Caching Compiler.run() seems likely to cause problems, but some users, like
.sizeof(), we know enough about the program run to make it safe.
This commit just adds the Compiler.cached_run(), a subsequent commit makes use
of it.
This solves rebuild issues when e.g. importing a .pxd header from a .pyx
file, just like C/C++ source headers. The transpiler needs to run again
in this case.
This functionality is present in the 3.0.0 alphas of cython, and is also
backported to 0.29.33.
Fixes#9049
Eventually we would probably be better served (to avoid unnecessary
copies) to use the ImmutableListProtocol here, but for the moment this
is effective, it's also what we do in every other case.
We assume /utf-8 for all C builds unless /source-charset or
/execution-charset is specified, but then this will cause trouble for
Visual Studio 2013 or earler since the /utf-8 flag is only supported
since Visual Studio 2015. Specifically, if we try to check whether
compiler flags are supported, those checks will fail since /utf-8 is
never supported on these older Visual Studio versions.
Drop /utf-8 from get_always_args() if we are using Visual Studio 2013
or earlier.
There are lots of warnings that become fatal, that are simply unfixable
by the end user. Things like using old versions of software (because
they're using some kind of LTS release), warnings about compilers not
supporting certain kinds of checks, or standards being upgraded due to
skipped implementations (MSVC has c++98 and c++14, but not c++11). None
of these should be fatal, they're informative, and too important to
reduce to notices, but not important enough to stop meson if they're
printed.
Profiling showed that we were spending 25s inside os.path.realpath()
on Windows while generating compile lines for build.ninja, inside
NinjaBackend.generate()
The real path for these will not (should not) change during a single
meson invocation, so cache all these.
Brings build.ninja generation from 73s to 47s on my machine.
Which adds the `use-set-for-membership` check. It's generally faster in
python to use a set with the `in` keyword, because it's a hash check
instead of a linear walk, this is especially true with strings, where
it's actually O(n^2), one loop over the container, and an inner loop of
the strings (as string comparison works by checking that `a[n] == b[n]`,
in a loop).
Also, I'm tired of complaining about this in reviews, let the tools do
it for me :)
Adds a new maximum warning level that is roughly equivalent to "all warnings".
This adds a way to use `/Wall` with MSVC (without the previous broken warning),
`-Weverything` with clang, and almost all general warnings in GCC with
strictness roughly equivalent to clang's `-Weverything`.
The GCC case must be implemented by meson since GCC doesn't provide a similar
option. To avoid maintenance headaches for meson, this warning level is
defined objectively: all warnings are included except those that require
specific values or are specific to particular language revisions. This warning
level is mainly intended for new code, and it is expected (nearly guaranteed)
that projects will need to add some suppressions to build cleanly with it.
More commonly, it's just a handy way to occasionally take a look at what
warnings are present with some compiler, in case anything interesting shows up
you might want to enable in general.
Since the warnings enabled at this level are inherently unstable with respect
to compiler versions, it is intended for use by developers and not to be set as
the default.
-Wnon-virtual-dtor is not what people think of as a standard warning
flag. It was previously removed from -Wall in
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=16190 on the grounds that
people didn't like it and were refusing to use -Wall at all because it
forced this warning. Instead, it is enabled by -Weffc++ which is
typically not enabled and even comes with GCC documentation warnings
stating that the standard library doesn't obey it, and you might need to
`grep -v` and filter out warnings. (!!!)
It doesn't fit into the typical semantics of Meson's warning_level
option, which usually aligns with compiler standard warning levels
rather than a niche ideological warning level.
It was originally added in commit 22af56e05a,
but without any specific rationale included, and has gone unquestioned
since then -- except by the Meson users who see it, assume there is a
finely crafted design behind it, and quietly opt out by rolling their own
warning options with `add_project_arguments('-Wall', ...)`.
Furthermore a GCC component maintainer for the C++ standard library
opened a Meson bug report specially to tell us that this warning flag is
a "dumb option" and "broken by design" and "doesn't warn about the right
thing anyway", thus it should not be used. This is a reasonably
authoritative source that maybe, just maybe, this flag... is too
opinionated to force upon Meson users without recourse. It's gone beyond
opinionated and into the realm of compiler vendors seem to think that
the state of the language would be better if the flag did not exist at
all, whether default or not.
Fixes#11096
ccache was used in all command lines but disabled using CCACHE_DISABLE
in Compiler.compile() method. Wrapping invokations still has a cost,
especially on Windows.
With sccache things are even worse because CCACHE_DISABLE was not
respected at all, making configure *extremely* slow on Windows when
sccache is installed.
https://github.com/mesonbuild/meson/pull/9287 changed the `optimization=0`
to pass `-O0` to the compiler. This change is reasonable by itself
but unfortunately, it breaks `buildtype=plain`, which promises
that “no extra build flags are used”.
`buildtype=plain` is important for distros like NixOS,
which manage compiler flags for optimization and hardening
themselves.
Let’s introduce a new optimization level that does nothing
and set it as the default for `buildtype=plain`.
Andres Freund
mtribiere
L. E. Segovia
Xavier Claessens
Luke Elliott
Simon McVittie
Eli Schwartz
Dylan Baker
Chun-wei Fan
Dudemanguy
Charles Brunet
David Seifert
Gijs Peskens
Kleis Auke Wolthuizen
Nirbheek Chauhan
Axel Ricard
David Robillard
Ole André Vadla Ravnås
Tristan Partin
Robert Cohn
Tatsuyuki Ishi
Jan Tojnar