6 files changed, 33 insertions, 15 deletions
diff --git a/src/core/lib/transport/connectivity_state.c b/src/core/lib/transport/connectivity_state.c
index afe1f6164d..3757b25267 100644
--- a/src/core/lib/transport/connectivity_state.c
+++ b/src/core/lib/transport/connectivity_state.c
@@ -79,7 +79,8 @@ void grpc_connectivity_state_destroy(grpc_exec_ctx *exec_ctx,
       *w->current = GRPC_CHANNEL_SHUTDOWN;
       error = GRPC_ERROR_NONE;
     } else {
-      error = GRPC_ERROR_CREATE("Shutdown connectivity owner");
+      error =
+          GRPC_ERROR_CREATE_FROM_STATIC_STRING("Shutdown connectivity owner");
     }
     grpc_closure_sched(exec_ctx, w->notify, error);
     gpr_free(w);
diff --git a/src/core/lib/transport/error_utils.c b/src/core/lib/transport/error_utils.c
index ef55e561fb..4e70f8749d 100644
--- a/src/core/lib/transport/error_utils.c
+++ b/src/core/lib/transport/error_utils.c
@@ -55,7 +55,7 @@ static grpc_error *recursively_find_error_with_field(grpc_error *error,
 }
 
 void grpc_error_get_status(grpc_error *error, gpr_timespec deadline,
-                           grpc_status_code *code, const char **msg,
+                           grpc_status_code *code, grpc_slice *slice,
                            grpc_http2_error_code *http_error) {
   // Start with the parent error and recurse through the tree of children
   // until we find the first one that has a status code.
@@ -97,11 +97,11 @@ void grpc_error_get_status(grpc_error *error, gpr_timespec deadline,
 
   // If the error has a status message, use it.  Otherwise, fall back to
   // the error description.
-  if (msg != NULL) {
-    *msg = grpc_error_get_str(found_error, GRPC_ERROR_STR_GRPC_MESSAGE);
-    if (*msg == NULL && error != GRPC_ERROR_NONE) {
-      *msg = grpc_error_get_str(found_error, GRPC_ERROR_STR_DESCRIPTION);
-      if (*msg == NULL) *msg = "unknown error";  // Just in case.
+  if (slice != NULL) {
+    if (!grpc_error_get_str(found_error, GRPC_ERROR_STR_GRPC_MESSAGE, slice)) {
+      if (!grpc_error_get_str(found_error, GRPC_ERROR_STR_DESCRIPTION, slice)) {
+        *slice = grpc_slice_from_static_string("unknown error");
+      }
     }
   }
 
diff --git a/src/core/lib/transport/error_utils.h b/src/core/lib/transport/error_utils.h
index 105338880a..3b44466ab8 100644
--- a/src/core/lib/transport/error_utils.h
+++ b/src/core/lib/transport/error_utils.h
@@ -44,7 +44,7 @@
 /// attributes (code, msg, http_status) are unneeded, they can be passed as
 /// NULL.
 void grpc_error_get_status(grpc_error *error, gpr_timespec deadline,
-                           grpc_status_code *code, const char **msg,
+                           grpc_status_code *code, grpc_slice *slice,
                            grpc_http2_error_code *http_status);
 
 /// A utility function to check whether there is a clear status code that
diff --git a/src/core/lib/transport/metadata_batch.c b/src/core/lib/transport/metadata_batch.c
index fc2c52bd8a..fa73244aa4 100644
--- a/src/core/lib/transport/metadata_batch.c
+++ b/src/core/lib/transport/metadata_batch.c
@@ -101,12 +101,10 @@ void grpc_metadata_batch_destroy(grpc_exec_ctx *exec_ctx,
 }
 
 grpc_error *grpc_attach_md_to_error(grpc_error *src, grpc_mdelem md) {
-  char *k = grpc_slice_to_c_string(GRPC_MDKEY(md));
-  char *v = grpc_slice_to_c_string(GRPC_MDVALUE(md));
   grpc_error *out = grpc_error_set_str(
-      grpc_error_set_str(src, GRPC_ERROR_STR_KEY, k), GRPC_ERROR_STR_VALUE, v);
-  gpr_free(k);
-  gpr_free(v);
+      grpc_error_set_str(src, GRPC_ERROR_STR_KEY,
+                         grpc_slice_ref_internal(GRPC_MDKEY(md))),
+      GRPC_ERROR_STR_VALUE, grpc_slice_ref_internal(GRPC_MDVALUE(md)));
   return out;
 }
 
@@ -126,7 +124,8 @@ static grpc_error *maybe_link_callout(grpc_metadata_batch *batch,
     return GRPC_ERROR_NONE;
   }
   return grpc_attach_md_to_error(
-      GRPC_ERROR_CREATE("Unallowed duplicate metadata"), storage->md);
+      GRPC_ERROR_CREATE_FROM_STATIC_STRING("Unallowed duplicate metadata"),
+      storage->md);
 }
 
 static void maybe_unlink_callout(grpc_metadata_batch *batch,
@@ -302,7 +301,7 @@ static void add_error(grpc_error **composite, grpc_error *error,
                       const char *composite_error_string) {
   if (error == GRPC_ERROR_NONE) return;
   if (*composite == GRPC_ERROR_NONE) {
-    *composite = GRPC_ERROR_CREATE(composite_error_string);
+    *composite = GRPC_ERROR_CREATE_FROM_COPIED_STRING(composite_error_string);
   }
   *composite = grpc_error_add_child(*composite, error);
 }
diff --git a/src/core/lib/transport/service_config.c b/src/core/lib/transport/service_config.c
index 12da2a88fe..1195f75044 100644
--- a/src/core/lib/transport/service_config.c
+++ b/src/core/lib/transport/service_config.c
@@ -93,6 +93,18 @@ void grpc_service_config_destroy(grpc_service_config* service_config) {
   gpr_free(service_config);
 }
 
+void grpc_service_config_parse_global_params(
+    const grpc_service_config* service_config,
+    void (*process_json)(const grpc_json* json, void* arg), void* arg) {
+  const grpc_json* json = service_config->json_tree;
+  if (json->type != GRPC_JSON_OBJECT || json->key != NULL) return;
+  for (grpc_json* field = json->child; field != NULL; field = field->next) {
+    if (field->key == NULL) return;
+    if (strcmp(field->key, "methodConfig") == 0) continue;
+    process_json(field, arg);
+  }
+}
+
 const char* grpc_service_config_get_lb_policy_name(
     const grpc_service_config* service_config) {
   const grpc_json* json = service_config->json_tree;
diff --git a/src/core/lib/transport/service_config.h b/src/core/lib/transport/service_config.h
index cd739a593c..ebfc59b534 100644
--- a/src/core/lib/transport/service_config.h
+++ b/src/core/lib/transport/service_config.h
@@ -42,6 +42,12 @@ typedef struct grpc_service_config grpc_service_config;
 grpc_service_config* grpc_service_config_create(const char* json_string);
 void grpc_service_config_destroy(grpc_service_config* service_config);
 
+/// Invokes \a process_json() for each global parameter in the service
+/// config.  \a arg is passed as the second argument to \a process_json().
+void grpc_service_config_parse_global_params(
+    const grpc_service_config* service_config,
+    void (*process_json)(const grpc_json* json, void* arg), void* arg);
+
 /// Gets the LB policy name from \a service_config.
 /// Returns NULL if no LB policy name was specified.
 /// Caller does NOT take ownership.