tools/jdk/local_java_repository.bzl - bazel - Git at Google

 # Copyright 2020 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.

 """Rules for importing and registering a local JDK."""

 load(":default_java_toolchain.bzl", "default_java_toolchain")

 def _detect_java_version(repository_ctx, java_bin):
     properties_out = repository_ctx.execute([java_bin, "-XshowSettings:properties"]).stderr
     # This returns an indented list of properties separated with newlines:
     # "  java.vendor.url.bug = ... \n"
     # "  java.version = 11.0.8\n"
     # "  java.version.date = 2020-11-05\"

     strip_properties = [property.strip() for property in properties_out.splitlines()]
     version_property = [property for property in strip_properties if property.startswith("java.version = ")]
     if len(version_property) != 1:
         return None

     version_value = version_property[0][len("java.version = "):]
     parts = version_value.split(".")
     major = parts[0]
     if len(parts) == 1:
         return major
     elif major == "1":  # handles versions below 1.8
         minor = parts[1]
         return minor
     return major

 def local_java_runtime(name, java_home, version, runtime_name = None, visibility = ["//visibility:public"]):
     """Defines a java_runtime target together with Java runtime and compile toolchain definitions.

     Java runtime toolchain is constrained by flag --java_runtime_version having
     value set to either name or version argument.

     Java compile toolchains are created for --java_language_version flags values
     between 8 and version (inclusive). Java compile toolchains use the same
     (local) JDK for compilation. This requires a different configuration for JDK8
     than the newer versions.

     Args:
       name: name of the target.
       java_home: Path to the JDK.
       version: Version of the JDK.
       runtime_name: name of java_runtime target if it already exists.
       visibility: Visibility that will be applied to the java runtime target
     """
     if runtime_name == None:
         runtime_name = name
         native.java_runtime(
             name = runtime_name,
             java_home = java_home,
             visibility = visibility,
             version = int(version) if version.isdigit() else 0,
         )

     native.config_setting(
         name = name + "_name_setting",
         values = {"java_runtime_version": name},
         visibility = ["//visibility:private"],
     )
     native.config_setting(
         name = name + "_version_setting",
         values = {"java_runtime_version": version},
         visibility = ["//visibility:private"],
     )
     native.config_setting(
         name = name + "_name_version_setting",
         values = {"java_runtime_version": name + "_" + version},
         visibility = ["//visibility:private"],
     )
     native.alias(
         name = name + "_settings_alias",
         actual = select({
             name + "_name_setting": name + "_name_setting",
             name + "_version_setting": name + "_version_setting",
             "//conditions:default": name + "_name_version_setting",
         }),
         visibility = ["//visibility:private"],
     )
     native.toolchain(
         name = "runtime_toolchain_definition",
         target_settings = [":%s_settings_alias" % name],
         toolchain_type = Label("@bazel_tools//tools/jdk:runtime_toolchain_type"),
         toolchain = runtime_name,
     )

     if type(version) == type("") and version.isdigit() and int(version) > 8:
         for version in range(8, int(version) + 1):
             default_java_toolchain(
                 name = name + "_toolchain_java" + str(version),
                 source_version = str(version),
                 target_version = str(version),
                 java_runtime = runtime_name,
             )

     # else version is not recognized and no compilation toolchains are predefined

 def _local_java_repository_impl(repository_ctx):
     """Repository rule local_java_repository implementation.

     Args:
       repository_ctx: repository context
     """
     java_home = repository_ctx.attr.java_home
     java_home_path = repository_ctx.path(java_home)
     if not java_home_path.exists:
         fail(('The path indicated by the "java_home" attribute "%s" (absolute: "%s") ' +
               "does not exist.") % (java_home, str(java_home_path)))

     repository_ctx.file(
         "WORKSPACE",
         "# DO NOT EDIT: automatically generated WORKSPACE file for local_java_repository\n" +
         "workspace(name = \"{name}\")\n".format(name = repository_ctx.name),
     )

     extension = ".exe" if repository_ctx.os.name.find("windows") != -1 else ""
     java_bin = java_home_path.get_child("bin", "java" + extension)

     if not java_bin.exists:
         # Java binary does not exist
         repository_ctx.file(
             "BUILD.bazel",
             _NOJDK_BUILD_TPL.format(
                 local_jdk = repository_ctx.name,
                 java_binary = "bin/java" + extension,
                 java_home = java_home,
             ),
             False,
         )
         return

     # Detect version
     version = repository_ctx.attr.version if repository_ctx.attr.version != "" else _detect_java_version(repository_ctx, java_bin)

     # Prepare BUILD file using "local_java_runtime" macro
     if repository_ctx.attr.build_file_content and repository_ctx.attr.build_file:
         fail("build_file and build_file_content are exclusive")
     if repository_ctx.attr.build_file_content:
         build_file = repository_ctx.attr.build_file_content
     elif repository_ctx.attr.build_file:
         build_file = repository_ctx.read(repository_ctx.path(repository_ctx.attr.build_file))
     else:
         build_file = ""
     build_file = build_file.replace("___RUNTIME_VERSION___", version if version.isdigit() else "0")

     runtime_name = '"jdk"' if build_file else None
     local_java_runtime_macro = """
 local_java_runtime(
     name = "%s",
     runtime_name = %s,
     java_home = "%s",
     version = "%s",
 )
 """ % (repository_ctx.name, runtime_name, java_home, version)

     repository_ctx.file(
         "BUILD.bazel",
         'load("@bazel_tools//tools/jdk:local_java_repository.bzl", "local_java_runtime")\n' +
         build_file +
         local_java_runtime_macro,
     )

     # Symlink all files
     for file in repository_ctx.path(java_home).readdir():
         repository_ctx.symlink(file, file.basename)

 # Build file template, when JDK does not exist
 _NOJDK_BUILD_TPL = '''load("@bazel_tools//tools/jdk:fail_rule.bzl", "fail_rule")
 fail_rule(
    name = "jdk",
    header = "Auto-Configuration Error:",
    message = ("Cannot find Java binary {java_binary} in {java_home}; either correct your JAVA_HOME, " +
           "PATH or specify Java from remote repository (e.g. " +
           "--java_runtime_version=remotejdk_11")
 )
 config_setting(
    name = "localjdk_setting",
    values = {{"java_runtime_version": "{local_jdk}"}},
    visibility = ["//visibility:private"],
 )
 toolchain(
    name = "runtime_toolchain_definition",
    target_settings = [":localjdk_setting"],
    toolchain_type = "@bazel_tools//tools/jdk:runtime_toolchain_type",
    toolchain = ":jdk",
 )
 '''

 _local_java_repository_rule = repository_rule(
     implementation = _local_java_repository_impl,
     local = True,
     configure = True,
     attrs = {
         "java_home": attr.string(),
         "version": attr.string(),
         "build_file": attr.label(),
         "build_file_content": attr.string(),
     },
 )

 def local_java_repository(name, java_home, version = "", build_file = None, build_file_content = None):
     """Registers a runtime toolchain for local JDK and creates an unregistered compile toolchain.

     Toolchain resolution is constrained with --java_runtime_version flag
     having value of the "name" or "version" parameter.

     Java compile toolchains are created for --java_language_version flags values
     between 8 and version (inclusive). Java compile toolchains use the same
     (local) JDK for compilation.

     If there is no JDK "virtual" targets are created, which fail only when actually needed.

     Args:
       name: A unique name for this rule.
       java_home: Location of the JDK imported.
       build_file: optionally BUILD file template
       build_file_content: optional BUILD file template as a string
       version: optionally java version
     """
     _local_java_repository_rule(name = name, java_home = java_home, version = version, build_file = build_file, build_file_content = build_file_content)
     native.register_toolchains("@" + name + "//:runtime_toolchain_definition")
	# Copyright 2020 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.

	"""Rules for importing and registering a local JDK."""

	load(":default_java_toolchain.bzl", "default_java_toolchain")

	def _detect_java_version(repository_ctx, java_bin):
	properties_out = repository_ctx.execute([java_bin, "-XshowSettings:properties"]).stderr
	# This returns an indented list of properties separated with newlines:
	# " java.vendor.url.bug = ... \n"
	# " java.version = 11.0.8\n"
	# " java.version.date = 2020-11-05\"

	strip_properties = [property.strip() for property in properties_out.splitlines()]
	version_property = [property for property in strip_properties if property.startswith("java.version = ")]
	if len(version_property) != 1:
	return None

	version_value = version_property[0][len("java.version = "):]
	parts = version_value.split(".")
	major = parts[0]
	if len(parts) == 1:
	return major
	elif major == "1": # handles versions below 1.8
	minor = parts[1]
	return minor
	return major

	def local_java_runtime(name, java_home, version, runtime_name = None, visibility = ["//visibility:public"]):
	"""Defines a java_runtime target together with Java runtime and compile toolchain definitions.

	Java runtime toolchain is constrained by flag --java_runtime_version having
	value set to either name or version argument.

	Java compile toolchains are created for --java_language_version flags values
	between 8 and version (inclusive). Java compile toolchains use the same
	(local) JDK for compilation. This requires a different configuration for JDK8
	than the newer versions.

	Args:
	name: name of the target.
	java_home: Path to the JDK.
	version: Version of the JDK.
	runtime_name: name of java_runtime target if it already exists.
	visibility: Visibility that will be applied to the java runtime target
	"""
	if runtime_name == None:
	runtime_name = name
	native.java_runtime(
	name = runtime_name,
	java_home = java_home,
	visibility = visibility,
	version = int(version) if version.isdigit() else 0,
	)

	native.config_setting(
	name = name + "_name_setting",
	values = {"java_runtime_version": name},
	visibility = ["//visibility:private"],
	)
	native.config_setting(
	name = name + "_version_setting",
	values = {"java_runtime_version": version},
	visibility = ["//visibility:private"],
	)
	native.config_setting(
	name = name + "_name_version_setting",
	values = {"java_runtime_version": name + "_" + version},
	visibility = ["//visibility:private"],
	)
	native.alias(
	name = name + "_settings_alias",
	actual = select({
	name + "_name_setting": name + "_name_setting",
	name + "_version_setting": name + "_version_setting",
	"//conditions:default": name + "_name_version_setting",
	}),
	visibility = ["//visibility:private"],
	)
	native.toolchain(
	name = "runtime_toolchain_definition",
	target_settings = [":%s_settings_alias" % name],
	toolchain_type = Label("@bazel_tools//tools/jdk:runtime_toolchain_type"),
	toolchain = runtime_name,
	)

	if type(version) == type("") and version.isdigit() and int(version) > 8:
	for version in range(8, int(version) + 1):
	default_java_toolchain(
	name = name + "_toolchain_java" + str(version),
	source_version = str(version),
	target_version = str(version),
	java_runtime = runtime_name,
	)

	# else version is not recognized and no compilation toolchains are predefined

	def _local_java_repository_impl(repository_ctx):
	"""Repository rule local_java_repository implementation.

	Args:
	repository_ctx: repository context
	"""
	java_home = repository_ctx.attr.java_home
	java_home_path = repository_ctx.path(java_home)
	if not java_home_path.exists:
	fail(('The path indicated by the "java_home" attribute "%s" (absolute: "%s") ' +
	"does not exist.") % (java_home, str(java_home_path)))

	repository_ctx.file(
	"WORKSPACE",
	"# DO NOT EDIT: automatically generated WORKSPACE file for local_java_repository\n" +
	"workspace(name = \"{name}\")\n".format(name = repository_ctx.name),
	)

	extension = ".exe" if repository_ctx.os.name.find("windows") != -1 else ""
	java_bin = java_home_path.get_child("bin", "java" + extension)

	if not java_bin.exists:
	# Java binary does not exist
	repository_ctx.file(
	"BUILD.bazel",
	_NOJDK_BUILD_TPL.format(
	local_jdk = repository_ctx.name,
	java_binary = "bin/java" + extension,
	java_home = java_home,
	),
	False,
	)
	return

	# Detect version
	version = repository_ctx.attr.version if repository_ctx.attr.version != "" else _detect_java_version(repository_ctx, java_bin)

	# Prepare BUILD file using "local_java_runtime" macro
	if repository_ctx.attr.build_file_content and repository_ctx.attr.build_file:
	fail("build_file and build_file_content are exclusive")
	if repository_ctx.attr.build_file_content:
	build_file = repository_ctx.attr.build_file_content
	elif repository_ctx.attr.build_file:
	build_file = repository_ctx.read(repository_ctx.path(repository_ctx.attr.build_file))
	else:
	build_file = ""
	build_file = build_file.replace("___RUNTIME_VERSION___", version if version.isdigit() else "0")

	runtime_name = '"jdk"' if build_file else None
	local_java_runtime_macro = """
	local_java_runtime(
	name = "%s",
	runtime_name = %s,
	java_home = "%s",
	version = "%s",
	)
	""" % (repository_ctx.name, runtime_name, java_home, version)

	repository_ctx.file(
	"BUILD.bazel",
	'load("@bazel_tools//tools/jdk:local_java_repository.bzl", "local_java_runtime")\n' +
	build_file +
	local_java_runtime_macro,
	)

	# Symlink all files
	for file in repository_ctx.path(java_home).readdir():
	repository_ctx.symlink(file, file.basename)

	# Build file template, when JDK does not exist
	_NOJDK_BUILD_TPL = '''load("@bazel_tools//tools/jdk:fail_rule.bzl", "fail_rule")
	fail_rule(
	name = "jdk",
	header = "Auto-Configuration Error:",
	message = ("Cannot find Java binary {java_binary} in {java_home}; either correct your JAVA_HOME, " +
	"PATH or specify Java from remote repository (e.g. " +
	"--java_runtime_version=remotejdk_11")
	)
	config_setting(
	name = "localjdk_setting",
	values = {{"java_runtime_version": "{local_jdk}"}},
	visibility = ["//visibility:private"],
	)
	toolchain(
	name = "runtime_toolchain_definition",
	target_settings = [":localjdk_setting"],
	toolchain_type = "@bazel_tools//tools/jdk:runtime_toolchain_type",
	toolchain = ":jdk",
	)
	'''

	_local_java_repository_rule = repository_rule(
	implementation = _local_java_repository_impl,
	local = True,
	configure = True,
	attrs = {
	"java_home": attr.string(),
	"version": attr.string(),
	"build_file": attr.label(),
	"build_file_content": attr.string(),
	},
	)

	def local_java_repository(name, java_home, version = "", build_file = None, build_file_content = None):
	"""Registers a runtime toolchain for local JDK and creates an unregistered compile toolchain.

	Toolchain resolution is constrained with --java_runtime_version flag
	having value of the "name" or "version" parameter.

	Java compile toolchains are created for --java_language_version flags values
	between 8 and version (inclusive). Java compile toolchains use the same
	(local) JDK for compilation.

	If there is no JDK "virtual" targets are created, which fail only when actually needed.

	Args:
	name: A unique name for this rule.
	java_home: Location of the JDK imported.
	build_file: optionally BUILD file template
	build_file_content: optional BUILD file template as a string
	version: optionally java version
	"""
	_local_java_repository_rule(name = name, java_home = java_home, version = version, build_file = build_file, build_file_content = build_file_content)
	native.register_toolchains("@" + name + "//:runtime_toolchain_definition")