Add an error mode to disable creation

src/core/lib/iomgr/error.cc

@@ -312,6 +312,12 @@ static void internal_add_error(grpc_error** err, grpc_error* new_err) {
 // It is very common to include and extra int and string in an error
 #define SURPLUS_CAPACITY (2 * SLOTS_PER_INT + SLOTS_PER_TIME)
 
+static bool g_error_creation_allowed = true;
+
+void grpc_disable_error_creation() { g_error_creation_allowed = false; }
+
+void grpc_enable_error_creation() { g_error_creation_allowed = true; }
+
 grpc_error* grpc_error_create(const char* file, int line, grpc_slice desc,
                               grpc_error** referencing,
                               size_t num_referencing) {
@@ -326,6 +332,12 @@ grpc_error* grpc_error_create(const char* file, int line, grpc_slice desc,
     return GRPC_ERROR_OOM;
   }
 #ifndef NDEBUG
+  if (!g_error_creation_allowed) {
+    gpr_log(GPR_ERROR,
+            "Error creation occurred when error creation was disabled [%s:%d]",
+            file, line);
+    abort();
+  }
   if (grpc_trace_error_refcount.enabled()) {
     gpr_log(GPR_DEBUG, "%p create [%s:%d]", err, file, line);
   }

src/core/lib/iomgr/error.h

@@ -123,6 +123,11 @@ typedef enum {
 #define GRPC_ERROR_OOM ((grpc_error*)2)
 #define GRPC_ERROR_CANCELLED ((grpc_error*)4)
 
+// debug only toggles that allow for a sanity to check that ensures we will
+// never create any errors in the per-RPC hotpath.
+void grpc_disable_error_creation();
+void grpc_enable_error_creation();
+
 const char* grpc_error_string(grpc_error* error);
 
 /// Create an error - but use GRPC_ERROR_CREATE instead