Add swift crash producer support

When swift compiler crashed with swift caching enabled, create a crash
reproducer automatically.

Author: cachemeifyoucan

Sources/SwiftDriver/Driver/Driver.swift

@@ -23,6 +23,7 @@ import struct TSCBasic.AbsolutePath
 import struct TSCBasic.ByteString
 import struct TSCBasic.Diagnostic
 import struct TSCBasic.FileInfo
+import struct TSCBasic.ProcessResult
 import struct TSCBasic.RelativePath
 import var TSCBasic.localFileSystem
 import var TSCBasic.stderrStream
@@ -68,6 +69,7 @@ public struct Driver {
     case conditionalCompilationFlagIsNotValidIdentifier(String)
     case baselineGenerationRequiresTopLevelModule(String)
     case optionRequiresAnother(String, String)
+    case unableToCreateReproducer
     // Explicit Module Build Failures
     case malformedModuleDependency(String, String)
     case missingModuleDependency(String)
@@ -137,6 +139,8 @@ public struct Driver {
         return "generating a baseline with '\(arg)' is only supported with '-emit-module' or '-emit-module-path'"
       case .optionRequiresAnother(let first, let second):
         return "'\(first)' cannot be specified if '\(second)' is not present"
+      case .unableToCreateReproducer:
+        return "failed to create reproducer"
       }
     }
   }
@@ -1978,7 +1982,8 @@ extension Driver {
       buildRecordInfo: buildRecordInfo,
       showJobLifecycle: showJobLifecycle,
       argsResolver: executor.resolver,
-      diagnosticEngine: diagnosticEngine)
+      diagnosticEngine: diagnosticEngine,
+      reproducerCallback: self.generateReproducer)
   }
 
   private mutating func performTheBuild(
@@ -4044,3 +4049,34 @@ extension Driver {
     return mapping
   }
 }
+
+// Generate reproducer.
+extension Driver {
+  func generateReproducer(_ job: Job, _ status: ProcessResult.ExitStatus) throws {
+    // If process is not terminated with certain error code, no need to create reproducer.
+#if os(Windows)
+    guard case .abnormal = status else {
+      return;
+    }
+#else
+    guard case .signalled = status else {
+      return;
+    }
+#endif
+    // TODO: check flag is supported.
+    try withTemporaryDirectory(dir: fileSystem.tempDirectory, prefix: "swift-reproducer", removeTreeOnDeinit: false) { tempDir in
+      var reproJob = job
+      reproJob.kind = .reproducer
+      reproJob.commandLine.appendFlag("-gen-reproducer")
+      reproJob.commandLine.appendFlag("-gen-reproducer-dir")
+      reproJob.commandLine.appendPath(tempDir)
+      reproJob.outputs.removeAll()
+      reproJob.outputCacheKeys.removeAll()
+      let result = try executor.execute(job: reproJob, forceResponseFiles: false, recordedInputModificationDates: [:])
+      guard case .terminated(let code) = result.exitStatus, code == 0 else {
+        throw Error.unableToCreateReproducer
+      }
+      diagnosticEngine.emit(.note_reproducer_created(tempDir.pathString))
+    }
+  }
+}

Sources/SwiftDriver/Driver/ToolExecutionDelegate.swift

@@ -30,6 +30,7 @@ import struct TSCBasic.Diagnostic
 import struct TSCBasic.ProcessResult
 import var TSCBasic.stderrStream
 import var TSCBasic.stdoutStream
+import class TSCBasic.Process
 
 /// Delegate for printing execution information on the command-line.
 @_spi(Testing) public final class ToolExecutionDelegate: JobExecutionDelegate {
@@ -49,6 +50,8 @@ import var TSCBasic.stdoutStream
     case silent
   }
 
+  public typealias ReproducerCallback = (Job, ProcessResult.ExitStatus) throws -> Void
+
   public let mode: Mode
   public let buildRecordInfo: BuildRecordInfo?
   public let showJobLifecycle: Bool
@@ -58,18 +61,21 @@ import var TSCBasic.stdoutStream
   private var nextBatchQuasiPID: Int
   private let argsResolver: ArgsResolver
   private var batchJobInputQuasiPIDMap = TwoLevelMap<Job, TypedVirtualPath, Int>()
+  private let reproducerCallback: ReproducerCallback?
 
   @_spi(Testing) public init(mode: ToolExecutionDelegate.Mode,
                              buildRecordInfo: BuildRecordInfo?,
                              showJobLifecycle: Bool,
                              argsResolver: ArgsResolver,
-                             diagnosticEngine: DiagnosticsEngine) {
+                             diagnosticEngine: DiagnosticsEngine,
+                             reproducerCallback: ReproducerCallback? = nil) {
     self.mode = mode
     self.buildRecordInfo = buildRecordInfo
     self.showJobLifecycle = showJobLifecycle
     self.diagnosticEngine = diagnosticEngine
     self.argsResolver = argsResolver
     self.nextBatchQuasiPID = ToolExecutionDelegate.QUASI_PID_START
+    self.reproducerCallback = reproducerCallback
   }
 
   public func jobStarted(job: Job, arguments: [String], pid: Int) {
@@ -107,6 +113,14 @@ import var TSCBasic.stdoutStream
     }
 #endif
 
+    if let reproducerCallback = reproducerCallback {
+      do {
+        try reproducerCallback(job, result.exitStatus)
+      } catch {
+        diagnosticEngine.emit(.error_failed_to_create_reproducer)
+      }
+    }
+
     switch mode {
     case .silent:
       break

Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift

@@ -104,7 +104,7 @@ extension Driver {
            .help, .link, .verifyDebugInfo, .scanDependencies,
            .emitSupportedFeatures, .moduleWrap,
            .generateAPIBaseline, .generateABIBaseline, .compareAPIBaseline,
-           .compareABIBaseline, .printSupportedFeatures:
+           .compareABIBaseline, .printSupportedFeatures, .reproducer:
         jobNeedPathRemap = false
       }
     } else {

Sources/SwiftDriver/Jobs/Job.swift

@@ -25,6 +25,7 @@ public struct Job: Codable, Equatable, Hashable {
     case emitModule = "emit-module"
     case generatePCH = "generate-pch"
     case moduleWrap = "module-wrap"
+    case reproducer = "gen-reproducer"
 
     /// Generate a compiled Clang module.
     case generatePCM = "generate-pcm"
@@ -255,6 +256,9 @@ extension Job : CustomStringConvertible {
 
     case .printSupportedFeatures:
       return "Print supported upcoming and experimental features"
+
+    case .reproducer:
+      return "Generate reproducer for the crash"
     }
   }
 
@@ -273,7 +277,7 @@ extension Job.Kind {
   public var isSwiftFrontend: Bool {
     switch self {
     case .backend, .compile, .mergeModule, .emitModule, .compileModuleFromInterface, .generatePCH,
-        .generatePCM, .dumpPCM, .interpret, .repl, .printTargetInfo,
+        .generatePCM, .dumpPCM, .interpret, .repl, .printTargetInfo, .reproducer,
         .versionRequest, .emitSupportedFeatures, .scanDependencies, .verifyModuleInterface, .printSupportedFeatures:
         return true
 
@@ -294,7 +298,7 @@ extension Job.Kind {
          .help, .link, .verifyDebugInfo, .scanDependencies,
          .emitSupportedFeatures, .moduleWrap, .verifyModuleInterface,
          .generateAPIBaseline, .generateABIBaseline, .compareAPIBaseline,
-         .compareABIBaseline, .printSupportedFeatures:
+         .compareABIBaseline, .printSupportedFeatures, .reproducer:
       return false
     }
   }
@@ -309,7 +313,7 @@ extension Job.Kind {
          .versionRequest, .autolinkExtract, .generateDSYM, .help, .link,
          .verifyDebugInfo, .scanDependencies, .emitSupportedFeatures, .moduleWrap,
          .generateAPIBaseline, .generateABIBaseline, .compareAPIBaseline,
-         .compareABIBaseline, .printSupportedFeatures:
+         .compareABIBaseline, .printSupportedFeatures, .reproducer:
       return false
     }
   }

Sources/SwiftDriver/Utilities/Diagnostics.swift

@@ -182,4 +182,12 @@ extension Diagnostic.Message {
   static var error_no_objc_interop_embedded: Diagnostic.Message {
     .error("Objective-C interop cannot be enabled with embedded Swift.")
   }
+
+  static var error_failed_to_create_reproducer: Diagnostic.Message {
+    .error("failed to create crash reproducer")
+  }
+
+  static func note_reproducer_created(_ path: String) -> Diagnostic.Message {
+    .note("crash reproducer is created at: \(path)")
+  }
 }