gdb/ada-exp.h

/* Definitions for Ada expressions

   Copyright (C) 2020, 2021 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#ifndef ADA_EXP_H
#define ADA_EXP_H

#include "expop.h"

extern struct value *ada_unop_neg (struct type *expect_type,
				   struct expression *exp,
				   enum noside noside, enum exp_opcode op,
				   struct value *arg1);
extern struct value *ada_atr_tag (struct type *expect_type,
				  struct expression *exp,
				  enum noside noside, enum exp_opcode op,
				  struct value *arg1);
extern struct value *ada_atr_size (struct type *expect_type,
				   struct expression *exp,
				   enum noside noside, enum exp_opcode op,
				   struct value *arg1);
extern struct value *ada_abs (struct type *expect_type,
			      struct expression *exp,
			      enum noside noside, enum exp_opcode op,
			      struct value *arg1);
extern struct value *ada_unop_in_range (struct type *expect_type,
					struct expression *exp,
					enum noside noside, enum exp_opcode op,
					struct value *arg1, struct type *type);
extern struct value *ada_mult_binop (struct type *expect_type,
				     struct expression *exp,
				     enum noside noside, enum exp_opcode op,
				     struct value *arg1, struct value *arg2);
extern struct value *ada_equal_binop (struct type *expect_type,
				      struct expression *exp,
				      enum noside noside, enum exp_opcode op,
				      struct value *arg1, struct value *arg2);
extern struct value *ada_ternop_slice (struct expression *exp,
				       enum noside noside,
				       struct value *array,
				       struct value *low_bound_val,
				       struct value *high_bound_val);
extern struct value *ada_binop_in_bounds (struct expression *exp,
					  enum noside noside,
					  struct value *arg1,
					  struct value *arg2,
					  int n);
extern struct value *ada_binop_minmax (struct type *expect_type,
				       struct expression *exp,
				       enum noside noside, enum exp_opcode op,
				       struct value *arg1,
				       struct value *arg2);
extern struct value *ada_pos_atr (struct type *expect_type,
				  struct expression *exp,
				  enum noside noside, enum exp_opcode op,
				  struct value *arg);
extern struct value *ada_val_atr (enum noside noside, struct type *type,
				  struct value *arg);
extern struct value *ada_binop_exp (struct type *expect_type,
				    struct expression *exp,
				    enum noside noside, enum exp_opcode op,
				    struct value *arg1, struct value *arg2);

namespace expr
{

/* The base class for Ada type resolution.  Ada operations that want
   to participate in resolution implement this interface.  */
struct ada_resolvable
{
  /* Resolve this object.  EXP is the expression being resolved.
     DEPROCEDURE_P is true if a symbol that refers to a zero-argument
     function may be turned into a function call.  PARSE_COMPLETION
     and TRACKER are passed in from the parser context.  CONTEXT_TYPE
     is the expected type of the expression, or nullptr if none is
     known.  This method should return true if the operation should be
     replaced by a function call with this object as the callee.  */
  virtual bool resolve (struct expression *exp,
			bool deprocedure_p,
			bool parse_completion,
			innermost_block_tracker *tracker,
			struct type *context_type) = 0;

  /* Possibly replace this object with some other expression object.
     This is like 'resolve', but can return a replacement.

     The default implementation calls 'resolve' and wraps this object
     in a function call if that call returns true.  OWNER is a
     reference to the unique pointer that owns the 'this'; it can be
     'move'd from to construct the replacement.

     This should either return a new object, or OWNER -- never
     nullptr.  */

  virtual operation_up replace (operation_up &&owner,
				struct expression *exp,
				bool deprocedure_p,
				bool parse_completion,
				innermost_block_tracker *tracker,
				struct type *context_type);
};

/* In Ada, some generic operations must be wrapped with a handler that
   handles some Ada-specific type conversions.  */
class ada_wrapped_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;

  enum exp_opcode opcode () const override
  { return std::get<0> (m_storage)->opcode (); }
};

/* An Ada string constant.  */
class ada_string_operation
  : public string_operation
{
public:

  using string_operation::string_operation;

  /* Return the underlying string.  */
  const char *get_name () const
  {
    return std::get<0> (m_storage).c_str ();
  }

  value *evaluate (struct type *expect_type,
		   struct expression *exp,
		   enum noside noside) override;
};

/* The Ada TYPE'(EXP) construct.  */
class ada_qual_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;

  enum exp_opcode opcode () const override
  { return UNOP_QUAL; }
};

/* Ternary in-range operator.  */
class ada_ternop_range_operation
  : public tuple_holding_operation<operation_up, 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;

  enum exp_opcode opcode () const override
  { return TERNOP_IN_RANGE; }
};

using ada_neg_operation = unop_operation<UNOP_NEG, ada_unop_neg>;
using ada_atr_tag_operation = unop_operation<OP_ATR_TAG, ada_atr_tag>;
using ada_atr_size_operation = unop_operation<OP_ATR_SIZE, ada_atr_size>;
using ada_abs_operation = unop_operation<UNOP_ABS, ada_abs>;
using ada_pos_operation = unop_operation<OP_ATR_POS, ada_pos_atr>;

/* The in-range operation, given a type.  */
class ada_unop_range_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 (nullptr, exp, noside);
    return ada_unop_in_range (expect_type, exp, noside, UNOP_IN_RANGE,
			      val, std::get<1> (m_storage));
  }

  enum exp_opcode opcode () const override
  { return UNOP_IN_RANGE; }
};

/* The Ada + and - operators.  */
class ada_binop_addsub_operation
  : public tuple_holding_operation<enum exp_opcode, 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;

  enum exp_opcode opcode () const override
  { return std::get<0> (m_storage); }
};

using ada_binop_mul_operation = binop_operation<BINOP_MUL, ada_mult_binop>;
using ada_binop_div_operation = binop_operation<BINOP_DIV, ada_mult_binop>;
using ada_binop_rem_operation = binop_operation<BINOP_REM, ada_mult_binop>;
using ada_binop_mod_operation = binop_operation<BINOP_MOD, ada_mult_binop>;

using ada_binop_min_operation = binop_operation<BINOP_MIN, ada_binop_minmax>;
using ada_binop_max_operation = binop_operation<BINOP_MAX, ada_binop_minmax>;

using ada_binop_exp_operation = binop_operation<BINOP_EXP, ada_binop_exp>;

/* Implement the equal and not-equal operations for Ada.  */
class ada_binop_equal_operation
  : public tuple_holding_operation<enum exp_opcode, 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<1> (m_storage)->evaluate (nullptr, exp, noside);
    value *arg2 = std::get<2> (m_storage)->evaluate (value_type (arg1),
						     exp, noside);
    return ada_equal_binop (expect_type, exp, noside, std::get<0> (m_storage),
			    arg1, arg2);
  }

  enum exp_opcode opcode () const override
  { return std::get<0> (m_storage); }
};

/* Bitwise operators for Ada.  */
template<enum exp_opcode OP>
class ada_bitwise_operation
  : public maybe_constant_operation<operation_up, operation_up>
{
public:

  using maybe_constant_operation::maybe_constant_operation;

  value *evaluate (struct type *expect_type,
		   struct expression *exp,
		   enum noside noside) override
  {
    value *lhs = std::get<0> (m_storage)->evaluate (nullptr, exp, noside);
    value *rhs = std::get<1> (m_storage)->evaluate (nullptr, exp, noside);
    value *result = eval_op_binary (expect_type, exp, noside, OP, lhs, rhs);
    return value_cast (value_type (lhs), result);
  }

  enum exp_opcode opcode () const override
  { return OP; }
};

using ada_bitwise_and_operation = ada_bitwise_operation<BINOP_BITWISE_AND>;
using ada_bitwise_ior_operation = ada_bitwise_operation<BINOP_BITWISE_IOR>;
using ada_bitwise_xor_operation = ada_bitwise_operation<BINOP_BITWISE_XOR>;

/* Ada array- or string-slice operation.  */
class ada_ternop_slice_operation
  : public maybe_constant_operation<operation_up, operation_up, operation_up>,
    public ada_resolvable
{
public:

  using maybe_constant_operation::maybe_constant_operation;

  value *evaluate (struct type *expect_type,
		   struct expression *exp,
		   enum noside noside) override
  {
    value *array = std::get<0> (m_storage)->evaluate (nullptr, exp, noside);
    value *low = std::get<1> (m_storage)->evaluate (nullptr, exp, noside);
    value *high = std::get<2> (m_storage)->evaluate (nullptr, exp, noside);
    return ada_ternop_slice (exp, noside, array, low, high);
  }

  enum exp_opcode opcode () const override
  { return TERNOP_SLICE; }

  bool resolve (struct expression *exp,
		bool deprocedure_p,
		bool parse_completion,
		innermost_block_tracker *tracker,
		struct type *context_type) override;
};

/* Implement BINOP_IN_BOUNDS for Ada.  */
class ada_binop_in_bounds_operation
  : public maybe_constant_operation<operation_up, operation_up, int>
{
public:

  using maybe_constant_operation::maybe_constant_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 ada_binop_in_bounds (exp, noside, arg1, arg2,
				std::get<2> (m_storage));
  }

  enum exp_opcode opcode () const override
  { return BINOP_IN_BOUNDS; }
};

/* Implement several unary Ada OP_ATR_* operations.  */
class ada_unop_atr_operation
  : public maybe_constant_operation<operation_up, enum exp_opcode, int>
{
public:

  using maybe_constant_operation::maybe_constant_operation;

  value *evaluate (struct type *expect_type,
		   struct expression *exp,
		   enum noside noside) override;

  enum exp_opcode opcode () const override
  { return std::get<1> (m_storage); }
};

/* Variant of var_value_operation for Ada.  */
class ada_var_value_operation
  : public var_value_operation, public ada_resolvable
{
public:

  using var_value_operation::var_value_operation;

  value *evaluate (struct type *expect_type,
		   struct expression *exp,
		   enum noside noside) override;

  value *evaluate_for_cast (struct type *expect_type,
			    struct expression *exp,
			    enum noside noside) override;

  const block *get_block () const
  { return std::get<0> (m_storage).block; }

  bool resolve (struct expression *exp,
		bool deprocedure_p,
		bool parse_completion,
		innermost_block_tracker *tracker,
		struct type *context_type) override;

protected:

  using operation::do_generate_ax;
};

/* Variant of var_msym_value_operation for Ada.  */
class ada_var_msym_value_operation
  : public var_msym_value_operation
{
public:

  using var_msym_value_operation::var_msym_value_operation;

  value *evaluate_for_cast (struct type *expect_type,
			    struct expression *exp,
			    enum noside noside) override;

protected:

  using operation::do_generate_ax;
};

/* Implement the Ada 'val attribute.  */
class ada_atr_val_operation
  : public tuple_holding_operation<struct type *, operation_up>
{
public:

  using tuple_holding_operation::tuple_holding_operation;

  value *evaluate (struct type *expect_type,
		   struct expression *exp,
		   enum noside noside) override;

  enum exp_opcode opcode () const override
  { 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;
};

/* Implement STRUCTOP_STRUCT for Ada.  */
class ada_structop_operation
  : public structop_base_operation
{
public:

  using structop_base_operation::structop_base_operation;

  value *evaluate (struct type *expect_type,
		   struct expression *exp,
		   enum noside noside) override;

  enum exp_opcode opcode () const override
  { return STRUCTOP_STRUCT; }
};

/* Function calls for Ada.  */
class ada_funcall_operation
  : public tuple_holding_operation<operation_up, std::vector<operation_up>>,
    public ada_resolvable
{
public:

  using tuple_holding_operation::tuple_holding_operation;

  value *evaluate (struct type *expect_type,
		   struct expression *exp,
		   enum noside noside) override;

  bool resolve (struct expression *exp,
		bool deprocedure_p,
		bool parse_completion,
		innermost_block_tracker *tracker,
		struct type *context_type) override;

  enum exp_opcode opcode () const override
  { return OP_FUNCALL; }
};

/* An Ada assignment operation.  */
class ada_assign_operation
  : public assign_operation
{
public:

  using assign_operation::assign_operation;

  value *evaluate (struct type *expect_type,
		   struct expression *exp,
		   enum noside noside) override;

  enum exp_opcode opcode () const override
  { return BINOP_ASSIGN; }
};

/* This abstract class represents a single component in an Ada
   aggregate assignment.  */
class ada_component
{
public:

  /* Assign to LHS, which is part of CONTAINER.  EXP is the expression
     being evaluated.  INDICES, LOW, and HIGH indicate which
     sub-components have already been assigned; INDICES should be
     updated by this call.  */
  virtual void assign (struct value *container,
		       struct value *lhs, struct expression *exp,
		       std::vector<LONGEST> &indices,
		       LONGEST low, LONGEST high) = 0;

  /* Same as operation::uses_objfile.  */
  virtual bool uses_objfile (struct objfile *objfile) = 0;

  /* Same as operation::dump.  */
  virtual void dump (ui_file *stream, int depth) = 0;

  virtual ~ada_component () = default;

protected:

  ada_component () = default;
  DISABLE_COPY_AND_ASSIGN (ada_component);
};

/* Unique pointer specialization for Ada assignment components.  */
typedef std::unique_ptr<ada_component> ada_component_up;

/* An operation that holds a single component.  */
class ada_aggregate_operation
  : public tuple_holding_operation<ada_component_up>
{
public:

  using tuple_holding_operation::tuple_holding_operation;

  /* Assuming that LHS represents an lvalue having a record or array
     type, evaluate an assignment of this aggregate's value to LHS.
     CONTAINER is an lvalue containing LHS (possibly LHS itself).
     Does not modify the inferior's memory, nor does it modify the
     contents of LHS (unless == CONTAINER).  Returns the modified
     CONTAINER.  */

  value *assign_aggregate (struct value *container,
			   struct value *lhs,
			   struct expression *exp);

  value *evaluate (struct type *expect_type,
		   struct expression *exp,
		   enum noside noside) override
  {
    error (_("Aggregates only allowed on the right of an assignment"));
  }

  enum exp_opcode opcode () const override
  { return OP_AGGREGATE; }
};

/* A component holding a vector of other components to assign.  */
class ada_aggregate_component : public ada_component
{
public:

  explicit ada_aggregate_component (std::vector<ada_component_up> &&components)
    : m_components (std::move (components))
  {
  }

  void assign (struct value *container,
	       struct value *lhs, struct expression *exp,
	       std::vector<LONGEST> &indices,
	       LONGEST low, LONGEST high) override;

  bool uses_objfile (struct objfile *objfile) override;

  void dump (ui_file *stream, int depth) override;

private:

  std::vector<ada_component_up> m_components;
};

/* A component that assigns according to a provided index (which is
   relative to the "low" value).  */
class ada_positional_component : public ada_component
{
public:

  ada_positional_component (int index, operation_up &&op)
    : m_index (index),
      m_op (std::move (op))
  {
  }

  void assign (struct value *container,
	       struct value *lhs, struct expression *exp,
	       std::vector<LONGEST> &indices,
	       LONGEST low, LONGEST high) override;

  bool uses_objfile (struct objfile *objfile) override;

  void dump (ui_file *stream, int depth) override;

private:

  int m_index;
  operation_up m_op;
};

/* A component which handles an "others" clause.  */
class ada_others_component : public ada_component
{
public:

  explicit ada_others_component (operation_up &&op)
    : m_op (std::move (op))
  {
  }

  void assign (struct value *container,
	       struct value *lhs, struct expression *exp,
	       std::vector<LONGEST> &indices,
	       LONGEST low, LONGEST high) override;

  bool uses_objfile (struct objfile *objfile) override;

  void dump (ui_file *stream, int depth) override;

private:

  operation_up m_op;
};

/* An interface that represents an association that is used in
   aggregate assignment.  */
class ada_association
{
public:

  /* Like ada_component::assign, but takes an operation as a
     parameter.  The operation is evaluated and then assigned into LHS
     according to the rules of the concrete implementation.  */
  virtual void assign (struct value *container,
		       struct value *lhs,
		       struct expression *exp,
		       std::vector<LONGEST> &indices,
		       LONGEST low, LONGEST high,
		       operation_up &op) = 0;

  /* Same as operation::uses_objfile.  */
  virtual bool uses_objfile (struct objfile *objfile) = 0;

  /* Same as operation::dump.  */
  virtual void dump (ui_file *stream, int depth) = 0;

  virtual ~ada_association () = default;

protected:

  ada_association () = default;
  DISABLE_COPY_AND_ASSIGN (ada_association);
};

/* Unique pointer specialization for Ada assignment associations.  */
typedef std::unique_ptr<ada_association> ada_association_up;

/* A component that holds a vector of associations and an operation.
   The operation is re-evaluated for each choice.  */
class ada_choices_component : public ada_component
{
public:

  explicit ada_choices_component (operation_up &&op)
    : m_op (std::move (op))
  {
  }

  /* Set the vector of associations.  This is done separately from the
     constructor because it was simpler for the implementation of the
     parser.  */
  void set_associations (std::vector<ada_association_up> &&assoc)
  {
    m_assocs = std::move (assoc);
  }

  void assign (struct value *container,
	       struct value *lhs, struct expression *exp,
	       std::vector<LONGEST> &indices,
	       LONGEST low, LONGEST high) override;

  bool uses_objfile (struct objfile *objfile) override;

  void dump (ui_file *stream, int depth) override;

private:

  std::vector<ada_association_up> m_assocs;
  operation_up m_op;
};

/* An association that uses a discrete range.  */
class ada_discrete_range_association : public ada_association
{
public:

  ada_discrete_range_association (operation_up &&low, operation_up &&high)
    : m_low (std::move (low)),
      m_high (std::move (high))
  {
  }

  void assign (struct value *container,
	       struct value *lhs, struct expression *exp,
	       std::vector<LONGEST> &indices,
	       LONGEST low, LONGEST high,
	       operation_up &op) override;

  bool uses_objfile (struct objfile *objfile) override;

  void dump (ui_file *stream, int depth) override;

private:

  operation_up m_low;
  operation_up m_high;
};

/* An association that uses a name.  The name may be an expression
   that evaluates to an integer (for arrays), or an Ada string or
   variable value operation.  */
class ada_name_association : public ada_association
{
public:

  explicit ada_name_association (operation_up val)
    : m_val (std::move (val))
  {
  }

  void assign (struct value *container,
	       struct value *lhs, struct expression *exp,
	       std::vector<LONGEST> &indices,
	       LONGEST low, LONGEST high,
	       operation_up &op) override;

  bool uses_objfile (struct objfile *objfile) override;

  void dump (ui_file *stream, int depth) override;

private:

  operation_up m_val;
};

/* A character constant expression.  This is a separate operation so
   that it can participate in resolution, so that TYPE'(CST) can
   work correctly for enums with character enumerators.  */
class ada_char_operation : public long_const_operation,
			   public ada_resolvable
{
public:

  using long_const_operation::long_const_operation;

  bool resolve (struct expression *exp,
		bool deprocedure_p,
		bool parse_completion,
		innermost_block_tracker *tracker,
		struct type *context_type) override
  {
    /* This should never be called, because this class also implements
       'replace'.  */
    gdb_assert_not_reached ("unexpected call");
  }

  operation_up replace (operation_up &&owner,
			struct expression *exp,
			bool deprocedure_p,
			bool parse_completion,
			innermost_block_tracker *tracker,
			struct type *context_type) override;
};

} /* namespace expr */

#endif /* ADA_EXP_H */