[PATCH 160/203] Introduce ada_var_msym_value_operation

Tom Tromey
2021-01-01T21:49:32Z

This adds class ada_var_msym_value_operation, which implements
OP_VAR_MSYM_VALUE for Ada.

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

* ada-lang.c (ada_var_msym_value_operation::evaluate_for_cast):
New method.
* ada-exp.h (class ada_var_msym_value_operation): New.
---
gdb/ChangeLog | 6 ++++++
gdb/ada-exp.h | 17 +++++++++++++++++
gdb/ada-lang.c | 25 +++++++++++++++++++++++++
3 files changed, 48 insertions(+)

diff --git a/gdb/ada-exp.h b/gdb/ada-exp.h
index 0f2f62f5978..0fe6ecf7e93 100644
--- a/gdb/ada-exp.h
+++ b/gdb/ada-exp.h
@@ -304,6 +304,23 @@ class ada_var_value_operation
using operation::do_generate_ax;
};

+/* Variant of var_msym_value_operation for Ada. */
+class ada_var_msym_value_operation
+ : public var_msym_value_operation
+{
+public:
+
+ using var_msym_value_operation::var_msym_value_operation;
+
+ value *evaluate_for_cast (struct type *expect_type,
+ struct expression *exp,
+ enum noside noside) override;
+
+protected:
+
+ using operation::do_generate_ax;
+};
+
} /* namespace expr */

#endif /* ADA_EXP_H */
diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index bdd574d033c..3560eee307a 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -10695,6 +10695,31 @@ ada_unop_atr_operation::evaluate (struct type *expect_type,
val, type_arg, std::get<2> (m_storage));
}

+value *
+ada_var_msym_value_operation::evaluate_for_cast (struct type *expect_type,
+ struct expression *exp,
+ enum noside noside)
+{
+ if (noside == EVAL_AVOID_SIDE_EFFECTS)
+ return value_zero (expect_type, not_lval);
+
+ value *val = evaluate_var_msym_value (noside,
+ std::get<1> (m_storage),
+ std::get<0> (m_storage));
+
+ val = ada_value_cast (expect_type, val);
+
+ /* Follow the Ada language semantics that do not allow taking
+ an address of the result of a cast (view conversion in Ada). */
+ if (VALUE_LVAL (val) == lval_memory)
+ {
+ if (value_lazy (val))
+ value_fetch_lazy (val);
+ VALUE_LVAL (val) = not_lval;
+ }
+ return val;
+}
+
value *
ada_var_value_operation::evaluate_for_cast (struct type *expect_type,
struct expression *exp,
--
2.26.2