These are not yet consumed by anything, but convert all the settings
from SCons variables to Kconfig variables.
If you have existing SConsopts files which need to be converted, you
should take a look at KCONFIG.md to learn about how kconfig is used in
gem5. You should decide if any variables need to be available to C++ or
kconfig itself, and whether those are options which should be detected
automatically, or should be up to the user. Options which should be
measured automatically should still be in SConsopts files, while user
facing options should be added to new or existing Kconfig files.
Generally, make sure you're storing c++/kconfig visible options in
env['CONF'][...]. Also remove references to sticky_vars since persistent
options should now be handled with kconfig, and export_vars since
everything in env['CONF'] is now exported automatically.
Switch SCons/gem5 to use Kconfig for configuration, except EXTRAS which
is still a sticky SCons variable. This is necessary because EXTRAS also
controls what config options exist. If it came from Kconfig itself, then
there would be a circular dependency. This dependency could
theoretically be handled by reparsing the Kconfig when EXTRAS
directories were added or removed, but that would be complicated, and
isn't supported by kconfiglib. It wouldn't be worth the significant
effort it would take to add it, just to use Kconfig more purely.
Change-Id: I29ab1940b2d7b0e6635a490452d05befe5b4a2c9
Currently the type of HAVE_DEPRECATED_NAMESPACE is used to detect
if the compiler support gnu::deprecated feature. The return type
of conf.TryCompile is int, but HAVE_DEPRECATED_NAMESPACE is used
as boolean type. The CL is add bool type caster to ensure the type
of it is boolean.
Change-Id: Ife7d9716e485a8be8722d58776f064e7c2268a30
This makes what are configuration and what are internal SCons variables
explicit and separate, and makes it unnecessary to call out what
variables to export to C++.
These variables will also be plumbed into and out of kconfiglib in later
changes.
Change-Id: Iaf5e098d7404af06285c421dbdf8ef4171b3f001
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/56892
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
On the new release, the compilation is polluted by the same warning:
> ''deprecated' attribute directive ignored
It seems that the hook added in this patch does not work:
https://gem5-review.googlesource.com/c/public/gem5/+/45246/1..7
The snippet of code compile with TryCompile on g++{8,9}.
It probably comes from the fact that the compilation
only creates a warning and not an error.
By adding temporarily '-Werror' for this compilation test,
it filters the faulty gcc versions.
Change-Id: I2b8b7a1a7e06df437b76e98d212947f4f9452311
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/48843
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The GEM5_DEPRECATED_NAMESPACE macro temporarily declares
a namespace with the deprecated name that prints a
warning message when used. It also make sure that when
the old namespace name is used the new name is referenced.
The GEM5_DEPRECATED_CLASS macro deprecates classes that
were renamed, or moved to different namespaces.
Attributes in namespaces are an issue, though.
- Clang only allows from version 6 on, and only when
using C++17.
- GCC has a bug before version 10 where the deprecated
attribute was not properly recognized in namespaces:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79817
Possible solutions for GCC < 10:
1)
\#define GEM5_DEPRECATED_NAMESPACE() \
namespace gem5 { namespace deprecated { \
auto namespace_##old_namespace = [](){ \
GEM5_DEPRECATED("Please use the new namespace: '" \
\#new_namespace "'") \
int old_namespace; \
return old_namespace; \
}; \
}} \
namespace new_namespace {} \
namespace old_namespace { \
using namespace new_namespace; \
}
Add the above macro to all headers that previously
declared the deprecated namespace to trigger a
warning. This is extremely inconvenient because
every file that includes that header will trigger
the deprecation warning, so the compilation output
gets VERY clogged.
2) Similar to 1), but do not use the temporary variable
on declaration. This would require using the variable
somewhere else, like a respective .c file. This is
not always possible, so we could resort to adding a
special file (e.g., base/deprecated_elements.cc)
containing all uses of the deprecated temporary
variables.
3)
\#define GEM5_DEPRECATED_NAMESPACE(old_ns, new_ns) \
namespace old_ns = new_ns;
Similar to 3), but simply declare an alias in the
header files (see above macro) to maintain backwards
compatibility. Then use the special file to declare
all deprecation messages.
4)
Rely on release notes / e-mail to the mailing list
to inform that those are deprecated.
We have selected option 4 for these problematic instances.
Checking if namespace deprecation is possible is done
through scons.
Jira issues:
https://gem5.atlassian.net/browse/GEM5-975https://gem5.atlassian.net/browse/GEM5-991
Change-Id: Ide234f6a8707d88a869fa843bf8c61ca7714e4f3
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/45246
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
These are HDF5, PNG, FENV, and TUNTAP support, all of which add
capabilities to gem5 which can be ignored if not wanted. It could be
argued that FENV changes behavior because it makes setting the FP
rounding mode work or not as used by SPARC, but since the difference is
trivial and in a niche area, that (along with the other options) doesn't
seem to justify having a top level control in the build system.
Since these are no longer options which say whether to *use* a
particular feature, and are instead flags which say whether we *have* a
particular feature, change their names from USE_* to HAVE_*, to stay
consistent with other variables.
Most of the remaining USE_* flags, KVM, FASTMODEL, SYSTEMC, and
(indirectly) USE_PYTHON, toggle on and off major systems which can have
a significant effect on boot time, or, in the case of FASTMODEL, even
consume external resources which may not be available and which may
break the build.
USE_POSIX_TIMER was also left alone since it selects between two
implementations of some functions. By forcing it to be on or off
depending on the host, we would be forcing some code to be excluded in
either case. That would make that other code impossible to test without
hacking up scons or modifying the host machine.
Change-Id: I0b03f23e65478caefd50cd3516974386e3dbf0db
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/40964
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This has two purposes. First, SCons assumes that once you call
Configure, you won't set up the environment the Configure is based on
until after you get the environment back from it again with
conf.Finish(). We get away with this when the cache mode for config
tests is not "force", since Configure just reuses the environment we
pass in, and any changes we make are immediately communicated between
the two.
If the cache mode *is* "force" though, SCons modifies the decider so
that everything the conf environment goes to build looks like it's out
of date. It does that by cloning the original environment, and then
using that clone to do its tests. That causes a problem because we have
a long lived "conf" object and make further changes to main, and since
the two environments are now separate the one in conf doesn't see those
updates.
Second, and more subtly, we export our "main" and "env" environments so
that other SConsopts and SConscript files can use them and define things
in them. The way Configure is designed, if the config caching mode is
"force", then it will create a new environment, and then that
environment will replace what the, for instance, "main" variable points
to when "main = conf.Finish()" is executed.
Unfortunately, if we've already Export()-ed main, we've exported what
the "main" variable pointed to at that time. Our view of "main" will
track with the value that conf.Finish() returned, but since that
construction environment is mearly derived from the main we Exported and
not actually the same thing, they have diverged at that point and will
behave independently.
To solve both of these problems, this change modifies the
gem5_scons.Configure() method so that it's a context manager instead of
a regular function. As before, it will call Configure for us and create
a configuration context, which it will yield as the "with" value. When
the context exits, all the variables in the context Finish() returns
will be shoved back into the original context with Replace(). This isn't
perfect since variables which were deleted in the environment (probably
very rare in practice) will not exist and so will not overwrite the
still existent variable in the original dict.
This has several advantages. The environment never splits into two
copies which continue on independently. It makes the lifetime of a
configuration context short, which is good because behavior during that
time is tricky and unintuitive. It also makes the scope of the context
very clear, so that you won't miss the fact that you're in a special
setting and need to pay attention to what environment you're modifying.
Also, this keeps the conceptual overhead of configuration localized to
where the configuration is happening. In parts of the SConscripts which
are not doing anything with conf, etc, they don't have to modify their
behavior since no configuration context is active.
This change is based on this change from Hanhwi Jang who identified this
problem and proposed an initial solution:
https://gem5-review.googlesource.com/c/public/gem5/+/44265
Change-Id: Iae0a292d6b375c5da98619f31392ca1de6216fcd
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/44389
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Hanhwi Jang <jang.hanhwi@gmail.com>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
Use SConsopts files local to individual domains to pull
non-foundational build code out of SConstruct. This greatly simplifies
SConstruct, and also makes it easier to find build configuration having
to do with particular pieces of gem5.
This change also converts some python level variables, all_protocols,
protocol_dirs, and slicc_includes, into the environment where the timing
of their initialization is more flexible.
Change-Id: Ie61ceb75ae9e5557cc400603c972a9582e99c1ea
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/40872
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Gabe Black <gabe.black@gmail.com>
