Rationale: this convention avoids forcing closely-related code to be far
apart in the namespace hierarchy, and vice versa. By the same token, it
makes the namespace hierarchy more consistent with the directory
hierarchy.
This shifts explorer's file_test to use ExplorerMain in order to be able
to pass arguments similar to how the command line would. It also means
that various output wrapping done by the command line is shared, no
longer copied by file_test.
In order to help make this work, I plugged vfs::FileSystem into
explorer, similar to how we're doing this on the toolchain side (might
try to share more code later). I was having trouble getting an overlay
working, I think due to how paths are specified -- but due to the issues
in fixing this, I'm just loading the prelude into the InMemoryFilesystem
for now.
Under this approach, I'm unifying more of the file versus string
handling. I think we should shift towards an approach where, like
toolchain code, anyone trying to use Explorer should use a vfs
implementation to supply code. This should reduce the number of distinct
code paths which we're maintaining/testing.
Short-term, this allows the trace testdata to be merged into file_test
with less special casing, using ARGS:. Long-term, it means that the
file_test knows the ARGS to pass to generate checks to match against,
which is the direction I'm planning for autoupdate.
This will be more correct if a user file is named prelude.carbon, and
reduces the explorer runtime by about 10% by removing a string
comparison from the check for whether trace output is enabled.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
In explorer, we already support parsing a string_view, so use that. In toolchain, we need to build support, probably using vfs, so that's a todo.
bazel test //explorer:file_test --runs_per_test=5
- branch: Stats over 250 runs: max = 18.3s, min = 5.2s, avg = 11.2s, dev = 2.9s
- trunk: Stats over 250 runs: max = 22.3s, min = 5.9s, avg = 12.1s, dev = 2.8s
Not a dramatic improvement, but maybe more effective long-term, and this'd been requested on #2876
Adds stack space handling similar to Clang's approach, but with more support for forwarding return values. Refactors ParseAndExecute for better sharing, and for centralization of the InitStackSpace handling.
Fixes#2795