avoid empty function names, problematic for Rprof files

R/api.R

@@ -96,6 +96,9 @@ validate_profile_v1 <- function(x) {
   stopifnot(!anyDuplicated(x$functions$function_id))
   #' The `name`, `system_name` and `filename` columns describe function names
   #' (demangled and mangled), and source file names for a function.
+  #' Both `name` and `system_name` must not contain empty strings.
+  stopifnot(x$functions$name != "")
+  stopifnot(x$functions$system_name != "")
   #' The `start_line` column describes the start line of a function in its
   #' source file, zero if unknown. All values must be nonnegative.
   stopifnot(x$functions$start_line >= 0)

R/pprof-from-ds.R

@@ -55,6 +55,9 @@ add_locations_to_msg <- function(locations, msg) {
 }
 
 add_functions_to_msg <- function(functions, msg) {
+  functions$name[functions$name == "<?>"] <- ""
+  functions$system_name[functions$system_name == "<?>"] <- ""
+
   functions$name <- match(functions$name, msg$string_table) - 1L
   functions$system_name <- match(functions$system_name, msg$string_table) - 1L
   functions$filename <- match(functions$filename, msg$string_table) - 1L

R/pprof-to-ds.R

@@ -73,7 +73,9 @@ get_functions_from_msg <- function(msg) {
   functions$id <- NULL
 
   functions$name <- msg$string_table[functions$name + 1]
+  functions$name[functions$name == ""] <- "<?>"
   functions$system_name <- msg$string_table[functions$system_name + 1]
+  functions$system_name[functions$system_name == ""] <- "<?>"
   functions$filename <- msg$string_table[functions$filename + 1]
 
   functions$start_line <- as.integer(functions$start_line)