Merge pull request #83944 from hamishknight/walkerr

[AST] Walk ErrorExpr's original expr in ASTWalker

Author: hamishknight

include/swift/AST/Expr.h

@@ -610,7 +610,8 @@ class ErrorExpr : public Expr {
 
   SourceRange getSourceRange() const { return Range; }
   Expr *getOriginalExpr() const { return OriginalExpr; }
-  
+  void setOriginalExpr(Expr *newExpr) { OriginalExpr = newExpr; }
+
   static bool classof(const Expr *E) {
     return E->getKind() == ExprKind::Error;
   }

lib/AST/ASTDumper.cpp

@@ -3425,6 +3425,8 @@ class PrintExpr : public ExprVisitor<PrintExpr, void, Label>,
 
   void visitErrorExpr(ErrorExpr *E, Label label) {
     printCommon(E, "error_expr", label);
+    if (auto *origExpr = E->getOriginalExpr())
+      printRec(origExpr, Label::optional("original_expr"));
     printFoot();
   }
 

lib/AST/ASTWalker.cpp

@@ -616,7 +616,15 @@ class Traversal : public ASTVisitor<Traversal, Expr*, Stmt*,
     }                                                      \
   } while (false)
 
-  Expr *visitErrorExpr(ErrorExpr *E) { return E; }
+  Expr *visitErrorExpr(ErrorExpr *E) {
+    if (auto *origExpr = E->getOriginalExpr()) {
+      auto *newOrigExpr = doIt(origExpr);
+      if (!newOrigExpr)
+        return nullptr;
+      E->setOriginalExpr(newOrigExpr);
+    }
+    return E;
+  }
   Expr *visitCodeCompletionExpr(CodeCompletionExpr *E) {
     if (Expr *baseExpr = E->getBase()) {
       Expr *newBaseExpr = doIt(baseExpr);

lib/IDE/Formatting.cpp

@@ -587,15 +587,6 @@ class RangeWalker: protected ASTWalker {
   }
 
   PreWalkResult<Expr *> walkToExprPre(Expr *E) override {
-    // Walk through error expressions.
-    if (auto *EE = dyn_cast<ErrorExpr>(E)) {
-      if (auto *OE = EE->getOriginalExpr()) {
-        llvm::SaveAndRestore<ASTWalker::ParentTy>(Parent, EE);
-        OE->walk(*this);
-      }
-      return Action::Continue(E);
-    }
-
     if (E->isImplicit())
       return Action::Continue(E);
 
@@ -1491,17 +1482,6 @@ class FormatWalker : public ASTWalker {
       }
     }
 
-    // Walk through error expressions.
-    if (auto *EE = dyn_cast<ErrorExpr>(E)) {
-      if (Action.shouldVisitChildren()) {
-        if (auto *OE = EE->getOriginalExpr()) {
-          llvm::SaveAndRestore<ASTWalker::ParentTy>(Parent, EE);
-          OE->walk(*this);
-        }
-        return Action::SkipNode(E);
-      }
-    }
-
     // FIXME: We ought to be able to use Action::VisitChildrenIf here, but we'd
     // need to ensure the AST is walked in source order (currently not the case
     // for things like postfix operators).

lib/Sema/CompletionContextFinder.cpp

@@ -49,11 +49,6 @@ CompletionContextFinder::walkToExprPre(Expr *E) {
 
   if (auto *Error = dyn_cast<ErrorExpr>(E)) {
     Contexts.push_back({ContextKind::ErrorExpression, E});
-    if (auto *OrigExpr = Error->getOriginalExpr()) {
-      OrigExpr->walk(*this);
-      if (hasCompletionExpr())
-        return Action::Stop();
-    }
   }
 
   if (auto *CCE = dyn_cast<CodeCompletionExpr>(E)) {

lib/Sema/PreCheckTarget.cpp

@@ -1252,7 +1252,8 @@ class PreCheckTarget final : public ASTWalker {
         }
 
         if (isa<UnresolvedDotExpr>(parentExpr) ||
-            isa<MemberRefExpr>(parentExpr)) {
+            isa<MemberRefExpr>(parentExpr) ||
+            isa<ErrorExpr>(parentExpr)) {
           return true;
         } else if (auto *SE = dyn_cast<SubscriptExpr>(parentExpr)) {
           // 'super[]' is valid, but 'x[super]' is not.

test/Constraints/diagnostics.swift

@@ -1578,3 +1578,10 @@ func testAddMemberVsRemoveCall() {
   let b = Foo_74617()
   let c = (a + b).bar() // expected-error {{cannot call value of non-function type 'Float'}} {{22-24=}}
 }
+
+// Make sure we can still type-check the closure.
+do {
+  _ = {
+    let x: String = 0 // expected-error {{cannot convert value of type 'Int' to specified type 'String'}}
+  }. // expected-error {{expected member name following '.'}}
+}

test/Parse/recovery.swift

@@ -550,7 +550,8 @@ func exprPostfix2() {
 
 class ExprSuper {
   init() {
-    super. // expected-error {{expected member name following '.'}} 
+    super. // expected-error {{expected member name following '.'}}
+    // expected-error@-1 {{'super' cannot be used in class 'ExprSuper' because it has no superclass}}
   }
 }
 

test/SourceKit/CursorInfo/rdar130771574.swift

@@ -0,0 +1,10 @@
+struct S {
+  var x: Int
+}
+
+// Make sure we can still resolve 'x' even with the trailing dot.
+func foo(_ s: S) {
+  s.x.
+  // RUN: %sourcekitd-test -req=cursor -pos=%(line-1):5 %s -- %s -module-name main | %FileCheck %s
+}
+// CHECK: s:4main1SV1xSivp

test/StringProcessing/Parse/forward-slash-regex.swift

@@ -445,6 +445,7 @@ _ = ^/"/"
 _ = ^/"[/"
 // expected-error@-1 {{'^' is not a prefix unary operator}}
 // expected-error@-2 {{unterminated string literal}}
+// expected-error@-3 {{cannot parse regular expression: expected custom character class members}}
 
 _ = (^/)("/")