[CSApply] Fixed type-checked subexpression output bug for multi-state…

lib/Sema/CSApply.cpp

@@ -8152,6 +8152,11 @@ namespace {
       return false;
     }
 
+    /// Check if there are any closures or tap expressions left to process separately.
+    bool hasDelayedTasks() {
+      return !ClosuresToTypeCheck.empty() || !TapsToTypeCheck.empty();
+    }
+
     /// Process delayed closure bodies and `Tap` expressions.
     ///
     /// \returns true if any part of the processing fails.
@@ -8993,8 +8998,31 @@ ExprWalker::rewriteTarget(SolutionApplicationTarget target) {
     result.setExpr(resultExpr);
 
     if (cs.isDebugMode()) {
+      // If target is a multi-statement closure or
+      // a tap expression, expression will not be fully
+      // type checked until these expressions are visited in
+      // processDelayed().
+      bool isPartial = false;
+      resultExpr->forEachChildExpr([&](Expr *child) -> Expr * {
+        if (auto *closure = dyn_cast<ClosureExpr>(child)) {
+          if (!closure->hasSingleExpressionBody()) {
+            isPartial = true;
+            return nullptr;
+          }
+        }
+        if (isa<TapExpr>(child)) {
+          isPartial = true;
+          return nullptr;
+        }
+      return child;
+      });
+
       auto &log = llvm::errs();
-      log << "---Type-checked expression---\n";
+      if (isPartial) {
+        log << "---Partially type-checked expression---\n";
+      } else {
+        log << "---Type-checked expression---\n";
+      }
       resultExpr->dump(log);
       log << "\n";
     }
@@ -9047,6 +9075,8 @@ Optional<SolutionApplicationTarget> ConstraintSystem::applySolution(
   if (!resultTarget)
     return None;
 
+  auto needsPostProcessing = walker.hasDelayedTasks();
+
   // Visit closures that have non-single expression bodies, tap expressions,
   // and possibly other types of AST nodes which could only be processed
   // after contextual expression.
@@ -9055,7 +9085,18 @@ Optional<SolutionApplicationTarget> ConstraintSystem::applySolution(
   // If any of them failed to type check, bail.
   if (hadError)
     return None;
-
+
+  if (isDebugMode()) {
+  // If we had partially type-checked expressions, lets print
+  // fully type-checked expression after processDelayed is done.
+    if (needsPostProcessing) {
+      auto &log = llvm::errs();
+      log << "---Fully type-checked expression---\n";
+      resultTarget->getAsExpr()->dump(log);
+      log << "\n";
+    }
+  }
+
   rewriter.finalize();
 
   return resultTarget;