[PATCH 125/203] Introduce ada_wrapped_operation

Tom Tromey
2021-01-01T21:48:57Z

This adds class ada_wrapped_operation, which is used to wrap some
generic operations with a bit of Ada-specific handling. This
corresponds to the old "default" case in ada_evaluate_subexp.

gdb/ChangeLog
2021-01-01 Tom Tromey <tom@tromey.com>

* ada-lang.c (ada_wrapped_operation::evaluate): New method.
* ada-exp.h: New file.
---
gdb/ChangeLog | 5 +++++
gdb/ada-exp.h | 47 +++++++++++++++++++++++++++++++++++++++++++++++
gdb/ada-lang.c | 29 +++++++++++++++++++++++++++++
3 files changed, 81 insertions(+)
create mode 100644 gdb/ada-exp.h

diff --git a/gdb/ada-exp.h b/gdb/ada-exp.h
new file mode 100644
index 00000000000..3f780dc9ff4
--- /dev/null
+++ b/gdb/ada-exp.h
@@ -0,0 +1,47 @@
+/* Definitions for Ada expressions
+
+ Copyright (C) 2020 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#ifndef ADA_EXP_H
+#define ADA_EXP_H
+
+#include "expop.h"
+
+namespace expr
+{
+
+/* In Ada, some generic operations must be wrapped with a handler that
+ handles some Ada-specific type conversions. */
+class ada_wrapped_operation
+ : public tuple_holding_operation<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 std::get<0> (m_storage)->opcode (); }
+};
+
+} /* namespace expr */
+
+#endif /* ADA_EXP_H */
diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index e46c2bdbbe5..7855cd32eb3 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -57,6 +57,7 @@
#include "gdbsupport/function-view.h"
#include "gdbsupport/byte-vector.h"
#include <algorithm>
+#include "ada-exp.h"

/* Define whether or not the C operator '/' truncates towards zero for
differently signed operands (truncation direction is undefined in C).
@@ -10543,6 +10544,34 @@ ada_binop_exp (struct type *expect_type,
}
}

+namespace expr
+{
+
+value *
+ada_wrapped_operation::evaluate (struct type *expect_type,
+ struct expression *exp,
+ enum noside noside)
+{
+ value *result = std::get<0> (m_storage)->evaluate (expect_type, exp, noside);
+ if (noside == EVAL_NORMAL)
+ result = unwrap_value (result);
+
+ /* If evaluating an OP_FLOAT and an EXPECT_TYPE was provided,
+ then we need to perform the conversion manually, because
+ evaluate_subexp_standard doesn't do it. This conversion is
+ necessary in Ada because the different kinds of float/fixed
+ types in Ada have different representations.
+
+ Similarly, we need to perform the conversion from OP_LONG
+ ourselves. */
+ if ((opcode () == OP_FLOAT || opcode () == OP_LONG) && expect_type != NULL)
+ result = ada_value_cast (expect_type, result);
+
+ return result;
+}
+
+}
+
/* Implement the evaluate_exp routine in the exp_descriptor structure
for the Ada language. */

--
2.26.2