERT(args->optional_transport != NULL);
@@ -428,6 +428,7 @@ static void init_channel_elem(grpc_exec_ctx *exec_ctx,
       GRPC_MDSTR_USER_AGENT,
       user_agent_from_args(args->channel_args,
                            args->optional_transport->vtable->name));
+  return GRPC_ERROR_NONE;
 }
 
 /* Destructor for channel data */
diff --git a/src/core/lib/channel/http_server_filter.c b/src/core/lib/channel/http_server_filter.c
index 6a33689fec..035124ade9 100644
--- a/src/core/lib/channel/http_server_filter.c
+++ b/src/core/lib/channel/http_server_filter.c
@@ -326,10 +326,11 @@ static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
 }
 
 /* Constructor for channel_data */
-static void init_channel_elem(grpc_exec_ctx *exec_ctx,
-                              grpc_channel_element *elem,
-                              grpc_channel_element_args *args) {
+static grpc_error* init_channel_elem(grpc_exec_ctx *exec_ctx,
+                                     grpc_channel_element *elem,
+                                     grpc_channel_element_args *args) {
   GPR_ASSERT(!args->is_last);
+  return GRPC_ERROR_NONE;
 }
 
 /* Destructor for channel data */
diff --git a/src/core/lib/channel/message_size_filter.c b/src/core/lib/channel/message_size_filter.c
index 1331fe1c65..c6bfb80d78 100644
--- a/src/core/lib/channel/message_size_filter.c
+++ b/src/core/lib/channel/message_size_filter.c
@@ -195,9 +195,9 @@ static void destroy_call_elem(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
                               void* ignored) {}
 
 // Constructor for channel_data.
-static void init_channel_elem(grpc_exec_ctx* exec_ctx,
-                              grpc_channel_element* elem,
-                              grpc_channel_element_args* args) {
+static grpc_error* init_channel_elem(grpc_exec_ctx* exec_ctx,
+                                     grpc_channel_element* elem,
+                                     grpc_channel_element_args* args) {
   GPR_ASSERT(!args->is_last);
   channel_data* chand = elem->channel_data;
   memset(chand, 0, sizeof(*chand));
@@ -228,6 +228,7 @@ static void init_channel_elem(grpc_exec_ctx* exec_ctx,
         (grpc_method_config_table*)channel_arg->value.pointer.p,
         method_config_convert_value, &message_size_limits_vtable);
   }
+  return GRPC_ERROR_NONE;
 }
 
 // Destructor for channel_data.
diff --git a/src/core/lib/security/transport/client_auth_filter.c b/src/core/lib/security/transport/client_auth_filter.c
index 053bf5972c..eeb11feeb2 100644
--- a/src/core/lib/security/transport/client_auth_filter.c
+++ b/src/core/lib/security/transport/client_auth_filter.c
@@ -303,9 +303,9 @@ static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
 }
 
 /* Constructor for channel_data */
-static void init_channel_elem(grpc_exec_ctx *exec_ctx,
-                              grpc_channel_element *elem,
-                              grpc_channel_element_args *args) {
+static grpc_error* init_channel_elem(grpc_exec_ctx *exec_ctx,
+                                     grpc_channel_element *elem,
+                                     grpc_channel_element_args *args) {
   grpc_security_connector *sc =
       grpc_find_security_connector_in_args(args->channel_args);
   grpc_auth_context *auth_context =
@@ -327,6 +327,7 @@ static void init_channel_elem(grpc_exec_ctx *exec_ctx,
           sc, "client_auth_filter");
   chand->auth_context =
       GRPC_AUTH_CONTEXT_REF(auth_context, "client_auth_filter");
+  return GRPC_ERROR_NONE;
 }
 
 /* Destructor for channel data */
diff --git a/src/core/lib/security/transport/server_auth_filter.c b/src/core/lib/security/transport/server_auth_filter.c
index eaa1d0720b..3abbeb35ef 100644
--- a/src/core/lib/security/transport/server_auth_filter.c
+++ b/src/core/lib/security/transport/server_auth_filter.c
@@ -238,9 +238,9 @@ static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                               void *ignored) {}
 
 /* Constructor for channel_data */
-static void init_channel_elem(grpc_exec_ctx *exec_ctx,
-                              grpc_channel_element *elem,
-                              grpc_channel_element_args *args) {
+static grpc_error* init_channel_elem(grpc_exec_ctx *exec_ctx,
+                                     grpc_channel_element *elem,
+                                     grpc_channel_element_args *args) {
   grpc_auth_context *auth_context =
       grpc_find_auth_context_in_args(args->channel_args);
   grpc_server_credentials *creds =
@@ -256,6 +256,7 @@ static void init_channel_elem(grpc_exec_ctx *exec_ctx,
   chand->auth_context =
       GRPC_AUTH_CONTEXT_REF(auth_context, "server_auth_filter");
   chand->creds = grpc_server_credentials_ref(creds);
+  return GRPC_ERROR_NONE;
 }
 
 /* Destructor for channel data */
diff --git a/src/core/lib/surface/channel.c b/src/core/lib/surface/channel.c
index 1389df6886..1b5cf5ffec 100644
--- a/src/core/lib/surface/channel.c
+++ b/src/core/lib/surface/channel.c
@@ -97,11 +97,16 @@ grpc_channel *grpc_channel_create(grpc_exec_ctx *exec_ctx, const char *target,
   if (!grpc_channel_init_create_stack(exec_ctx, builder, channel_stack_type)) {
     grpc_channel_stack_builder_destroy(builder);
     return NULL;
-  } else {
-    args = grpc_channel_args_copy(
-        grpc_channel_stack_builder_get_channel_arguments(builder));
-    channel = grpc_channel_stack_builder_finish(
-        exec_ctx, builder, sizeof(grpc_channel), 1, destroy_channel, NULL);
+  }
+  args = grpc_channel_args_copy(
+      grpc_channel_stack_builder_get_channel_arguments(builder));
+  grpc_error* error = grpc_channel_stack_builder_finish(
+      exec_ctx, builder, sizeof(grpc_channel), 1, destroy_channel, NULL,
+      (void**)&channel);
+  if (error != GRPC_ERROR_NONE) {
+    grpc_channel_stack_destroy(exec_ctx, (grpc_channel_stack *)channel);
+    gpr_free(channel);
+    return NULL;
   }
 
   memset(channel, 0, sizeof(*channel));
diff --git a/src/core/lib/surface/lame_client.c b/src/core/lib/surface/lame_client.c
index d0df8e7e17..995a88de9e 100644
--- a/src/core/lib/surface/lame_client.c
+++ b/src/core/lib/surface/lame_client.c
@@ -123,11 +123,12 @@ static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
   gpr_free(and_free_memory);
 }
 
-static void init_channel_elem(grpc_exec_ctx *exec_ctx,
-                              grpc_channel_element *elem,
-                              grpc_channel_element_args *args) {
+static grpc_error* init_channel_elem(grpc_exec_ctx *exec_ctx,
+                                     grpc_channel_element *elem,
+                                     grpc_channel_element_args *args) {
   GPR_ASSERT(args->is_first);
   GPR_ASSERT(args->is_last);
+  return GRPC_ERROR_NONE;
 }
 
 static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
diff --git a/src/core/lib/surface/server.c b/src/core/lib/surface/server.c
index 89dd825460..eeeb6cd432 100644
--- a/src/core/lib/surface/server.c
+++ b/src/core/lib/surface/server.c
@@ -913,9 +913,9 @@ static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
   server_unref(exec_ctx, chand->server);
 }
 
-static void init_channel_elem(grpc_exec_ctx *exec_ctx,
-                              grpc_channel_element *elem,
-                              grpc_channel_element_args *args) {
+static grpc_error* init_channel_elem(grpc_exec_ctx *exec_ctx,
+                                     grpc_channel_element *elem,
+                                     grpc_channel_element_args *args) {
   channel_data *chand = elem->channel_data;
   GPR_ASSERT(args->is_first);
   GPR_ASSERT(!args->is_last);
@@ -926,6 +926,7 @@ static void init_channel_elem(grpc_exec_ctx *exec_ctx,
   chand->connectivity_state = GRPC_CHANNEL_IDLE;
   grpc_closure_init(&chand->channel_connectivity_changed,
                     channel_connectivity_changed, chand);
+  return GRPC_ERROR_NONE;
 }
 
 static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
diff --git a/test/core/end2end/tests/filter_call_init_fails.c b/test/core/end2end/tests/filter_call_init_fails.c
index 41ae575fff..13a32bf64d 100644
--- a/test/core/end2end/tests/filter_call_init_fails.c
+++ b/test/core/end2end/tests/filter_call_init_fails.c
@@ -216,9 +216,11 @@ static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                               const grpc_call_final_info *final_info,
                               void *and_free_memory) {}
 
-static void init_channel_elem(grpc_exec_ctx *exec_ctx,
-                              grpc_channel_element *elem,
-                              grpc_channel_element_args *args) {}
+static grpc_error* init_channel_elem(grpc_exec_ctx *exec_ctx,
+                                     grpc_channel_element *elem,
+                                     grpc_channel_element_args *args) {
+  return GRPC_ERROR_NONE;
+}
 
 static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
                                  grpc_channel_element *elem) {}
diff --git a/test/core/end2end/tests/filter_causes_close.c b/test/core/end2end/tests/filter_causes_close.c
index bf9fd9073d..4c1ff8459a 100644
--- a/test/core/end2end/tests/filter_causes_close.c
+++ b/test/core/end2end/tests/filter_causes_close.c
@@ -243,9 +243,11 @@ static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                               const grpc_call_final_info *final_info,
                               void *and_free_memory) {}
 
-static void init_channel_elem(grpc_exec_ctx *exec_ctx,
-                              grpc_channel_element *elem,
-                              grpc_channel_element_args *args) {}
+static grpc_error* init_channel_elem(grpc_exec_ctx *exec_ctx,
+                                     grpc_channel_element *elem,
+                                     grpc_channel_element_args *args) {
+  return GRPC_ERROR_NONE;
+}
 
 static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
                                  grpc_channel_element *elem) {}
diff --git a/test/core/end2end/tests/filter_latency.c b/test/core/end2end/tests/filter_latency.c
index 37ce3b1222..3e9c0352a5 100644
--- a/test/core/end2end/tests/filter_latency.c
+++ b/test/core/end2end/tests/filter_latency.c
@@ -275,9 +275,11 @@ static void server_destroy_call_elem(grpc_exec_ctx *exec_ctx,
   gpr_mu_unlock(&g_mu);
 }
 
-static void init_channel_elem(grpc_exec_ctx *exec_ctx,
-                              grpc_channel_element *elem,
-                              grpc_channel_element_args *args) {}
+static grpc_error* init_channel_elem(grpc_exec_ctx *exec_ctx,
+                                     grpc_channel_element *elem,
+                                     grpc_channel_element_args *args) {
+  return GRPC_ERROR_NONE;
+}
 
 static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
                                  grpc_channel_element *elem) {}