1 files changed, 24 insertions, 0 deletions
diff --git a/gcc/tree-flow.h b/gcc/tree-flow.h
index 2bf40df..da49ed1 100644
--- a/gcc/tree-flow.h
+++ b/gcc/tree-flow.h
@@ -389,11 +389,35 @@ typedef struct
 } referenced_var_iterator;
 
 
+/* This macro loops over all the referenced vars, one at a time, putting the
+   current var in VAR.  Note:  You are not allowed to add referenced variables
+   to the hashtable while using this macro.  Doing so may cause it to behave
+   erratically.  */
+
 #define FOR_EACH_REFERENCED_VAR(VAR, ITER) \
   for ((VAR) = first_referenced_var (&(ITER)); \
        !end_referenced_vars_p (&(ITER)); \
        (VAR) = next_referenced_var (&(ITER))) 
 
+
+typedef struct
+{
+  int i;
+} safe_referenced_var_iterator;
+
+/* This macro loops over all the referenced vars, one at a time, putting the
+   current var in VAR.  You are allowed to add referenced variables during the
+   execution of this macro, however, the macro will not iterate over them.  It
+   requires a temporary vector of trees, VEC, whose lifetime is controlled by
+   the caller.  The purpose of the vector is to temporarily store the
+   referenced_variables hashtable so that adding referenced variables does not
+   affect the hashtable.  */
+
+#define FOR_EACH_REFERENCED_VAR_SAFE(VAR, VEC, ITER) \
+  for ((ITER).i = 0, fill_referenced_var_vec (&(VEC)); \
+       VEC_iterate (tree, (VEC), (ITER).i, (VAR)); \
+       (ITER).i++)
+
 /* Array of all variables referenced in the function.  */
 extern GTY((param_is (struct int_tree_map))) htab_t referenced_vars;