[NFC] PreCheckExpr: Simplify RebindSelfInConstructorExpr insertion point computation

Author: AnthonyLatsis

lib/Sema/PreCheckExpr.cpp

@@ -1184,10 +1184,6 @@ namespace {
       assert(ExprStack.back() == expr);
       ExprStack.pop_back();
 
-      // Mark the direct callee as being a callee.
-      if (auto *call = dyn_cast<ApplyExpr>(expr))
-        markDirectCallee(call->getFn());
-
       // Fold sequence expressions.
       if (auto *seqExpr = dyn_cast<SequenceExpr>(expr)) {
         auto result = TypeChecker::foldSequence(seqExpr, DC);
@@ -1215,66 +1211,55 @@ namespace {
       if (isa<SingleValueStmtExpr>(expr))
         SingleValueStmtExprDepth -= 1;
 
-      // A 'self.init' or 'super.init' application inside a constructor will
-      // evaluate to void, with the initializer's result implicitly rebound
-      // to 'self'. Recognize the unresolved constructor expression and
-      // determine where to place the RebindSelfInConstructorExpr node.
-      // When updating this logic, also update
-      // RebindSelfInConstructorExpr::getCalledConstructor.
-      auto &ctx = getASTContext();
-      if (auto unresolvedDot = dyn_cast<UnresolvedDotExpr>(expr)) {
-        if (auto self = TypeChecker::getSelfForInitDelegationInConstructor(
-                DC, unresolvedDot)) {
+      if (auto *apply = dyn_cast<ApplyExpr>(expr)) {
+        // Mark the direct callee as being a callee.
+        markDirectCallee(apply->getFn());
+
+        // A 'self.init' or 'super.init' application inside a constructor will
+        // evaluate to void, with the initializer's result implicitly rebound
+        // to 'self'. Recognize the unresolved constructor expression and
+        // determine where to place the RebindSelfInConstructorExpr node.
+        //
+        // When updating this logic, also may need to also update
+        // RebindSelfInConstructorExpr::getCalledConstructor.
+        VarDecl *self = nullptr;
+        if (auto *unresolvedDot =
+                dyn_cast<UnresolvedDotExpr>(apply->getSemanticFn())) {
+          self = TypeChecker::getSelfForInitDelegationInConstructor(
+              DC, unresolvedDot);
+        }
+
+        if (self) {
           // Walk our ancestor expressions looking for the appropriate place
           // to insert the RebindSelfInConstructorExpr.
-          Expr *target = nullptr;
-          bool foundApply = false;
-          bool foundRebind = false;
+          Expr *target = apply;
           for (auto ancestor : llvm::reverse(ExprStack)) {
-            if (isa<RebindSelfInConstructorExpr>(ancestor)) {
-              // If we already have a rebind, then we're re-typechecking an
-              // expression and are done.
-              foundRebind = true;
-              break;
-            }
-
-            // Recognize applications.
-            if (auto apply = dyn_cast<ApplyExpr>(ancestor)) {
-              // If we already saw an application, we're done.
-              if (foundApply)
-                break;
-
-              // If the function being called is not our unresolved initializer
-              // reference, we're done.
-              if (apply->getSemanticFn() != unresolvedDot)
-                break;
-
-              foundApply = true;
+            if (isa<IdentityExpr>(ancestor) || isa<ForceValueExpr>(ancestor) ||
+                isa<AnyTryExpr>(ancestor)) {
               target = ancestor;
               continue;
             }
 
-            // Look through identity, force-value, and 'try' expressions.
-            if (isa<IdentityExpr>(ancestor) ||
-                isa<ForceValueExpr>(ancestor) ||
-                isa<AnyTryExpr>(ancestor)) {
-              if (target)
-                target = ancestor;
-              continue;
+            if (isa<RebindSelfInConstructorExpr>(ancestor)) {
+              // If we already have a rebind, then we're re-typechecking an
+              // expression and are done.
+              target = nullptr;
             }
 
             // No other expression kinds are permitted.
             break;
           }
 
           // If we found a rebind target, note the insertion point.
-          if (target && !foundRebind) {
+          if (target) {
             UnresolvedCtorRebindTarget = target;
             UnresolvedCtorSelf = self;
           }
         }
       }
 
+      auto &ctx = getASTContext();
+
       // If the expression we've found is the intended target of an
       // RebindSelfInConstructorExpr, wrap it in the
       // RebindSelfInConstructorExpr.