[RangeInfo] Avoid analyzing implicit ASTNodes. rdar://31773556 (swiftlang#9210)

Author: nkcsgexi

include/swift/AST/ASTNode.h

@@ -61,6 +61,9 @@ namespace swift {
     FUNC(Expr)
     FUNC(Decl)
 #undef FUNC
+
+    /// Whether the AST node is implicit.
+    bool isImplicit() const;
   };
 } // namespace swift
 

lib/AST/ASTNode.cpp

@@ -56,6 +56,16 @@ DeclContext *ASTNode::getAsDeclContext() const {
   return nullptr;
 }
 
+bool ASTNode::isImplicit() const {
+  if (const Expr *E = this->dyn_cast<Expr*>())
+    return E->isImplicit();
+  if (const Stmt *S = this->dyn_cast<Stmt*>())
+    return S->isImplicit();
+  if (const Decl *D = this->dyn_cast<Decl*>())
+    return D->isImplicit();
+  llvm_unreachable("unsupported AST node");
+}
+
 void ASTNode::walk(ASTWalker &Walker) {
   if (Expr *E = this->dyn_cast<Expr*>())
     E->walk(Walker);

lib/IDE/SwiftSourceDocInfo.cpp

@@ -649,6 +649,8 @@ struct RangeResolver::Implementation {
   }
 
   void analyze(ASTNode Node) {
+    if (!shouldAnalyze(Node))
+      return;
     Decl *D = Node.is<Decl*>() ? Node.get<Decl*>() : nullptr;
     analyzeDecl(D);
     auto &DCInfo = getCurrentDC();
@@ -675,16 +677,12 @@ struct RangeResolver::Implementation {
       break;
     }
 
-    // If the node's parent is not contained in the range under question but the
-    // node itself is, we keep track of the node as top-level contained node.
-    if (!getCurrentDC().ContainedInRange &&
-        isContainedInSelection(CharSourceRange(SM, Node.getStartLoc(),
-                                               Node.getEndLoc()))) {
-      if (std::find_if(ContainedASTNodes.begin(), ContainedASTNodes.end(),
-          [&](ASTNode N) { return SM.rangeContains(N.getSourceRange(),
-            Node.getSourceRange()); }) == ContainedASTNodes.end()) {
-        ContainedASTNodes.push_back(Node);
-      }
+    // If no parent is considered as a contained node; this node should be
+    // a top-level contained node.
+    if (std::none_of(ContainedASTNodes.begin(), ContainedASTNodes.end(),
+      [&](ASTNode N) { return SM.rangeContains(N.getSourceRange(),
+                                               Node.getSourceRange()); })) {
+      ContainedASTNodes.push_back(Node);
     }
 
     if (DCInfo.isMultiStatement()) {
@@ -713,6 +711,18 @@ struct RangeResolver::Implementation {
     return true;
   }
 
+  bool shouldAnalyze(ASTNode Node) {
+    // Avoid analyzing implicit nodes.
+    if (Node.isImplicit())
+      return false;
+    // Avoid analyzing nodes that are not enclosed.
+    if (SM.isBeforeInBuffer(End, Node.getEndLoc()))
+      return false;
+    if (SM.isBeforeInBuffer(Node.getStartLoc(), Start))
+      return false;
+    return true;
+  }
+
   ResolvedRangeInfo getResult() {
     if (Result.hasValue())
       return Result.getValue();

test/IDE/range_info_basics.swift

@@ -164,9 +164,9 @@ func test_no_pattern_binding(_ parameters: [String: Any]) -> String {
 // RUN: %target-swift-ide-test -range -pos=109:6 -end-pos=111:4 -source-filename %s | %FileCheck %s -check-prefix=CHECK-INVALID
 // RUN: %target-swift-ide-test -range -pos=114:1 -end-pos=115:15 -source-filename %s | %FileCheck %s -check-prefix=CHECK27
 // RUN: %target-swift-ide-test -range -pos=118:1 -end-pos=119:15 -source-filename %s | %FileCheck %s -check-prefix=CHECK27
-// RUN: %target-swift-ide-test -range -pos=126:11 -end-pos=126:12 -source-filename %s | %FileCheck %s -check-prefix=CHECK-INT
+// RUN: %target-swift-ide-test -range -pos=126:11 -end-pos=126:12 -source-filename %s | %FileCheck %s -check-prefix=CHECK-INT-LVALUE
 // RUN: %target-swift-ide-test -range -pos=126:11 -end-pos=126:20 -source-filename %s | %FileCheck %s -check-prefix=CHECK-INT
-// RUN: %target-swift-ide-test -range -pos=127:7 -end-pos=127:8 -source-filename %s | %FileCheck %s -check-prefix=CHECK-INT
+// RUN: %target-swift-ide-test -range -pos=127:7 -end-pos=127:8 -source-filename %s | %FileCheck %s -check-prefix=CHECK-INT-LVALUE
 // RUN: %target-swift-ide-test -range -pos=127:3 -end-pos=127:4 -source-filename %s | %FileCheck %s -check-prefix=CHECK-INT-LVALUE
 // RUN: %target-swift-ide-test -range -pos=128:13 -end-pos=128:15 -source-filename %s | %FileCheck %s -check-prefix=CHECK-INT-INOUT
 // RUN: %target-swift-ide-test -range -pos=118:1 -end-pos=120:22 -source-filename %s | %FileCheck %s -check-prefix=CHECK-INT

test/IDE/range_info_implicit.swift

@@ -0,0 +1,7 @@
+public class CC {
+  public init() {
+  }
+}
+
+// RUN: %target-swift-ide-test -range -pos=3:1 -end-pos=3:4 -source-filename %s | %FileCheck %s -check-prefix=CHECK-INVALID
+// CHECK-INVALID: <Kind>Invalid</Kind>