We use bazel
1 to build Vere, which is packaged as a single binary,
urbit
. We support the following (host, target)
pairs, where the host platform
is where bazel
runs and the target platform is where urbit
will
run:
Host Platform | Target Platform |
---|---|
linux-aarch64 |
linux-aarch64 |
linux-x86_64 |
linux-x86_64 |
macos-aarch64 |
macos-aarch64 |
macos-x86_64 |
macos-x86_64 |
The first step is to install bazel
using the instructions found on the bazel
1 site.
All platforms require the automake
and libtool
suite of tools installed in
order to build Vere. Before going any further, install them using your package
manager. For example, on macOS:
brew install automake libtool
After installing automake
and libtool
, you need to install the musl libc toolchain. We use musl libc instead of glibc on Linux, which enables us to generate statically linked binaries. As a prerequisite, you need to install the musl libc toolchain appropriate for your target platform.
To install the x86_64-linux-musl-gcc
toolchain at
/usr/local/x86_64-linux-musl-gcc
, run:
bazel run //bazel/toolchain:x86_64-linux-musl-gcc
This will take a few minutes.
To install the aarch64-linux-musl-gcc
toolchain at
/usr/local/aarch64-linux-musl-gcc
, run:
bazel run //bazel/toolchain:aarch64-linux-musl-gcc
This will take a few minutes.
After installing automake
, autoconf-archive
, pkg-config
, and libtool
, you're ready to build Vere.
Once you install the prerequisites, you're ready to build:
bazel build :urbit
If you want a debug build, which changes the optimization level from -O3
to
-O0
and includes more debugging information, specify dbg
as the
compilation_mode
:
bazel build --compilation_mode=dbg :urbit
Note that you cannot change the optimization level for third party
dependencies--those targets specified in bazel/third_party
--from the command
line.
You can turn on CPU and memory debugging by specifying the cpu_dbg
and/or the
mem_dbg
build config.
bazel build --config=cpu_dbg --config=mem_dbg :urbit
Note that ships booted from builds with one or both of these configs specified are incompatible with builds of vere without them and vice versa.
If you need to specify arbitrary C compiler or linker options, use
--copt
or --linkopt
, respectively:
bazel build --copt='-Wall' :urbit
Note --copt
can be used to specify arbitrary C compiler
optimizations. They're passed directly to the compiler commands generated by
bazel.
Additionally, --copt
is propagated to all dependencies. This has the
undesirable side effect of considerably slowing down build times when you're
switching between different copts (say the inclusion or exclusion of some macro
define with --copt='-DMACRO'
) since all dependencies will be rebuilt. If you
want only to pass the copt to the compiler commands invoked to build :urbit
,
you can pass them with --per_file_copt
like so:
bazel build --per_file_copt='pkg/.*@-DMACRO'
You can build and run unit tests only on native builds. If you have a native build and want to run all unit tests, run:
bazel test --build_tests_only ...
If you want to run a specific test, say
pkg/noun/hashtable_tests.c
, run:
bazel test //pkg/noun:hashtable_tests
Any options you specify at the command line can instead be specified in
.user.bazelrc
if you find yourself using the same options over and over. This
file is not tracked by git
, so whatever you add to it will not affect anyone
else. As an example, if you want to change the optimization level but don't want
type --copt='-O0'
each time, you can do the following:
echo "build --copt='-O0'" >> .user.bazelrc
bazel build :urbit
For more information on Bazel configuration files, consult the Bazel docs.
If bazel build
or bazel test
generates an undeclared inclusion(s) in rule
error on macOS, the version of clang
expected by the build system likely
doesn't match the version of clang
installed on your system. To address this,
run clang --version
and pass the version number via
--clang_version="<version_string>"
to the failing command.
Footnotes
-
If you're interested in digging into the details of the build system, check out
WORKSPACE.bazel
,BUILD.bazel
,bazel/
, and the multipleBUILD.bazel
files inpkg/
. ↩ ↩2