[PATCH 131/203] Introduce rust_unop_ind_operation

Tom Tromey
2021-01-01T21:49:02Z

This adds class rust_unop_ind_operation, which implements UNOP_IND for
Rust. Rust requires a special case here to handle trait objects.

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

* rust-lang.c (eval_op_rust_ind): No longer static. Add "opcode"
parameter.
(rust_evaluate_subexp): Update.
* rust-exp.h (class rust_unop_ind_operation): New.
---
gdb/ChangeLog | 7 +++++++
gdb/rust-exp.h | 25 +++++++++++++++++++++++++
gdb/rust-lang.c | 5 +++--
3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/gdb/rust-exp.h b/gdb/rust-exp.h
index cce1fd9a7d9..d16f921ca00 100644
--- a/gdb/rust-exp.h
+++ b/gdb/rust-exp.h
@@ -33,6 +33,11 @@ extern struct value *eval_op_rust_array (struct type *expect_type,
enum exp_opcode opcode,
struct value *ncopies,
struct value *elt);
+extern struct value *eval_op_rust_ind (struct type *expect_type,
+ struct expression *exp,
+ enum noside noside,
+ enum exp_opcode opcode,
+ struct value *value);

namespace expr
{
@@ -42,6 +47,26 @@ using rust_unop_compl_operation = unop_operation<UNOP_COMPLEMENT,
using rust_array_operation = binop_operation<OP_RUST_ARRAY,
eval_op_rust_array>;

+/* The Rust indirection operation. */
+class rust_unop_ind_operation
+ : public unop_ind_operation
+{
+public:
+
+ using unop_ind_operation::unop_ind_operation;
+
+ value *evaluate (struct type *expect_type,
+ struct expression *exp,
+ enum noside noside) override
+ {
+ if (noside != EVAL_NORMAL)
+ return unop_ind_operation::evaluate (expect_type, exp, noside);
+
+ value *arg1 = std::get<0> (m_storage)->evaluate (nullptr, exp, noside);
+ return eval_op_rust_ind (expect_type, exp, noside, UNOP_IND, arg1);
+ }
+};
+
} /* namespace expr */

#endif /* RUST_EXP_H */
diff --git a/gdb/rust-lang.c b/gdb/rust-lang.c
index 1305ee092fa..2c3f72ed404 100644
--- a/gdb/rust-lang.c
+++ b/gdb/rust-lang.c
@@ -1325,9 +1325,10 @@ rust_subscript (struct type *expect_type, struct expression *exp,

/* A helper function for UNOP_IND. */

-static struct value *
+struct value *
eval_op_rust_ind (struct type *expect_type, struct expression *exp,
enum noside noside,
+ enum exp_opcode opcode,
struct value *value)
{
gdb_assert (noside == EVAL_NORMAL);
@@ -1521,7 +1522,7 @@ rust_evaluate_subexp (struct type *expect_type, struct expression *exp,
++*pos;
struct value *value = evaluate_subexp (expect_type, exp, pos,
noside);
- result = eval_op_rust_ind (expect_type, exp, noside, value);
+ result = eval_op_rust_ind (expect_type, exp, noside, op, value);
}
}
break;
--
2.26.2