Work Around IDE Structure Markers

Structure analysis trusts what should be implicit pattern nodes have the
right source location information in them. Preserve that behavior for
now.

Author: CodaFi

lib/Parse/ParsePattern.cpp

@@ -887,9 +887,14 @@ ParserResult<Pattern> Parser::parseTypedPattern() {
     SyntaxParsingContext TypeAnnoCtx(SyntaxContext, SyntaxKind::TypeAnnotation);
     SourceLoc colonLoc = consumeToken(tok::colon);
 
-    if (result.isNull())  // Recover by creating AnyPattern.
-      result = makeParserErrorResult(new (Context) AnyPattern(colonLoc));
-    
+    if (result.isNull()) {
+      // Recover by creating AnyPattern.
+      auto *AP = new (Context) AnyPattern(colonLoc);
+      if (colonLoc.isInvalid())
+        AP->setImplicit();
+      result = makeParserErrorResult(AP);
+    }
+
     ParserResult<TypeRepr> Ty = parseDeclResultType(diag::expected_type);
     if (Ty.hasCodeCompletion())
       return makeParserCodeCompletionResult<Pattern>();

lib/Parse/ParseStmt.cpp

@@ -1108,9 +1108,12 @@ static void parseGuardedPattern(Parser &P, GuardedPattern &result,
 
   // If that didn't work, use a bogus pattern so that we can fill out
   // the AST.
-  if (patternResult.isNull())
-    patternResult =
-      makeParserErrorResult(new (P.Context) AnyPattern(P.PreviousLoc));
+  if (patternResult.isNull()) {
+    auto *AP = new (P.Context) AnyPattern(P.PreviousLoc);
+    if (P.PreviousLoc.isInvalid())
+      AP->setImplicit();
+    patternResult = makeParserErrorResult(AP);
+  }
 
   // Fill in the pattern.
   status |= patternResult;
@@ -1506,7 +1509,10 @@ Parser::parseStmtConditionElement(SmallVectorImpl<StmtConditionElement> &result,
 
   if (ThePattern.isNull()) {
     // Recover by creating AnyPattern.
-    ThePattern = makeParserResult(new (Context) AnyPattern(PreviousLoc));
+    auto *AP = new (Context) AnyPattern(PreviousLoc);
+    if (PreviousLoc.isInvalid())
+      AP->setImplicit();
+    ThePattern = makeParserResult(AP);
   }
 
   // Conditional bindings must have an initializer.
@@ -2133,7 +2139,7 @@ ParserResult<Stmt> Parser::parseStmtForEach(LabeledStmtInfo LabelInfo) {
   SourceLoc InLoc;
   if (pattern.isNull()) {
     // Recover by creating a "_" pattern.
-    pattern = makeParserErrorResult(new (Context) AnyPattern(SourceLoc()));
+    pattern = makeParserErrorResult(AnyPattern::createImplicit(Context));
     consumeIf(tok::kw_in, InLoc);
   } else if (!IsCStyleFor) {
     parseToken(tok::kw_in, InLoc, diag::expected_foreach_in);
@@ -2422,6 +2428,8 @@ parseStmtCaseDefault(Parser &P, SourceLoc &CaseLoc,
 
   // Create an implicit AnyPattern to represent the default match.
   auto Any = new (P.Context) AnyPattern(CaseLoc);
+  if (CaseLoc.isInvalid())
+    Any->setImplicit();
   LabelItems.push_back(
       CaseLabelItem::getDefault(Any, WhereLoc, Guard.getPtrOrNull()));