diff --git a/gcc/rust/expand/rust-macro-builtins.cc b/gcc/rust/expand/rust-macro-builtins.cc
index a2129e84a46133954330af5955407f4cb88523b5..9bed3ddbe79b357551cd381da70e5248de24dfaa 100644
--- a/gcc/rust/expand/rust-macro-builtins.cc
+++ b/gcc/rust/expand/rust-macro-builtins.cc
@@ -265,7 +265,7 @@ load_file_bytes (const char *filename)
 } // namespace
 
 AST::Fragment
-MacroBuiltin::assert (Location invoc_locus, AST::MacroInvocData &invoc)
+MacroBuiltin::assert_handler (Location invoc_locus, AST::MacroInvocData &invoc)
 {
   rust_debug ("assert!() called");
 
@@ -273,7 +273,7 @@ MacroBuiltin::assert (Location invoc_locus, AST::MacroInvocData &invoc)
 }
 
 AST::Fragment
-MacroBuiltin::file (Location invoc_locus, AST::MacroInvocData &invoc)
+MacroBuiltin::file_handler (Location invoc_locus, AST::MacroInvocData &invoc)
 {
   auto current_file
     = Session::get_instance ().linemap->location_file (invoc_locus);
@@ -283,7 +283,7 @@ MacroBuiltin::file (Location invoc_locus, AST::MacroInvocData &invoc)
 }
 
 AST::Fragment
-MacroBuiltin::column (Location invoc_locus, AST::MacroInvocData &invoc)
+MacroBuiltin::column_handler (Location invoc_locus, AST::MacroInvocData &invoc)
 {
   auto current_column
     = Session::get_instance ().linemap->location_to_column (invoc_locus);
@@ -300,7 +300,8 @@ MacroBuiltin::column (Location invoc_locus, AST::MacroInvocData &invoc)
    &'static [u8; N].  */
 
 AST::Fragment
-MacroBuiltin::include_bytes (Location invoc_locus, AST::MacroInvocData &invoc)
+MacroBuiltin::include_bytes_handler (Location invoc_locus,
+				     AST::MacroInvocData &invoc)
 {
   /* Get target filename from the macro invocation, which is treated as a path
      relative to the include!-ing file (currently being compiled).  */
@@ -343,7 +344,8 @@ MacroBuiltin::include_bytes (Location invoc_locus, AST::MacroInvocData &invoc)
    expression of type &'static str.  */
 
 AST::Fragment
-MacroBuiltin::include_str (Location invoc_locus, AST::MacroInvocData &invoc)
+MacroBuiltin::include_str_handler (Location invoc_locus,
+				   AST::MacroInvocData &invoc)
 {
   /* Get target filename from the macro invocation, which is treated as a path
      relative to the include!-ing file (currently being compiled).  */
@@ -368,7 +370,8 @@ MacroBuiltin::include_str (Location invoc_locus, AST::MacroInvocData &invoc)
 /* Expand builtin macro compile_error!("error"), which forces a compile error
    during the compile time. */
 AST::Fragment
-MacroBuiltin::compile_error (Location invoc_locus, AST::MacroInvocData &invoc)
+MacroBuiltin::compile_error_handler (Location invoc_locus,
+				     AST::MacroInvocData &invoc)
 {
   auto lit_expr
     = parse_single_string_literal (invoc.get_delim_tok_tree (), invoc_locus,
@@ -386,7 +389,7 @@ MacroBuiltin::compile_error (Location invoc_locus, AST::MacroInvocData &invoc)
    into a string with no delimiter. */
 
 AST::Fragment
-MacroBuiltin::concat (Location invoc_locus, AST::MacroInvocData &invoc)
+MacroBuiltin::concat_handler (Location invoc_locus, AST::MacroInvocData &invoc)
 {
   auto invoc_token_tree = invoc.get_delim_tok_tree ();
   MacroInvocLexer lex (invoc_token_tree.to_token_stream ());
@@ -437,7 +440,7 @@ MacroBuiltin::concat (Location invoc_locus, AST::MacroInvocData &invoc)
    compile time. */
 
 AST::Fragment
-MacroBuiltin::env (Location invoc_locus, AST::MacroInvocData &invoc)
+MacroBuiltin::env_handler (Location invoc_locus, AST::MacroInvocData &invoc)
 {
   auto invoc_token_tree = invoc.get_delim_tok_tree ();
   MacroInvocLexer lex (invoc_token_tree.to_token_stream ());
@@ -495,7 +498,7 @@ MacroBuiltin::env (Location invoc_locus, AST::MacroInvocData &invoc)
 }
 
 AST::Fragment
-MacroBuiltin::cfg (Location invoc_locus, AST::MacroInvocData &invoc)
+MacroBuiltin::cfg_handler (Location invoc_locus, AST::MacroInvocData &invoc)
 {
   // only parse if not already parsed
   if (!invoc.is_parsed ())
@@ -534,7 +537,7 @@ MacroBuiltin::cfg (Location invoc_locus, AST::MacroInvocData &invoc)
  scope compile time. */
 
 AST::Fragment
-MacroBuiltin::include (Location invoc_locus, AST::MacroInvocData &invoc)
+MacroBuiltin::include_handler (Location invoc_locus, AST::MacroInvocData &invoc)
 {
   /* Get target filename from the macro invocation, which is treated as a path
      relative to the include!-ing file (currently being compiled).  */
@@ -588,7 +591,7 @@ MacroBuiltin::include (Location invoc_locus, AST::MacroInvocData &invoc)
 }
 
 AST::Fragment
-MacroBuiltin::line (Location invoc_locus, AST::MacroInvocData &invoc)
+MacroBuiltin::line_handler (Location invoc_locus, AST::MacroInvocData &invoc)
 {
   auto current_line
     = Session::get_instance ().linemap->location_to_line (invoc_locus);
diff --git a/gcc/rust/expand/rust-macro-builtins.h b/gcc/rust/expand/rust-macro-builtins.h
index c65bd940189035011be56f9bdded473ab41bb82e..6d7a0123ab34d9bd9ab0e8353c106a6e66b8c2b9 100644
--- a/gcc/rust/expand/rust-macro-builtins.h
+++ b/gcc/rust/expand/rust-macro-builtins.h
@@ -60,45 +60,42 @@
  * of the `Mappings` class.
  */
 
-/* If assert is defined as a macro this file will not parse, so undefine this
-   before continuing.  */
-// TODO: Rename all functions here `*_handler`
-#ifdef assert
-#undef assert
-#endif
-
 namespace Rust {
 class MacroBuiltin
 {
 public:
-  static AST::Fragment assert (Location invoc_locus,
-			       AST::MacroInvocData &invoc);
+  static AST::Fragment assert_handler (Location invoc_locus,
+				       AST::MacroInvocData &invoc);
 
-  static AST::Fragment file (Location invoc_locus, AST::MacroInvocData &invoc);
+  static AST::Fragment file_handler (Location invoc_locus,
+				     AST::MacroInvocData &invoc);
 
-  static AST::Fragment column (Location invoc_locus,
-			       AST::MacroInvocData &invoc);
+  static AST::Fragment column_handler (Location invoc_locus,
+				       AST::MacroInvocData &invoc);
 
-  static AST::Fragment include_bytes (Location invoc_locus,
-				      AST::MacroInvocData &invoc);
+  static AST::Fragment include_bytes_handler (Location invoc_locus,
+					      AST::MacroInvocData &invoc);
 
-  static AST::Fragment include_str (Location invoc_locus,
-				    AST::MacroInvocData &invoc);
+  static AST::Fragment include_str_handler (Location invoc_locus,
+					    AST::MacroInvocData &invoc);
 
-  static AST::Fragment compile_error (Location invoc_locus,
-				      AST::MacroInvocData &invoc);
+  static AST::Fragment compile_error_handler (Location invoc_locus,
+					      AST::MacroInvocData &invoc);
 
-  static AST::Fragment concat (Location invoc_locus,
-			       AST::MacroInvocData &invoc);
+  static AST::Fragment concat_handler (Location invoc_locus,
+				       AST::MacroInvocData &invoc);
 
-  static AST::Fragment env (Location invoc_locus, AST::MacroInvocData &invoc);
+  static AST::Fragment env_handler (Location invoc_locus,
+				    AST::MacroInvocData &invoc);
 
-  static AST::Fragment cfg (Location invoc_locus, AST::MacroInvocData &invoc);
+  static AST::Fragment cfg_handler (Location invoc_locus,
+				    AST::MacroInvocData &invoc);
 
-  static AST::Fragment include (Location invoc_locus,
-				AST::MacroInvocData &invoc);
+  static AST::Fragment include_handler (Location invoc_locus,
+					AST::MacroInvocData &invoc);
 
-  static AST::Fragment line (Location invoc_locus, AST::MacroInvocData &invoc);
+  static AST::Fragment line_handler (Location invoc_locus,
+				     AST::MacroInvocData &invoc);
 };
 } // namespace Rust
 
diff --git a/gcc/rust/util/rust-hir-map.cc b/gcc/rust/util/rust-hir-map.cc
index bee0682e9b41900e70bed03f7a73b6c8a75a3283..1fc32038d19a17c7bdf6013f0a6e16858bd802ab 100644
--- a/gcc/rust/util/rust-hir-map.cc
+++ b/gcc/rust/util/rust-hir-map.cc
@@ -843,17 +843,17 @@ Mappings::insert_macro_def (AST::MacroRulesDefinition *macro)
   static std::map<
     std::string, std::function<AST::Fragment (Location, AST::MacroInvocData &)>>
     builtin_macros = {
-      {"assert", MacroBuiltin::assert},
-      {"file", MacroBuiltin::file},
-      {"line", MacroBuiltin::line},
-      {"column", MacroBuiltin::column},
-      {"include_bytes", MacroBuiltin::include_bytes},
-      {"include_str", MacroBuiltin::include_str},
-      {"compile_error", MacroBuiltin::compile_error},
-      {"concat", MacroBuiltin::concat},
-      {"env", MacroBuiltin::env},
-      {"cfg", MacroBuiltin::cfg},
-      {"include", MacroBuiltin::include},
+      {"assert", MacroBuiltin::assert_handler},
+      {"file", MacroBuiltin::file_handler},
+      {"line", MacroBuiltin::line_handler},
+      {"column", MacroBuiltin::column_handler},
+      {"include_bytes", MacroBuiltin::include_bytes_handler},
+      {"include_str", MacroBuiltin::include_str_handler},
+      {"compile_error", MacroBuiltin::compile_error_handler},
+      {"concat", MacroBuiltin::concat_handler},
+      {"env", MacroBuiltin::env_handler},
+      {"cfg", MacroBuiltin::cfg_handler},
+      {"include", MacroBuiltin::include_handler},
     };
 
   auto outer_attrs = macro->get_outer_attrs ();