[PATCH 114/203] Implement UNOP_MEMVAL and UNOP_MEMVAL_TYPE

Tom Tromey
2021-01-01T21:48:49Z

This adds class unop_memval_operation and unop_memval_type_operation,
which implement UNOP_MEMVAL and UNOP_MEMVAL_TYPE.

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

* expop.h (class unop_memval_operation)
(class unop_memval_type_operation): New.
* eval.c (eval_op_memval): No longer static.
(unop_memval_operation::evaluate_for_address)
(unop_memval_type_operation::evaluate_for_address)
(unop_memval_operation::evaluate_for_sizeof)
(unop_memval_type_operation::evaluate_for_sizeof): New methods.
* ax-gdb.c (unop_memval_operation::do_generate_ax)
(unop_memval_type_operation::do_generate_ax): New methods.
---
gdb/ChangeLog | 12 ++++++++
gdb/ax-gdb.c | 40 ++++++++++++++++++++++++++
gdb/eval.c | 37 ++++++++++++++++++++++++-
gdb/expop.h | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 165 insertions(+), 1 deletion(-)

diff --git a/gdb/ax-gdb.c b/gdb/ax-gdb.c
index 756f4d7969a..6514e40cdbf 100644
--- a/gdb/ax-gdb.c
+++ b/gdb/ax-gdb.c
@@ -2514,6 +2514,46 @@ unop_sizeof_operation::do_generate_ax (struct expression *exp,
value->type = builtin_type (ax->gdbarch)->builtin_int;
}

+void
+unop_memval_operation::do_generate_ax (struct expression *exp,
+ struct agent_expr *ax,
+ struct axs_value *value,
+ struct type *cast_type)
+{
+ std::get<0> (m_storage)->generate_ax (exp, ax, value);
+ /* If we have an axs_rvalue or an axs_lvalue_memory, then we
+ already have the right value on the stack. For
+ axs_lvalue_register, we must convert. */
+ if (value->kind == axs_lvalue_register)
+ require_rvalue (ax, value);
+
+ value->type = std::get<1> (m_storage);
+ value->kind = axs_lvalue_memory;
+}
+
+void
+unop_memval_type_operation::do_generate_ax (struct expression *exp,
+ struct agent_expr *ax,
+ struct axs_value *value,
+ struct type *cast_type)
+{
+ struct value *val
+ = std::get<0> (m_storage)->evaluate (nullptr, exp,
+ EVAL_AVOID_SIDE_EFFECTS);
+ struct type *type = value_type (val);
+
+ std::get<1> (m_storage)->generate_ax (exp, ax, value);
+
+ /* If we have an axs_rvalue or an axs_lvalue_memory, then we
+ already have the right value on the stack. For
+ axs_lvalue_register, we must convert. */
+ if (value->kind == axs_lvalue_register)
+ require_rvalue (ax, value);
+
+ value->type = type;
+ value->kind = axs_lvalue_memory;
+}
+
}

/* This handles the middle-to-right-side of code generation for binary
diff --git a/gdb/eval.c b/gdb/eval.c
index 526c80de92b..1ada2f3986b 100644
--- a/gdb/eval.c
+++ b/gdb/eval.c
@@ -1872,7 +1872,7 @@ eval_op_alignof (struct type *expect_type, struct expression *exp,

/* A helper function for UNOP_MEMVAL. */

-static struct value *
+struct value *
eval_op_memval (struct type *expect_type, struct expression *exp,
enum noside noside,
struct value *arg1, struct type *type)
@@ -3308,6 +3308,25 @@ var_msym_value_operation::evaluate_for_address (struct expression *exp,
return value_addr (val);
}

+value *
+unop_memval_operation::evaluate_for_address (struct expression *exp,
+ enum noside noside)
+{
+ return value_cast (lookup_pointer_type (std::get<1> (m_storage)),
+ std::get<0> (m_storage)->evaluate (nullptr, exp, noside));
+}
+
+value *
+unop_memval_type_operation::evaluate_for_address (struct expression *exp,
+ enum noside noside)
+{
+ value *typeval = std::get<0> (m_storage)->evaluate (nullptr, exp,
+ EVAL_AVOID_SIDE_EFFECTS);
+ struct type *type = value_type (typeval);
+ return value_cast (lookup_pointer_type (type),
+ std::get<1> (m_storage)->evaluate (nullptr, exp, noside));
+}
+
}

/* Evaluate like `evaluate_subexp' except coercing arrays to pointers.
@@ -3579,6 +3598,22 @@ unop_ind_base_operation::evaluate_for_sizeof (struct expression *exp,
return value_from_longest (size_type, (LONGEST) TYPE_LENGTH (type));
}

+value *
+unop_memval_operation::evaluate_for_sizeof (struct expression *exp,
+ enum noside noside)
+{
+ return evaluate_subexp_for_sizeof_base (exp, std::get<1> (m_storage));
+}
+
+value *
+unop_memval_type_operation::evaluate_for_sizeof (struct expression *exp,
+ enum noside noside)
+{
+ value *typeval = std::get<0> (m_storage)->evaluate (nullptr, exp,
+ EVAL_AVOID_SIDE_EFFECTS);
+ return evaluate_subexp_for_sizeof_base (exp, value_type (typeval));
+}
+
}

/* Evaluate a subexpression of EXP, at index *POS, and return a value
diff --git a/gdb/expop.h b/gdb/expop.h
index b5f01550d85..867cd85ead5 100644
--- a/gdb/expop.h
+++ b/gdb/expop.h
@@ -192,6 +192,10 @@ extern struct value *eval_op_alignof (struct type *expect_type,
struct expression *exp,
enum noside noside,
struct value *arg1);
+extern struct value *eval_op_memval (struct type *expect_type,
+ struct expression *exp,
+ enum noside noside,
+ struct value *arg1, struct type *type);

namespace expr
{
@@ -1625,6 +1629,79 @@ class unop_alignof_operation
{ return UNOP_ALIGNOF; }
};

+/* Implement UNOP_MEMVAL. */
+class unop_memval_operation
+ : public tuple_holding_operation<operation_up, struct type *>
+{
+public:
+
+ using tuple_holding_operation::tuple_holding_operation;
+
+ value *evaluate (struct type *expect_type,
+ struct expression *exp,
+ enum noside noside) override
+ {
+ value *val = std::get<0> (m_storage)->evaluate (expect_type, exp, noside);
+ return eval_op_memval (expect_type, exp, noside, val,
+ std::get<1> (m_storage));
+ }
+
+ value *evaluate_for_sizeof (struct expression *exp,
+ enum noside noside) override;
+
+ value *evaluate_for_address (struct expression *exp,
+ enum noside noside) override;
+
+ enum exp_opcode opcode () const override
+ { return UNOP_MEMVAL; }
+
+protected:
+
+ void do_generate_ax (struct expression *exp,
+ struct agent_expr *ax,
+ struct axs_value *value,
+ struct type *cast_type)
+ override;
+};
+
+/* Implement UNOP_MEMVAL_TYPE. */
+class unop_memval_type_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 *typeval
+ = std::get<0> (m_storage)->evaluate (expect_type, exp,
+ EVAL_AVOID_SIDE_EFFECTS);
+ struct type *type = value_type (typeval);
+ value *val = std::get<1> (m_storage)->evaluate (expect_type, exp, noside);
+ return eval_op_memval (expect_type, exp, noside, val, type);
+ }
+
+ value *evaluate_for_sizeof (struct expression *exp,
+ enum noside noside) override;
+
+ value *evaluate_for_address (struct expression *exp,
+ enum noside noside) override;
+
+ enum exp_opcode opcode () const override
+ { return UNOP_MEMVAL_TYPE; }
+
+protected:
+
+ void do_generate_ax (struct expression *exp,
+ struct agent_expr *ax,
+ struct axs_value *value,
+ struct type *cast_type)
+ override;
+};
+
} /* namespace expr */

#endif /* EXPOP_H */
--
2.26.2