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Diffstat (limited to 'absl/abseil.podspec.gen.py')
-rwxr-xr-x | absl/abseil.podspec.gen.py | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/absl/abseil.podspec.gen.py b/absl/abseil.podspec.gen.py new file mode 100755 index 000000000000..2bf153c002ab --- /dev/null +++ b/absl/abseil.podspec.gen.py @@ -0,0 +1,247 @@ +#!/usr/bin/env python3 +# -*- coding: utf-8 -*- +"""This script generates abseil.podspec from all BUILD.bazel files. + +This is expected to run on abseil git repository with Bazel 1.0 on Linux. +It recursively analyzes BUILD.bazel files using query command of Bazel to +dump its build rules in XML format. From these rules, it constructs podspec +structure. +""" + +import argparse +import collections +import os +import re +import subprocess +import xml.etree.ElementTree + +# Template of root podspec. +SPEC_TEMPLATE = """ +# This file has been automatically generated from a script. +# Please make modifications to `abseil.podspec.gen.py` instead. +Pod::Spec.new do |s| + s.name = 'abseil' + s.version = '${version}' + s.summary = 'Abseil Common Libraries (C++) from Google' + s.homepage = 'https://abseil.io' + s.license = 'Apache License, Version 2.0' + s.authors = { 'Abseil Team' => 'abseil-io@googlegroups.com' } + s.source = { + :git => 'https://github.com/abseil/abseil-cpp.git', + :tag => '${tag}', + } + s.module_name = 'absl' + s.header_mappings_dir = 'absl' + s.header_dir = 'absl' + s.libraries = 'c++' + s.compiler_flags = '-Wno-everything' + s.pod_target_xcconfig = { + 'USER_HEADER_SEARCH_PATHS' => '$(inherited) "$(PODS_TARGET_SRCROOT)"', + 'USE_HEADERMAP' => 'NO', + 'ALWAYS_SEARCH_USER_PATHS' => 'NO', + } + s.ios.deployment_target = '7.0' + s.osx.deployment_target = '10.9' + s.tvos.deployment_target = '9.0' + s.watchos.deployment_target = '2.0' +""" + +# Limited platforms that abseil supports. +# This is mainly because of sigaltstack unavailable on watchOS. +LIMITED_SUPPORT_PLATFORMS = [ + "ios.deployment_target = '7.0'", + "osx.deployment_target = '10.9'", +] + +# Custom specification per rule. +CUSTOM_SPEC_MAP = { + "//absl/debugging:failure_signal_handler": LIMITED_SUPPORT_PLATFORMS, +} + +# Rule object representing the rule of Bazel BUILD. +Rule = collections.namedtuple( + "Rule", "type name package srcs hdrs textual_hdrs deps visibility testonly") + + +def get_elem_value(elem, name): + """Returns the value of XML element with the given name.""" + for child in elem: + if child.attrib.get("name") != name: + continue + if child.tag == "string": + return child.attrib.get("value") + if child.tag == "boolean": + return child.attrib.get("value") == "true" + if child.tag == "list": + return [nested_child.attrib.get("value") for nested_child in child] + raise "Cannot recognize tag: " + child.tag + return None + + +def normalize_paths(paths): + """Returns the list of normalized path.""" + # e.g. ["//absl/strings:dir/header.h"] -> ["absl/strings/dir/header.h"] + return [path.lstrip("/").replace(":", "/") for path in paths] + + +def parse_rule(elem, package): + """Returns a rule from bazel XML rule.""" + return Rule( + type=elem.attrib["class"], + name=get_elem_value(elem, "name"), + package=package, + srcs=normalize_paths(get_elem_value(elem, "srcs") or []), + hdrs=normalize_paths(get_elem_value(elem, "hdrs") or []), + textual_hdrs=normalize_paths(get_elem_value(elem, "textual_hdrs") or []), + deps=get_elem_value(elem, "deps") or [], + visibility=get_elem_value(elem, "visibility") or [], + testonly=get_elem_value(elem, "testonly") or False) + + +def read_build(package): + """Runs bazel query on given package file and returns all cc rules.""" + result = subprocess.check_output( + ["bazel", "query", package + ":all", "--output", "xml"]) + root = xml.etree.ElementTree.fromstring(result) + return [ + parse_rule(elem, package) + for elem in root + if elem.tag == "rule" and elem.attrib["class"].startswith("cc_") + ] + + +def collect_rules(root_path): + """Collects and returns all rules from root path recursively.""" + rules = [] + for cur, _, _ in os.walk(root_path): + build_path = os.path.join(cur, "BUILD.bazel") + if os.path.exists(build_path): + rules.extend(read_build("//" + cur)) + return rules + + +def relevant_rule(rule): + """Returns true if a given rule is relevant when generating a podspec.""" + return ( + # cc_library only (ignore cc_test, cc_binary) + rule.type == "cc_library" and + # ignore empty rule + (rule.hdrs + rule.textual_hdrs + rule.srcs) and + # ignore test-only rule + not rule.testonly) + + +def get_spec_var(depth): + """Returns the name of variable for spec with given depth.""" + return "s" if depth == 0 else "s{}".format(depth) + + +def get_spec_name(label): + """Converts the label of bazel rule to the name of podspec.""" + assert label.startswith("//absl/"), "{} doesn't start with //absl/".format( + label) + # e.g. //absl/apple/banana -> abseil/apple/banana + return "abseil/" + label[7:] + + +def write_podspec(f, rules, args): + """Writes a podspec from given rules and args.""" + rule_dir = build_rule_directory(rules)["abseil"] + # Write root part with given arguments + spec = re.sub(r"\$\{(\w+)\}", lambda x: args[x.group(1)], + SPEC_TEMPLATE).lstrip() + f.write(spec) + # Write all target rules + write_podspec_map(f, rule_dir, 0) + f.write("end\n") + + +def build_rule_directory(rules): + """Builds a tree-style rule directory from given rules.""" + rule_dir = {} + for rule in rules: + cur = rule_dir + for frag in get_spec_name(rule.package).split("/"): + cur = cur.setdefault(frag, {}) + cur[rule.name] = rule + return rule_dir + + +def write_podspec_map(f, cur_map, depth): + """Writes podspec from rule map recursively.""" + for key, value in sorted(cur_map.items()): + indent = " " * (depth + 1) + f.write("{indent}{var0}.subspec '{key}' do |{var1}|\n".format( + indent=indent, + key=key, + var0=get_spec_var(depth), + var1=get_spec_var(depth + 1))) + if isinstance(value, dict): + write_podspec_map(f, value, depth + 1) + else: + write_podspec_rule(f, value, depth + 1) + f.write("{indent}end\n".format(indent=indent)) + + +def write_podspec_rule(f, rule, depth): + """Writes podspec from given rule.""" + indent = " " * (depth + 1) + spec_var = get_spec_var(depth) + # Puts all files in hdrs, textual_hdrs, and srcs into source_files. + # Since CocoaPods treats header_files a bit differently from bazel, + # this won't generate a header_files field so that all source_files + # are considered as header files. + srcs = sorted(set(rule.hdrs + rule.textual_hdrs + rule.srcs)) + write_indented_list( + f, "{indent}{var}.source_files = ".format(indent=indent, var=spec_var), + srcs) + # Writes dependencies of this rule. + for dep in sorted(rule.deps): + name = get_spec_name(dep.replace(":", "/")) + f.write("{indent}{var}.dependency '{dep}'\n".format( + indent=indent, var=spec_var, dep=name)) + # Writes custom specification. + custom_spec = CUSTOM_SPEC_MAP.get(rule.package + ":" + rule.name) + if custom_spec: + for spec in custom_spec: + f.write("{indent}{var}.{spec}\n".format( + indent=indent, var=spec_var, spec=spec)) + + +def write_indented_list(f, leading, values): + """Writes leading values in an indented style.""" + f.write(leading) + f.write((",\n" + " " * len(leading)).join("'{}'".format(v) for v in values)) + f.write("\n") + + +def generate(args): + """Generates a podspec file from all BUILD files under absl directory.""" + rules = filter(relevant_rule, collect_rules("absl")) + with open(args.output, "wt") as f: + write_podspec(f, rules, vars(args)) + + +def main(): + parser = argparse.ArgumentParser( + description="Generates abseil.podspec from BUILD.bazel") + parser.add_argument( + "-v", "--version", help="The version of podspec", required=True) + parser.add_argument( + "-t", + "--tag", + default=None, + help="The name of git tag (default: version)") + parser.add_argument( + "-o", + "--output", + default="abseil.podspec", + help="The name of output file (default: abseil.podspec)") + args = parser.parse_args() + if args.tag is None: + args.tag = args.version + generate(args) + + +if __name__ == "__main__": + main() |