Merge pull request #29338 from nathawes/dont-require-extensions-to-be-bound-in-astwalker

[AST|ASTWalker] Fix assertion hit walking an invalid AST with a protocol decl inside an extension

Author: Nathan Hawes

lib/AST/ASTWalker.cpp

@@ -223,9 +223,7 @@ class Traversal : public ASTVisitor<Traversal, Expr*, Stmt*,
   }
 
   bool visitTypeAliasDecl(TypeAliasDecl *TAD) {
-    if (TAD->getGenericParams() &&
-        Walker.shouldWalkIntoGenericParams()) {
-
+    if (Walker.shouldWalkIntoGenericParams() && TAD->getGenericParams()) {
       if (visitGenericParamList(TAD->getGenericParams()))
         return true;
     }
@@ -237,8 +235,7 @@ class Traversal : public ASTVisitor<Traversal, Expr*, Stmt*,
   }
 
   bool visitOpaqueTypeDecl(OpaqueTypeDecl *OTD) {
-    if (OTD->getGenericParams() &&
-        Walker.shouldWalkIntoGenericParams()) {
+    if (Walker.shouldWalkIntoGenericParams() && OTD->getGenericParams()) {
       if (visitGenericParamList(OTD->getGenericParams()))
         return true;
     }
@@ -272,16 +269,15 @@ class Traversal : public ASTVisitor<Traversal, Expr*, Stmt*,
     }
 
     // Visit requirements
-    if (auto *Protocol = dyn_cast<ProtocolDecl>(NTD)) {
-      if (auto *WhereClause = Protocol->getTrailingWhereClause()) {
-        for (auto &Req: WhereClause->getRequirements()) {
-          if (doIt(Req))
-            return true;
-        }
-      }
-    }
     if (WalkGenerics) {
-      for (auto Req: NTD->getGenericParams()->getTrailingRequirements()) {
+      ArrayRef<swift::RequirementRepr> Reqs = None;
+      if (auto *Protocol = dyn_cast<ProtocolDecl>(NTD)) {
+        if (auto *WhereClause = Protocol->getTrailingWhereClause())
+          Reqs = WhereClause->getRequirements();
+      } else {
+        Reqs = NTD->getGenericParams()->getTrailingRequirements();
+      }
+      for (auto Req: Reqs) {
         if (doIt(Req))
           return true;
       }
@@ -1329,7 +1325,6 @@ class Traversal : public ASTVisitor<Traversal, Expr*, Stmt*,
 
 private:
   bool visitGenericParamListIfNeeded(GenericContext *gc) {
-    // Must check this first in case extensions have not been bound yet
     if (Walker.shouldWalkIntoGenericParams()) {
       if (auto *params = gc->getGenericParams()) {
         visitGenericParamList(params);

lib/AST/Decl.cpp

@@ -3613,7 +3613,7 @@ static Type computeNominalType(NominalTypeDecl *decl, DeclTypeKind kind) {
   // Get the parent type.
   Type Ty;
   DeclContext *dc = decl->getDeclContext();
-  if (dc->isTypeContext()) {
+  if (!isa<ProtocolDecl>(decl) && dc->isTypeContext()) {
     switch (kind) {
     case DeclTypeKind::DeclaredType: {
       auto *nominal = dc->getSelfNominalTypeDecl();

test/IDE/coloring_invalid.swift

@@ -1,5 +1,13 @@
 // RUN: %target-swift-ide-test -syntax-coloring -source-filename %s | %FileCheck %s
 
+public enum Foo {}
+// CHECK: <attr-builtin>public</attr-builtin> <kw>enum</kw> Foo {}
+public extension Foo {
+// CHECK: <attr-builtin>public</attr-builtin> <kw>extension</kw> <type>Foo</type> {
+	protocol Bar {}
+// CHECK: <kw>protocol</kw> Bar {}
+}
+
 public enum Result {
 // CHECK: <attr-builtin>public</attr-builtin> <kw>enum</kw> Result {
   case success(a b = {