Merge pull request #5289 from DougGregor/scope-map-fixes

Scope map fixes

Author: DougGregor

lib/AST/ASTScope.cpp

@@ -1420,9 +1420,14 @@ SourceRange ASTScope::getSourceRangeImpl() const {
     return typeDecl->getSourceRange();
 
   case ASTScopeKind::ExtensionGenericParams: {
-    // The generic parameters of an extension are available from the trailing
+    // The generic parameters of an extension are available from the ':' of
+    // the inheritance clause (if available), or else that from the
     // 'where' (if present) or from the start of the body.
+    // FIXME: Approximating the ':' with the start of the first inherited entry.
     SourceLoc startLoc;
+    if (!extension->getInherited().empty() &&
+        extension->getInherited().front().getSourceRange().Start.isValid())
+      startLoc = extension->getInherited().front().getSourceRange().Start;
     if (auto trailingWhere = extension->getTrailingWhereClause())
       startLoc = trailingWhere->getWhereLoc();
     else
@@ -1807,7 +1812,13 @@ SmallVector<ValueDecl *, 4> ASTScope::getLocalBindings() const {
     // No local declarations.
     break;
 
-  case ASTScopeKind::ExtensionGenericParams:
+  case ASTScopeKind::ExtensionGenericParams: {
+    // If the source range containing the extension parameters is empty,
+    // do nothing.
+    SourceRange range = getSourceRangeImpl();
+    if (range.Start == range.End)
+      break;
+
     // Bind this extension, if we haven't done so already.
     if (!extension->getExtendedType())
       if (auto resolver = extension->getASTContext().getLazyResolver())
@@ -1821,6 +1832,7 @@ SmallVector<ValueDecl *, 4> ASTScope::getLocalBindings() const {
         result.push_back(param);
     }
     break;
+  }
 
   case ASTScopeKind::GenericParams:
     result.push_back(genericParams.params->getParams()[genericParams.index]);
@@ -1873,6 +1885,8 @@ SmallVector<ValueDecl *, 4> ASTScope::getLocalBindings() const {
     break;
 
   case ASTScopeKind::PatternInitializer:
+    // FIXME: This causes recursion that we cannot yet handle.
+#if false
     // 'self' is available within the pattern initializer of a 'lazy' variable.
     if (auto singleVar = patternBinding.decl->getSingleVar()) {
       if (singleVar->getAttrs().hasAttribute<LazyAttr>() &&
@@ -1890,6 +1904,7 @@ SmallVector<ValueDecl *, 4> ASTScope::getLocalBindings() const {
             result.push_back(self);
       }
     }
+#endif
     break;
 
   case ASTScopeKind::Closure:

lib/Parse/ParseStmt.cpp

@@ -2213,7 +2213,7 @@ ParserResult<Stmt> Parser::parseStmtForCStyle(SourceLoc ForLoc,
   // If we're missing a semicolon, try to recover.
   if (Tok.isNot(tok::semi)) {
     // Provide a reasonable default location for the first semicolon.
-    Semi1Loc = Tok.getLoc();
+    Semi1Loc = PreviousLoc;
 
     if (auto *BS = ConvertClosureToBraceStmt(First.getPtrOrNull(), Context)) {
       // We have seen:

test/NameBinding/scope_map.swift

@@ -459,7 +459,9 @@ class LazyProperties {
 // CHECK-SEARCHES-NEXT:   FileUnit file="{{.*}}scope_map.swift"
 // CHECK-SEARCHES-NEXT:     ClassDecl name=LazyProperties
 // CHECK-SEARCHES-NEXT:       Initializer PatternBinding {{.*}} #0
-// CHECK-SEARCHES-NEXT: Local bindings: self
+
+// FIXME: Re-enable the binding below
+// CHECK-SEARCHES-NOT: Local bindings: self
 
 // CHECK-SEARCHES-LABEL: ***Complete scope map***
 // CHECK-SEARCHES-NEXT: SourceFile {{.*}} '{{.*}}scope_map.swift' [1:1 - [[EOF:[0-9]+:[0-9]+]]] unexpanded

test/NameBinding/scope_map_lookup.swift

@@ -37,10 +37,11 @@ extension P2 {
   }
 }
 
+#if false
 // Lazy properties
 class LazyProperties {
   init() {
-    lazy var localvar = 42  // expected-error {{lazy is only valid for members of a struct or class}} {{5-10=}}
+    lazy var localvar = 42  // FIXME: should error {{lazy is only valid for members of a struct or class}} {{5-10=}}
     localvar += 1
     _ = localvar
   }
@@ -57,6 +58,7 @@ class LazyProperties {
 
   lazy var prop5: Int = { self.value + 1 }()
 }
+#endif
 
 // Protocol extensions.
 // Extending via a superclass constraint.
@@ -110,6 +112,10 @@ protocol Fooable {
   var foo: Foo { get }
 }
 
+// The extension below once caused infinite recursion.
+struct S<T> // expected-error{{expected '{' in struct}}
+extension S // expected-error{{expected '{' in extension}}
+
 let a = b ; let b = a // expected-error{{could not infer type for 'a'}} 
 // expected-error@-1 {{'a' used within its own type}}
 // FIXME: That second error is bogus.

test/Parse/toplevel_library_invalid.swift

@@ -1,4 +1,5 @@
 // RUN: %target-parse-verify-swift -parse-as-library
+// RUN: %target-parse-verify-swift -parse-as-library -enable-astscope-lookup
 
 let x = 42 // expected-note{{did you mean 'x'?}}
 x + x; // expected-error {{expressions are not allowed at the top level}} expected-warning {{result of operator '+' is unused}}