Introduce multi_subscript_operation

This adds class multi_subscript_operation, which implements
MULTI_SUBSCRIPT.

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

	* expop.h (class multi_subscript_operation): New.
	* eval.c (multi_subscript_operation::evaluate): New method.

3 files changed, 34 insertions, 0 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 37fe24a..10a738a 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,10 @@
 2021-03-08  Tom Tromey  <tom@tromey.com>
 
+	* expop.h (class multi_subscript_operation): New.
+	* eval.c (multi_subscript_operation::evaluate): New method.
+
+2021-03-08  Tom Tromey  <tom@tromey.com>
+
 	* eval.c (objc_msgcall_operation::evaluate): New method.
 	* c-exp.h (class objc_msgcall_operation): New.
 
diff --git a/gdb/eval.c b/gdb/eval.c
index 9196517..655e4ef 100644
--- a/gdb/eval.c
+++ b/gdb/eval.c
@@ -2472,8 +2472,21 @@ objc_msgcall_operation::evaluate (struct type *expect_type,
 						     args.size () + 3));
 }
 
+value *
+multi_subscript_operation::evaluate (struct type *expect_type,
+				     struct expression *exp,
+				     enum noside noside)
+{
+  value *arg1 = std::get<0> (m_storage)->evaluate_with_coercion (exp, noside);
+  std::vector<operation_up> &values = std::get<1> (m_storage);
+  value **argvec = XALLOCAVEC (struct value *, values.size ());
+  for (int ix = 0; ix < values.size (); ++ix)
+    argvec[ix] = values[ix]->evaluate_with_coercion (exp, noside);
+  return eval_multi_subscript (expect_type, exp, noside, arg1,
+			       gdb::make_array_view (argvec, values.size ()));
 }
 
+}
 
 struct value *
 evaluate_subexp_standard (struct type *expect_type,
diff --git a/gdb/expop.h b/gdb/expop.h
index ef5b9bb..6b1a875 100644
--- a/gdb/expop.h
+++ b/gdb/expop.h
@@ -1966,6 +1966,22 @@ using dynamic_cast_operation = cxx_cast_operation<UNOP_DYNAMIC_CAST,
 using reinterpret_cast_operation = cxx_cast_operation<UNOP_REINTERPRET_CAST,
 						      value_reinterpret_cast>;
 
+/* Multi-dimensional subscripting.  */
+class multi_subscript_operation
+  : public tuple_holding_operation<operation_up, std::vector<operation_up>>
+{
+public:
+
+  using tuple_holding_operation::tuple_holding_operation;
+
+  value *evaluate (struct type *expect_type,
+		   struct expression *exp,
+		   enum noside noside) override;
+
+  enum exp_opcode opcode () const override
+  { return MULTI_SUBSCRIPT; }
+};
+
 } /* namespace expr */
 
 #endif /* EXPOP_H */