binutils-gdb/include/diagnostics.h
Simon Marchi 6cade9185c gdb, include: replace pragmas with DIAGNOSTIC macros, fix build with g++ 4.8
When introducing this code, I forgot that we had some macros for this.
Replace some "manual" pragma diagnostic with some DIAGNOSTIC_* macros,
provided by include/diagnostics.h.

In diagnostics.h:

 - Add DIAGNOSTIC_ERROR, to enable a diagnostic at error level.
 - Add DIAGNOSTIC_ERROR_SWITCH, to enable -Wswitch at error level, for
   both gcc and clang.

Additionally, using DIAGNOSTIC_PUSH, DIAGNOSTIC_ERROR_SWITCH and
DIAGNOSTIC_POP seems to misbehave with g++ 4.8, where we see these
errors:

      CXX    ada-tasks.o
    /home/smarchi/src/binutils-gdb/gdb/ada-tasks.c: In function void read_known_tasks():
    /home/smarchi/src/binutils-gdb/gdb/ada-tasks.c:998:10: error: enumeration value ADA_TASKS_UNKNOWN not handled in switch [-Werror=switch]
       switch (data->known_tasks_kind)
              ^

Because of the POP, the diagnostic should go back to being disabled,
since it was disabled in the beginning, but that's not what we see
here.  Versions of GCC >= 5 compile correctly.

Work around this by making DIAGNOSTIC_ERROR_SWITCH a no-op for GCC < 5.

Note that this code (already as it exists in master today) enables
-Wswitch at the error level even if --disable-werror is passed.  It
shouldn't be a problem, as it's not like a new enumerator will appear
out of nowhere and cause a build error if building with future
compilers.  Still, for correctness, we would ideally want to ask the
compiler to enable -Wswitch at its default level (as if the user had
passed -Wswitch on the command-line).  There doesn't seem to be a way to
do this.

Change-Id: Id33ebec3de39bd449409ea0bab59831289ffe82d
2021-12-02 08:24:25 -05:00

120 lines
3.9 KiB
C

/* Copyright (C) 2017-2021 Free Software Foundation, Inc.
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 DIAGNOSTICS_H
#define DIAGNOSTICS_H
/* If at all possible, fix the source rather than using these macros
to silence warnings. If you do use these macros be aware that
you'll need to condition their use on particular compiler versions,
which can be done for gcc using ansidecl.h's GCC_VERSION macro.
gcc versions between 4.2 and 4.6 do not allow pragma control of
diagnostics inside functions, giving a hard error if you try to use
the finer control available with later versions.
gcc prior to 4.2 warns about diagnostic push and pop.
The other macros have restrictions too, for example gcc-5, gcc-6
and gcc-7 warn that -Wstringop-truncation is unknown, unless you
also add DIAGNOSTIC_IGNORE ("-Wpragma"). */
#ifdef __GNUC__
# define DIAGNOSTIC_PUSH _Pragma ("GCC diagnostic push")
# define DIAGNOSTIC_POP _Pragma ("GCC diagnostic pop")
/* Stringification. */
# define DIAGNOSTIC_STRINGIFY_1(x) #x
# define DIAGNOSTIC_STRINGIFY(x) DIAGNOSTIC_STRINGIFY_1 (x)
# define DIAGNOSTIC_IGNORE(option) \
_Pragma (DIAGNOSTIC_STRINGIFY (GCC diagnostic ignored option))
# define DIAGNOSTIC_ERROR(option) \
_Pragma (DIAGNOSTIC_STRINGIFY (GCC diagnostic error option))
#else
# define DIAGNOSTIC_PUSH
# define DIAGNOSTIC_POP
# define DIAGNOSTIC_IGNORE(option)
#endif
#if defined (__clang__) /* clang */
# define DIAGNOSTIC_IGNORE_SELF_MOVE DIAGNOSTIC_IGNORE ("-Wself-move")
# define DIAGNOSTIC_IGNORE_DEPRECATED_DECLARATIONS \
DIAGNOSTIC_IGNORE ("-Wdeprecated-declarations")
# define DIAGNOSTIC_IGNORE_DEPRECATED_REGISTER \
DIAGNOSTIC_IGNORE ("-Wdeprecated-register")
# if __has_warning ("-Wenum-compare-switch")
# define DIAGNOSTIC_IGNORE_SWITCH_DIFFERENT_ENUM_TYPES \
DIAGNOSTIC_IGNORE ("-Wenum-compare-switch")
# endif
# define DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL \
DIAGNOSTIC_IGNORE ("-Wformat-nonliteral")
# define DIAGNOSTIC_ERROR_SWITCH \
DIAGNOSTIC_ERROR ("-Wswitch")
#elif defined (__GNUC__) /* GCC */
# if __GNUC__ >= 7
# define DIAGNOSTIC_IGNORE_DEPRECATED_REGISTER \
DIAGNOSTIC_IGNORE ("-Wregister")
# endif
# define DIAGNOSTIC_IGNORE_STRINGOP_TRUNCATION \
DIAGNOSTIC_IGNORE ("-Wstringop-truncation")
# define DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL \
DIAGNOSTIC_IGNORE ("-Wformat-nonliteral")
/* GCC 4.8's "diagnostic push/pop" seems broken when using this, -Wswitch
remains enabled at the error level even after a pop. Therefore, don't
use it for GCC < 5. */
# if __GNUC__ >= 5
# define DIAGNOSTIC_ERROR_SWITCH DIAGNOSTIC_ERROR ("-Wswitch")
# endif
#endif
#ifndef DIAGNOSTIC_IGNORE_SELF_MOVE
# define DIAGNOSTIC_IGNORE_SELF_MOVE
#endif
#ifndef DIAGNOSTIC_IGNORE_DEPRECATED_DECLARATIONS
# define DIAGNOSTIC_IGNORE_DEPRECATED_DECLARATIONS
#endif
#ifndef DIAGNOSTIC_IGNORE_DEPRECATED_REGISTER
# define DIAGNOSTIC_IGNORE_DEPRECATED_REGISTER
#endif
#ifndef DIAGNOSTIC_IGNORE_SWITCH_DIFFERENT_ENUM_TYPES
# define DIAGNOSTIC_IGNORE_SWITCH_DIFFERENT_ENUM_TYPES
#endif
#ifndef DIAGNOSTIC_IGNORE_STRINGOP_TRUNCATION
# define DIAGNOSTIC_IGNORE_STRINGOP_TRUNCATION
#endif
#ifndef DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL
# define DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL
#endif
#ifndef DIAGNOSTIC_ERROR_SWITCH
# define DIAGNOSTIC_ERROR_SWITCH
#endif
#endif /* DIAGNOSTICS_H */