I have a following rule in WORKSPACE:
new_local_repository(
name = "llvm",
path = "/opt/local/libexec/llvm-4.0",
build_file= "llvm.BUILD")
I would like to now use hardcoded path for llvm. llvm-config --prefix can give me the directory for llvm. What is the correct way to get this? Can I just use standard python commands (e.g. subprocess package)?
As @abergmeier said, you can create a custom repository rule, run the command, create a symlink pointing to its output, and create a BUILD file for the repository:
WORKSPACE file:
workspace(name = "io_bazel")
load("//foo:repo.bzl", "llvm_configure")
llvm_configure(name = "local_config_llvm")
foo/repo.bzl:
def _impl(repository_ctx):
result = repository_ctx.execute(["echo", "/tmp/dummy/path"])
llvm_path = result.stdout.splitlines()[0]
repository_ctx.symlink(llvm_path, "llvm-4.0")
repository_ctx.file("BUILD", """
filegroup(
name = "llvm_files",
srcs = glob(["llvm-4.0/**"]),
visibility = ["//visibility:public"],
)
""")
llvm_configure = repository_rule(
implementation=_impl,
local = True,
environ = [])
Targets in the repo:
$ bazel query @local_config_llvm//:*
@local_config_llvm//:llvm_files
@local_config_llvm//:llvm-4.0/a.txt
@local_config_llvm//:BUILD
Generated files:
$ ls -la $(bazel info output_base)/external/local_config_llvm
total 16
drwxr-x--- 2 laszlocsomor eng 4096 May 12 13:06 .
drwxr-x--- 6 laszlocsomor eng 4096 May 12 13:06 ..
-rwxr-x--x 1 laszlocsomor eng 115 May 12 13:06 BUILD
lrwxrwxrwx 1 laszlocsomor eng 15 May 12 13:06 llvm-4.0 -> /tmp/dummy/path
-rw-r----- 1 laszlocsomor eng 116 May 12 13:06 WORKSPACE
$ cat $(bazel info output_base)/external/local_config_llvm/BUILD
filegroup(
name = "llvm_files",
srcs = glob(["llvm-4.0/**"]),
visibility = ["//visibility:public"],
)
$ cat $(bazel info output_base)/external/local_config_llvm/WORKSPACE
# DO NOT EDIT: automatically generated WORKSPACE file for llvm_configure rule
workspace(name = "local_config_llvm")