[PATCH 135/203] Introduce rust_aggregate_operation

Tom Tromey
2021-01-01T21:49:08Z

This adds class rust_aggregate_operation, which implements
OP_AGGREGATE for Rust.

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

* rust-lang.c (rust_aggregate_operation::evaluate): New method.
* rust-exp.h (class rust_aggregate_operation): New.
---
gdb/ChangeLog | 5 +++++
gdb/rust-exp.h | 18 +++++++++++++++
gdb/rust-lang.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 81 insertions(+)

diff --git a/gdb/rust-exp.h b/gdb/rust-exp.h
index 19e945c806b..6e529f8e600 100644
--- a/gdb/rust-exp.h
+++ b/gdb/rust-exp.h
@@ -207,6 +207,24 @@ class rust_structop
{ return STRUCTOP_STRUCT; }
};

+/* Rust aggregate initialization. */
+class rust_aggregate_operation
+ : public tuple_holding_operation<struct type *, operation_up,
+ std::vector<std::pair<std::string,
+ 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 OP_AGGREGATE; }
+};
+
} /* namespace expr */

#endif /* RUST_EXP_H */
diff --git a/gdb/rust-lang.c b/gdb/rust-lang.c
index 95b19776edf..992319ffd2b 100644
--- a/gdb/rust-lang.c
+++ b/gdb/rust-lang.c
@@ -1700,6 +1700,64 @@ rust_evaluate_subexp (struct type *expect_type, struct expression *exp,
return result;
}

+namespace expr
+{
+
+value *
+rust_aggregate_operation::evaluate (struct type *expect_type,
+ struct expression *exp,
+ enum noside noside)
+{
+ struct type *type = std::get<0> (m_storage);
+ CORE_ADDR addr = 0;
+ struct value *addrval = NULL;
+ value *result;
+
+ if (noside == EVAL_NORMAL)
+ {
+ addrval = value_allocate_space_in_inferior (TYPE_LENGTH (type));
+ addr = value_as_long (addrval);
+ result = value_at_lazy (type, addr);
+ }
+
+ if (std::get<1> (m_storage) != nullptr)
+ {
+ struct value *init = std::get<1> (m_storage)->evaluate (nullptr, exp,
+ noside);
+
+ if (noside == EVAL_NORMAL)
+ {
+ /* This isn't quite right but will do for the time
+ being, seeing that we can't implement the Copy
+ trait anyway. */
+ value_assign (result, init);
+ }
+ }
+
+ for (const auto &item : std::get<2> (m_storage))
+ {
+ value *val = item.second->evaluate (nullptr, exp, noside);
+ if (noside == EVAL_NORMAL)
+ {
+ const char *fieldname = item.first.c_str ();
+ value *field = value_struct_elt (&result, nullptr, fieldname,
+ nullptr, "structure");
+ value_assign (field, val);
+ }
+ }
+
+ if (noside == EVAL_SKIP)
+ result = value_from_longest (builtin_type (exp->gdbarch)->builtin_int, 1);
+ else if (noside == EVAL_AVOID_SIDE_EFFECTS)
+ result = allocate_value (type);
+ else
+ result = value_at_lazy (type, addr);
+
+ return result;
+}
+
+}
+
/* operator_length implementation for Rust. */

static void
--
2.26.2