The broken condition can be replicated with:
``shell
export MYARCH=x86_64-apple-darwin && mkdir -p build/$MYARCH/subdir &&
touch build/$MYARCH/subdir/file && ln -s build/$MYARCH/subdir/file
build/$MYARCH/subdir/symlink
``
`src/bootstrap/clean.rs` has a custom implementation of removing a tree
`fn rm_rf` that used `std::path::Path::{is_file, is_dir, exists}` while
recursively deleting directories and files. Unfortunately, `Path`'s
implementation of `is_file()` and `is_dir()` and `exists()` always
unconditionally follow symlinks, which is the exact opposite of standard
implementations of deleting file trees.
It appears that this custom implementation is being used to workaround a
behavior in Windows where the files often get marked as read-only, which
prevents us from simply using something nice and simple like
`std::fs::remove_dir_all`, which properly deletes links instead of
following them.
So it looks like the fix is to use `.symlink_metadata()` to figure out
whether tree items are files/symlinks/directories. The one corner case
this won't cover is if there is a broken symlink in the "root"
`build/$MYARCH` directory, because those initial entries are run through
`Path::canonicalize()`, which panics with broken symlinks. So lets just
never use symlinks in that one directory. :-)
This commit switches the default build system for Rust from the makefiles to
rustbuild. The rustbuild build system has been in development for almost a year
now and has become quite mature over time. This commit is an implementation of
the proposal on [internals] which slates deletion of the makefiles on
2016-01-02.
[internals]: https://internals.rust-lang.org/t/proposal-for-promoting-rustbuild-to-official-status/4368
This commit also updates various documentation in `README.md`,
`CONTRIBUTING.md`, `src/bootstrap/README.md`, and throughout the source code of
rustbuild itself.
Closes#37858
This commit is a rewrite of the user-facing interface to the rustbuild build
system. The intention here is to make it much easier to compile/test the project
without having to remember weird rule names and such. An overall view of the new
interface is:
# build everything
./x.py build
# document everyting
./x.py doc
# test everything
./x.py test
# test libstd
./x.py test src/libstd
# build libcore stage0
./x.py build src/libcore --stage 0
# run stage1 run-pass tests
./x.py test src/test/run-pass --stage 1
The `src/bootstrap/bootstrap.py` script is now aliased as a top-level `x.py`
script. This `x` was chosen to be both short and easily tab-completable (no
collisions in that namespace!). The build system now accepts a "subcommand" of
what to do next, the main ones being build/doc/test.
Each subcommand then receives an optional list of arguments. These arguments are
paths in the source repo of what to work with. That is, if you want to test a
directory, you just pass that directory as an argument.
The purpose of this rewrite is to do away with all of the arcane renames like
"rpass" is the "run-pass" suite, "cfail" is the "compile-fail" suite, etc. By
simply working with directories and files it's much more intuitive of how to run
a test (just pass it as an argument).
The rustbuild step/dependency management was also rewritten along the way to
make this easy to work with and define, but that's largely just a refactoring of
what was there before.
The *intention* is that this support is extended for arbitrary files (e.g.
`src/test/run-pass/my-test-case.rs`), but that isn't quite implemented just yet.
Instead directories work for now but we can follow up with stricter path
filtering logic to plumb through all the arguments.
libcompiler-rt.a is dead, long live libcompiler-builtins.rlib
This commit moves the logic that used to build libcompiler-rt.a into a
compiler-builtins crate on top of the core crate and below the std crate.
This new crate still compiles the compiler-rt instrinsics using gcc-rs
but produces an .rlib instead of a static library.
Also, with this commit rustc no longer passes -lcompiler-rt to the
linker. This effectively makes the "no-compiler-rt" field of target
specifications a no-op. Users of `no_std` will have to explicitly add
the compiler-builtins crate to their crate dependency graph *if* they
need the compiler-rt intrinsics. Users of the `std` have to do nothing
extra as the std crate depends on compiler-builtins.
Finally, this a step towards lazy compilation of std with Cargo as the
compiler-rt intrinsics can now be built by Cargo instead of having to
be supplied by the user by some other method.
closes#34400
The organization in rustbuild was a little odd at the moment where the `lib.rs`
was quite small but the binary `main.rs` was much larger. Unfortunately as well
there was a `build/` directory with the implementation of the build system, but
this directory was ignored by GitHub on the file-search prompt which was a
little annoying.
This commit reorganizes rustbuild slightly where all the library files (the
build system) is located directly inside of `src/bootstrap` and all the binaries
now live in `src/bootstrap/bin` (they're small). Hopefully this should allow
GitHub to index and allow navigating all the files while maintaining a
relatively similar layout to the other libraries in `src/`.
