Give the FrontendTool library its own header and allow users

to observe progress through the frontend.

include/swift/FrontendTool/FrontendTool.h

@@ -0,0 +1,84 @@
+//===--- FrontendTool.h - Frontend control ----------------------*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See http://swift.org/LICENSE.txt for license information
+// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+//
+// This file provides a high-level API for interacting with the basic
+// frontend tool operation.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SWIFT_FRONTENDTOOL_H
+#define SWIFT_FRONTENDTOOL_H
+
+#include "swift/Basic/LLVM.h"
+
+namespace llvm {
+class Module;
+}
+
+namespace swift {
+class CompilerInvocation;
+class CompilerInstance;
+class SILModule;
+
+/// A simple observer of frontend activity.
+///
+/// Don't let this interface block enhancements to the frontend pipeline.
+class FrontendObserver {
+public:
+  FrontendObserver() = default;
+  virtual ~FrontendObserver() = default;
+
+  /// The frontend has parsed the command line.
+  virtual void parsedArgs(CompilerInvocation &invocation);
+
+  /// The frontend has configured the compiler instance.
+  virtual void configuredCompiler(CompilerInstance &instance);
+
+  /// The frontend has performed semantic analysis.
+  virtual void performedSemanticAnalysis(CompilerInstance &instance);
+
+  /// The frontend has performed basic SIL generation.
+  /// SIL diagnostic passes have not yet been applied.
+  virtual void performedSILGeneration(SILModule &module);
+
+  /// The frontend has executed the SIL diagnostic passes.
+  virtual void performedSILDiagnostics(SILModule &module);
+
+  /// The frontend has executed the SIL optimization pipeline.
+  virtual void performedSILOptimization(SILModule &module);
+
+  /// The frontend is about to run the program as an immediate script.
+  virtual void aboutToRunImmediately(CompilerInstance &instance);
+
+  // TODO: maybe enhance this interface to hear about IRGen and LLVM
+  // progress.
+};
+
+/// Perform all the operations of the frontend, exactly as if invoked
+/// with -frontend.
+///
+/// \param args the arguments to use as the arguments to the frontend
+/// \param argv0 the name used as the frontend executable
+/// \param mainAddr an address from the main executable
+///
+/// \return the exit value of the frontend: 0 or 1 on success unless
+///   the frontend executes in immediate mode, in which case this will be
+///   the exit value of the script, assuming it exits normally
+int performFrontend(ArrayRef<const char *> args,
+                    const char *argv0,
+                    void *mainAddr,
+                    FrontendObserver *observer = nullptr);
+
+
+} // namespace swift
+
+#endif

include/swift/Subsystems.h

@@ -88,20 +88,6 @@ namespace swift {
 
   /// @}
 
-  /// Perform all the operations of the frontend, exactly as if invoked
-  /// with -frontend.
-  ///
-  /// \param args the arguments to use as the arguments to the frontend
-  /// \param argv0 the name used as the frontend executable
-  /// \param mainAddr an address from the main executable
-  ///
-  /// \return the exit value of the frontend: 0 or 1 on success unless
-  ///   the frontend executes in immediate mode, in which case this will be
-  ///   the exit value of the script, assuming it exits normally
-  int performFrontend(ArrayRef<const char *> args,
-                      const char *argv0,
-                      void *mainAddr);
-
   /// \brief Parse a single buffer into the given source file.
   ///
   /// If the source file is the main file, stop parsing after the next

lib/FrontendTool/FrontendTool.cpp

@@ -20,6 +20,8 @@
 ///
 //===----------------------------------------------------------------------===//
 
+#include "swift/FrontendTool/FrontendTool.h"
+
 #include "swift/Subsystems.h"
 #include "swift/AST/DiagnosticsFrontend.h"
 #include "swift/AST/DiagnosticsSema.h"
@@ -614,7 +616,8 @@ static void debugFailWithCrash() {
 static bool performCompile(CompilerInstance &Instance,
                            CompilerInvocation &Invocation,
                            ArrayRef<const char *> Args,
-                           int &ReturnValue) {
+                           int &ReturnValue,
+                           FrontendObserver *observer) {
   FrontendOptions opts = Invocation.getFrontendOptions();
   FrontendOptions::ActionType Action = opts.RequestedAction;
 
@@ -669,6 +672,10 @@ static bool performCompile(CompilerInstance &Instance,
   else
     Instance.performSema();
 
+  if (observer) {
+    observer->performedSemanticAnalysis(Instance);
+  }
+
   FrontendOptions::DebugCrashMode CrashMode = opts.CrashMode;
   if (CrashMode == FrontendOptions::DebugCrashMode::AssertAfterParse)
     debugFailWithAssertion();
@@ -759,6 +766,10 @@ static bool performCompile(CompilerInstance &Instance,
     }
   }
 
+  if (observer) {
+    observer->performedSILGeneration(*SM);
+  }
+
   // We've been told to emit SIL after SILGen, so write it now.
   if (Action == FrontendOptions::EmitSILGen) {
     // If we are asked to link all, link all.
@@ -787,10 +798,15 @@ static bool performCompile(CompilerInstance &Instance,
   }
 
   // Perform "stable" optimizations that are invariant across compiler versions.
-  if (!Invocation.getDiagnosticOptions().SkipDiagnosticPasses &&
-      runSILDiagnosticPasses(*SM))
+  if (!Invocation.getDiagnosticOptions().SkipDiagnosticPasses) {
+    if (runSILDiagnosticPasses(*SM))
       return true;
 
+    if (observer) {
+      observer->performedSILDiagnostics(*SM);
+    }
+  }
+
   // Now if we are asked to link all, link all.
   if (Invocation.getSILOptions().LinkMode == SILOptions::LinkAll)
     performSILLinking(SM.get(), true);
@@ -818,6 +834,10 @@ static bool performCompile(CompilerInstance &Instance,
     }
   }
 
+  if (observer) {
+    observer->performedSILOptimization(*SM);
+  }
+
   {
     SharedTimer timer("SIL verification (post-optimization)");
     SM->verify();
@@ -915,6 +935,11 @@ static bool performCompile(CompilerInstance &Instance,
     const ProcessCmdLine &CmdLine = ProcessCmdLine(opts.ImmediateArgv.begin(),
                                                    opts.ImmediateArgv.end());
     Instance.setSILModule(std::move(SM));
+
+    if (observer) {
+      observer->aboutToRunImmediately(Instance);
+    }
+
     ReturnValue =
       RunImmediately(Instance, CmdLine, IRGenOpts, Invocation.getSILOptions());
     return false;
@@ -997,7 +1022,8 @@ static bool dumpAPI(Module *Mod, StringRef OutDir) {
 }
 
 int swift::performFrontend(ArrayRef<const char *> Args,
-                           const char *Argv0, void *MainAddr) {
+                           const char *Argv0, void *MainAddr,
+                           FrontendObserver *observer) {
   llvm::InitializeAllTargets();
   llvm::InitializeAllTargetMCs();
   llvm::InitializeAllAsmPrinters();
@@ -1031,6 +1057,11 @@ int swift::performFrontend(ArrayRef<const char *> Args,
   if (Invocation.getLangOptions().Target.isWindowsCygwinEnvironment())
     IRGenOpts.DWARFVersion = swift::CygwinDWARFVersion;
 
+  // The compiler invocation is now fully configured; notify our observer.
+  if (observer) {
+    observer->parsedArgs(Invocation);
+  }
+
   if (Invocation.getFrontendOptions().PrintHelp ||
       Invocation.getFrontendOptions().PrintHelpHidden) {
     unsigned IncludedFlagsBitmask = options::FrontendOption;
@@ -1125,8 +1156,14 @@ int swift::performFrontend(ArrayRef<const char *> Args,
     return 1;
   }
 
+  // The compiler instance has been configured; notify our observer.
+  if (observer) {
+    observer->configuredCompiler(Instance);
+  }
+
   int ReturnValue = 0;
-  bool HadError = performCompile(Instance, Invocation, Args, ReturnValue) ||
+  bool HadError =
+    performCompile(Instance, Invocation, Args, ReturnValue, observer) ||
     Instance.getASTContext().hadError();
 
   if (!HadError && !Invocation.getFrontendOptions().DumpAPIPath.empty()) {
@@ -1148,3 +1185,11 @@ int swift::performFrontend(ArrayRef<const char *> Args,
 
   return (HadError ? 1 : ReturnValue);
 }
+
+void FrontendObserver::parsedArgs(CompilerInvocation &invocation) {}
+void FrontendObserver::configuredCompiler(CompilerInstance &instance) {}
+void FrontendObserver::performedSemanticAnalysis(CompilerInstance &instance) {}
+void FrontendObserver::performedSILGeneration(SILModule &module) {}
+void FrontendObserver::performedSILDiagnostics(SILModule &module) {}
+void FrontendObserver::performedSILOptimization(SILModule &module) {}
+void FrontendObserver::aboutToRunImmediately(CompilerInstance &instance) {}

tools/driver/driver.cpp

@@ -24,7 +24,7 @@
 #include "swift/Driver/Job.h"
 #include "swift/Frontend/Frontend.h"
 #include "swift/Frontend/PrintingDiagnosticConsumer.h"
-#include "swift/Subsystems.h"
+#include "swift/FrontendTool/FrontendTool.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Errno.h"