gcc/calls.h

   1 /* Declarations and data types for RTL call insn generation.
   2    Copyright (C) 2013-2023 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef GCC_CALLS_H
  21 #define GCC_CALLS_H
  22
  23 /* Describes a function argument.
  24
  25    Each argument conceptually has a gimple-level type.  Usually this type
  26    is available directly as a tree via the TYPE field, but when calling
  27    libgcc support functions it might instead be inferred from a mode,
  28    in which case the type isn't available directly.
  29
  30    This gimple-level type might go through promotion before being passed to
  31    the target function.  Depending on the context, the MODE field is either
  32    the mode of the gimple-level type (whether explicitly given or not)
  33    or the mode after promotion has been performed.  */
  34 class function_arg_info
  35 {
  36 public:
  37   function_arg_info ()
  38     : type (NULL_TREE), mode (VOIDmode), named (false),
  39       pass_by_reference (false)
  40   {}
  41
  42   /* Initialize an argument of mode MODE, either before or after promotion.  */
  43   function_arg_info (machine_mode mode, bool named)
  44     : type (NULL_TREE), mode (mode), named (named), pass_by_reference (false)
  45   {}
  46
  47   /* Initialize an unpromoted argument of type TYPE.  */
  48   function_arg_info (tree type, bool named)
  49     : type (type), mode (TYPE_MODE (type)), named (named),
  50       pass_by_reference (false)
  51   {}
  52
  53   /* Initialize an argument with explicit properties.  */
  54   function_arg_info (tree type, machine_mode mode, bool named)
  55     : type (type), mode (mode), named (named), pass_by_reference (false)
  56   {}
  57
  58   /* Return true if the gimple-level type is an aggregate.  */
  59   bool aggregate_type_p () const { return type && AGGREGATE_TYPE_P (type); }
  60
  61   /* Return the size of the gimple-level type, or -1 if the size is
  62      variable or otherwise not representable as a poly_int64.
  63
  64      Use this function when MODE is the mode of the type before promotion,
  65      or in any context if the target never promotes function arguments.  */
  66   poly_int64 type_size_in_bytes () const
  67   {
  68     if (type)
  69       return int_size_in_bytes (type);
  70     return GET_MODE_SIZE (mode);
  71   }
  72
  73   /* Return the size of the argument after promotion, or -1 if the size
  74      is variable or otherwise not representable as a poly_int64.
  75
  76      Use this function when MODE is the mode of the type after promotion.  */
  77   poly_int64 promoted_size_in_bytes () const
  78   {
  79     if (mode == BLKmode)
  80       return int_size_in_bytes (type);
  81     return GET_MODE_SIZE (mode);
  82   }
  83
  84   /* True if the argument represents the end of the argument list,
  85      as returned by end_marker ().  */
  86   bool end_marker_p () const { return mode == VOIDmode; }
  87
  88   /* Return a function_arg_info that represents the end of the
  89      argument list.  */
  90   static function_arg_info end_marker ()
  91   {
  92     return function_arg_info (void_type_node, /*named=*/true);
  93   }
  94
  95   /* The type of the argument, or null if not known (which is true for
  96      libgcc support functions).  */
  97   tree type;
  98
  99   /* The mode of the argument.  Depending on context, this might be
 100      the mode of the argument type or the mode after promotion.  */
 101   machine_mode mode;
 102
 103   /* True if the argument is treated as a named argument, false if it is
 104      treated as an unnamed variadic argument (i.e. one passed through
 105      "...").  See also TARGET_STRICT_ARGUMENT_NAMING.  */
 106   unsigned int named : 1;
 107
 108   /* True if we have decided to pass the argument by reference, in which case
 109      the function_arg_info describes a pointer to the original argument.  */
 110   unsigned int pass_by_reference : 1;
 111 };
 112
 113 extern int flags_from_decl_or_type (const_tree);
 114 extern int call_expr_flags (const_tree);
 115 extern int setjmp_call_p (const_tree);
 116 extern bool gimple_maybe_alloca_call_p (const gimple *);
 117 extern bool gimple_alloca_call_p (const gimple *);
 118 extern bool alloca_call_p (const_tree);
 119 extern bool must_pass_in_stack_var_size (const function_arg_info &);
 120 extern bool must_pass_in_stack_var_size_or_pad (const function_arg_info &);
 121 extern bool must_pass_va_arg_in_stack (tree);
 122 extern rtx prepare_call_address (tree, rtx, rtx, rtx *, int, int);
 123 extern bool shift_return_value (machine_mode, bool, rtx);
 124 extern rtx expand_call (tree, rtx, int);
 125 extern void fixup_tail_calls (void);
 126
 127 extern bool pass_by_reference (CUMULATIVE_ARGS *, function_arg_info);
 128 extern bool pass_va_arg_by_reference (tree);
 129 extern bool apply_pass_by_reference_rules (CUMULATIVE_ARGS *,
 130                                            function_arg_info &);
 131 extern bool reference_callee_copied (CUMULATIVE_ARGS *,
 132                                      const function_arg_info &);
 133 extern void maybe_complain_about_tail_call (tree, const char *);
 134
 135 extern rtx rtx_for_static_chain (const_tree, bool);
 136 extern bool cxx17_empty_base_field_p (const_tree);
 137
 138 #endif // GCC_CALLS_H