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`.
We need to support cases where the library might be called "foo.so" and
therefore we check for exact matches too. But this also allows
`cc.find_library('libfoo')` to find libfoo.so, which is strange and
won't work in many cases. Emit a warning when this happens.
Fixes#10838
We *mostly* just need to do the same thing. Plug in one utility method
to make sanity_check_impl find the right compile args, and plug in
DEVNULL to the test run. It's that simple.
This solves a few inconsistencies. The main one is that fortran never
logged the sanity checks to the Meson debug log, making it hard to
debug.
There's also some interesting quirks we built up in the dedicated
fortran handling. For example:
- in commit 5b109c9ad2 we added cwd to
building the fortran executable, with a wordy comment about how the
compiler has defects. But the clike base has always done that on
general principle anyway, so we would never have had that bug in the
first place.
- in commit d6be7822a0 we added special
deletion of an old "bad existing exe file" just for fortran. Looking
at the PR discussion for this odd requirement, it turns out that the
real problem is mixing WSL and native Windows without deleting the
build directory. This is apparently fortran specific simply because
"contemporary Windows 10 Fortran users" switch between the two?
The actual problem is that this never used .exe as the output name, so
Windows thinks you want to run something other than the thing you
asked to run, because it's not even a Window executable. But... the
common clike handling could have fixed that without needing special
cases.
This used to be fine, until imports were removed from this file. Now a
function annotated as T.NoReturn doesn't actually tell mypy that it
cannot return, though, so we manually do it.
We no longer need these upfront at all, since we now import the ones we
need for the language we are detecting, at the time of actual detection.
This avoids importing 28 files, consisting of just under 9,000 lines of
code, at interpreter startup. Now, it is only imported depending on
which languages are invoked by add_languages, which may not even be
anything. And even if we do end up importing a fair chunk of it for
C/C++ projects, spreading the import cost around the interpreter runtime
helps responsiveness.
Only import the ones we need for the language we are detecting, once we
actually detect that language.
This will allow finally dropping the main imports of these files in a
followup commit.
Instead of comparing against specific compiler classes, check the
logical compiler id or language etc.
In a couple cases, we seem to be missing a couple things by being a bit
too strict about the exact class type.
This is wasteful and generally unneeded, since code can just use the
compiler they detected instead of manually poking at the internals of
this subpackage.
It also avoids importing an absolute ton of code the instant one runs
`from . import compilers`
In commit d326c87fe2 we added a special
holder object for cached compilation results, with some broken
attributes:
- "command", that was never set, but used to print the log
- "args", that was set to some, but not all, of the information a fresh
compilation would log, but never used
Remove the useless args attribute, call it command, and use it properly.
We compared a Visual Studio (the IDE) version, but we wanted a MSVC (the
compiler) version. This caused the option to be passed for a few too
many versions of MSVC, and emit a "D9002 : ignoring unknown option" on
those systems.
Compare the correct version using the version mapping from
https://walbourn.github.io/vs-2017-15-7-update/Fixes#10787
Co-authored-by: CorrodedCoder <38778644+CorrodedCoder@users.noreply.github.com>
Meson internally knows about many languages and tools, and *FLAGS
variables, and which languages to use them for. Instead of duplicating
this logic, import it from mesonbuild.*
This logic was originally standalone, but now that it is merged into the
Meson tree we can have a single source of truth.
If this command fails, for example when CXX is something not generic
enough to be a valid universal compiler command (clang -std=c++11
perhaps), we end up with two problems:
- it's impossible to figure out what Meson ran to get that error
- the error report isn't clear on what is stdout and what is stderr, or
even that that is what the message is about.
```
meson.build:1:0: ERROR: Unable to get clang pre-processor defines:
error: invalid argument '-std=c++11' not allowed with 'C'
```
What's C doing there and why is Meson talking about it? Answer: that's
compiler stdout. Say so.
We do something similar when running get_compiler() method checks from
the DSL. This ensures that if errors happen, the log file we tell people
to check actually works.
Specifically, this is a combination of the following:
- Revert "visualstudio.py: Apply /utf-8 only on clang or VS2015+"
This reverts commit 6e7c3efa79.
- Revert "Visual Studio: Only use /utf-8 on VS2015 or later or clang-cl"
This reverts commit 8ed151bbd7.
The changes were broken and untested, although this is because of a lack
of general CI testing for all languages on Windows. At least, this broke
the use of ifort, and possibly more.
The changes are fundamentally a bit "exciting", as they step out of the
hierarchy of compiler definitions and apply arguments almost willy-nilly.
And apparently it's leaky all over the place. I don't understand all of
what is going on with it, but it plainly failed to achieve its desired
goal and needs to be rolled back ASAP.
Transpilers need to run on the build machine in order to generate their
output, which can then be taken by a cross-compiler to create the final
output.
MachineChoice is a mesonlib object, not a compilers object, so it makes
no sense to import it from the latter simply because the latter imports
it too. This results in brittle module dependencies and everything
breaking when a refactor removes it from the latter.
... also it is a typing-only import so while we are fixing it to import
from the right place, we can also put it in a type-checking block.
In PR 10263, we didn't account for that we may have initialize the Visual
Studio-like compiler two times, once for a C compiler and once for the
C++ compiler, so we end up with Meson breaking on Visual Studio 2013
or earlier, such as when building GLib.
Fix this by setting up the always_args member of
the VisualStudioLikeCompiler instance during __init__() as needed, so that
we avoid falling into modifying shared objects.
Tristan Partin
Robert Cohn
Xavier Claessens
Tatsuyuki Ishi
Jan Tojnar
Dylan Baker
Eli Schwartz
Yang Bo
Alf Henrik Sauge
Justin Blanchard
Tristan Partin
Chun-wei Fan
Stepan Nassyr