Merge pull request #18663 from rintaro/ide-rdar43135727

[IDE] Don't walk to ExplicitCast expr twice in ModelASTWalker

Author: rintaro

lib/IDE/SyntaxModel.cpp

@@ -425,6 +425,18 @@ std::pair<bool, Expr *> ModelASTWalker::walkToExprPre(Expr *E) {
   if (isVisitedBeforeInIfConfig(E))
     return {false, E};
 
+  // In SequenceExpr, explicit cast expressions (e.g. 'as', 'is') appear twice.
+  // Skip pointers we've already seen.
+  if (auto SE = dyn_cast<SequenceExpr>(E)) {
+    SmallPtrSet<Expr *, 5> seenExpr;
+    for (auto subExpr : SE->getElements()) {
+      if (!seenExpr.insert(subExpr).second)
+        continue;
+      subExpr->walk(*this);
+    }
+    return { false, SE };
+  }
+
   auto addCallArgExpr = [&](Expr *Elem, TupleExpr *ParentTupleExpr) {
     if (isCurrentCallArgExpr(ParentTupleExpr)) {
       CharSourceRange NR = parameterNameRangeOfCallArg(ParentTupleExpr, Elem);
@@ -962,7 +974,8 @@ bool ModelASTWalker::walkToTypeReprPre(TypeRepr *T) {
   } else if (auto IdT = dyn_cast<ComponentIdentTypeRepr>(T)) {
     if (!passTokenNodesUntil(IdT->getIdLoc(), ExcludeNodeAtLocation))
       return false;
-    if (TokenNodes.front().Range.getStart() != IdT->getIdLoc())
+    if (TokenNodes.empty() ||
+        TokenNodes.front().Range.getStart() != IdT->getIdLoc())
       return false;
     if (!passNode({SyntaxNodeKind::TypeId, TokenNodes.front().Range}))
       return false;

test/IDE/coloring.swift

@@ -285,8 +285,8 @@ class Observers {
 
 // CHECK: <kw>func</kw> test3(o: <type>AnyObject</type>) {
 func test3(o: AnyObject) {
-  // CHECK: <kw>let</kw> x = o <kw>as</kw>! <type>MyCls</type>
-  let x = o as! MyCls
+  // CHECK: <kw>_</kw> = o <kw>is</kw> <type>MyCls</type> ? o <kw>as</kw> <type>MyCls</type> : o <kw>as</kw>! <type>MyCls</type> <kw>as</kw> <type>MyCls</type> + <int>1</int>
+  _ = o is MyCls ? o as MyCls : o as! MyCls as MyCls + 1
 }
 
 // CHECK: <kw>class</kw> MySubClass : <type>MyCls</type> {

test/IDE/structure.swift

@@ -276,9 +276,9 @@ struct Tuples {
   }
 }
 
-completion(a: 1) { (x: Int, y: Int) -> Int in
-  return x + y
+completion(a: 1) { (x: Any, y: Int) -> Int in
+  return x as! Int + y
 }
-// CHECK: <call><name>completion</name>(<arg><name>a</name>: 1</arg>) <arg><closure>{ (<param>x: <type>Int</type></param>, <param>y: <type>Int</type></param>) -> <type>Int</type> in
-// CHECK:    return x + y
+// CHECK: <call><name>completion</name>(<arg><name>a</name>: 1</arg>) <arg><closure>{ (<param>x: <type>Any</type></param>, <param>y: <type>Int</type></param>) -> <type>Int</type> in
+// CHECK:    return x as! Int + y
 // CHECK: }</closure></arg></call>