[PATCH 077/203] Introduce scope_operation

Tom Tromey
2021-01-01T21:48:21Z

This adds class scope_operation, an implementation of OP_SCOPE.

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

* expop.h (class scope_operation): New.
* eval.c (eval_op_scope): No longer static.
(scope_operation::evaluate_for_address): New method.
* ax-gdb.c (scope_operation::do_generate_ax): New method.
---
gdb/ChangeLog | 7 +++++++
gdb/ax-gdb.c | 14 ++++++++++++++
gdb/eval.c | 14 +++++++++++++-
gdb/expop.h | 36 ++++++++++++++++++++++++++++++++++++
4 files changed, 70 insertions(+), 1 deletion(-)

diff --git a/gdb/ax-gdb.c b/gdb/ax-gdb.c
index 1ffa8e49bf1..6d568a71e03 100644
--- a/gdb/ax-gdb.c
+++ b/gdb/ax-gdb.c
@@ -45,6 +45,7 @@
#include "typeprint.h"
#include "valprint.h"
#include "c-lang.h"
+#include "expop.h"

#include "gdbsupport/format.h"

@@ -2300,6 +2301,19 @@ operation::generate_ax (struct expression *exp,
}
}

+void
+scope_operation::do_generate_ax (struct expression *exp,
+ struct agent_expr *ax,
+ struct axs_value *value,
+ struct type *cast_type)
+{
+ struct type *type = std::get<0> (m_storage);
+ const std::string &name = std::get<1> (m_storage);
+ int found = gen_aggregate_elt_ref (ax, value, type, name.c_str ());
+ if (!found)
+ error (_("There is no field named %s"), name.c_str ());
+}
+
}

/* This handles the middle-to-right-side of code generation for binary
diff --git a/gdb/eval.c b/gdb/eval.c
index 970e7d7c0bc..fe8698342db 100644
--- a/gdb/eval.c
+++ b/gdb/eval.c
@@ -1182,7 +1182,7 @@ is_integral_or_integral_reference (struct type *type)

/* Helper function that implements the body of OP_SCOPE. */

-static struct value *
+struct value *
eval_op_scope (struct type *expect_type, struct expression *exp,
enum noside noside,
struct type *type, const char *string)
@@ -3264,6 +3264,18 @@ operation::evaluate_for_address (struct expression *exp, enum noside noside)
return evaluate_subexp_for_address_base (exp, noside, val);
}

+value *
+scope_operation::evaluate_for_address (struct expression *exp,
+ enum noside noside)
+{
+ value *x = value_aggregate_elt (std::get<0> (m_storage),
+ std::get<1> (m_storage).c_str (),
+ NULL, 1, noside);
+ if (x == NULL)
+ error (_("There is no field named %s"), std::get<1> (m_storage).c_str ());
+ return x;
+}
+
}

/* Evaluate like `evaluate_subexp' except coercing arrays to pointers.
diff --git a/gdb/expop.h b/gdb/expop.h
index 6af6504332e..3fcd25ddcea 100644
--- a/gdb/expop.h
+++ b/gdb/expop.h
@@ -41,6 +41,11 @@ extern void gen_expr_structop (struct expression *exp,
const char *name,
struct agent_expr *ax, struct axs_value *value);

+extern struct value *eval_op_scope (struct type *expect_type,
+ struct expression *exp,
+ enum noside noside,
+ struct type *type, const char *string);
+
namespace expr
{

@@ -413,6 +418,37 @@ class float_const_operation
float_data m_data;
};

+class scope_operation
+ : public maybe_constant_operation<struct type *, std::string>
+{
+public:
+
+ using maybe_constant_operation::maybe_constant_operation;
+
+ value *evaluate (struct type *expect_type,
+ struct expression *exp,
+ enum noside noside) override
+ {
+ return eval_op_scope (expect_type, exp, noside,
+ std::get<0> (m_storage),
+ std::get<1> (m_storage).c_str ());
+ }
+
+ value *evaluate_for_address (struct expression *exp,
+ enum noside noside) override;
+
+ enum exp_opcode opcode () const override
+ { return OP_SCOPE; }
+
+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