bazel-lib/lib/private/copy_directory.bzl

131 lines
5.0 KiB
Python

"""Implementation of copy_directory macro and underlying rules.
This rule copies a directory to another location using Bash (on Linux/macOS) or
cmd.exe (on Windows).
"""
load(":copy_common.bzl", _COPY_EXECUTION_REQUIREMENTS = "COPY_EXECUTION_REQUIREMENTS")
def _copy_cmd(ctx, src, dst):
# Most Windows binaries built with MSVC use a certain argument quoting
# scheme. Bazel uses that scheme too to quote arguments. However,
# cmd.exe uses different semantics, so Bazel's quoting is wrong here.
# To fix that we write the command to a .bat file so no command line
# quoting or escaping is required.
# Put a hash of the file name into the name of the generated batch file to
# make it unique within the package, so that users can define multiple copy_file's.
bat = ctx.actions.declare_file("%s-%s-cmd.bat" % (ctx.label.name, hash(src.path)))
# Flags are documented at
# https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/robocopy
# NB: robocopy return non-zero exit codes on success so we must exit 0 after calling it
cmd_tmpl = "@robocopy \"{src}\" \"{dst}\" /E >NUL & @exit 0"
mnemonic = "CopyDirectory"
progress_message = "Copying directory %s" % src.path
ctx.actions.write(
output = bat,
# Do not use lib/shell.bzl's shell.quote() method, because that uses
# Bash quoting syntax, which is different from cmd.exe's syntax.
content = cmd_tmpl.format(
src = src.path.replace("/", "\\"),
dst = dst.path.replace("/", "\\"),
),
is_executable = True,
)
ctx.actions.run(
inputs = [src],
tools = [bat],
outputs = [dst],
executable = "cmd.exe",
arguments = ["/C", bat.path.replace("/", "\\")],
mnemonic = mnemonic,
progress_message = progress_message,
use_default_shell_env = True,
execution_requirements = _COPY_EXECUTION_REQUIREMENTS,
)
def _copy_bash(ctx, src, dst):
cmd = "rm -rf \"$2\" && cp -fR \"$1/\" \"$2\""
mnemonic = "CopyDirectory"
progress_message = "Copying directory %s" % src.path
ctx.actions.run_shell(
tools = [src],
outputs = [dst],
command = cmd,
arguments = [src.path, dst.path],
mnemonic = mnemonic,
progress_message = progress_message,
use_default_shell_env = True,
execution_requirements = _COPY_EXECUTION_REQUIREMENTS,
)
def copy_directory_action(ctx, src, dst, is_windows = False):
"""Helper function that creates an action to copy a directory from src to dst.
This helper is used by copy_directory. It is exposed as a public API so it can be used within
other rule implementations.
Args:
ctx: The rule context.
src: The directory to make a copy of. Can be a source directory or TreeArtifact.
dst: The directory to copy to. Must be a TreeArtifact.
is_windows: If true, an cmd.exe action is created so there is no bash dependency.
"""
if not src.is_source and not dst.is_directory:
fail("src must be a source directory or TreeArtifact")
if dst.is_source or not dst.is_directory:
fail("dst must be a TreeArtifact")
if is_windows:
_copy_cmd(ctx, src, dst)
else:
_copy_bash(ctx, src, dst)
def _copy_directory_impl(ctx):
is_windows = ctx.target_platform_has_constraint(ctx.attr._windows_constraint[platform_common.ConstraintValueInfo])
dst = ctx.actions.declare_directory(ctx.attr.out)
copy_directory_action(ctx, ctx.file.src, dst, is_windows)
files = depset(direct = [dst])
runfiles = ctx.runfiles(files = [dst])
return [DefaultInfo(files = files, runfiles = runfiles)]
_copy_directory = rule(
implementation = _copy_directory_impl,
provides = [DefaultInfo],
attrs = {
"src": attr.label(mandatory = True, allow_single_file = True),
# Cannot declare out as an output here, because there's no API for declaring
# TreeArtifact outputs.
"out": attr.string(mandatory = True),
"_windows_constraint": attr.label(default = "@platforms//os:windows"),
},
)
def copy_directory(name, src, out, **kwargs):
"""Copies a directory to another location.
This rule uses a Bash command on Linux/macOS/non-Windows, and a cmd.exe command on Windows (no Bash is required).
If using this rule with source directories, it is recommended that you use the
`--host_jvm_args=-DBAZEL_TRACK_SOURCE_DIRECTORIES=1` startup option so that changes
to files within source directories are detected. See
https://github.com/bazelbuild/bazel/commit/c64421bc35214f0414e4f4226cc953e8c55fa0d2
for more context.
Args:
name: Name of the rule.
src: The directory to make a copy of. Can be a source directory or TreeArtifact.
out: Path of the output directory, relative to this package.
**kwargs: further keyword arguments, e.g. `visibility`
"""
_copy_directory(
name = name,
src = src,
out = out,
**kwargs
)