/* Some code common to C++ and ObjC++ front ends.
   Copyright (C) 2004-2017 Free Software Foundation, Inc.
   Contributed by Ziemowit Laski  <zlaski@apple.com>

This file is part of GCC.

GCC 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, or (at your option) any later
version.

GCC 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 GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "cp-tree.h"
#include "cp-objcp-common.h"
#include "dwarf2.h"

/* Special routine to get the alias set for C++.  */

alias_set_type
cxx_get_alias_set (tree t)
{
  if (IS_FAKE_BASE_TYPE (t))
    /* The base variant of a type must be in the same alias set as the
       complete type.  */
    return get_alias_set (TYPE_CONTEXT (t));

  /* Punt on PMFs until we canonicalize functions properly.  */
  if (TYPE_PTRMEMFUNC_P (t)
      || (POINTER_TYPE_P (t)
	  && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))))
    return 0;

  return c_common_get_alias_set (t);
}

/* Called from check_global_declaration.  */

bool
cxx_warn_unused_global_decl (const_tree decl)
{
  if (TREE_CODE (decl) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (decl))
    return false;
  if (DECL_IN_SYSTEM_HEADER (decl))
    return false;

  return true;
}

/* Langhook for tree_size: determine size of our 'x' and 'c' nodes.  */
size_t
cp_tree_size (enum tree_code code)
{
  switch (code)
    {
    case PTRMEM_CST:		return sizeof (struct ptrmem_cst);
    case BASELINK:		return sizeof (struct tree_baselink);
    case TEMPLATE_PARM_INDEX:	return sizeof (template_parm_index);
    case DEFAULT_ARG:		return sizeof (struct tree_default_arg);
    case DEFERRED_NOEXCEPT:	return sizeof (struct tree_deferred_noexcept);
    case OVERLOAD:		return sizeof (struct tree_overload);
    case STATIC_ASSERT:         return sizeof (struct tree_static_assert);
    case TYPE_ARGUMENT_PACK:
    case TYPE_PACK_EXPANSION:
      return sizeof (struct tree_common);

    case NONTYPE_ARGUMENT_PACK:
    case EXPR_PACK_EXPANSION:
      return sizeof (struct tree_exp);

    case ARGUMENT_PACK_SELECT:
      return sizeof (struct tree_argument_pack_select);

    case TRAIT_EXPR:
      return sizeof (struct tree_trait_expr);

    case LAMBDA_EXPR:           return sizeof (struct tree_lambda_expr);

    case TEMPLATE_INFO:         return sizeof (struct tree_template_info);

    case CONSTRAINT_INFO:       return sizeof (struct tree_constraint_info);

    case USERDEF_LITERAL:	return sizeof (struct tree_userdef_literal);

    case TEMPLATE_DECL:		return sizeof (struct tree_template_decl);

    default:
      if (TREE_CODE_CLASS (code) == tcc_declaration)
	return sizeof (struct tree_decl_non_common);
      gcc_unreachable ();
    }
  /* NOTREACHED */
}

/* Returns true if T is a variably modified type, in the sense of C99.
   FN is as passed to variably_modified_p.
   This routine needs only check cases that cannot be handled by the
   language-independent logic in tree.c.  */

bool
cp_var_mod_type_p (tree type, tree fn)
{
  /* If TYPE is a pointer-to-member, it is variably modified if either
     the class or the member are variably modified.  */
  if (TYPE_PTRMEM_P (type))
    return (variably_modified_type_p (TYPE_PTRMEM_CLASS_TYPE (type), fn)
	    || variably_modified_type_p (TYPE_PTRMEM_POINTED_TO_TYPE (type),
					 fn));

  /* All other types are not variably modified.  */
  return false;
}

/* This compares two types for equivalence ("compatible" in C-based languages).
   This routine should only return 1 if it is sure.  It should not be used
   in contexts where erroneously returning 0 causes problems.  */

int
cxx_types_compatible_p (tree x, tree y)
{
  return same_type_ignoring_top_level_qualifiers_p (x, y);
}

/* Return a type to use in the debug info instead of TYPE, or NULL_TREE to
   keep TYPE.  */

tree
cp_get_debug_type (const_tree type)
{
  if (TYPE_PTRMEMFUNC_P (type) && !typedef_variant_p (type))
    return build_offset_type (TYPE_PTRMEMFUNC_OBJECT_TYPE (type),
			      TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (type)));

  return NULL_TREE;
}

/* Return -1 if dwarf ATTR shouldn't be added for DECL, or the attribute
   value otherwise.  */
int
cp_decl_dwarf_attribute (const_tree decl, int attr)
{
  if (decl == NULL_TREE)
    return -1;

  switch (attr)
    {
    case DW_AT_explicit:
      if (TREE_CODE (decl) == FUNCTION_DECL
	  && DECL_LANG_SPECIFIC (STRIP_TEMPLATE (decl))
	  && DECL_NONCONVERTING_P (decl))
	return 1;
      break;

    case DW_AT_deleted:
      if (TREE_CODE (decl) == FUNCTION_DECL
	  && DECL_LANG_SPECIFIC (STRIP_TEMPLATE (decl))
	  && DECL_DELETED_FN (decl))
	return 1;
      break;

    case DW_AT_defaulted:
      if (TREE_CODE (decl) == FUNCTION_DECL
	  && DECL_LANG_SPECIFIC (STRIP_TEMPLATE (decl))
	  && DECL_DEFAULTED_FN (decl))
	{
	  if (DECL_DEFAULTED_IN_CLASS_P (decl))
	    return DW_DEFAULTED_in_class;

	  if (DECL_DEFAULTED_OUTSIDE_CLASS_P (decl))
	    return DW_DEFAULTED_out_of_class;
	}
      break;

    case DW_AT_const_expr:
      if (VAR_OR_FUNCTION_DECL_P (decl) && DECL_DECLARED_CONSTEXPR_P (decl))
	return 1;
      break;

    case DW_AT_reference:
      if (TREE_CODE (decl) == FUNCTION_DECL
	  && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl)
	  && FUNCTION_REF_QUALIFIED (TREE_TYPE (decl))
	  && !FUNCTION_RVALUE_QUALIFIED (TREE_TYPE (decl)))
	return 1;
      break;

    case DW_AT_rvalue_reference:
      if (TREE_CODE (decl) == FUNCTION_DECL
	  && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl)
	  && FUNCTION_REF_QUALIFIED (TREE_TYPE (decl))
	  && FUNCTION_RVALUE_QUALIFIED (TREE_TYPE (decl)))
	return 1;
      break;

    case DW_AT_inline:
      if (VAR_P (decl) && DECL_INLINE_VAR_P (decl))
	{
	  if (DECL_VAR_DECLARED_INLINE_P (decl))
	    return DW_INL_declared_inlined;
	  else
	    return DW_INL_inlined;
	}
      break;

    default:
      break;
    }

  return -1;
}

/* Return -1 if dwarf ATTR shouldn't be added for TYPE, or the attribute
   value otherwise.  */
int
cp_type_dwarf_attribute (const_tree type, int attr)
{
  if (type == NULL_TREE)
    return -1;

  switch (attr)
    {
    case DW_AT_reference:
      if ((TREE_CODE (type) == FUNCTION_TYPE
	   || TREE_CODE (type) == METHOD_TYPE)
	  && FUNCTION_REF_QUALIFIED (type)
	  && !FUNCTION_RVALUE_QUALIFIED (type))
	return 1;
      break;

    case DW_AT_rvalue_reference:
      if ((TREE_CODE (type) == FUNCTION_TYPE
	   || TREE_CODE (type) == METHOD_TYPE)
	  && FUNCTION_REF_QUALIFIED (type)
	  && FUNCTION_RVALUE_QUALIFIED (type))
	return 1;
      break;

    default:
      break;
    }

  return -1;
}

/* Return the unit size of TYPE without reusable tail padding.  */

tree
cp_unit_size_without_reusable_padding (tree type)
{
  if (CLASS_TYPE_P (type))
    return CLASSTYPE_SIZE_UNIT (type);
  return TYPE_SIZE_UNIT (type);
}

/* Stubs to keep c-opts.c happy.  */
void
push_file_scope (void)
{
}

void
pop_file_scope (void)
{
}

/* c-pragma.c needs to query whether a decl has extern "C" linkage.  */
bool
has_c_linkage (const_tree decl)
{
  return DECL_EXTERN_C_P (decl);
}

static GTY ((cache))
     hash_table<tree_decl_map_cache_hasher> *shadowed_var_for_decl;

/* Lookup a shadowed var for FROM, and return it if we find one.  */

tree
decl_shadowed_for_var_lookup (tree from)
{
  struct tree_decl_map *h, in;
  in.base.from = from;

  h = shadowed_var_for_decl->find_with_hash (&in, DECL_UID (from));
  if (h)
    return h->to;
  return NULL_TREE;
}

/* Insert a mapping FROM->TO in the shadowed var hashtable.  */

void
decl_shadowed_for_var_insert (tree from, tree to)
{
  struct tree_decl_map *h;

  h = ggc_alloc<tree_decl_map> ();
  h->base.from = from;
  h->to = to;
  *shadowed_var_for_decl->find_slot_with_hash (h, DECL_UID (from), INSERT) = h;
}

void
init_shadowed_var_for_decl (void)
{
  shadowed_var_for_decl
    = hash_table<tree_decl_map_cache_hasher>::create_ggc (512);
}

/* Return true if stmt can fall through.  Used by block_may_fallthru
   default case.  */

bool
cxx_block_may_fallthru (const_tree stmt)
{
  switch (TREE_CODE (stmt))
    {
    case EXPR_STMT:
      return block_may_fallthru (EXPR_STMT_EXPR (stmt));

    case THROW_EXPR:
      return false;

    default:
      return true;
    }
}

void
cp_common_init_ts (void)
{
  MARK_TS_DECL_NON_COMMON (USING_DECL);
  MARK_TS_DECL_COMMON (TEMPLATE_DECL);
  MARK_TS_DECL_COMMON (WILDCARD_DECL);

  MARK_TS_COMMON (TEMPLATE_TEMPLATE_PARM);
  MARK_TS_COMMON (TEMPLATE_TYPE_PARM);
  MARK_TS_COMMON (TEMPLATE_PARM_INDEX);
  MARK_TS_COMMON (OVERLOAD);
  MARK_TS_COMMON (TEMPLATE_INFO);
  MARK_TS_COMMON (TYPENAME_TYPE);
  MARK_TS_COMMON (TYPEOF_TYPE);
  MARK_TS_COMMON (UNDERLYING_TYPE);
  MARK_TS_COMMON (BASELINK);
  MARK_TS_COMMON (TYPE_PACK_EXPANSION);
  MARK_TS_COMMON (TYPE_ARGUMENT_PACK);
  MARK_TS_COMMON (DECLTYPE_TYPE);
  MARK_TS_COMMON (BOUND_TEMPLATE_TEMPLATE_PARM);
  MARK_TS_COMMON (UNBOUND_CLASS_TEMPLATE);

  MARK_TS_TYPED (EXPR_PACK_EXPANSION);
  MARK_TS_TYPED (SWITCH_STMT);
  MARK_TS_TYPED (IF_STMT);
  MARK_TS_TYPED (FOR_STMT);
  MARK_TS_TYPED (RANGE_FOR_STMT);
  MARK_TS_TYPED (AGGR_INIT_EXPR);
  MARK_TS_TYPED (EXPR_STMT);
  MARK_TS_TYPED (EH_SPEC_BLOCK);
  MARK_TS_TYPED (CLEANUP_STMT);
  MARK_TS_TYPED (SCOPE_REF);
  MARK_TS_TYPED (CAST_EXPR);
  MARK_TS_TYPED (NON_DEPENDENT_EXPR);
  MARK_TS_TYPED (MODOP_EXPR);
  MARK_TS_TYPED (TRY_BLOCK);
  MARK_TS_TYPED (THROW_EXPR);
  MARK_TS_TYPED (HANDLER);
  MARK_TS_TYPED (REINTERPRET_CAST_EXPR);
  MARK_TS_TYPED (CONST_CAST_EXPR);
  MARK_TS_TYPED (STATIC_CAST_EXPR);
  MARK_TS_TYPED (DYNAMIC_CAST_EXPR);
  MARK_TS_TYPED (IMPLICIT_CONV_EXPR);
  MARK_TS_TYPED (TEMPLATE_ID_EXPR);
  MARK_TS_TYPED (ARROW_EXPR);
  MARK_TS_TYPED (SIZEOF_EXPR);
  MARK_TS_TYPED (ALIGNOF_EXPR);
  MARK_TS_TYPED (AT_ENCODE_EXPR);
  MARK_TS_TYPED (UNARY_PLUS_EXPR);
  MARK_TS_TYPED (TRAIT_EXPR);
  MARK_TS_TYPED (TYPE_ARGUMENT_PACK);
  MARK_TS_TYPED (NOEXCEPT_EXPR);
  MARK_TS_TYPED (NONTYPE_ARGUMENT_PACK);
  MARK_TS_TYPED (WHILE_STMT);
  MARK_TS_TYPED (NEW_EXPR);
  MARK_TS_TYPED (VEC_NEW_EXPR);
  MARK_TS_TYPED (BREAK_STMT);
  MARK_TS_TYPED (MEMBER_REF);
  MARK_TS_TYPED (DOTSTAR_EXPR);
  MARK_TS_TYPED (DO_STMT);
  MARK_TS_TYPED (DELETE_EXPR);
  MARK_TS_TYPED (VEC_DELETE_EXPR);
  MARK_TS_TYPED (CONTINUE_STMT);
  MARK_TS_TYPED (TAG_DEFN);
  MARK_TS_TYPED (PSEUDO_DTOR_EXPR);
  MARK_TS_TYPED (TYPEID_EXPR);
  MARK_TS_TYPED (MUST_NOT_THROW_EXPR);
  MARK_TS_TYPED (STMT_EXPR);
  MARK_TS_TYPED (OFFSET_REF);
  MARK_TS_TYPED (OFFSETOF_EXPR);
  MARK_TS_TYPED (ADDRESSOF_EXPR);
  MARK_TS_TYPED (PTRMEM_CST);
  MARK_TS_TYPED (EMPTY_CLASS_EXPR);
  MARK_TS_TYPED (VEC_INIT_EXPR);
  MARK_TS_TYPED (USING_STMT);
  MARK_TS_TYPED (LAMBDA_EXPR);
  MARK_TS_TYPED (CTOR_INITIALIZER);
  MARK_TS_TYPED (ARRAY_NOTATION_REF);
  MARK_TS_TYPED (REQUIRES_EXPR);
  MARK_TS_TYPED (UNARY_LEFT_FOLD_EXPR);
  MARK_TS_TYPED (UNARY_RIGHT_FOLD_EXPR);
  MARK_TS_TYPED (BINARY_LEFT_FOLD_EXPR);
  MARK_TS_TYPED (BINARY_RIGHT_FOLD_EXPR);
}

#include "gt-cp-cp-objcp-common.h"
