The warning seems questionable and overly strict.
For now, just disable it to allow building with gcc7.
src/systemd/src/basic/time-util.c: In function ‘format_timespan’:
src/systemd/src/basic/time-util.c:509:46: error: ‘%0*lu’ directive output between 1 and 2147483648 bytes may cause result to exceed ‘INT_MAX’ [-Werror=format-truncation=]
"%s"USEC_FMT".%0*"PRI_USEC"%s",
^~~~
src/systemd/src/basic/time-util.c:509:60: note: format string is defined here
"%s"USEC_FMT".%0*"PRI_USEC"%s",
src/systemd/src/basic/time-util.c:509:46: note: directive argument in the range [0, 18446744073709551614]
"%s"USEC_FMT".%0*"PRI_USEC"%s",
^~~~
https://mail.gnome.org/archives/networkmanager-list/2017-February/msg00001.html
We already use several GCC extenions, like typeof() and
__attribute__((cleanup)). They are too convinient to miss
and every supported compiler must support these.
Currently, gcc and clang does. Maybe other compilers would
support that too, but who knows, nobody seems to test that.
We also already use stdbool.h (C99) and the imported systemd
code is mostly gnu99 too (it's not clear to me, because I don't
find it precisely documented. Certainly it makes use of C99 features
too).
C99/gnu99 has some nice improvements that we no longer should miss
out. For example "flexible array members" or "variable declaration
in init-part of for loop".
It doesn't mean we have to use every obscure (badly supported?)
feature, it means we don't have to forgo features that are well
supported. C99 is 17 years old, I mean, really...
If somebody comes along and ports NM to non-gcc/clang, we can address
bugs about unsupported language features as they surface.
But let's not restrict us to some hypothetical compiler (or language
specification).
Also, NetworkManager is not ported on environment beside Linux.
We don't have to be so considerate about the required build environment.
Gcc is probably the most portable compiler out there. I doubt porting
NetworkManager to *BSD fails due to missing gnu99 features. And if that
causes issues, we should fix them after they happen in practice.
We want to embed the current commit-id in the ./configure script.
That way the generated ./configure file in the source tarball
references the commit-id from which the tarball was created.
Then, in a second step, a script can check ./configure to find
the parent commit. This is for example done by the 'makerepo.sh'
script.
This is generally useful, and also done by network-manager-applet
and libnl3 projects. Move the function to a separate m4 macro
to reuse it. It should also be re-used in NetworkManager's VPN plugins.
We break the aliasing rules in the code, and thus the flag should
always be enabled to prevent wrong optimizations, even without
--enable-more-warnings.
It contains useful macros for determining compiler support for
flags/attributes. We already similar macros in compiler_options.m4,
but the plan is to replace them.
Duplicated const specifiers are allowed by C99 and can easily
happen in macros. Also, systemd's interal code will use them.
Disable this warning, it doesn't seem useful.
Originally m4/introspection.m4 was copied from gobject-introspection
repository. We however modified it in commit f6272144e9.
Reimport the file with latest changes, but still preserving our
workaround.
The autoconf macro for GIR passes $CFLAGS to g-ir-scanner.
g-ir-scanner extends those flags with the system-default which
includes -D_FORTIFY_SOURCE=2. Probably it should not do that,
but if you disable optimization, this results in a compler warning
in "/usr/include/features.h" [1]
export CFLAGS='-O0'
# Happens both with clang or gcc.
#export CC=clang
git clean -fdx
./autogen.sh
make
Work around that by injecting -Wno-error to $CFLAGS when invoking
g-ir-scanner.
[1] Related: https://sourceware.org/bugzilla/show_bug.cgi?id=13979
Otherwise the check is effectively a no-op and unknown options still get
turned on. This results in unknown warnings when build without
--with-extra-warnings=error:
warning: unknown warning option '-Wno-unused-but-set-variable'; did you mean '-Wno-unused-const-variable'? [-Wunknown-warning-option]
It seems like a poor default for various downstream toolchains. We can't
anticipate the compiler warnings for future compiler versions and older
ones are prone to false positives. Also, older gdbus-codegen is known
to generate code that triggers compiler warnings.
Let's keep it enabled for maintainer builds and distcheck so that we're
sure a tool chain that builds releases without warnings exists.
Since GCC 4.4, gcc does not warn about unknown -Wno-* flags. At
least, it does not warning unless another warning is raised as well
(https://gcc.gnu.org/wiki/FAQ#wnowarning).
We didn't notice up to now, because we only tested flags that GCC
actually supports.
Hack around this, by checking for the -W* counterpart instead.
Every Makefile in the subtrees would include -lreadline
as part of LIBS, hence every application would link against
the library.
This was broken since we added 'm4/ax_lib_readline.m4'.
Fixes: 29297f8531
We must also remove -Waggregate-return from m4/compiler-warnings.m4 because systemd
uses aggregate return (correctly) in a couple cases, and we cannot keep single-level
makefiles and override aggregate-return only for the systemd sub-library.
This client currently only supports DHCPv4 because the base systemd code
does not yet fully support DHCPv6.
The warning -Wstrict-prototypes was disabled by commit
db9b1df0e4 .
Enable it again, but avoid warnings for WiMax SDK by explicitly disabling the
compiler warning where needed.
Apparently clang does not produce a warning for -Wstrict-prototypes,
hence we don't need a clang specific #pragma.
Signed-off-by: Thomas Haller <thaller@redhat.com>
NM_COMPILER_WARNINGS still works the same, but
rename variables to have a CFLAGS_* prefix.
Also cleanup the construction of CFLAGS by appending
to CFLAGS_MORE_WARNINGS variable instead of appending
to CFLAGS, and resetting to SAVE_CFLAGS.
Signed-off-by: Thomas Haller <thaller@redhat.com>
clang does not exit with error when it is called with an
unrecognized (warning) option. Instead it just prints
a warning that makes the configure script believe the
warning is supported. Later, during build we might pass
-Werror, which causes clang to fail due to unrecognized
arguments.
Fix the script to detect compiler warnings by passing
'-Werror=unknown-warning-option', which lets clang fail too.
Signed-off-by: Thomas Haller <thaller@redhat.com>
Not all distros build their readline linked with a termcap library,
since apps are (apparently) supposed to choose one for themselves
and explicitly link to it when using readline. So add some checks
to figure out whether readline is already linked, and if not, prefer
ncurses since we use that for nmtui already.
ax_lib_readline based off:
http://www.gnu.org/software/autoconf-archive/ax_lib_readline.html
Update gnome-code-coverage.m4 from gnome-common to fix some (harmless)
error messages when coverage is disabled (bug 699943), and to add
support for lcov 1.10.
Use the following in Makefile.am to enable code coverage for individual modules:
@GNOME_CODE_COVERAGE_RULES@
my_program_LIBS = … $(CODE_COVERAGE_LDFLAGS) …
my_program_CFLAGS = … $(CODE_COVERAGE_CFLAGS) …
This patch adds the autotools facilities to generate vapi files so that
libnm-util and libnm-glib can be consumed from Vala.
It depends on vapigen and it is a soft dependency.
First, -Wstrict-prototypes wasn't actually getting used because
-Werror was already in CFLAGS and AC_TRY_COMPILE doesn't produce
main() functions with valid strict prototypes. Suck. But even
fixing that, the WiMAX SDK won't build with the flag, so just rip
it out.
Add the necessary annotations (the mininum required, that is those
on return values. NULL parameters or container types may require
more), and the Autotools stuff to get a NetworkManager GIR for
libnm-util and a NMClient for libnm-glib.
rtnl_addr requires that all addresses have the "peer" attribute set in
order to be compared for equality, but this attribute is not normally
set. As a result, most addresses will not compare as equal even to
themselves, busting caching. We fix this for now by poking into the
guts of libnl if it is broken...
