Switch from destructor based time report to defer based time report t…

…o silent unsude variable warnings within Profiling probes

Sources/CodeGen/LLVM/LLVMProgram.swift

@@ -29,7 +29,9 @@ public struct LLVMProgram {
     self.target = try target ?? SwiftyLLVM.TargetMachine(for: .host())
     for m in ir.modules.keys {
       var context = CodeGenerationContext(forCompiling: m, of: ir)
-      let _convertProbe = profiler?.createTimeMeasurementProbe(MeasurementType.IRConversion)
+      let probe = profiler?.createAndStartProfilingProbe(MeasurementType.IRConversion)
+      defer { probe?.stop() }
+
       let transpilation = SwiftyLLVM.Module(transpiling: m, in: &context)
       do {
         try transpilation.verify()
@@ -43,7 +45,8 @@ public struct LLVMProgram {
 
   /// Applies the mandatory IR simplification passes on each module in `self`.
   public mutating func applyMandatoryPasses() {
-    let _optimizeProbe = profiler?.createTimeMeasurementProbe(MeasurementType.MandatoryPass)
+    let probe = profiler?.createAndStartProfilingProbe(MeasurementType.MandatoryPass)
+    defer { probe?.stop() }
     for k in llvmModules.keys {
       llvmModules[k]!.runDefaultModulePasses(optimization: .none, for: target)
     }
@@ -53,7 +56,8 @@ public struct LLVMProgram {
   ///
   /// Optimization applied are similar to clang's `-O3`.
   public mutating func optimize() {
-    let _mandatoryProbe = profiler?.createTimeMeasurementProbe(MeasurementType.Optimizations)
+    let probe = profiler?.createAndStartProfilingProbe(MeasurementType.Optimizations)
+    defer { probe?.stop() }
     for k in llvmModules.keys {
       llvmModules[k]!.runDefaultModulePasses(optimization: .aggressive, for: target)
     }
@@ -70,7 +74,8 @@ public struct LLVMProgram {
     var result: [URL] = []
     for m in llvmModules.values {
       let f = directory.appendingPathComponent(m.name).appendingPathExtension("o")
-      let _writeProbe = profiler?.createTimeMeasurementProbe(MeasurementType.EmitPhase)
+      let probe = profiler?.createAndStartProfilingProbe(MeasurementType.EmitPhase)
+      defer { probe?.stop() }
       try m.write(type, for: target, to: f.fileSystemPath)
       result.append(f)
     }

Sources/Driver/Driver.swift

@@ -397,7 +397,8 @@ public struct Driver: ParsableCommand {
     program: TypedProgram, reportingDiagnosticsTo log: inout DiagnosticSet,
     profileWith profiler: ProfilingMeasurements?
   ) throws -> IR.Program {
-    let _irProbe = profiler?.createTimeMeasurementProbe(MeasurementType.IRLowering)
+    let probe = profiler?.createAndStartProfilingProbe(MeasurementType.IRLowering)
+    defer { probe?.stop() }
     var loweredModules: [ModuleDecl.ID: IR.Module] = [:]
     for d in program.ast.modules {
       loweredModules[d] = try lower(d, in: program, reportingDiagnosticsTo: &log)
@@ -433,7 +434,8 @@ public struct Driver: ParsableCommand {
     let xcrun = try findExecutable(invokedAs: "xcrun").fileSystemPath
 
     // linking profiling probe
-    let _probe = profiler?.createTimeMeasurementProbe(MeasurementType.LinkPhase)
+    let probe = profiler?.createAndStartProfilingProbe(MeasurementType.LinkPhase)
+    defer { probe?.stop() }
 
     let sdk =
       try runCommandLine(xcrun, ["--sdk", "macosx", "--show-sdk-path"], diagnostics: &diagnostics)
@@ -467,7 +469,8 @@ public struct Driver: ParsableCommand {
     arguments.append(contentsOf: libraries.map({ "-l\($0)" }))
 
     // linking profiling probe
-    let _probe = profiler?.createTimeMeasurementProbe(MeasurementType.LinkPhase)
+    let probe = profiler?.createAndStartProfilingProbe(MeasurementType.LinkPhase)
+    defer { probe?.stop() }
 
     // Note: We use "clang" rather than "ld" so that to deal with the entry point of the program.
     // See https://stackoverflow.com/questions/51677440
@@ -484,7 +487,8 @@ public struct Driver: ParsableCommand {
     profileWith profiler: ProfilingMeasurements?
   ) throws {
     // linking profiling probe
-    let _probe = profiler?.createTimeMeasurementProbe(MeasurementType.LinkPhase)
+    let probe = profiler?.createAndStartProfilingProbe(MeasurementType.LinkPhase)
+    defer { probe?.stop() }
 
     try runCommandLine(
       findExecutable(invokedAs: "lld-link").fileSystemPath,

Sources/FrontEnd/Parse/Lexer.swift

@@ -27,7 +27,8 @@ public struct Lexer: IteratorProtocol, Sequence {
   /// Advances to the next token and returns it, or returns `nil` if no next token exists.
   public mutating func next() -> Token? {
     // Start measuring Lexer time
-    let _probe = profiler?.createTimeMeasurementProbe(MeasurementType.Lexer)
+    let probe = profiler?.createAndStartProfilingProbe(MeasurementType.Lexer)
+    defer { probe?.stop() }
 
     // Skip whitespaces and comments.
     while true {

Sources/FrontEnd/Parse/Parser.swift

@@ -41,7 +41,8 @@ public enum Parser {
     var members: [AnyDeclID] = []
 
     // start time measurement if needed
-    let _probe = profiler?.createTimeMeasurementProbe(MeasurementType.Parser)
+    let probe = profiler?.createAndStartProfilingProbe(MeasurementType.Parser)
+    defer { probe?.stop() }
 
     while let head = state.peek() {
       // Ignore semicolons.

Sources/FrontEnd/TypedProgram.swift

@@ -82,7 +82,8 @@ public struct TypedProgram {
         tasks.append(t)
       }
 
-      let _probe = profiler?.createTimeMeasurementProbe(MeasurementType.TypeChecker)
+      let probe = profiler?.createAndStartProfilingProbe(MeasurementType.TypeChecker)
+      defer { probe?.stop() }
       let queue = OperationQueue()
       queue.addOperations(tasks, waitUntilFinished: true)
       for t in tasks {
@@ -95,7 +96,8 @@ public struct TypedProgram {
         constructing: $0,
         tracingInferenceIf: typeCheckingIsParallel ? nil : shouldTraceInference,
         loggingRequirementSystemIf: typeCheckingIsParallel ? nil : shouldLogRequirements)
-      let _probe = profiler?.createTimeMeasurementProbe(MeasurementType.TypeChecker)
+      let probe = profiler?.createAndStartProfilingProbe(MeasurementType.TypeChecker)
+      defer { probe?.stop() }
       checker.checkAllDeclarations()
 
       log.formUnion(checker.diagnostics)
@@ -126,7 +128,8 @@ public struct TypedProgram {
       tracingInferenceIf: shouldTraceInference,
       loggingRequirementSystemIf: shouldLogRequirements)
 
-    let _probe = profiler?.createTimeMeasurementProbe(MeasurementType.TypeChecker)
+    let probe = profiler?.createAndStartProfilingProbe(MeasurementType.TypeChecker)
+    defer { probe?.stop() }
     checker.checkModule(m)
 
     log.formUnion(checker.diagnostics)

Sources/IR/Analysis/Module+Depolymorphize.swift

@@ -6,7 +6,8 @@ extension IR.Program {
 
   /// Generates the non-parametric reslient APIs of the modules in `self`.
   public mutating func depolymorphize(profileWith profiler: ProfilingMeasurements? = nil) {
-    let _probe = profiler?.createTimeMeasurementProbe(MeasurementType.Depolymorphize)
+    let probe = profiler?.createAndStartProfilingProbe(MeasurementType.Depolymorphize)
+    defer { probe?.stop() }
     for m in modules.keys {
       depolymorphize(m)
     }

Sources/Utils/Profiling.swift

@@ -16,6 +16,8 @@ public enum MeasurementType: Int, CaseIterable {
   }
 }
 
+/// Time measurement probe. Will report time between init() and stop()
+/// to the associate ProfilingMeasurements object
 public struct TimeMeasurementProbe: ~Copyable {
 
   var beginning: ContinuousClock.Instant
@@ -28,29 +30,33 @@ public struct TimeMeasurementProbe: ~Copyable {
     self.measure_type = measure_type
   }
 
-  deinit {
+  public func stop() {
     let time: Duration = ContinuousClock.Instant.now - beginning
     pool.addProfiledDuration(self.measure_type, time)
   }
 
 }
 
-/// A container for profiling measurement
+/// A container for profiling measurements
 public class ProfilingMeasurements {
 
   public init() {}
 
   var cumulatedDurations: [Duration] = [Duration](
     repeating: Duration.seconds(0), count: MeasurementType.count)
 
-  public func createTimeMeasurementProbe(_ measure_type: MeasurementType) -> TimeMeasurementProbe {
+  /// Create a new TimeMeasurementProbe for a given measure type
+  public func createAndStartProfilingProbe(_ measure_type: MeasurementType) -> TimeMeasurementProbe
+  {
     return TimeMeasurementProbe(measure_type, self)
   }
 
-  public func addProfiledDuration(_ measure_type: MeasurementType, _ duration: Duration) {
+  /// Internal. Reserved for TimeMeasurementProbe
+  internal func addProfiledDuration(_ measure_type: MeasurementType, _ duration: Duration) {
     self.cumulatedDurations[measure_type.rawValue] += duration
   }
 
+  /// Print the current profiling report
   public func printProfilingReport() {
     let profilingReport = """
       **Compile time profiling summary**
@@ -71,7 +77,7 @@ public class ProfilingMeasurements {
     print(profilingReport)
   }
 
-  public func measurement(_ measure_type: MeasurementType) -> Duration {
+  public func durationFor(_ measure_type: MeasurementType) -> Duration {
     switch measure_type {
     case .Parser:
       return cumulatedDurations[MeasurementType.Parser.rawValue]
@@ -82,13 +88,13 @@ public class ProfilingMeasurements {
   }
 
   public func formattedMeasurement(_ measure_type: MeasurementType) -> String {
-    let measure = measurement(measure_type)
-    let measurementDouble =
+    let measure = durationFor(measure_type)
+    let measureDouble =
       Double(measure.components.seconds) + Double(measure.components.attoseconds) / 1e18
     let unitArrays = ["s", "ms", "us", "ns", "ps"]
     var factor = 1
     for i in 0...unitArrays.count {
-      let scaledMeasurement = measurementDouble * Double(factor)
+      let scaledMeasurement = measureDouble * Double(factor)
       if scaledMeasurement > 1.0 {
         return "\(String(format: "%.03f", scaledMeasurement)) \(unitArrays[i])"
       }