gcc/target-hooks-macros.h

   1 /* Common macros for target hook definitions.
   2    Copyright (C) 2001-2021 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify it
   5    under the terms of the GNU General Public License as published by the
   6    Free Software Foundation; either version 3, or (at your option) any
   7    later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; see the file COPYING3.  If not see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 /* The following macros should be provided by the including file:
  19
  20    DEFHOOK(NAME, DOC, TYPE, PARAMS, INIT): Define a function-valued hook.
  21    DEFHOOKPOD(NAME, DOC, TYPE, INIT): Define a piece-of-data 'hook'.  */
  22
  23 /* Defaults for optional macros:
  24    DEFHOOKPODX(NAME, TYPE, INIT): Like DEFHOOKPOD, but share documentation
  25    with the previous 'hook'.  */
  26 #ifndef DEFHOOKPODX
  27 #define DEFHOOKPODX(NAME, TYPE, INIT) DEFHOOKPOD (NAME, 0, TYPE, INIT)
  28 #endif
  29
  30 /* HOOKSTRUCT(FRAGMENT): Declarator fragments to encapsulate all the
  31    members into a struct gcc_target, which in turn contains several
  32    sub-structs.  */
  33 #ifndef HOOKSTRUCT
  34 #define HOOKSTRUCT(FRAGMENT)
  35 #endif
  36 /* HOOK_VECTOR: Start a struct declaration, which then gets its own initializer.
  37    HOOK_VECTOR_END: Close a struct declaration, providing a member declarator
  38                     name for nested use.  */
  39 #ifndef HOOK_VECTOR_1
  40 #define HOOK_VECTOR_1(NAME, FRAGMENT) HOOKSTRUCT (FRAGMENT)
  41 #endif
  42 #define HOOK_VECTOR(INIT_NAME, SNAME) HOOK_VECTOR_1 (INIT_NAME, struct SNAME {)
  43 #define HOOK_VECTOR_END(DECL_NAME) HOOK_VECTOR_1(,} DECL_NAME ;)
  44
  45 /* FIXME: For pre-existing hooks, we can't place the documentation in the
  46    documentation field here till we get permission from the FSF to include
  47    it in GPLed software - the target hook documentation is so far only
  48    available under the GFDL.  */
  49
  50 /* A hook should generally be documented by a string in the DOC parameter,
  51    which should contain texinfo markup.  If the documentation is only available
  52    under the GPL, but not under the GFDL, put it in a comment above the hook
  53    definition.  If the function declaration is available both under GPL and
  54    GFDL, but the documentation is only available under the GFDL, put the
  55    documentaton in tm.texi.in, heading with @hook <hookname> and closing
  56    the paragraph with @end deftypefn / deftypevr as appropriate, and marking
  57    the next autogenerated hook with @hook <hookname>.
  58    In both these cases, leave the DOC string empty, i.e. "".
  59    Sometimes, for some historic reason the function declaration
  60    has to be documented differently
  61    than what it is.  In that case, use DEFHOOK_UNDOC to suppress auto-generation
  62    of documentation.  DEFHOOK_UNDOC takes a DOC string which it ignores, so
  63    you can put GPLed documentation string there if you have hopes that you
  64    can clear the declaration & documentation for GFDL distribution later,
  65    in which case you can then simply change the DEFHOOK_UNDOC to DEFHOOK
  66    to turn on the autogeneration of the documentation.
  67
  68     A documentation string of "*" means not to emit any documentation at all,
  69    and is mainly used internally for DEFHOOK_UNDOC.  It should generally not
  70    be used otherwise, but it has its use for exceptional cases where automatic
  71    documentation is not wanted, and the real documentation is elsewere, like
  72    for TARGET_ASM_{,UN}ALIGNED_INT_OP, which are hooks only for implementation
  73    purposes; they refer to structs, the components of which are documented as
  74    separate hooks TARGET_ASM_{,UN}ALIGNED_[HSDT]I_OP.
  75    A DOC string of 0 is for internal use of DEFHOOKPODX and special table
  76    entries only.  */
  77
  78 /* Empty macro arguments are undefined in C90, so use an empty macro
  79    to close top-level hook structures.  */
  80 #define C90_EMPTY_HACK