[Evaluator] Refactor evaluator's GraphViz output to the destructor of the evaluator. NFC

This allows us to output dependency-graph while using the compiler in
other tools, like swift-ide-test, sourcekitd-test, etc.

Author: nkcsgexi

include/swift/AST/Evaluator.h

@@ -238,6 +238,9 @@ class Evaluator {
   /// diagnostics through the given diagnostics engine.
   Evaluator(DiagnosticEngine &diags, CycleDiagnosticKind shouldDiagnoseCycles);
 
+  /// Emit GraphViz output visualizing the request graph.
+  void emitRequestEvaluatorGraphViz(llvm::StringRef graphVizPath);
+
   /// Set the unified stats reporter through which evaluated-request
   /// statistics will be recorded.
   void setStatsReporter(UnifiedStatsReporter *stats) { this->stats = stats; }

include/swift/Basic/LangOptions.h

@@ -176,6 +176,10 @@ namespace swift {
     CycleDiagnosticKind EvaluatorCycleDiagnostics =
         CycleDiagnosticKind::NoDiagnose;
 
+    /// \brief The path to which we should emit GraphViz output for the complete
+    /// request-evaluator graph.
+    std::string RequestEvaluatorGraphVizPath;
+
     /// \brief The upper bound, in bytes, of temporary data that can be
     /// allocated by the constraint solver.
     unsigned SolverMemoryThreshold = 512 * 1024 * 1024;

include/swift/Frontend/FrontendOptions.h

@@ -72,10 +72,6 @@ class FrontendOptions {
   /// The path to which we should store indexing data, if any.
   std::string IndexStorePath;
 
-  /// The path to which we should emit GraphViz output for the complete
-  /// request-evaluator graph.
-  std::string RequestEvaluatorGraphVizPath;
-
   /// Emit index data for imported serialized swift system modules.
   bool IndexSystemModules = false;
 

lib/AST/ASTContext.cpp

@@ -518,6 +518,11 @@ ASTContext::ASTContext(LangOptions &langOpts, SearchPathOptions &SearchPathOpts,
 }
 
 ASTContext::~ASTContext() {
+  // Emit evaluator dependency graph if requested.
+  auto graphPath = LangOpts.RequestEvaluatorGraphVizPath;
+  if (!graphPath.empty()) {
+    evaluator.emitRequestEvaluatorGraphViz(graphPath);
+  }
   getImpl().~Implementation();
 }
 

lib/AST/Evaluator.cpp

@@ -18,6 +18,7 @@
 #include "swift/Basic/Range.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/Debug.h"
+#include "llvm/Support/FileSystem.h"
 
 using namespace swift;
 
@@ -62,6 +63,12 @@ Evaluator::Evaluator(DiagnosticEngine &diags,
                      CycleDiagnosticKind shouldDiagnoseCycles)
   : diags(diags), shouldDiagnoseCycles(shouldDiagnoseCycles) { }
 
+void Evaluator::emitRequestEvaluatorGraphViz(llvm::StringRef graphVizPath) {
+  std::error_code error;
+  llvm::raw_fd_ostream out(graphVizPath, error, llvm::sys::fs::F_Text);
+  printDependenciesGraphviz(out);
+}
+
 bool Evaluator::checkDependency(const AnyRequest &request) {
   // If there is an active request, record it's dependency on this request.
   if (!activeRequests.empty())

lib/Frontend/ArgsToFrontendOptionsConverter.cpp

@@ -60,9 +60,6 @@ bool ArgsToFrontendOptionsConverter::convert(
   if (const Arg *A = Args.getLastArg(OPT_index_store_path)) {
     Opts.IndexStorePath = A->getValue();
   }
-  if (const Arg *A = Args.getLastArg(OPT_output_request_graphviz)) {
-    Opts.RequestEvaluatorGraphVizPath = A->getValue();
-  }
 
   Opts.IndexSystemModules |= Args.hasArg(OPT_index_system_modules);
 

lib/Frontend/CompilerInvocation.cpp

@@ -259,6 +259,10 @@ static bool ParseLangArgs(LangOptions &Opts, ArgList &Args,
     Opts.EvaluatorCycleDiagnostics = CycleDiagnosticKind::DebugDiagnose;
   }
 
+  if (const Arg *A = Args.getLastArg(OPT_output_request_graphviz)) {
+    Opts.RequestEvaluatorGraphVizPath = A->getValue();
+  }
+
   if (const Arg *A = Args.getLastArg(OPT_solver_memory_threshold)) {
     unsigned threshold;
     if (StringRef(A->getValue()).getAsInteger(10, threshold)) {

lib/FrontendTool/FrontendTool.cpp

@@ -868,13 +868,6 @@ emitIndexData(CompilerInvocation &Invocation, CompilerInstance &Instance) {
   return hadEmitIndexDataError;
 }
 
-/// Emits the request-evaluator graph to the given file in GraphViz format.
-void emitRequestEvaluatorGraphViz(ASTContext &ctx, StringRef graphVizPath) {
-  std::error_code error;
-  llvm::raw_fd_ostream out(graphVizPath, error, llvm::sys::fs::F_Text);
-  ctx.evaluator.printDependenciesGraphviz(out);
-}
-
 static bool performCompileStepsPostSILGen(
     CompilerInstance &Instance, CompilerInvocation &Invocation,
     std::unique_ptr<SILModule> SM, bool astGuaranteedToCorrespondToSIL,
@@ -917,17 +910,6 @@ static bool performCompile(CompilerInstance &Instance,
     Instance.performSema();
   }
 
-  SWIFT_DEFER {
-    // Emit request-evaluator graph via GraphViz, if requested.
-    if (!Invocation.getFrontendOptions().RequestEvaluatorGraphVizPath.empty() &&
-        Instance.hasASTContext()) {
-      ASTContext &ctx = Instance.getASTContext();
-      emitRequestEvaluatorGraphViz(
-        ctx,
-        Invocation.getFrontendOptions().RequestEvaluatorGraphVizPath);
-    }
-  };
-
   ASTContext &Context = Instance.getASTContext();
   if (Action == FrontendOptions::ActionType::Parse)
     return Context.hadError();