We defined G_NO_RETURN as [[noreturn]] in the C++ case, but only after
trying the __attribute__ syntax, so it was never used in GNUC compatible
compilers.
Give it priority instead when supporting a C++11 compiler and onwards.
As per this we need to adapt the code in the places where it was not
properly used (leading to compilation warnings).
Sadly, in C++ there's not an universal way to get what language standard
is used to compile GLib-based programs, in fact while most compilers
relies on `__cplusplus`, MSVC is defining that, but it does not use it
to expose such information (unless `/Zc:__cplusplus` arg is used).
On the other side, MSVC reports the language standard via _MSVC_LANG [1].
This complication makes us defining some macros in a very complex way
(such as glib_typeof()), because we need to perform many checks just to
understand if a C++ compiler is used and what standard is expecting.
To avoid this, define multiple macros that can be used to figure out
what C++ standard is being used.
[1] https://docs.microsoft.com/en-us/cpp/build/reference/zc-cplusplus?view=msvc-170
This avoids a -Wshadow warning when nesting G_LIKELY() inside
each other due to _g_boolean_var_.
This can be easily encountered when using macros:
```
#define GET_VALUE(arg) \
({ \
typeof (arg) _arg = (arg); \
\
g_assert (_arg); \
get_value (_arg); \
})
g_assert (GET_VALUE (a) > 5);
```
__COUNTER__ is a GCC extension, but the definition of _G_BOOLEAN_EXPR()
is already inside a
#if defined(__GNUC__) && (__GNUC__ > 2) && defined(__OPTIMIZE__)
block.
Closes: #1211
Inspired by libglnx's glnx_close_fd() and glnx_autofd, these let us
have the same patterns as g_clear_object() and g_autoptr(GObject), but
for file descriptors. g_clear_fd() is cross-platform, while g_autofd
is syntactic sugar requiring a supported compiler (gcc or clang).
Now that g_close() checks for EBADF as a programming error, we can
implement the equivalent of glnx_autofd as an inline function without
needing to have errno and EBADF in the header file.
g_clear_fd() is like glnx_close_fd(), but with error checking.
The private _g_clear_fd_ignore_error() function used to implement
g_autofd is a closer equivalent of glnx_close_fd().
Signed-off-by: Simon McVittie <smcv@collabora.com>
There is currently no `dllimport` attribute on any of our function,
which prevents MSVC to optimize function calls.
To fix that issue, we need to redeclare all our visibility macros for
each of our libraries, because when compiling e.g. GIO code, we need
dllimport in GLIB headers and dllexport in GIO headers. That means they
cannot use the same GLIB_AVAILABLE_* macro.
Since that's a lot of boilerplate to copy/paste after each version bump,
this MR generate all those macros using a python script.
Also simplify the meson side by using `gnu_symbol_visibility : 'hidden'`
keyword argument instead of passing the cflag manually.
This leaves only API index to add manually into glib-docs.xml when
bumping GLib version. That file cannot be generated because Meson does
not allow passing a buit file to gnome.gtkdoc()'s main_xml kwarg
unfortunately.
We had gcc-only implementations for them while both can be used in all
the supported platforms we have.
So let's just provide generic definitions, while we keep the old ones
for both consistency and retro-compatibility.
Add SPDX license (but not copyright) headers to all files which follow a
certain pattern in their existing non-machine-readable header comment.
This commit was entirely generated using the command:
```
git ls-files glib/*.[ch] | xargs perl -0777 -pi -e 's/\n \*\n \* This library is free software; you can redistribute it and\/or\n \* modify it under the terms of the GNU Lesser General Public/\n \*\n \* SPDX-License-Identifier: LGPL-2.1-or-later\n \*\n \* This library is free software; you can redistribute it and\/or\n \* modify it under the terms of the GNU Lesser General Public/igs'
```
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #1415
Use g_macro__has_attribute to detect it instead of
hardcoding __GNUC__ || __clang__. This adds support
for a few compiler and is consistent with the rest
of the gmacros.h file.
It is cleaner to define glib_typeof() in a header included after
gversionmacros.h so we can use GLIB_VERSION_MIN_REQUIRED directly
instead of doing it everywhere glib_typeof() is used.
`#define G_GNUC_NORETURN __attribute__((__noreturn__))` was previously under
`#if G_GNUC_CHECK_VERSION(2, 4)`.
But `# define G_NORETURN __attribute__ ((__noreturn__))` was under
`#if G_GNUC_CHECK_VERSION(2, 8) || (0x5110 <= __SUNPRO_C)`.
Take the latter for `g_macro__has_attribute(__noreturn__)` fallback. This will
disable `G_GNUC_NORETURN` for GCC 2.4-2.7 though.
Fall back to compiler version checks only when `__has_attribute()` is not
available.
clang-cl doesn't define `__GNU__`, but still accepts attributes. This change
gets rid of a lot of warnings when building GLib with clang-cl. For GCC and
non-cl Clang nothing should change.
This change is proposed by Kamil Dudka. It teaches Coverity to assume
that g_critical() will never return, which is desirable for the same
reasons it is for scan-build: once you've triggered undefined behavior,
the game is already lost, and there's limited benefit from trying to
avoid every possible memory leak on such codepaths. Notably, this
affects g_return_if_fail().
Arguably it might be desirable to fix every such issue, but if we're
already not doing so for scan-build, it doesn't make sense to hold
developers working with Coverity to a higher standard. This allows
focusing on more serious issues found by Coverity.
Thanks Kamil!
Use the GCC/Clang macros __has_extension() and __has_feature() on
c_static_assert, which is the documented way for GCC/CLang to check for
_Static_assert if C11 mode is not enabled, as suggested by Aleksandr Mezin.
As a result, add a private macro that is defined to be __has_extension if it
exists, otherwise it is considered to be always false.
It appears that CLang supports _Static_assert() even when not in C11
mode, since at least CLang 3.1, so let's just use that for CLang builds.
Fixes issue #2338.
When included inside an `extern "C"` block, this causes build failures
that look something like:
/usr/include/c++/10/type_traits:2930:3: error: template with C linkage
2930 | template<typename _Fn, typename... _Args>
| ^~~~~~~~
../../disas/arm-a64.cc:20:1: note: ‘extern "C"’ linkage started here
20 | extern "C" {
| ^~~~~~~~~~
Commit 4273c43902a7e6b22cea0041436ee5715c93be76 made this opt in for
projects which are defining `GLIB_VERSION_MIN_REQUIRED`, but the include
of `<type_traits>` via `gmacros.h` was not included in this. If we move
the include out to the places where `glib_typeof` is called, we can make
it covered by this macro too, and save a few consumers from FTBFSing.
That also means that, if you don't want to fix your use of the headers,
and as long as this version is sufficient for you, a quick workaround is
to define `GLIB_VERSION_MIN_REQUIRED` to `GLIB_VERSION_2_66` or lower.
Suggested by Simon McVittie.
Alternative to: https://gitlab.gnome.org/GNOME/glib/-/merge_requests/1935
Fixes: https://gitlab.gnome.org/GNOME/glib/-/issues/2331
That changes the return type of functions like g_object_ref() that can
break C++ applications like Webkit. Note that it is not an ABI break.
It must thus be opt-in the same way we did when adding this to
g_object_ref() for GNU C compilers in the first place. Unfortunately it
cannot be done directly in gmacros.h because GLIB_VERSION_2_68 is not
defined there, and gversionmacros.h cannot be included there because
there is some strict ordering in which those headers must be included.
This means that applications that does not define
GLIB_VERSION_MIN_REQUIRED will still get an API break, so we encourage
them to declare their minimum requirement to avoir such issues in the
future too.
There are various places glib uses __typeof__ for type safety, but
that's a GNUC extension. C++11 has standard decltype() that does a
similar job, at least for cases we care about.
This avoids C++ code to always have to cast return value of
g_object_ref() which was causing type kind of error:
error: invalid conversion from ‘gpointer’ {aka ‘void*’} to
‘GstElementFactory*’ {aka ‘_GstElementFactory*’} [-fpermissive]
It still works, and deprecating it would be quite disruptive (as it’s
used in headers), so amend the documentation to point people to
`G_NORETURN` instead.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #994
Just like gcc, clang has supported `__typeof__` for a long time, so
allow it to be used. This fixes compilation of `gio/gcredentials.c` on
macOS (which uses clang by default).
I don’t know which version clang started supporting `__typeof__` in, so
there’s no version check. One can be added in future if there are
problems.
This fixes commit 5b2bee3f539.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
There are various places glib uses __typeof__ for type safety, but
that's a GNUC extension. C++11 has standard decltype() that does a
similar job, at least for cases we care about.
This avoids C++ code to always have to cast return value of
g_object_ref() which was causing type kind of error:
error: invalid conversion from ‘gpointer’ {aka ‘void*’} to
‘GstElementFactory*’ {aka ‘_GstElementFactory*’} [-fpermissive]
g_has_typeof macro is wrongly in the public g_ namespace, internaly
symbols are usually in the glib_ namespace. This will also allow to
define glib_typeof differently on non-GNUC compilers (e.g. c++11
decltype).
This was mostly machine generated with the following command:
```
codespell \
--builtin clear,rare,usage \
--skip './po/*' --skip './.git/*' --skip './NEWS*' \
--write-changes .
```
using the latest git version of `codespell` as per [these
instructions](https://github.com/codespell-project/codespell#user-content-updating).
Then I manually checked each change using `git add -p`, made a few
manual fixups and dropped a load of incorrect changes.
There are still some outdated or loaded terms used in GLib, mostly to do
with git branch terminology. They will need to be changed later as part
of a wider migration of git terminology.
If I’ve missed anything, please file an issue!
Signed-off-by: Philip Withnall <withnall@endlessm.com>
This reverts commit c0146be3a4e0cda7a23d7fd54cc60a0bc7ba7f7a.
The revert was originally added because the original change broke
gnome-build-meta. Now that the problem has been diagnosed, the original
commit can be fixed — see the commit which follows this one.
See: !1487
The public functions exposed as static inlines currently don't have
annotations to describe when they were introduced. This means that
compiling this file:
#include <glib.h>
void foo (void)
{
g_rec_mutex_locker_new (NULL);
}
with:
gcc -c test.c \
-I/tmp/glib/include/glib-2.0 \
-I/tmp/glib/lib/x86_64-linux-gnu/glib-2.0/include \
-Werror \
-DGLIB_VERSION_MAX_ALLOWED=GLIB_VERSION_2_28 \
-DGLIB_VERSION_MIN_REQUIRED=GLIB_VERSION_2_28
will not produce any error message, despite using
`g_rec_mutex_locker_new`, a function that was introduced after 2.28.
This patch adds some annotations to all the publicly exposed static
inline functions I could find.
I could not use the existing G_AVAILABLE* macros, because they may
expand to `extern`. This would then clash with the `static` keyword and
produce:
../glib/gthread.h:397:1: error: multiple storage classes in declaration specifiers
397 | static inline GRecMutexLocker *
| ^~~~~~
So I opted for adding a new set of macros,
GLIB_AVAILABLE_STATIC_INLINE_IN_2_XY.
With this patch applied, the example from above produces the expected
warning:
test.c: In function ‘foo’:
test.c:5:3: error: ‘g_rec_mutex_locker_new’ is deprecated: Not available before 2.60 [-Werror=deprecated-declarations]
5 | g_rec_mutex_locker_new (NULL);
| ^~~~~~~~~~~~~~~~~~~~~~
In file included from /tmp/glib/include/glib-2.0/glib/gasyncqueue.h:32,
from /tmp/glib/include/glib-2.0/glib.h:32,
from test.c:1:
/tmp/glib/include/glib-2.0/glib/gthread.h:398:1: note: declared here
398 | g_rec_mutex_locker_new (GRecMutex *rec_mutex)
| ^~~~~~~~~~~~~~~~~~~~~~
Some compilers have __GNUC__ defined as a value less than 6, but do
support implicit-fallthrough via __attribute__((fallthrough)). Define
G_GNUC_FALLTHROUGH for those that support __has_attribute.
See the mailing list thread <https://lists.fedoraproject.org/archives/list/
devel@lists.fedoraproject.org/thread/SZ676IHHSLOQD6UN2I5J5VKXJ5P5SOVO/>
"glib-2.0 G_CONST_RETURN causing GCC 'warning: const' on F31", where the GCC
diagnostic
> test.c:2:13: warning: const
> 2 | G_CONST_RETURN char * f();
> | ^~~~~~~
had confused me, and "Deprecated pre-processor symbol, repace with const" is
probably a better warning message than just "const".
(That recent GCC only prints "Deprecated pre-processor symbol, repace with "
appears to be a bug in GCC that GLIB_UNAVAILABLE_MACRO already suffers from,
too. Recent Clang correctly prints "Deprecated pre-processor symbol, repace
with const".)
clang will warn with -Wunused-function if the g_autoptr macros are
ever used inside a .c file. This would break a lot of -Werror builds
with clang.
Mark such functions as explicitly unsed so clang will not warn about
them.
Use the GCC-style definition for the deprecation warning macros so that
builds using those won't break due to how they are placed as clang-cl
seems to not support __declspec(deprecated) very well. Also make sure
that we do indeed support the temparary disabling of deprecation
warnings on clang-cl, as the MSVC ones don't really work on clang-cl.
