copy_file: add rule and tests (#123)

This PR adds two new rules: copy_file and
copy_xfile.

Both rules solve a common problem: to copy one
file to another location. The problem is routinely
solved using a genrule. That however requires
Bash, since genrules execute Bash commands.
Requiring Bash is a problem on Windows.

The new rules do not require Bash on Windows (only
on other platforms).

The only difference between the rules is that
copy_xfile creates an executable file while
copy_file doesn't.

See https://github.com/bazelbuild/bazel/issues/4319
This commit is contained in:
László Csomor 2019-03-18 13:23:15 +01:00 committed by Laurent Le Brun
parent f26e8ac863
commit db27394846
8 changed files with 367 additions and 0 deletions

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@ -92,6 +92,13 @@ stardoc(
deps = ["//lib:versions"], deps = ["//lib:versions"],
) )
stardoc(
name = "copy_file_docs",
out = "copy_file_doc_gen.md",
input = "//rules:copy_file.bzl",
deps = ["//rules:copy_file"],
)
stardoc( stardoc(
name = "maprule_docs", name = "maprule_docs",
out = "maprule_doc_gen.md", out = "maprule_doc_gen.md",

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@ -10,6 +10,18 @@ bzl_library(
deps = ["//lib:new_sets"], deps = ["//lib:new_sets"],
) )
bzl_library(
name = "copy_file",
srcs = ["copy_file.bzl"],
deps = [":copy_file_private"],
)
bzl_library(
name = "copy_file_private",
srcs = ["copy_file_private.bzl"],
visibility = ["//visibility:private"],
)
bzl_library( bzl_library(
name = "maprule", name = "maprule",
srcs = ["maprule.bzl"], srcs = ["maprule.bzl"],

29
rules/copy_file.bzl Normal file
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@ -0,0 +1,29 @@
# Copyright 2019 The Bazel Authors. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""A rule that copies a file to another place.
native.genrule() is sometimes used to copy files (often wishing to rename them).
The 'copy_file' rule does this with a simpler interface than genrule.
The rule uses a Bash command on Linux/macOS/non-Windows, and a cmd.exe command
on Windows (no Bash is required).
"""
load(
":copy_file_private.bzl",
_copy_file = "copy_file",
)
copy_file = _copy_file

130
rules/copy_file_private.bzl Normal file
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@ -0,0 +1,130 @@
# Copyright 2019 The Bazel Authors. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Implementation of copy_file macro and underlying rules.
These rules copy a file to another location using Bash (on Linux/macOS) or
cmd.exe (on Windows). '_copy_xfile' marks the resulting file executable,
'_copy_file' does not.
"""
def _common_impl(ctx, is_executable):
if ctx.attr.is_windows:
# 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.
bat = ctx.actions.declare_file(ctx.label.name + "-cmd.bat")
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 = "@copy /Y \"%s\" \"%s\" >NUL" % (
ctx.file.src.path.replace("/", "\\"),
ctx.outputs.out.path.replace("/", "\\"),
),
is_executable = True,
)
ctx.actions.run(
inputs = [ctx.file.src, bat],
outputs = [ctx.outputs.out],
executable = "cmd.exe",
arguments = ["/C", bat.path.replace("/", "\\")],
mnemonic = "CopyFile",
progress_message = "Copying files",
use_default_shell_env = True,
)
else:
ctx.actions.run_shell(
inputs = [ctx.file.src],
outputs = [ctx.outputs.out],
command = "cp -f \"$1\" \"$2\"",
arguments = [ctx.file.src.path, ctx.outputs.out.path],
mnemonic = "CopyFile",
progress_message = "Copying files",
use_default_shell_env = True,
)
files = depset(direct = [ctx.outputs.out])
runfiles = ctx.runfiles(files = [ctx.outputs.out])
if is_executable:
return [DefaultInfo(files = files, runfiles = runfiles, executable = ctx.outputs.out)]
else:
return [DefaultInfo(files = files, runfiles = runfiles)]
def _impl(ctx):
return _common_impl(ctx, False)
def _ximpl(ctx):
return _common_impl(ctx, True)
_ATTRS = {
"src": attr.label(mandatory = True, allow_single_file = True),
"out": attr.output(mandatory = True),
"is_windows": attr.bool(mandatory = True),
}
_copy_file = rule(
implementation = _impl,
provides = [DefaultInfo],
attrs = _ATTRS,
)
_copy_xfile = rule(
implementation = _ximpl,
executable = True,
provides = [DefaultInfo],
attrs = _ATTRS,
)
def copy_file(name, src, out, is_executable = False, **kwargs):
"""Copies a file to another location.
`native.genrule()` is sometimes used to copy files (often wishing to rename them). The 'copy_file' rule does this with a simpler interface than genrule.
This rule uses a Bash command on Linux/macOS/non-Windows, and a cmd.exe command on Windows (no Bash is required).
Args:
name: Name of the rule.
src: A Label. The file to make a copy of. (Can also be the label of a rule
that generates a file.)
out: Path of the output file, relative to this package.
is_executable: A boolean. Whether to make the output file executable. When
True, the rule's output can be executed using `bazel run` and can be
in the srcs of binary and test rules that require executable sources.
**kwargs: further keyword arguments, e.g. `visibility`
"""
if is_executable:
_copy_xfile(
name = name,
src = src,
out = out,
is_windows = select({
"@bazel_tools//src/conditions:host_windows": True,
"//conditions:default": False,
}),
**kwargs
)
else:
_copy_file(
name = name,
src = src,
out = out,
is_windows = select({
"@bazel_tools//src/conditions:host_windows": True,
"//conditions:default": False,
}),
**kwargs
)

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@ -16,6 +16,11 @@ load(":versions_tests.bzl", "versions_test_suite")
licenses(["notice"]) licenses(["notice"])
exports_files(
["unittest.bash"],
visibility = ["//tests:__subpackages__"],
)
build_test_test_suite() build_test_test_suite()
collections_test_suite() collections_test_suite()

119
tests/copy_file/BUILD Normal file
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@ -0,0 +1,119 @@
# This package aids testing the 'copy_file' rule.
#
# The package contains 4 copy_file rules:
# - 'copy_src' and 'copy_gen' copy a source file and a generated file
# respectively
# - 'copy_xsrc' and 'copy_xgen' copy a source file and a generated file
# respectively (both are shell scripts), and mark their output as executable
#
# The generated file is the output of the 'gen' genrule.
#
# The 'bin_src' and 'bin_gen' rules are sh_binary rules. They use the
# 'copy_xsrc' and 'copy_xgen' rules respectively. The sh_binary rule requires
# its source to be executable, so building these two rules successfully means
# that 'copy_file' managed to make its output executable.
#
# The 'run_executables' genrule runs the 'bin_src' and 'bin_gen' binaries,
# partly to ensure they can be run, and partly so we can observe their output
# and assert the contents in the 'copy_file_tests' test.
#
# The 'file_deps' filegroup depends on 'copy_src'. The filegroup rule uses the
# DefaultInfo.files field from its dependencies. When we data-depend on the
# filegroup from 'copy_file_tests', we transitively data-depend on the
# DefaultInfo.files of the 'copy_src' rule.
#
# The 'copy_file_tests' test is the actual integration test. It data-depends
# on:
# - the 'run_executables' rule, to get the outputs of 'bin_src' and 'bin_gen'
# - the 'file_deps' rule, and by nature of using a filegroup, we get the files
# from the DefaultInfo.files of the 'copy_file' rule, and thereby assert that
# that field contains the output file of the rule
# - the 'copy_nonempty_text' rule, and thereby on the DefaultInfo.runfiles field
# of it, so we assert that that field contains the output file of the rule
load("//rules:copy_file.bzl", "copy_file")
package(default_testonly = 1)
sh_test(
name = "copy_file_tests",
srcs = ["copy_file_tests.sh"],
data = [
":run_executables",
# Use DefaultInfo.files from 'copy_src' (via 'file_deps').
":file_deps",
# Use DefaultInfo.runfiles from 'copy_gen'.
":copy_gen",
"//tests:unittest.bash",
],
deps = ["@bazel_tools//tools/bash/runfiles"],
)
filegroup(
name = "file_deps",
# Use DefaultInfo.files from 'copy_src'.
srcs = [
":copy_src",
],
)
# If 'run_executables' is built, then 'bin_gen' and 'bin_src' are
# executable, asserting that copy_file makes the output executable.
genrule(
name = "run_executables",
outs = [
"xsrc-out.txt",
"xgen-out.txt",
],
cmd = ("$(location :bin_src) > $(location xsrc-out.txt) && " +
"$(location :bin_gen) > $(location xgen-out.txt)"),
output_to_bindir = 1,
tools = [
":bin_gen",
":bin_src",
],
)
# If 'bin_src' is built, then 'copy_xsrc' made its output executable.
sh_binary(
name = "bin_src",
srcs = [":copy_xsrc"],
)
# If 'bin_gen' is built, then 'copy_xgen' made its output executable.
sh_binary(
name = "bin_gen",
srcs = [":copy_xgen"],
)
copy_file(
name = "copy_src",
src = "a.txt",
out = "out/a-out.txt",
)
copy_file(
name = "copy_gen",
src = ":gen",
out = "out/gen-out.txt",
)
copy_file(
name = "copy_xsrc",
src = "a.txt",
out = "xout/a-out.sh",
is_executable = True,
)
copy_file(
name = "copy_xgen",
src = ":gen",
out = "xout/gen-out.sh",
is_executable = True,
)
genrule(
name = "gen",
outs = ["b.txt"],
cmd = "echo -e '#!/bin/bash\necho potato' > $@",
)

2
tests/copy_file/a.txt Normal file
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@ -0,0 +1,2 @@
#!/bin/bash
echo aaa

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@ -0,0 +1,63 @@
# Copyright 2019 The Bazel Authors. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# --- begin runfiles.bash initialization ---
# Copy-pasted from Bazel's Bash runfiles library (tools/bash/runfiles/runfiles.bash).
set -euo pipefail
if [[ ! -d "${RUNFILES_DIR:-/dev/null}" && ! -f "${RUNFILES_MANIFEST_FILE:-/dev/null}" ]]; then
if [[ -f "$0.runfiles_manifest" ]]; then
export RUNFILES_MANIFEST_FILE="$0.runfiles_manifest"
elif [[ -f "$0.runfiles/MANIFEST" ]]; then
export RUNFILES_MANIFEST_FILE="$0.runfiles/MANIFEST"
elif [[ -f "$0.runfiles/bazel_tools/tools/bash/runfiles/runfiles.bash" ]]; then
export RUNFILES_DIR="$0.runfiles"
fi
fi
if [[ -f "${RUNFILES_DIR:-/dev/null}/bazel_tools/tools/bash/runfiles/runfiles.bash" ]]; then
source "${RUNFILES_DIR}/bazel_tools/tools/bash/runfiles/runfiles.bash"
elif [[ -f "${RUNFILES_MANIFEST_FILE:-/dev/null}" ]]; then
source "$(grep -m1 "^bazel_tools/tools/bash/runfiles/runfiles.bash " \
"$RUNFILES_MANIFEST_FILE" | cut -d ' ' -f 2-)"
else
echo >&2 "ERROR: cannot find @bazel_tools//tools/bash/runfiles:runfiles.bash"
exit 1
fi
# --- end runfiles.bash initialization ---
source "$(rlocation bazel_skylib/tests/unittest.bash)" \
|| { echo "Could not source bazel_skylib/tests/unittest.bash" >&2; exit 1; }
function test_copy_src() {
cat "$(rlocation bazel_skylib/tests/copy_file/out/a-out.txt)" >"$TEST_log"
expect_log '^#!/bin/bash$'
expect_log '^echo aaa$'
}
function test_copy_gen() {
cat "$(rlocation bazel_skylib/tests/copy_file/out/gen-out.txt)" >"$TEST_log"
expect_log '^#!/bin/bash$'
expect_log '^echo potato$'
}
function test_copy_xsrc() {
cat "$(rlocation bazel_skylib/tests/copy_file/xsrc-out.txt)" >"$TEST_log"
expect_log '^aaa$'
}
function test_copy_xgen() {
cat "$(rlocation bazel_skylib/tests/copy_file/xgen-out.txt)" >"$TEST_log"
expect_log '^potato$'
}
run_suite "copy_file_tests test suite"