Introduce ada_unop_ind_operation

This adds class ada_unop_ind_operation, which implements UNOP_IND for
Ada.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* ada-lang.c (ada_unop_ind_operation::evaluate): New method.
	* ada-exp.h (class ada_unop_ind_operation): New.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 95659b4818ae2ae1df2dfd005f6296de3e933f77..5f6dcfbf389523f630b274305b5066575595829d 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2021-03-08  Tom Tromey  <tom@tromey.com>
+
+       * ada-lang.c (ada_unop_ind_operation::evaluate): New method.
+       * ada-exp.h (class ada_unop_ind_operation): New.
+
 2021-03-08  Tom Tromey  <tom@tromey.com>
 
        * ada-lang.c (ada_binop_exp): No longer static.

diff --git a/gdb/ada-exp.h b/gdb/ada-exp.h
index 8e908464f1f7b892c746478ea3d099cef31ca807..c87036e2d19ad129bbe5e8353e090136e2ac236b 100644 (file)
--- a/gdb/ada-exp.h
+++ b/gdb/ada-exp.h
@@ -358,6 +358,19 @@ public:
   { return OP_ATR_VAL; }
 };
 
+/* The indirection operator for Ada.  */
+class ada_unop_ind_operation
+  : public unop_ind_base_operation
+{
+public:
+
+  using unop_ind_base_operation::unop_ind_base_operation;
+
+  value *evaluate (struct type *expect_type,
+                  struct expression *exp,
+                  enum noside noside) override;
+};
+
 } /* namespace expr */
 
 #endif /* ADA_EXP_H */

diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index 8a4de779aa680c24e604057f6e0dfe7ea6aa2894..5998ae7096e6eba0844c51a6370ba67588fef4e5 100644 (file)
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -10703,6 +10703,91 @@ ada_atr_val_operation::evaluate (struct type *expect_type,
   return ada_val_atr (noside, std::get<0> (m_storage), arg);
 }
 
+value *
+ada_unop_ind_operation::evaluate (struct type *expect_type,
+                                 struct expression *exp,
+                                 enum noside noside)
+{
+  value *arg1 = std::get<0> (m_storage)->evaluate (expect_type, exp, noside);
+
+  struct type *type = ada_check_typedef (value_type (arg1));
+  if (noside == EVAL_AVOID_SIDE_EFFECTS)
+    {
+      if (ada_is_array_descriptor_type (type))
+       /* GDB allows dereferencing GNAT array descriptors.  */
+       {
+         struct type *arrType = ada_type_of_array (arg1, 0);
+
+         if (arrType == NULL)
+           error (_("Attempt to dereference null array pointer."));
+         return value_at_lazy (arrType, 0);
+       }
+      else if (type->code () == TYPE_CODE_PTR
+              || type->code () == TYPE_CODE_REF
+              /* In C you can dereference an array to get the 1st elt.  */
+              || type->code () == TYPE_CODE_ARRAY)
+       {
+         /* As mentioned in the OP_VAR_VALUE case, tagged types can
+            only be determined by inspecting the object's tag.
+            This means that we need to evaluate completely the
+            expression in order to get its type.  */
+
+         if ((type->code () == TYPE_CODE_REF
+              || type->code () == TYPE_CODE_PTR)
+             && ada_is_tagged_type (TYPE_TARGET_TYPE (type), 0))
+           {
+             arg1 = std::get<0> (m_storage)->evaluate (nullptr, exp,
+                                                       EVAL_NORMAL);
+             type = value_type (ada_value_ind (arg1));
+           }
+         else
+           {
+             type = to_static_fixed_type
+               (ada_aligned_type
+                (ada_check_typedef (TYPE_TARGET_TYPE (type))));
+           }
+         ada_ensure_varsize_limit (type);
+         return value_zero (type, lval_memory);
+       }
+      else if (type->code () == TYPE_CODE_INT)
+       {
+         /* GDB allows dereferencing an int.  */
+         if (expect_type == NULL)
+           return value_zero (builtin_type (exp->gdbarch)->builtin_int,
+                              lval_memory);
+         else
+           {
+             expect_type =
+               to_static_fixed_type (ada_aligned_type (expect_type));
+             return value_zero (expect_type, lval_memory);
+           }
+       }
+      else
+       error (_("Attempt to take contents of a non-pointer value."));
+    }
+  arg1 = ada_coerce_ref (arg1);     /* FIXME: What is this for??  */
+  type = ada_check_typedef (value_type (arg1));
+
+  if (type->code () == TYPE_CODE_INT)
+    /* GDB allows dereferencing an int.  If we were given
+       the expect_type, then use that as the target type.
+       Otherwise, assume that the target type is an int.  */
+    {
+      if (expect_type != NULL)
+       return ada_value_ind (value_cast (lookup_pointer_type (expect_type),
+                                         arg1));
+      else
+       return value_at_lazy (builtin_type (exp->gdbarch)->builtin_int,
+                             (CORE_ADDR) value_as_address (arg1));
+    }
+
+  if (ada_is_array_descriptor_type (type))
+    /* GDB allows dereferencing GNAT array descriptors.  */
+    return ada_coerce_to_simple_array (arg1);
+  else
+    return ada_value_ind (arg1);
+}
+
 }
 
 /* Implement the evaluate_exp routine in the exp_descriptor structure