Rustc-1.52.0
Introduction to Rust
The Rust programming language is
designed to be a safe, concurrent, practical language.
This package is updated on a six-weekly release cycle. Because it
is such a large and slow package to build, is at the moment only
required by a few packages in this book, and particularly because
newer versions tend to break older mozilla packages, the BLFS
editors take the view that it should only be updated when that is
necessary (either to fix problems, or to allow a new version of a
package to build).
As with many other programming languages, rustc (the rust compiler)
needs a binary from which to bootstrap. It will download a stage0
binary and many cargo crates (these are actually .tar.gz source
archives) at the start of the build, so you cannot compile it
without an internet connection.
These crates will then remain in various forms (cache, directories
of extracted source), in ~/.cargo
for
ever more. It is common for large rust packages to use multiple versions of some
crates. If you purge the files before updating this package, very
few crates will need to be updated by the packages in this book
which use it (and they will be downloaded as required). But if you
retain an older version as a fallback option and then use it (when
not building in /usr
), it is likely that it will then have to
re-download some crates. For a full download (i.e. starting with an
empty or missing ~/.cargo
)
downloading the external cargo files for this version only takes a
minute or so on a fast network.
Note
Although BLFS usually installs in /usr
, when you later upgrade to a newer version
of rust the old libraries in
/usr/lib/rustlib
will remain, with
various hashes in their names, but will not be usable and will
waste space. The editors recommend placing the files in the
/opt
directory. In particular, if
you have reason to rebuild with a modified configuration (e.g.
using the shipped LLVM after building with shared LLVM, or for
the reverse situation) it is possible for the install to leave a
broken cargo
program. In such a situation, either remove the existing
installation first, or use a different prefix such as
/opt/rustc-1.52.0-build2.
If you prefer, you can of course change the prefix to
/usr
and omit the ldconfig and the actions to add
rustc to the PATH.
The current rustbuild build-system
will use all processors, although it does not scale well and often
falls back to just using one core while waiting for a library to
compile. However it can be mostly limited to a specified number of
processors by a combination of adding the switch --jobs <N>
(e.g. '--jobs 4' to limit to 4
processors) on each invocation of python3 ./x.py and using an environment variable
CARGO_BUILD_JOBS=<N>
. At the
moment this is not effective when some of the rustc tests are run.
The current version of rust's num_cpus crate now recognizes that
cgroups can be used to restrict which processors it is allowed to
use. So if your machine lacks DRAM (typically, less than 2GB DRAM
per core) that might be an alternative to taking CPUs offline.
That can apparently be achieved by writing
custom unit files.
At the moment Rust does not
provide any guarantees of a stable ABI.
Note
Rustc defaults to building for ALL supported architectures, using
a shipped copy of LLVM. In BLFS the build is only for the X86
architecture. If you intend to develop rust crates, this build
may not be good enough for your purposes.
The build times of this version when repeated on the same machine
are often reasonably consistent, but as with all compilations
using rustc there
can be some very slow outliers.
Unusually, a DESTDIR-style method is being used to install this
package. This is because running the install as root not only
downloads all of the cargo files again (to /root/.cargo
), it then spends a very long time
recompiling. Using this method saves a lot of time, at the cost
of extra disk space.
This package is known to build and work properly using an LFS-11.0
platform.
Package Information
-
Download (HTTP): https://static.rust-lang.org/dist/rustc-1.52.0-src.tar.gz
-
Download MD5 sum: bd6fbe9ba5fe457d2514e92a6ccd7b24
-
Download size: 161 MB
-
Estimated disk space required: 9.3 GB (407 MB installed)
including 291 MB of ~/.cargo files for the user building
this. Add 4.0 GB including extra 179 MB of ~/.cargo files if
running the tests
-
Estimated build time: 31 SBU (add 13 SBU for tests, both on a
4-core machine)
Rust Dependencies
Required
cURL-7.78.0, CMake-3.21.2, and libssh2-1.9.0
Recommended
clang from LLVM-12.0.1 (built with
-DLLVM_LINK_LLVM_DYLIB=ON so that rust can link to system LLVM
instead of building its shipped version) If using an older version,
see the config.toml file below re using the shipped llvm, because
of rust issue 69225.
Optional
GDB-10.2 (used
by the testsuite if it is present)
User Notes: https://wiki.linuxfromscratch.org/blfs/wiki/rust
Installation of Rust
To install into the /opt
directory,
remove the symlink and create a new directory (i.e. with a
different name if trying a modified build). As the root
user:
mkdir /opt/rustc-1.52.0 &&
ln -svfin rustc-1.52.0 /opt/rustc
Note
If multiple versions of Rust are
installed in /opt
, changing to
another version only requires changing the /opt/rustc
symbolic link and then running
ldconfig.
Create a suitable config.toml
file
which will configure the build.
cat << EOF > config.toml
# see config.toml.example for more possible options
# See the 8.4 book for an example using shipped LLVM
# e.g. if not installing clang, or using a version before 10.0
[llvm]
# by default, rust will build for a myriad of architectures
targets = "X86"
# When using system llvm prefer shared libraries
link-shared = true
[build]
# omit docs to save time and space (default is to build them)
docs = false
# install cargo as well as rust
extended = true
[install]
prefix = "/opt/rustc-1.52.0"
docdir = "share/doc/rustc-1.52.0"
[rust]
channel = "stable"
rpath = false
# BLFS does not install the FileCheck executable from llvm,
# so disable codegen tests
codegen-tests = false
[target.x86_64-unknown-linux-gnu]
# NB the output of llvm-config (i.e. help options) may be
# dumped to the screen when config.toml is parsed.
llvm-config = "/usr/bin/llvm-config"
[target.i686-unknown-linux-gnu]
# NB the output of llvm-config (i.e. help options) may be
# dumped to the screen when config.toml is parsed.
llvm-config = "/usr/bin/llvm-config"
EOF
Compile Rust by running the
following commands:
export RUSTFLAGS="$RUSTFLAGS -C link-args=-lffi" &&
python3 ./x.py build --exclude src/tools/miri
Note
The testsuite will generate some messages in the systemd journal for traps on invalid opcodes, and
for segmentation faults. In themselves these are nothing to worry
about, just a way for the test to be terminated.
To run the tests issue python3 ./x.py
test --verbose --no-fail-fast | tee rustc-testlog:
as with the build, that will use all available CPUs.
At a minimum, seven tests will fail: ui/asm/inline-syntax.rs#arm,
assembly/target-feature-multiple.rs#SINGLEFLAG,
assembly/target-feature-multiple.rs#TWOFLAGS,
run-make-fulldeps/long-linker-command-lines,
run-make-fulldeps/split-debuginfo, run-make-fulldeps/split-dwarf,
run-make-fulldeps/sysroot-crates-are-unstable. With any recent
version of gdb, four
more failures (debuginfo/extern-c-fn.rs,
debuginfo/generator-objects.rs, debuginfo/issue-57822.rs,
debuginfo/pretty-huge-vec.rs) can be expected.
As with all large testsuites, other tests might fail on some
machines - if the number of additional failures is in the single
digits, check the log for 'FAILED' and review lines above that,
particularly the 'stderr:' lines. Any mention of SIGSEGV or signal
11 in a failing test is a cause for concern.
If you get any other failing
test which reports an issue number then you should search for that
issue. For example, when rustc >= 1.41.1 was built with a
version of sysllvm before 10.0 the test for issue 69225 failed
https://github.com/rust-lang/rust/issues/69225
and that should be regarded as a critical failure (they released
1.41.1 because of it). Most other failures will not be critical.
Therefore, you should determine the number of failures.
The number of tests which failed can be found by running:
grep '^test result:' rustc-testlog | awk '{ sum += $6 } END { print sum }'
And similarly if you care about how many tests passed use $4, for
those which were ignored (i.e. skipped) use $8 (and $10 for
'measured', $12 for 'filtered out' but both are probably zero).
Still as your normal user, do a DESTDIR install:
export LIBSSH2_SYS_USE_PKG_CONFIG=1 &&
DESTDIR=${PWD}/install python3 ./x.py install &&
unset LIBSSH2_SYS_USE_PKG_CONFIG
Now, as the root
user install the
files from the DESTDIR:
chown -R root:root install &&
cp -a install/* /
Command Explanations
ln -svfn rustc-1.52.0
/opt/rustc: if this is not the first use of the
/opt/rustc
symlink, overwrite it by
forcing, and use the '-n' flag to avoid getting confusing results
from e.g. ls -l.
targets = "X86": this
avoids building all the available linux cross-compilers (Aarch64,
MIPS, PowerPC, SystemZ, etc). Unfortunately, rust insists on
installing source files for these below /opt/rustc/lib/src
.
extended = true: this
installs Cargo alongside Rust.
channel = "stable":
this ensures only stable features can be used, the default in
config.toml
is to use development
features, which is not appropriate for a released version.
rpath = false: by
default, rust can be
run from where it was built, without being installed. That adds
DT_RPATH entries to all of the ELF files, which produces very messy
output from ldd,
showing the libraries in the place they were built, even if they
have been deleted from there after the install.
[target.x86_64-unknown-linux-gnu]:
the syntax of config.toml
requires an
llvm-config
entry for each target for
which system-llvm is to be used. Change the target to [target.i686-unknown-linux-gnu]
if you are
building on 32-bit x86. This whole section may be omitted if you
wish to build against the shipped llvm, or do not have clang, but
the resulting build will be larger and take longer.
export RUSTFLAGS="$RUSTFLAGS -C
link-args=-lffi": This adds a link to libffi to any
RUSTFLAGS you may already be passing to the build. On some systems,
linking fails to include libffi unless this is used. The reason why
this is needed is not clear.
--exclude
src/tools/miri: For a long time, the miri crate (an
interpreter for the Midlevel Intermediate Representation) has
failed to build on releases. It is optional, but the failure
messages can persuade people that the whole build failed. However,
although it is not built in the main compile, with rustc-1.35.0 it
now got compiled during the install, but it was broken in that
version. Omitting it should save a little time.
--verbose: this
switch can sometimes provide more information about a test which
fails.
--no-fail-fast: this
switch ensures that the testsuite will not stop at the first error.
export
LIBSSH2_SYS_USE_PKG_CONFIG=1: On some systems,
cairo fails to link during the install because it cannot find
libssh2. This seems to fix it, but again the reason why the problem
occurs is not understood.
DESTDIR=${PWD}/install python3 ./x.py
install: This effects a DESTDIR-style install in
the source tree,creating an install
directory. Note that DESTDIR installs need an absolute path,
passing 'install' will not work.
chown -R root:root
install: the DESTDIR install was run by a regular
user, who owns the files. For security, change their owner before
doing a simple copy to install them.
Configuring Rust
Configuration
Information
If you installed rustc in
/opt
, you need to update the
following configuration files so that rustc is correctly found by other packages
and system processes.
As the root
user, update the
/etc/ld.so.conf
file and the
dynamic linker's run-time cache file:
cat >> /etc/ld.so.conf << EOF
# Begin rustc addition
/opt/rustc/lib
# End rustc addition
EOF
ldconfig
As the root
user, create the
/etc/profile.d/rustc.sh
file:
cat > /etc/profile.d/rustc.sh << "EOF"
# Begin /etc/profile.d/rustc.sh
pathprepend /opt/rustc/bin PATH
# End /etc/profile.d/rustc.sh
EOF
Immediately after installation, update the current PATH for your
current shell as a normal user:
source /etc/profile.d/rustc.sh
Contents
Installed Programs:
cargo-clippy, cargo-fmt, cargo-miri,
cargo, clippy-driver, miri, rls, rust-analyzer, rust-gdb,
rust-gdbgui, rust-lldb, rustc, rustdoc, rustfmt.
Installed Libraries:
Many lib*<16-byte-hash>.so
libraries.
Installed Directories:
~/.cargo, /opt/rustc/lib/rustlib,
/opt/rustc/share/doc/rustc-1.52.0, and
/opt/rustc/share/zsh/site-functions
Short Descriptions
cargo-clippy
|
provides lint checks for a cargo package
|
cargo-fmt
|
formats all bin and lib files of the current crate using
rustfmt
|
cargo-miri
|
is for use by Miri to interpret bin crates and tests
|
cargo
|
is the Package Manager for Rust
|
clippy-driver
|
provides lint checks for Rust
|
miri
|
is an interpreter for Rust's mid-level intermediate
representation (MIR). It is broken in this version
|
rls
|
is the Rust Language Server. This can run in the
background to provide IDEs, editors, and other tools with
information about Rust programs
|
rust-analyzer
|
is an implementation of Language Server Protocol for the
Rust programming language.
|
rust-gdb
|
is a wrapper script for gdb, pulling in Python
pretty-printing modules installed in /opt/rustc-1.52.0/lib/rustlib/etc
|
rust-gdbgui
|
is a wrapper script for a graphical front end to gdb that
runs in a browser
|
rust-lldb
|
is a wrapper script for LLDB (the LLVM debugger) pulling
in the Python pretty-printing modules
|
rustc
|
is the rust compiler
|
rustdoc
|
generates documentation from rust source code
|
rustfmt
|
formats rust code
|
libstd-<16-byte-hash>.so
|
is the Rust Standard Library, the foundation of portable
Rust software
|
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