Introduce string_operation

This adds string_operation, which implements OP_STRING for most
languages (C has its own variant).

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

	* expop.h (class string_operation): New.
	* eval.c (eval_op_string): No longer static.

1 files changed, 24 insertions, 0 deletions

diff --git a/gdb/expop.h b/gdb/expop.h
index d143815..802be81 100644
--- a/gdb/expop.h
+++ b/gdb/expop.h
@@ -61,6 +61,10 @@ extern struct value *eval_op_func_static_var (struct type *expect_type,
 extern struct value *eval_op_register (struct type *expect_type,
 				       struct expression *exp,
 				       enum noside noside, const char *name);
+extern struct value *eval_op_string (struct type *expect_type,
+				     struct expression *exp,
+				     enum noside noside, int len,
+				     const char *string);
 
 namespace expr
 {
@@ -681,6 +685,26 @@ protected:
     override;
 };
 
+class string_operation
+  : public tuple_holding_operation<std::string>
+{
+public:
+
+  using tuple_holding_operation::tuple_holding_operation;
+
+  value *evaluate (struct type *expect_type,
+		   struct expression *exp,
+		   enum noside noside) override
+  {
+    const std::string &str = std::get<0> (m_storage);
+    return eval_op_string (expect_type, exp, noside,
+			   str.size (), str.c_str ());
+  }
+
+  enum exp_opcode opcode () const override
+  { return OP_STRING; }
+};
+
 } /* namespace expr */
 
 #endif /* EXPOP_H */