When the '-Wl,-rpath-link' option refers to several folders, we can
either use one single entry, like this:
-Wl,-rpath-link,/path/to/folder1:/path/to/folder2:/path/to/folder3
...or we can use multiple entries, like this:
-Wl,-rpath-link,/path/to/folder1
-Wl,-rpath-link,/path/to/folder2
-Wl,-rpath-link,/path/to/folder3
Because the '-rpath-link' requires full folder paths, using the one
single entry option can result in a very long argument.
While this shouldn't be a problem, at least *one* toolchain (the latest
version of the Tensilica toolchain for Xtensa processors) segfaults when
using arguments that are too long.
Because other toolchains might be affected and because using multiple
entries instead of a very long one doesn't seem to have any drawback,
this patch changes the arguments building logic to use multiple
'-Wl,-rpath-link' entries.
Instad of having special casing of threads in the backends and
everywehre else, do what we did for openmp, create a real
dependency. Then make use of the fact that dependencies can now have
sub dependencies to add threads.
Previously cross, but not native, external args were used. Then in
d451a4bd97 the cross special cases were
removed, so external args are never used.
This commit switches that so they are always used. Sanity checking works
just the same as compiler checks like has header / has library.
I recall that @jpakkane never wanted this, but @nirbheek did, but then
@nirbheek changed his mind.
I am fine either way except for the cross inconsistency that exists
today: There is no `c_preproc_args` or similar one can put in the cross
file, so no way to replicate the effect of CPPFLAGS during cross
compilation.
This patch creates an enum for selecting libtype as static, shared,
prefer-static, or prefer-shared. This also renames 'static-shared'
with 'prefer_static' and 'shared-static' with 'prefer_shared'. This is
just a refactor with no behavioral changes or user facing changes.
Currently we specialcase OpenMP like we do threads, with a special
`need_openmp` method. This seems like a great idea, but doesn't work
out in practice, as well as it complicates the opemp
implementation. If GCC is built without opemp support for example, we
still add -fopenmp to the the command line, which results in
compilation errors.
This patch discards that and treats it like a normal dependency,
removes the need_openmp() method, and sets the compile_args attributes
from the compiler.
Fixes#5115
OpenBSD does not link libc into shared libraries by default to avoid binding
libraries to specific libc majors. So prevent passing "-Wl,--no-undefined" or
"-zdefs" when linking (those options have always suffered false positives on
this operating system).
Before, the logic initialization compiler options from environment
variables vs config files was strewn about. Now, it is consolidated. We
leverage the new `envconfig.py` module to expose the configuration data
to `compilers.py` without creating an import cycle.
This does two things:
* On windows GCC-like compilers, the subsystem is always explicitly
specified (either -mwindows or -mconsole). MSVC is already explicit.
* The gui_app linker flags are now added after those mandated by
external dependencies. This is because some misguided libraries (such
as SDL) think that hijacking `main()` and forcing `-mwindows` in link
flags is clever. We must unconditionally override such misuses to let
gui_app work as intended.