Split out eval_op_sub

This splits BINOP_SUB into a new function for future use.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* eval.c (eval_op_sub): New function.
	(evaluate_subexp_standard): Use it.

2 files changed, 34 insertions, 19 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 674f176..7533e9b 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,10 @@
 2021-03-08  Tom Tromey  <tom@tromey.com>
 
+	* eval.c (eval_op_sub): New function.
+	(evaluate_subexp_standard): Use it.
+
+2021-03-08  Tom Tromey  <tom@tromey.com>
+
 	* eval.c (eval_op_add): New function.
 	(evaluate_subexp_standard): Use it.
 
diff --git a/gdb/eval.c b/gdb/eval.c
index 4152c34..ba18723 100644
--- a/gdb/eval.c
+++ b/gdb/eval.c
@@ -1480,6 +1480,34 @@ eval_op_add (struct type *expect_type, struct expression *exp,
     }
 }
 
+/* A helper function for BINOP_SUB.  */
+
+static struct value *
+eval_op_sub (struct type *expect_type, struct expression *exp,
+	     enum noside noside, enum exp_opcode op,
+	     struct value *arg1, struct value *arg2)
+{
+  if (noside == EVAL_SKIP)
+    return eval_skip_value (exp);
+  if (binop_user_defined_p (op, arg1, arg2))
+    return value_x_binop (arg1, arg2, op, OP_NULL, noside);
+  else if (ptrmath_type_p (exp->language_defn, value_type (arg1))
+	   && ptrmath_type_p (exp->language_defn, value_type (arg2)))
+    {
+      /* FIXME -- should be ptrdiff_t */
+      struct type *type = builtin_type (exp->gdbarch)->builtin_long;
+      return value_from_longest (type, value_ptrdiff (arg1, arg2));
+    }
+  else if (ptrmath_type_p (exp->language_defn, value_type (arg1))
+	   && is_integral_or_integral_reference (value_type (arg2)))
+    return value_ptradd (arg1, - value_as_long (arg2));
+  else
+    {
+      binop_promote (exp->language_defn, exp->gdbarch, &arg1, &arg2);
+      return value_binop (arg1, arg2, BINOP_SUB);
+    }
+}
+
 struct value *
 evaluate_subexp_standard (struct type *expect_type,
 			  struct expression *exp, int *pos,
@@ -2171,25 +2199,7 @@ evaluate_subexp_standard (struct type *expect_type,
     case BINOP_SUB:
       arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
       arg2 = evaluate_subexp_with_coercion (exp, pos, noside);
-      if (noside == EVAL_SKIP)
-	return eval_skip_value (exp);
-      if (binop_user_defined_p (op, arg1, arg2))
-	return value_x_binop (arg1, arg2, op, OP_NULL, noside);
-      else if (ptrmath_type_p (exp->language_defn, value_type (arg1))
-	       && ptrmath_type_p (exp->language_defn, value_type (arg2)))
-	{
-	  /* FIXME -- should be ptrdiff_t */
-	  type = builtin_type (exp->gdbarch)->builtin_long;
-	  return value_from_longest (type, value_ptrdiff (arg1, arg2));
-	}
-      else if (ptrmath_type_p (exp->language_defn, value_type (arg1))
-	       && is_integral_or_integral_reference (value_type (arg2)))
-	return value_ptradd (arg1, - value_as_long (arg2));
-      else
-	{
-	  binop_promote (exp->language_defn, exp->gdbarch, &arg1, &arg2);
-	  return value_binop (arg1, arg2, BINOP_SUB);
-	}
+      return eval_op_sub (expect_type, exp, noside, op, arg1, arg2);
 
     case BINOP_EXP:
     case BINOP_MUL: