[PATCH 132/203] Introduce rust_subscript_operation

Tom Tromey
2021-01-01T21:49:04Z

This adds class rust_subscript_operation, which implements
BINOP_SUBSCRIPT for Rust.

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

* rust-lang.c (rust_subscript): No longer static.
* rust-exp.h (class rust_subscript_operation): New.
---
gdb/ChangeLog | 5 +++++
gdb/rust-exp.h | 57 +++++++++++++++++++++++++++++++++++++++++++++++++
gdb/rust-lang.c | 2 +-
3 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/gdb/rust-exp.h b/gdb/rust-exp.h
index d16f921ca00..7571009ea39 100644
--- a/gdb/rust-exp.h
+++ b/gdb/rust-exp.h
@@ -38,6 +38,10 @@ extern struct value *eval_op_rust_ind (struct type *expect_type,
enum noside noside,
enum exp_opcode opcode,
struct value *value);
+extern struct value *rust_subscript (struct type *expect_type,
+ struct expression *exp,
+ enum noside noside, bool for_addr,
+ struct value *lhs, struct value *rhs);

namespace expr
{
@@ -67,6 +71,59 @@ class rust_unop_ind_operation
}
};

+/* Subscript operator for Rust. */
+class rust_subscript_operation
+ : public tuple_holding_operation<operation_up, operation_up>
+{
+public:
+
+ using tuple_holding_operation::tuple_holding_operation;
+
+ value *evaluate (struct type *expect_type,
+ struct expression *exp,
+ enum noside noside) override
+ {
+ value *arg1 = std::get<0> (m_storage)->evaluate (nullptr, exp, noside);
+ value *arg2 = std::get<1> (m_storage)->evaluate (nullptr, exp, noside);
+ return rust_subscript (expect_type, exp, noside, false, arg1, arg2);
+ }
+
+ value *slice (struct type *expect_type,
+ struct expression *exp,
+ enum noside noside)
+ {
+ value *arg1 = std::get<0> (m_storage)->evaluate (nullptr, exp, noside);
+ value *arg2 = std::get<1> (m_storage)->evaluate (nullptr, exp, noside);
+ return rust_subscript (expect_type, exp, noside, true, arg1, arg2);
+ }
+
+ enum exp_opcode opcode () const override
+ { return BINOP_SUBSCRIPT; }
+};
+
+class rust_unop_addr_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
+ {
+ operation *oper = std::get<0> (m_storage).get ();
+ rust_subscript_operation *sub_op
+ = dynamic_cast<rust_subscript_operation *> (oper);
+ if (sub_op != nullptr)
+ return sub_op->slice (expect_type, exp, noside);
+ return oper->evaluate_for_address (exp, noside);
+ }
+
+ enum exp_opcode opcode () const override
+ { return UNOP_ADDR; }
+};
+
} /* namespace expr */

#endif /* RUST_EXP_H */
diff --git a/gdb/rust-lang.c b/gdb/rust-lang.c
index 2c3f72ed404..0035a58adc4 100644
--- a/gdb/rust-lang.c
+++ b/gdb/rust-lang.c
@@ -1168,7 +1168,7 @@ rust_compute_range (struct type *type, struct value *range,

/* A helper for rust_evaluate_subexp that handles BINOP_SUBSCRIPT. */

-static struct value *
+struct value *
rust_subscript (struct type *expect_type, struct expression *exp,
enum noside noside, bool for_addr,
struct value *lhs, struct value *rhs)
--
2.26.2