1/* Common macros for target hook definitions.
2 Copyright (C) 2001-2023 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
81

source code of gcc/target-hooks-macros.h