AST: Remove the 'legacy' request dependency graph implementation

Author: slavapestov

include/swift/AST/Evaluator.h

@@ -188,9 +188,6 @@ class Evaluator {
   /// Whether to dump detailed debug info for cycles.
   bool debugDumpCycles;
 
-  /// Whether we're building a request dependency graph.
-  bool buildDependencyGraph;
-
   /// Used to report statistics about which requests were evaluated, if
   /// non-null.
   UnifiedStatsReporter *stats = nullptr;
@@ -214,17 +211,6 @@ class Evaluator {
   /// A cache that stores the results of requests.
   evaluator::RequestCache cache;
 
-  /// Track the dependencies of each request.
-  ///
-  /// This is an adjacency-list representation expressing, for each known
-  /// request, the requests that it directly depends on. It is populated
-  /// lazily while the request is being evaluated.
-  ///
-  /// In a well-formed program, the graph should be a directed acycle graph
-  /// (DAG). However, cyclic dependencies will be recorded within this graph,
-  /// so all clients must cope with cycles.
-  llvm::DenseMap<AnyRequest, std::vector<AnyRequest>> dependencies;
-
   evaluator::DependencyRecorder recorder;
 
   /// Retrieve the request function for the given zone and request IDs.
@@ -363,11 +349,6 @@ class Evaluator {
           std::make_unique<CyclicalRequestError<Request>>(request, *this));
     }
 
-    // Clear out the dependencies on this request; we're going to recompute
-    // them now anyway.
-    if (buildDependencyGraph)
-      dependencies.find_as(request)->second.clear();
-
     PrettyStackTraceRequest<Request> prettyStackTrace(request);
 
     // Trace and/or count statistics.
@@ -470,45 +451,12 @@ class Evaluator {
       recorder.handleDependencySourceRequest(r, source.get());
     }
   }
-
-public:
-  /// Print the dependencies of the given request as a tree.
-  ///
-  /// This is the core printing operation; most callers will want to use
-  /// the other overload.
-  void printDependencies(const AnyRequest &request,
-                         llvm::raw_ostream &out,
-                         llvm::DenseSet<AnyRequest> &visitedAnywhere,
-                         llvm::SmallVectorImpl<AnyRequest> &visitedAlongPath,
-                         ArrayRef<AnyRequest> highlightPath,
-                         std::string &prefixStr,
-                         bool lastChild) const;
-
-  /// Print the dependencies of the given request as a tree.
-  template <typename Request>
-  void printDependencies(const Request &request, llvm::raw_ostream &out) const {
-    std::string prefixStr;
-    llvm::DenseSet<AnyRequest> visitedAnywhere;
-    llvm::SmallVector<AnyRequest, 4> visitedAlongPath;
-    printDependencies(AnyRequest(request), out, visitedAnywhere,
-                      visitedAlongPath, { }, prefixStr, /*lastChild=*/true);
-  }
-
-  /// Dump the dependencies of the given request to the debugging stream
-  /// as a tree.
-  SWIFT_DEBUG_DUMPER(dumpDependencies(const AnyRequest &request));
-
-  /// Print all dependencies known to the evaluator as a single Graphviz
-  /// directed graph.
-  void printDependenciesGraphviz(llvm::raw_ostream &out) const;
-
-  SWIFT_DEBUG_DUMPER(dumpDependenciesGraphviz());
 };
 
 template <typename Request>
 void CyclicalRequestError<Request>::log(llvm::raw_ostream &out) const {
   out << "Cycle detected:\n";
-  evaluator.printDependencies(request, out);
+  simple_display(out, request);
   out << "\n";
 }
 

include/swift/Basic/LangOptions.h

@@ -221,16 +221,9 @@ namespace swift {
     /// Whether to record request references for incremental builds.
     bool RecordRequestReferences = true;
 
-    /// The path to which we should emit GraphViz output for the complete
-    /// request-evaluator graph.
-    std::string RequestEvaluatorGraphVizPath;
-    
     /// Whether to dump debug info for request evaluator cycles.
     bool DebugDumpCycles = false;
 
-    /// Whether to build a request dependency graph for debugging.
-    bool BuildRequestDependencyGraph = false;
-
     /// Enable SIL type lowering
     bool EnableSubstSILFunctionTypesForFunctionValues = true;
 

include/swift/Option/FrontendOptions.td

@@ -266,10 +266,6 @@ def debug_emit_invalid_swiftinterface_syntax : Flag<["-"], "debug-emit-invalid-s
 
 def debug_cycles : Flag<["-"], "debug-cycles">,
   HelpText<"Print out debug dumps when cycles are detected in evaluation">;
-def build_request_dependency_graph : Flag<["-"], "build-request-dependency-graph">,
-  HelpText<"Build request dependency graph">;
-def output_request_graphviz : Separate<["-"], "output-request-graphviz">,
-  HelpText<"Emit GraphViz output visualizing the request dependency graph">;
 
 def debug_time_function_bodies : Flag<["-"], "debug-time-function-bodies">,
   HelpText<"Dumps the time it takes to type-check each function body">;

lib/AST/ASTContext.cpp

@@ -628,11 +628,6 @@ ASTContext::ASTContext(LangOptions &langOpts, TypeCheckerOptions &typeckOpts,
 }
 
 ASTContext::~ASTContext() {
-  // Emit evaluator dependency graph if requested.
-  auto graphPath = LangOpts.RequestEvaluatorGraphVizPath;
-  if (!graphPath.empty()) {
-    evaluator.emitRequestEvaluatorGraphViz(graphPath);
-  }
   getImpl().~Implementation();
 }