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// Copyright 2016 The Tulsi 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.
import Foundation
// Provides methods utilizing Bazel query (http://bazel.build/docs/query.html) to extract
// information from a workspace.
final class BazelQueryInfoExtractor: QueuedLogging {
enum ExtractorError: Error {
/// A valid Bazel binary could not be located.
case invalidBazelPath
}
/// The location of the bazel binary.
var bazelURL: URL
/// The location of the directory in which the workspace enclosing this BUILD file can be found.
let workspaceRootURL: URL
/// Universal flags for all Bazel invocations.
private let bazelUniversalFlags: BazelFlags
private let localizedMessageLogger: LocalizedMessageLogger
private var queuedInfoMessages = [String]()
private typealias CompletionHandler = (Process, Data, String?, String) -> Void
init(bazelURL: URL,
workspaceRootURL: URL,
bazelUniversalFlags: BazelFlags,
localizedMessageLogger: LocalizedMessageLogger) {
self.bazelURL = bazelURL
self.workspaceRootURL = workspaceRootURL
self.bazelUniversalFlags = bazelUniversalFlags
self.localizedMessageLogger = localizedMessageLogger
}
func extractTargetRulesFromPackages(_ packages: [String]) -> [RuleInfo] {
guard !packages.isEmpty else {
return []
}
let profilingStart = localizedMessageLogger.startProfiling("fetch_rules",
message: "Fetching rules for packages \(packages)")
var infos = [RuleInfo]()
let query = packages.map({ "kind(rule, \($0):all)"}).joined(separator: "+")
do {
let (process, data, stderr, debugInfo) =
try self.bazelSynchronousQueryProcess(query,
outputKind: "xml",
loggingIdentifier: "bazel_query_fetch_rules")
if process.terminationStatus != 0 {
showExtractionError(debugInfo, stderr: stderr, displayLastLineIfNoErrorLines: true)
} else if let entries = self.extractRuleInfosFromBazelXMLOutput(data) {
infos = entries
}
} catch {
// The error has already been displayed to the user.
return []
}
localizedMessageLogger.logProfilingEnd(profilingStart)
return infos
}
/// Extracts all of the transitive BUILD and skylark (.bzl) files used by the given targets.
func extractBuildfiles<T: Collection>(_ targets: T) -> Set<BuildLabel> where T.Iterator.Element == BuildLabel {
if targets.isEmpty { return Set() }
let profilingStart = localizedMessageLogger.startProfiling("extracting_skylark_files",
message: "Finding Skylark files for \(targets.count) rules")
let labelDeps = targets.map {"deps(\($0.value))"}
let joinedLabelDeps = labelDeps.joined(separator: "+")
let query = "buildfiles(\(joinedLabelDeps))"
let buildFiles: Set<BuildLabel>
do {
// Errors in the BUILD structure being examined should not prevent partial extraction, so this
// command is considered successful if it returns any valid data at all.
let (_, data, _, debugInfo) = try self.bazelSynchronousQueryProcess(query,
outputKind: "xml",
additionalArguments: ["--keep_going"],
loggingIdentifier: "bazel_query_extracting_skylark_files")
self.queuedInfoMessages.append(debugInfo)
if let labels = extractSourceFileLabelsFromBazelXMLOutput(data) {
buildFiles = Set(labels)
} else {
localizedMessageLogger.warning("BazelBuildfilesQueryFailed",
comment: "Bazel 'buildfiles' query failed to extract information.")
buildFiles = Set()
}
localizedMessageLogger.logProfilingEnd(profilingStart)
} catch {
// Error will be displayed at the end of project generation.
return Set()
}
return buildFiles
}
// MARK: - Private methods
private func showExtractionError(_ debugInfo: String,
stderr: String?,
displayLastLineIfNoErrorLines: Bool = false) {
localizedMessageLogger.infoMessage(debugInfo)
let details: String?
if let stderr = stderr {
if displayLastLineIfNoErrorLines {
details = BazelErrorExtractor.firstErrorLinesOrLastLinesFromString(stderr)
} else {
details = BazelErrorExtractor.firstErrorLinesFromString(stderr)
}
} else {
details = nil
}
localizedMessageLogger.error("BazelInfoExtractionFailed",
comment: "Error message for when a Bazel extractor did not complete successfully. Details are logged separately.",
details: details)
}
// Generates a Process that will perform a bazel query, capturing the output data and passing it
// to the terminationHandler.
private func bazelQueryProcess(_ query: String,
outputKind: String? = nil,
additionalArguments: [String] = [],
message: String = "",
loggingIdentifier: String? = nil,
terminationHandler: @escaping CompletionHandler) throws -> Process {
guard FileManager.default.fileExists(atPath: bazelURL.path) else {
localizedMessageLogger.error("BazelBinaryNotFound",
comment: "Error to show when the bazel binary cannot be found at the previously saved location %1$@.",
values: bazelURL as NSURL)
throw ExtractorError.invalidBazelPath
}
var arguments = [
"--max_idle_secs=60",
]
arguments.append(contentsOf: bazelUniversalFlags.startup)
arguments.append("query")
arguments.append(contentsOf: bazelUniversalFlags.build)
arguments.append(contentsOf: [
"--announce_rc", // Print the RC files used by this operation.
"--noimplicit_deps",
"--order_output=no",
"--noshow_loading_progress",
"--noshow_progress",
query
])
arguments.append(contentsOf: additionalArguments)
if let kind = outputKind {
arguments.append(contentsOf: ["--output", kind])
}
var message = message
if message != "" {
message = "\(message)\n"
}
let process = TulsiProcessRunner.createProcess(bazelURL.path,
arguments: arguments,
messageLogger: localizedMessageLogger,
loggingIdentifier: loggingIdentifier) {
completionInfo in
let debugInfoFormatString = NSLocalizedString("DebugInfoForBazelCommand",
bundle: Bundle(for: type(of: self)),
comment: "Provides general information about a Bazel failure; a more detailed error may be reported elsewhere. The Bazel command is %1$@, exit code is %2$d, stderr %3$@.")
let stderr = NSString(data: completionInfo.stderr, encoding: String.Encoding.utf8.rawValue)
let debugInfo = String(format: debugInfoFormatString,
completionInfo.commandlineString,
completionInfo.terminationStatus,
stderr ?? "<No STDERR>")
terminationHandler(completionInfo.process,
completionInfo.stdout,
stderr as String?,
debugInfo)
}
return process
}
/// Performs the given Bazel query synchronously in the workspaceRootURL directory.
private func bazelSynchronousQueryProcess(_ query: String,
outputKind: String? = nil,
additionalArguments: [String] = [],
message: String = "",
loggingIdentifier: String? = nil) throws -> (bazelProcess: Process,
returnedData: Data,
stderrString: String?,
debugInfo: String) {
let semaphore = DispatchSemaphore(value: 0)
var data: Data! = nil
var stderr: String? = nil
var info: String! = nil
let process = try bazelQueryProcess(query,
outputKind: outputKind,
additionalArguments: additionalArguments,
message: message,
loggingIdentifier: loggingIdentifier) {
(_: Process, returnedData: Data, stderrString: String?, debugInfo: String) in
data = returnedData
stderr = stderrString
info = debugInfo
semaphore.signal()
}
process.currentDirectoryPath = workspaceRootURL.path
process.launch()
_ = semaphore.wait(timeout: DispatchTime.distantFuture)
return (process, data, stderr, info)
}
private func extractRuleInfosWithRuleInputsFromBazelXMLOutput(_ bazelOutput: Data) -> [RuleInfo: Set<BuildLabel>]? {
do {
var infos = [RuleInfo: Set<BuildLabel>]()
let doc = try XMLDocument(data: bazelOutput, options: XMLNode.Options(rawValue: 0))
let rules = try doc.nodes(forXPath: "/query/rule")
for ruleNode in rules {
guard let ruleElement = ruleNode as? XMLElement else {
localizedMessageLogger.error("BazelResponseXMLNonElementType",
comment: "General error to show when the XML parser returns something other " +
"than an NSXMLElement. This should never happen in practice.")
continue
}
guard let ruleLabel = ruleElement.attribute(forName: "name")?.stringValue else {
localizedMessageLogger.error("BazelResponseMissingRequiredAttribute",
comment: "Bazel response XML element %1$@ was found but was missing an attribute named %2$@.",
values: ruleElement, "name")
continue
}
guard let ruleType = ruleElement.attribute(forName: "class")?.stringValue else {
localizedMessageLogger.error("BazelResponseMissingRequiredAttribute",
comment: "Bazel response XML element %1$@ was found but was missing an attribute named %2$@.",
values: ruleElement, "class")
continue
}
func extractLabelsFromXpath(_ xpath: String) throws -> Set<BuildLabel> {
var labelSet = Set<BuildLabel>()
let nodes = try ruleElement.nodes(forXPath: xpath)
for node in nodes {
guard let label = node.stringValue else {
localizedMessageLogger.error("BazelResponseLabelAttributeInvalid",
comment: "Bazel response XML element %1$@ should have a valid string value but does not.",
values: node)
continue
}
labelSet.insert(BuildLabel(label))
}
return labelSet
}
// Retrieve the list of linked targets through the test_host attribute. This provides a
// link between the test target and the test host so they can be linked in Xcode.
var linkedTargetLabels = Set<BuildLabel>()
linkedTargetLabels.formUnion(
try extractLabelsFromXpath("./label[@name='test_host']/@value"))
let entry = RuleInfo(label: BuildLabel(ruleLabel),
type: ruleType,
linkedTargetLabels: linkedTargetLabels)
infos[entry] = try extractLabelsFromXpath("./rule-input/@name")
}
return infos
} catch let e as NSError {
localizedMessageLogger.error("BazelResponseXMLParsingFailed",
comment: "Extractor Bazel output failed to be parsed as XML with error %1$@. This may be a Bazel bug or a bad BUILD file.",
values: e.localizedDescription)
return nil
}
}
private func extractRuleInfosFromBazelXMLOutput(_ bazelOutput: Data) -> [RuleInfo]? {
if let infoMap = extractRuleInfosWithRuleInputsFromBazelXMLOutput(bazelOutput) {
return [RuleInfo](infoMap.keys)
}
return nil
}
private func extractSourceFileLabelsFromBazelXMLOutput(_ bazelOutput: Data) -> Set<BuildLabel>? {
do {
let doc = try XMLDocument(data: bazelOutput, options: XMLNode.Options(rawValue: 0))
let fileLabels = try doc.nodes(forXPath: "/query/source-file/@name")
var extractedLabels = Set<BuildLabel>()
for labelNode in fileLabels {
guard let value = labelNode.stringValue else {
localizedMessageLogger.error("BazelResponseLabelAttributeInvalid",
comment: "Bazel response XML element %1$@ should have a valid string value but does not.",
values: labelNode)
continue
}
extractedLabels.insert(BuildLabel(value))
}
return extractedLabels
} catch let e as NSError {
localizedMessageLogger.error("BazelResponseXMLParsingFailed",
comment: "Extractor Bazel output failed to be parsed as XML with error %1$@. This may be a Bazel bug or a bad BUILD file.",
values: e.localizedDescription)
return nil
}
}
// MARK: - QueuedLogging
func logQueuedInfoMessages() {
guard !self.queuedInfoMessages.isEmpty else {
return
}
localizedMessageLogger.debugMessage("Log of Bazel query output follows:")
for message in self.queuedInfoMessages {
localizedMessageLogger.debugMessage(message)
}
self.queuedInfoMessages.removeAll()
}
var hasQueuedInfoMessages: Bool {
return !self.queuedInfoMessages.isEmpty
}
}