Handle parsing of require...impls declarations

toolchain/check/handle_impl.cpp

@@ -54,7 +54,7 @@ auto HandleParseNode(Context& context, Parse::ForallId /*node_id*/) -> bool {
   return true;
 }
 
-auto HandleParseNode(Context& context, Parse::TypeImplAsId node_id) -> bool {
+auto HandleParseNode(Context& context, Parse::ImplTypeAsId node_id) -> bool {
   auto [self_node, self_id] = context.node_stack().PopExprWithNodeId();
   auto self_type_inst_id = ExprAsType(context, self_node, self_id).inst_id;
   context.node_stack().Push(node_id, self_type_inst_id);
@@ -67,7 +67,7 @@ auto HandleParseNode(Context& context, Parse::TypeImplAsId node_id) -> bool {
   return true;
 }
 
-auto HandleParseNode(Context& context, Parse::DefaultSelfImplAsId node_id)
+auto HandleParseNode(Context& context, Parse::ImplDefaultSelfAsId node_id)
     -> bool {
   auto self_inst_id = SemIR::TypeInstId::None;
 

toolchain/check/handle_require.cpp

@@ -0,0 +1,30 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#include "toolchain/check/context.h"
+#include "toolchain/check/handle.h"
+#include "toolchain/parse/node_ids.h"
+
+namespace Carbon::Check {
+
+auto HandleParseNode(Context& context, Parse::RequireIntroducerId node_id)
+    -> bool {
+  return context.TODO(node_id, "require");
+}
+
+auto HandleParseNode(Context& context, Parse::RequireDefaultSelfImplsId node_id)
+    -> bool {
+  return context.TODO(node_id, "require");
+}
+
+auto HandleParseNode(Context& context, Parse::RequireTypeImplsId node_id)
+    -> bool {
+  return context.TODO(node_id, "require");
+}
+
+auto HandleParseNode(Context& context, Parse::RequireDeclId node_id) -> bool {
+  return context.TODO(node_id, "require");
+}
+
+}  // namespace Carbon::Check

toolchain/check/impl.cpp

@@ -433,7 +433,7 @@ static auto ExtendImpl(Context& context, Parse::NodeId extend_node,
   const auto& impl = context.impls().Get(impl_id);
 
   if (context.parse_tree().node_kind(self_type_node_id) ==
-      Parse::NodeKind::TypeImplAs) {
+      Parse::NodeKind::ImplTypeAs) {
     CARBON_DIAGNOSTIC(ExtendImplSelfAs, Error,
                       "cannot `extend` an `impl` with an explicit self type");
     auto diag = context.emitter().Build(extend_node, ExtendImplSelfAs);
@@ -448,7 +448,7 @@ static auto ExtendImpl(Context& context, Parse::NodeId extend_node,
     // The explicit self type is the same as the default self type, so suggest
     // removing it and recover as if it were not present.
     if (auto self_as =
-            context.parse_tree_and_subtrees().ExtractAs<Parse::TypeImplAs>(
+            context.parse_tree_and_subtrees().ExtractAs<Parse::ImplTypeAs>(
                 self_type_node_id)) {
       CARBON_DIAGNOSTIC(ExtendImplSelfAsDefault, Note,
                         "remove the explicit `Self` type here");

toolchain/check/merge.cpp

@@ -461,17 +461,17 @@ static auto CheckRedeclParamSyntax(Context& context,
       // https://github.com/carbon-language/carbon-lang/blob/trunk/proposals/p3763.md#redeclarations
       auto new_node_kind = context.parse_tree().node_kind(new_node_id);
       auto prev_node_kind = context.parse_tree().node_kind(prev_node_id);
-      if (new_node_kind == Parse::NodeKind::DefaultSelfImplAs &&
+      if (new_node_kind == Parse::NodeKind::ImplDefaultSelfAs &&
           prev_node_kind == Parse::NodeKind::SelfTypeNameExpr &&
           context.parse_tree().node_kind(prev_iter[1]) ==
-              Parse::NodeKind::TypeImplAs) {
+              Parse::NodeKind::ImplTypeAs) {
         ++prev_iter;
         continue;
       }
-      if (prev_node_kind == Parse::NodeKind::DefaultSelfImplAs &&
+      if (prev_node_kind == Parse::NodeKind::ImplDefaultSelfAs &&
           new_node_kind == Parse::NodeKind::SelfTypeNameExpr &&
           context.parse_tree().node_kind(new_iter[1]) ==
-              Parse::NodeKind::TypeImplAs) {
+              Parse::NodeKind::ImplTypeAs) {
         ++new_iter;
         continue;
       }

toolchain/check/node_stack.h

@@ -523,6 +523,9 @@ class NodeStack {
       case Parse::NodeKind::ParenExprStart:
       case Parse::NodeKind::PatternListComma:
       case Parse::NodeKind::Placeholder:
+      case Parse::NodeKind::RequireIntroducer:
+      case Parse::NodeKind::RequireDefaultSelfImpls:
+      case Parse::NodeKind::RequireTypeImpls:
       case Parse::NodeKind::RequirementAnd:
       case Parse::NodeKind::RequirementEqual:
       case Parse::NodeKind::RequirementEqualEqual:

toolchain/check/testdata/facet/require_invalid.carbon

@@ -0,0 +1,54 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// INCLUDE-FILE: toolchain/testing/testdata/min_prelude/none.carbon
+//
+// AUTOUPDATE
+// TIP: To test this file alone, run:
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/facet/require_invalid.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/facet/require_invalid.carbon
+
+// --- fail_todo_require_outside_scope.carbon
+library "[[@TEST_NAME]]";
+
+interface Y {}
+
+// CHECK:STDERR: fail_todo_require_outside_scope.carbon:[[@LINE+4]]:1: error: semantics TODO: `require` [SemanticsTodo]
+// CHECK:STDERR: require impls Y;
+// CHECK:STDERR: ^~~~~~~
+// CHECK:STDERR:
+require impls Y;
+
+// --- fail_todo_require_in_class.carbon
+library "[[@TEST_NAME]]";
+
+interface Y {}
+
+class C {
+  // TODO: require is not allowed outside of `interface` or `constraint`.
+  // CHECK:STDERR: fail_todo_require_in_class.carbon:[[@LINE+4]]:3: error: semantics TODO: `require` [SemanticsTodo]
+  // CHECK:STDERR:   require impls Y;
+  // CHECK:STDERR:   ^~~~~~~
+  // CHECK:STDERR:
+  require impls Y;
+}
+
+// --- fail_require_in_fn.carbon
+library "[[@TEST_NAME]]";
+
+interface Y {}
+
+fn F() {
+  // require is not allowed outside of `interface` or `constraint`.
+  // CHECK:STDERR: fail_require_in_fn.carbon:[[@LINE+8]]:3: error: expected expression [ExpectedExpr]
+  // CHECK:STDERR:   require impls Y;
+  // CHECK:STDERR:   ^~~~~~~
+  // CHECK:STDERR:
+  // CHECK:STDERR: fail_require_in_fn.carbon:[[@LINE+4]]:3: error: semantics TODO: `handle invalid parse trees in `check`` [SemanticsTodo]
+  // CHECK:STDERR:   require impls Y;
+  // CHECK:STDERR:   ^~~~~~~
+  // CHECK:STDERR:
+  require impls Y;
+}