(substitute_in_expr): Preserve TREE_READONLY.

From-SVN: r9546

diff --git a/gcc/tree.c b/gcc/tree.c
index fcbfd5373c712fedc708badd8db45a039a4c3718..e8038d7445a0bc2e2feee6f33bb235004187eb20 100644 (file)
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -2197,6 +2197,7 @@ substitute_in_expr (exp, f, r)
      tree r;
 {
   enum tree_code code = TREE_CODE (exp);
+  tree new = 0;
   tree inner;
 
   switch (TREE_CODE_CLASS (code))
@@ -2217,9 +2218,10 @@ substitute_in_expr (exp, f, r)
       switch (tree_code_length[(int) code])
        {
        case 1:
-         return fold (build1 (code, TREE_TYPE (exp),
-                              substitute_in_expr (TREE_OPERAND (exp, 0),
-                                                  f, r)));
+         new = fold (build1 (code, TREE_TYPE (exp),
+                             substitute_in_expr (TREE_OPERAND (exp, 0),
+                                                 f, r)));
+         break;
 
        case 2:
          /* An RTL_EXPR cannot contain a PLACEHOLDER_EXPR; a CONSTRUCTOR
@@ -2229,10 +2231,11 @@ substitute_in_expr (exp, f, r)
          else if (code == CONSTRUCTOR)
            abort ();
 
-         return fold (build (code, TREE_TYPE (exp),
-                             substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
-                             substitute_in_expr (TREE_OPERAND (exp, 1),
-                                                 f, r)));
+         new = fold (build (code, TREE_TYPE (exp),
+                            substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
+                            substitute_in_expr (TREE_OPERAND (exp, 1),
+                                                f, r)));
+         break;
 
        case 3:
          /* It cannot be that anything inside a SAVE_EXPR contains a
@@ -2243,11 +2246,11 @@ substitute_in_expr (exp, f, r)
          if (code != COND_EXPR)
            abort ();
 
-         return fold (build (code, TREE_TYPE (exp),
-                             substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
-                             substitute_in_expr (TREE_OPERAND (exp, 1), f, r),
-                             substitute_in_expr (TREE_OPERAND (exp, 2),
-                                                 f, r)));
+         new = fold (build (code, TREE_TYPE (exp),
+                            substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
+                            substitute_in_expr (TREE_OPERAND (exp, 1), f, r),
+                            substitute_in_expr (TREE_OPERAND (exp, 2),
+                                                f, r)));
        }
 
       break;
@@ -2266,29 +2269,39 @@ substitute_in_expr (exp, f, r)
              && TREE_OPERAND (exp, 1) == f)
            return r;
 
-         return fold (build (code, TREE_TYPE (exp),
-                             substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
-                             TREE_OPERAND (exp, 1)));
+         new = fold (build (code, TREE_TYPE (exp),
+                            substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
+                            TREE_OPERAND (exp, 1)));
+         break;
+
        case BIT_FIELD_REF:
-         return fold (build (code, TREE_TYPE (exp),
-                             substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
-                             substitute_in_expr (TREE_OPERAND (exp, 1), f, r),
-                             substitute_in_expr (TREE_OPERAND (exp, 2), f, r)));
+         new = fold (build (code, TREE_TYPE (exp),
+                            substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
+                            substitute_in_expr (TREE_OPERAND (exp, 1), f, r),
+                            substitute_in_expr (TREE_OPERAND (exp, 2), f, r)));
+         break;
+
        case INDIRECT_REF:
        case BUFFER_REF:
-         return fold (build1 (code, TREE_TYPE (exp),
-                              substitute_in_expr (TREE_OPERAND (exp, 0),
-                                                f, r)));
+         new = fold (build1 (code, TREE_TYPE (exp),
+                             substitute_in_expr (TREE_OPERAND (exp, 0),
+                                                 f, r)));
+         break;
+
        case OFFSET_REF:
-         return fold (build (code, TREE_TYPE (exp),
-                             substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
-                             substitute_in_expr (TREE_OPERAND (exp, 1), f, r)));
+         new = fold (build (code, TREE_TYPE (exp),
+                            substitute_in_expr (TREE_OPERAND (exp, 0), f, r),
+                            substitute_in_expr (TREE_OPERAND (exp, 1), f, r)));
+         break;
        }
     }
 
   /* If it wasn't one of the cases we handle, give up.  */
+  if (new == 0)
+    abort ();
 
-  abort ();
+  TREE_READONLY (new) = TREE_READONLY (exp);
+  return new;
 }
 \f
 /* Given a type T, a FIELD_DECL F, and a replacement value R,