Adds an optional (default false) compile option to enable comparing
`Ref` to `nullptr` to ensure correct use, as well as future expandsion
for more general dev checks (enabled with `dev_mode`)
Prevents cache issues by not purging cache before starting a build.
Splits cache purge related code from progress code and delays the purge
until after final build is done.
After upgrading, I noticed that the SCons ninja output had a different
filename which messed up the "flaky file" logic.
This patch explicitly passes it to the tool and switches to
`build.ninja` (ninja's default).
The `-j` flag is only settable via the command line, which makes it hard
to configure when running builds from places like VS, where the flag isn't
easily exposed or configurable.
This lets users configure the number of jobs to be used by default if `-j`
isn't specified, instead of always defaulting to number of cores - 1.
Co-authored-by: Rémi Verschelde <rverschelde@gmail.com>
Some of the logic in SCons depends on flags that get overridden in the
platform-specific `detect.py`, so it needs to be processed first.
For example the Android/iOS/Web platforms override the default `target`
to `template_debug`, but this was processed too late so e.g. the logic
that sets `env.editor_build` would set it to true due to the default
`target` value in the environment being `editor`.
The min SCons version had to be bumped as SCons 3.0 before 3.0.3 seems
broken (see #92043), and there's little gain from supporting 3.0.3-3.0.5.
3.1.2 is also the first version to avoid ambiguities between Python 2
and Python 3 usage, so we finally use it as the minimum baseline.
Also test against Python 3.6 which is also our minimum supported version.
This should help prevent regressions whenever we modernize the build scripts.
- GCC 7 supports C++17 but seems to have breaking regressions, see #79352.
- GCC 8 broke C++17 guaranteed copy elision support, fixed in 8.4, but...
- GCC 9 is old enough (2022) to use as a baseline and stop dealing with
unmaintained and less efficient compiler versions.
Finally reading the docs for `SCons.Variables.Update` let me find this optional
parameter, which solves the hacks and pain we've dealt with for years:
> args (optional) – a dictionary of keys and values to update in env.
> If omitted, uses the variables from the commandline.
By passing the environment itself, we preserve the values we've overridden in
`SConstruct` or `detect.py`.
