[PATCH v5 1/2] c: Refactor implementation of _Countof()

[Alejandro Colomar]

No changes intended.  This refactor prepares the code so that a future
patch extending the semantic of _Countof() will be smaller.

gcc/c/ChangeLog:

        * c-typeck.cc (c_expr_countof_expr): Refactor.

Co-authored-by: Martin Uecker <uec...@tugraz.at>
Signed-off-by: Alejandro Colomar <a...@kernel.org>
---
 gcc/c/c-typeck.cc | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
index 60ed44c2f672..32dfaf031e91 100644
--- a/gcc/c/c-typeck.cc
+++ b/gcc/c/c-typeck.cc
@@ -4059,16 +4059,19 @@ c_expr_countof_expr (location_t loc, struct c_expr expr)
   else
     {
       bool expr_const_operands = true;
-
-      tree folded_expr = c_fully_fold (expr.value, require_constant_value,
-                                      &expr_const_operands);
-      ret.value = c_countof_type (loc, TREE_TYPE (folded_expr));
-      c_last_sizeof_arg = expr.value;
-      c_last_sizeof_loc = loc;
       ret.original_code = COUNTOF_EXPR;
       ret.original_type = NULL;
       ret.m_decimal = 0;
-      if (is_top_array_vla (TREE_TYPE (folded_expr)))
+
+      tree folded_expr = c_fully_fold (expr.value, require_constant_value,
+                                      &expr_const_operands);
+
+      tree type = TREE_TYPE (folded_expr);
+      ret.value = c_countof_type (loc, type);
+      c_last_sizeof_arg = expr.value;
+      c_last_sizeof_loc = loc;
+
+      if (is_top_array_vla (type))
        {
          /* countof is evaluated when given a vla.  */
          ret.value = build2 (C_MAYBE_CONST_EXPR, TREE_TYPE (ret.value),
@@ -4076,7 +4079,7 @@ c_expr_countof_expr (location_t loc, struct c_expr expr)
          C_MAYBE_CONST_EXPR_NON_CONST (ret.value) = !expr_const_operands;
          SET_EXPR_LOCATION (ret.value, loc);
        }
-      pop_maybe_used (is_top_array_vla (TREE_TYPE (folded_expr)));
+      pop_maybe_used (is_top_array_vla (type));
     }
   return ret;
 }
-- 
2.51.0