Toolchain: Semantics for indexing (#3044)

Co-authored-by: Farzana Ahmed Siddique <fasiddique@google.com>

toolchain/diagnostics/diagnostic_kind.def

@@ -104,6 +104,9 @@ CARBON_DIAGNOSTIC_KIND(CallArgCountMismatch)
 CARBON_DIAGNOSTIC_KIND(CallArgTypeMismatch)
 CARBON_DIAGNOSTIC_KIND(MissingReturnStatement)
 CARBON_DIAGNOSTIC_KIND(RepeatedConst)
+CARBON_DIAGNOSTIC_KIND(InvalidIndexExpression)
+CARBON_DIAGNOSTIC_KIND(NondeterministicType)
+CARBON_DIAGNOSTIC_KIND(OutOfBoundsAccess)
 CARBON_DIAGNOSTIC_KIND(ReturnStatementDisallowExpression)
 CARBON_DIAGNOSTIC_KIND(ReturnStatementImplicitNote)
 CARBON_DIAGNOSTIC_KIND(ReturnStatementMissingExpression)

toolchain/lowering/lowering_handle.cpp

@@ -145,6 +145,12 @@ auto LoweringHandleFunctionDeclaration(LoweringFunctionContext& /*context*/,
       << node;
 }
 
+auto LoweringHandleIndex(LoweringFunctionContext& /*context*/,
+                         SemanticsNodeId /*node_id*/, SemanticsNode node)
+    -> void {
+  CARBON_FATAL() << "TODO: Add support: " << node;
+}
+
 auto LoweringHandleIntegerLiteral(LoweringFunctionContext& context,
                                   SemanticsNodeId node_id, SemanticsNode node)
     -> void {

toolchain/semantics/semantics_handle_index.cpp

@@ -2,20 +2,66 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-#include <utility>
+#include <cstdint>
 
 #include "toolchain/semantics/semantics_context.h"
+#include "toolchain/semantics/semantics_node.h"
+#include "toolchain/semantics/semantics_node_kind.h"
 
 namespace Carbon {
 
-auto SemanticsHandleIndexExpressionStart(SemanticsContext& context,
-                                         ParseTree::Node parse_node) -> bool {
-  return context.TODO(parse_node, "HandleIndexExpressionStart");
+auto SemanticsHandleIndexExpressionStart(SemanticsContext& /*context*/,
+                                         ParseTree::Node /*parse_node*/)
+    -> bool {
+  // Leave the expression on the stack for IndexExpression.
+  return true;
 }
 
 auto SemanticsHandleIndexExpression(SemanticsContext& context,
                                     ParseTree::Node parse_node) -> bool {
-  return context.TODO(parse_node, "HandleIndexExpression");
+  auto index_node_id = context.node_stack().PopExpression();
+  auto index_node = context.semantics_ir().GetNode(index_node_id);
+  auto name_node_id = context.node_stack().PopExpression();
+  auto name_node = context.semantics_ir().GetNode(name_node_id);
+  auto name_type_id =
+      context.semantics_ir().GetTypeAllowBuiltinTypes(name_node.type_id());
+  auto name_type_node = context.semantics_ir().GetNode(name_type_id);
+
+  if (name_type_node.kind() == SemanticsNodeKind::TupleType &&
+      index_node.kind() == SemanticsNodeKind::IntegerLiteral) {
+    const auto& index_val = (context.semantics_ir().GetIntegerLiteral(
+        index_node.GetAsIntegerLiteral()));
+    auto type_block =
+        context.semantics_ir().GetTypeBlock(name_type_node.GetAsTupleType());
+
+    if (index_val.uge(static_cast<uint64_t>(type_block.size()))) {
+      CARBON_DIAGNOSTIC(OutOfBoundsAccess, Error,
+                        "Index `{0}` is past the end of `{1}`.", llvm::APSInt,
+                        std::string);
+      context.emitter().Emit(
+          parse_node, OutOfBoundsAccess,
+          llvm::APSInt(index_val, /*isUnsigned=*/true),
+          context.semantics_ir().StringifyType(name_node.type_id()));
+    } else {
+      context.AddNodeAndPush(
+          parse_node, SemanticsNode::Index::Make(
+                          parse_node, type_block[index_val.getZExtValue()],
+                          name_node_id, index_node_id));
+      return true;
+    }
+  } else if (index_node.kind() != SemanticsNodeKind::IntegerLiteral) {
+    CARBON_DIAGNOSTIC(NondeterministicType, Error,
+                      "Type cannot be determined at compile time.");
+    context.emitter().Emit(parse_node, NondeterministicType);
+  } else if (name_type_node.kind() != SemanticsNodeKind::TupleType &&
+             name_type_id != SemanticsNodeId::BuiltinError) {
+    CARBON_DIAGNOSTIC(InvalidIndexExpression, Error,
+                      "Invalid index expression.");
+    context.emitter().Emit(parse_node, InvalidIndexExpression);
+  }
+
+  context.node_stack().Push(parse_node, SemanticsNodeId::BuiltinError);
+  return true;
 }
 
 }  // namespace Carbon

toolchain/semantics/semantics_ir.cpp

@@ -227,6 +227,7 @@ static auto GetTypePrecedence(SemanticsNodeKind kind) -> int {
     case SemanticsNodeKind::BranchWithArg:
     case SemanticsNodeKind::Call:
     case SemanticsNodeKind::FunctionDeclaration:
+    case SemanticsNodeKind::Index:
     case SemanticsNodeKind::IntegerLiteral:
     case SemanticsNodeKind::Invalid:
     case SemanticsNodeKind::Namespace:
@@ -365,6 +366,7 @@ auto SemanticsIR::StringifyType(SemanticsTypeId type_id) -> std::string {
       case SemanticsNodeKind::Call:
       case SemanticsNodeKind::CrossReference:
       case SemanticsNodeKind::FunctionDeclaration:
+      case SemanticsNodeKind::Index:
       case SemanticsNodeKind::IntegerLiteral:
       case SemanticsNodeKind::Namespace:
       case SemanticsNodeKind::RealLiteral:

toolchain/semantics/semantics_node.h

@@ -380,6 +380,9 @@ class SemanticsNode {
       FactoryNoType<SemanticsNodeKind::FunctionDeclaration,
                     SemanticsFunctionId /*function_id*/>;
 
+  using Index = Factory<SemanticsNodeKind::Index, SemanticsNodeId /*tuple_id*/,
+                        SemanticsNodeId /*index*/>;
+
   using IntegerLiteral = Factory<SemanticsNodeKind::IntegerLiteral,
                                  SemanticsIntegerLiteralId /*integer_id*/>;
 

toolchain/semantics/semantics_node_kind.def

@@ -39,6 +39,7 @@ CARBON_SEMANTICS_NODE_KIND(Builtin)
 CARBON_SEMANTICS_NODE_KIND(Call)
 CARBON_SEMANTICS_NODE_KIND(ConstType)
 CARBON_SEMANTICS_NODE_KIND(FunctionDeclaration)
+CARBON_SEMANTICS_NODE_KIND(Index)
 CARBON_SEMANTICS_NODE_KIND(IntegerLiteral)
 CARBON_SEMANTICS_NODE_KIND(Namespace)
 CARBON_SEMANTICS_NODE_KIND(PointerType)

toolchain/semantics/semantics_node_stack.h

@@ -244,6 +244,7 @@ class SemanticsNodeStack {
       case ParseNodeKind::CallExpression:
       case ParseNodeKind::CallExpressionStart:
       case ParseNodeKind::IfExpressionElse:
+      case ParseNodeKind::IndexExpression:
       case ParseNodeKind::InfixOperator:
       case ParseNodeKind::Literal:
       case ParseNodeKind::MemberAccessExpression:

toolchain/semantics/testdata/index/element_access.carbon

@@ -0,0 +1,93 @@
+// 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
+//
+// AUTOUPDATE
+// CHECK:STDOUT: cross_reference_irs_size: 1
+// CHECK:STDOUT: functions: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: integer_literals: [
+// CHECK:STDOUT:   12,
+// CHECK:STDOUT:   0,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: real_literals: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: strings: [
+// CHECK:STDOUT:   a,
+// CHECK:STDOUT:   b,
+// CHECK:STDOUT:   c,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: types: [
+// CHECK:STDOUT:   node+1,
+// CHECK:STDOUT:   nodeIntegerType,
+// CHECK:STDOUT:   node+3,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: type_blocks: [
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     typeTypeType,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     type1,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: nodes: [
+// CHECK:STDOUT:   {kind: StubReference, arg0: nodeIntegerType, type: typeTypeType},
+// CHECK:STDOUT:   {kind: TupleType, arg0: typeBlock0, type: typeTypeType},
+// CHECK:STDOUT:   {kind: TupleValue, arg0: block2, type: type0},
+// CHECK:STDOUT:   {kind: TupleType, arg0: typeBlock1, type: typeTypeType},
+// CHECK:STDOUT:   {kind: VarStorage, type: type2},
+// CHECK:STDOUT:   {kind: BindName, arg0: str0, arg1: node+4, type: type2},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int0, type: type1},
+// CHECK:STDOUT:   {kind: StubReference, arg0: node+6, type: type1},
+// CHECK:STDOUT:   {kind: TupleValue, arg0: block3, type: type2},
+// CHECK:STDOUT:   {kind: Assign, arg0: node+4, arg1: node+8},
+// CHECK:STDOUT:   {kind: StubReference, arg0: nodeIntegerType, type: typeTypeType},
+// CHECK:STDOUT:   {kind: TupleValue, arg0: block4, type: type0},
+// CHECK:STDOUT:   {kind: VarStorage, type: type2},
+// CHECK:STDOUT:   {kind: BindName, arg0: str1, arg1: node+12, type: type2},
+// CHECK:STDOUT:   {kind: Assign, arg0: node+12, arg1: node+4},
+// CHECK:STDOUT:   {kind: VarStorage, type: type1},
+// CHECK:STDOUT:   {kind: BindName, arg0: str2, arg1: node+15, type: type1},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int1, type: type1},
+// CHECK:STDOUT:   {kind: Index, arg0: node+12, arg1: node+17, type: type1},
+// CHECK:STDOUT:   {kind: Assign, arg0: node+15, arg1: node+18},
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: node_blocks: [
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+0,
+// CHECK:STDOUT:     node+1,
+// CHECK:STDOUT:     node+2,
+// CHECK:STDOUT:     node+3,
+// CHECK:STDOUT:     node+4,
+// CHECK:STDOUT:     node+5,
+// CHECK:STDOUT:     node+6,
+// CHECK:STDOUT:     node+7,
+// CHECK:STDOUT:     node+8,
+// CHECK:STDOUT:     node+9,
+// CHECK:STDOUT:     node+10,
+// CHECK:STDOUT:     node+11,
+// CHECK:STDOUT:     node+12,
+// CHECK:STDOUT:     node+13,
+// CHECK:STDOUT:     node+14,
+// CHECK:STDOUT:     node+15,
+// CHECK:STDOUT:     node+16,
+// CHECK:STDOUT:     node+17,
+// CHECK:STDOUT:     node+18,
+// CHECK:STDOUT:     node+19,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+0,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+7,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+10,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT: ]
+
+var a: (i32,) = (12,);
+var b: (i32,) = a;
+var c: i32 = b[0];

toolchain/semantics/testdata/index/fail_empty_tuple_access.carbon

@@ -0,0 +1,62 @@
+// 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
+//
+// AUTOUPDATE
+// CHECK:STDOUT: cross_reference_irs_size: 1
+// CHECK:STDOUT: functions: [
+// CHECK:STDOUT:   {name: str0, param_refs: block0, body: {block2}}},
+// CHECK:STDOUT:   {name: str1, param_refs: block0, body: {block3}}},
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: integer_literals: [
+// CHECK:STDOUT:   0,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: real_literals: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: strings: [
+// CHECK:STDOUT:   F,
+// CHECK:STDOUT:   Run,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: types: [
+// CHECK:STDOUT:   node+3,
+// CHECK:STDOUT:   nodeIntegerType,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: type_blocks: [
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: nodes: [
+// CHECK:STDOUT:   {kind: FunctionDeclaration, arg0: function0},
+// CHECK:STDOUT:   {kind: Return},
+// CHECK:STDOUT:   {kind: FunctionDeclaration, arg0: function1},
+// CHECK:STDOUT:   {kind: TupleType, arg0: typeBlock0, type: typeTypeType},
+// CHECK:STDOUT:   {kind: Call, arg0: block0, arg1: function0, type: type0},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int0, type: type1},
+// CHECK:STDOUT:   {kind: Return},
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: node_blocks: [
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+0,
+// CHECK:STDOUT:     node+2,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+1,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+3,
+// CHECK:STDOUT:     node+4,
+// CHECK:STDOUT:     node+5,
+// CHECK:STDOUT:     node+6,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT: ]
+
+fn F() {}
+
+fn Run() {
+  // CHECK:STDERR: fail_empty_tuple_access.carbon:[[@LINE+3]]:8: Index `0` is past the end of `() as type`.
+  // CHECK:STDERR:   F()[0];
+  // CHECK:STDERR:        ^
+  F()[0];
+}

toolchain/semantics/testdata/index/fail_large_index.carbon

@@ -0,0 +1,94 @@
+// 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
+//
+// AUTOUPDATE
+// CHECK:STDOUT: cross_reference_irs_size: 1
+// CHECK:STDOUT: functions: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: integer_literals: [
+// CHECK:STDOUT:   12,
+// CHECK:STDOUT:   -1,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: real_literals: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: strings: [
+// CHECK:STDOUT:   a,
+// CHECK:STDOUT:   b,
+// CHECK:STDOUT:   c,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: types: [
+// CHECK:STDOUT:   node+1,
+// CHECK:STDOUT:   nodeIntegerType,
+// CHECK:STDOUT:   node+3,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: type_blocks: [
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     typeTypeType,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     type1,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: nodes: [
+// CHECK:STDOUT:   {kind: StubReference, arg0: nodeIntegerType, type: typeTypeType},
+// CHECK:STDOUT:   {kind: TupleType, arg0: typeBlock0, type: typeTypeType},
+// CHECK:STDOUT:   {kind: TupleValue, arg0: block2, type: type0},
+// CHECK:STDOUT:   {kind: TupleType, arg0: typeBlock1, type: typeTypeType},
+// CHECK:STDOUT:   {kind: VarStorage, type: type2},
+// CHECK:STDOUT:   {kind: BindName, arg0: str0, arg1: node+4, type: type2},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int0, type: type1},
+// CHECK:STDOUT:   {kind: StubReference, arg0: node+6, type: type1},
+// CHECK:STDOUT:   {kind: TupleValue, arg0: block3, type: type2},
+// CHECK:STDOUT:   {kind: Assign, arg0: node+4, arg1: node+8},
+// CHECK:STDOUT:   {kind: StubReference, arg0: nodeIntegerType, type: typeTypeType},
+// CHECK:STDOUT:   {kind: TupleValue, arg0: block4, type: type0},
+// CHECK:STDOUT:   {kind: VarStorage, type: type2},
+// CHECK:STDOUT:   {kind: BindName, arg0: str1, arg1: node+12, type: type2},
+// CHECK:STDOUT:   {kind: Assign, arg0: node+12, arg1: node+4},
+// CHECK:STDOUT:   {kind: VarStorage, type: type1},
+// CHECK:STDOUT:   {kind: BindName, arg0: str2, arg1: node+15, type: type1},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int1, type: type1},
+// CHECK:STDOUT:   {kind: Assign, arg0: node+15, arg1: nodeError},
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: node_blocks: [
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+0,
+// CHECK:STDOUT:     node+1,
+// CHECK:STDOUT:     node+2,
+// CHECK:STDOUT:     node+3,
+// CHECK:STDOUT:     node+4,
+// CHECK:STDOUT:     node+5,
+// CHECK:STDOUT:     node+6,
+// CHECK:STDOUT:     node+7,
+// CHECK:STDOUT:     node+8,
+// CHECK:STDOUT:     node+9,
+// CHECK:STDOUT:     node+10,
+// CHECK:STDOUT:     node+11,
+// CHECK:STDOUT:     node+12,
+// CHECK:STDOUT:     node+13,
+// CHECK:STDOUT:     node+14,
+// CHECK:STDOUT:     node+15,
+// CHECK:STDOUT:     node+16,
+// CHECK:STDOUT:     node+17,
+// CHECK:STDOUT:     node+18,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+0,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+7,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+10,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT: ]
+
+var a: (i32,) = (12,);
+var b: (i32,) = a;
+// CHECK:STDERR: fail_large_index.carbon:[[@LINE+3]]:35: Index `295147905179352825855` is past the end of `(i32,) as type`.
+// CHECK:STDERR: var c: i32 = b[0xFFFFFFFFFFFFFFFFF];
+// CHECK:STDERR:                                   ^
+var c: i32 = b[0xFFFFFFFFFFFFFFFFF];

toolchain/semantics/testdata/index/fail_name_not_found.carbon

@@ -0,0 +1,53 @@
+// 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
+//
+// AUTOUPDATE
+// CHECK:STDOUT: cross_reference_irs_size: 1
+// CHECK:STDOUT: functions: [
+// CHECK:STDOUT:   {name: str0, param_refs: block0, body: {block2}}},
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: integer_literals: [
+// CHECK:STDOUT:   0,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: real_literals: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: strings: [
+// CHECK:STDOUT:   Main,
+// CHECK:STDOUT:   b,
+// CHECK:STDOUT:   a,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: types: [
+// CHECK:STDOUT:   nodeIntegerType,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: type_blocks: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: nodes: [
+// CHECK:STDOUT:   {kind: FunctionDeclaration, arg0: function0},
+// CHECK:STDOUT:   {kind: VarStorage, type: type0},
+// CHECK:STDOUT:   {kind: BindName, arg0: str1, arg1: node+1, type: type0},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int0, type: type0},
+// CHECK:STDOUT:   {kind: Assign, arg0: node+1, arg1: nodeError},
+// CHECK:STDOUT:   {kind: Return},
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: node_blocks: [
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+0,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+1,
+// CHECK:STDOUT:     node+2,
+// CHECK:STDOUT:     node+3,
+// CHECK:STDOUT:     node+4,
+// CHECK:STDOUT:     node+5,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT: ]
+
+fn Main() {
+  // CHECK:STDERR: fail_name_not_found.carbon:[[@LINE+3]]:16: Name `a` not found
+  // CHECK:STDERR:   var b: i32 = a[0];
+  // CHECK:STDERR:                ^
+  var b: i32 = a[0];
+}

toolchain/semantics/testdata/index/fail_negative_indexing.carbon

@@ -0,0 +1,88 @@
+// 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
+//
+// AUTOUPDATE
+// CHECK:STDOUT: cross_reference_irs_size: 1
+// CHECK:STDOUT: functions: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: integer_literals: [
+// CHECK:STDOUT:   12,
+// CHECK:STDOUT:   6,
+// CHECK:STDOUT:   10,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: real_literals: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: strings: [
+// CHECK:STDOUT:   a,
+// CHECK:STDOUT:   b,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: types: [
+// CHECK:STDOUT:   node+2,
+// CHECK:STDOUT:   nodeIntegerType,
+// CHECK:STDOUT:   node+4,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: type_blocks: [
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     typeTypeType,
+// CHECK:STDOUT:     typeTypeType,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     type1,
+// CHECK:STDOUT:     type1,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: nodes: [
+// CHECK:STDOUT:   {kind: StubReference, arg0: nodeIntegerType, type: typeTypeType},
+// CHECK:STDOUT:   {kind: StubReference, arg0: nodeIntegerType, type: typeTypeType},
+// CHECK:STDOUT:   {kind: TupleType, arg0: typeBlock0, type: typeTypeType},
+// CHECK:STDOUT:   {kind: TupleValue, arg0: block2, type: type0},
+// CHECK:STDOUT:   {kind: TupleType, arg0: typeBlock1, type: typeTypeType},
+// CHECK:STDOUT:   {kind: VarStorage, type: type2},
+// CHECK:STDOUT:   {kind: BindName, arg0: str0, arg1: node+5, type: type2},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int0, type: type1},
+// CHECK:STDOUT:   {kind: StubReference, arg0: node+7, type: type1},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int1, type: type1},
+// CHECK:STDOUT:   {kind: StubReference, arg0: node+9, type: type1},
+// CHECK:STDOUT:   {kind: TupleValue, arg0: block3, type: type2},
+// CHECK:STDOUT:   {kind: Assign, arg0: node+5, arg1: node+11},
+// CHECK:STDOUT:   {kind: VarStorage, type: type1},
+// CHECK:STDOUT:   {kind: BindName, arg0: str1, arg1: node+13, type: type1},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int2, type: type1},
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: node_blocks: [
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+0,
+// CHECK:STDOUT:     node+1,
+// CHECK:STDOUT:     node+2,
+// CHECK:STDOUT:     node+3,
+// CHECK:STDOUT:     node+4,
+// CHECK:STDOUT:     node+5,
+// CHECK:STDOUT:     node+6,
+// CHECK:STDOUT:     node+7,
+// CHECK:STDOUT:     node+8,
+// CHECK:STDOUT:     node+9,
+// CHECK:STDOUT:     node+10,
+// CHECK:STDOUT:     node+11,
+// CHECK:STDOUT:     node+12,
+// CHECK:STDOUT:     node+13,
+// CHECK:STDOUT:     node+14,
+// CHECK:STDOUT:     node+15,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+0,
+// CHECK:STDOUT:     node+1,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+8,
+// CHECK:STDOUT:     node+10,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT: ]
+
+var a: (i32, i32) = (12, 6);
+// CHECK:STDERR: fail_negative_indexing.carbon:[[@LINE+3]]:16: Semantics TODO: Handle -
+// CHECK:STDERR: var b: i32 = a[-10];
+// CHECK:STDERR:                ^
+var b: i32 = a[-10];

toolchain/semantics/testdata/index/fail_non_deterministic_type.carbon

@@ -0,0 +1,98 @@
+// 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
+//
+// AUTOUPDATE
+// CHECK:STDOUT: cross_reference_irs_size: 1
+// CHECK:STDOUT: functions: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: integer_literals: [
+// CHECK:STDOUT:   2,
+// CHECK:STDOUT:   3,
+// CHECK:STDOUT:   0,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: real_literals: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: strings: [
+// CHECK:STDOUT:   a,
+// CHECK:STDOUT:   b,
+// CHECK:STDOUT:   c,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: types: [
+// CHECK:STDOUT:   node+2,
+// CHECK:STDOUT:   nodeIntegerType,
+// CHECK:STDOUT:   node+4,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: type_blocks: [
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     typeTypeType,
+// CHECK:STDOUT:     typeTypeType,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     type1,
+// CHECK:STDOUT:     type1,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: nodes: [
+// CHECK:STDOUT:   {kind: StubReference, arg0: nodeIntegerType, type: typeTypeType},
+// CHECK:STDOUT:   {kind: StubReference, arg0: nodeIntegerType, type: typeTypeType},
+// CHECK:STDOUT:   {kind: TupleType, arg0: typeBlock0, type: typeTypeType},
+// CHECK:STDOUT:   {kind: TupleValue, arg0: block2, type: type0},
+// CHECK:STDOUT:   {kind: TupleType, arg0: typeBlock1, type: typeTypeType},
+// CHECK:STDOUT:   {kind: VarStorage, type: type2},
+// CHECK:STDOUT:   {kind: BindName, arg0: str0, arg1: node+5, type: type2},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int0, type: type1},
+// CHECK:STDOUT:   {kind: StubReference, arg0: node+7, type: type1},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int1, type: type1},
+// CHECK:STDOUT:   {kind: StubReference, arg0: node+9, type: type1},
+// CHECK:STDOUT:   {kind: TupleValue, arg0: block3, type: type2},
+// CHECK:STDOUT:   {kind: Assign, arg0: node+5, arg1: node+11},
+// CHECK:STDOUT:   {kind: VarStorage, type: type1},
+// CHECK:STDOUT:   {kind: BindName, arg0: str1, arg1: node+13, type: type1},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int2, type: type1},
+// CHECK:STDOUT:   {kind: Assign, arg0: node+13, arg1: node+15},
+// CHECK:STDOUT:   {kind: VarStorage, type: type1},
+// CHECK:STDOUT:   {kind: BindName, arg0: str2, arg1: node+17, type: type1},
+// CHECK:STDOUT:   {kind: Assign, arg0: node+17, arg1: nodeError},
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: node_blocks: [
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+0,
+// CHECK:STDOUT:     node+1,
+// CHECK:STDOUT:     node+2,
+// CHECK:STDOUT:     node+3,
+// CHECK:STDOUT:     node+4,
+// CHECK:STDOUT:     node+5,
+// CHECK:STDOUT:     node+6,
+// CHECK:STDOUT:     node+7,
+// CHECK:STDOUT:     node+8,
+// CHECK:STDOUT:     node+9,
+// CHECK:STDOUT:     node+10,
+// CHECK:STDOUT:     node+11,
+// CHECK:STDOUT:     node+12,
+// CHECK:STDOUT:     node+13,
+// CHECK:STDOUT:     node+14,
+// CHECK:STDOUT:     node+15,
+// CHECK:STDOUT:     node+16,
+// CHECK:STDOUT:     node+17,
+// CHECK:STDOUT:     node+18,
+// CHECK:STDOUT:     node+19,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+0,
+// CHECK:STDOUT:     node+1,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+8,
+// CHECK:STDOUT:     node+10,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT: ]
+
+var a: (i32, i32) = (2, 3);
+var b: i32 = 0;
+// CHECK:STDERR: fail_non_deterministic_type.carbon:[[@LINE+3]]:17: Type cannot be determined at compile time.
+// CHECK:STDERR: var c: i32 = a[b];
+// CHECK:STDERR:                 ^
+var c: i32 = a[b];

toolchain/semantics/testdata/index/fail_non_int_indexing.carbon

@@ -0,0 +1,91 @@
+// 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
+//
+// AUTOUPDATE
+// CHECK:STDOUT: cross_reference_irs_size: 1
+// CHECK:STDOUT: functions: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: integer_literals: [
+// CHECK:STDOUT:   12,
+// CHECK:STDOUT:   6,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: real_literals: [
+// CHECK:STDOUT:   {mantissa: 26, exponent: -1, is_decimal: 1},
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: strings: [
+// CHECK:STDOUT:   a,
+// CHECK:STDOUT:   b,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: types: [
+// CHECK:STDOUT:   node+2,
+// CHECK:STDOUT:   nodeIntegerType,
+// CHECK:STDOUT:   node+4,
+// CHECK:STDOUT:   nodeFloatingPointType,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: type_blocks: [
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     typeTypeType,
+// CHECK:STDOUT:     typeTypeType,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     type1,
+// CHECK:STDOUT:     type1,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: nodes: [
+// CHECK:STDOUT:   {kind: StubReference, arg0: nodeIntegerType, type: typeTypeType},
+// CHECK:STDOUT:   {kind: StubReference, arg0: nodeIntegerType, type: typeTypeType},
+// CHECK:STDOUT:   {kind: TupleType, arg0: typeBlock0, type: typeTypeType},
+// CHECK:STDOUT:   {kind: TupleValue, arg0: block2, type: type0},
+// CHECK:STDOUT:   {kind: TupleType, arg0: typeBlock1, type: typeTypeType},
+// CHECK:STDOUT:   {kind: VarStorage, type: type2},
+// CHECK:STDOUT:   {kind: BindName, arg0: str0, arg1: node+5, type: type2},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int0, type: type1},
+// CHECK:STDOUT:   {kind: StubReference, arg0: node+7, type: type1},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int1, type: type1},
+// CHECK:STDOUT:   {kind: StubReference, arg0: node+9, type: type1},
+// CHECK:STDOUT:   {kind: TupleValue, arg0: block3, type: type2},
+// CHECK:STDOUT:   {kind: Assign, arg0: node+5, arg1: node+11},
+// CHECK:STDOUT:   {kind: VarStorage, type: type1},
+// CHECK:STDOUT:   {kind: BindName, arg0: str1, arg1: node+13, type: type1},
+// CHECK:STDOUT:   {kind: RealLiteral, arg0: real0, type: type3},
+// CHECK:STDOUT:   {kind: Assign, arg0: node+13, arg1: nodeError},
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: node_blocks: [
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+0,
+// CHECK:STDOUT:     node+1,
+// CHECK:STDOUT:     node+2,
+// CHECK:STDOUT:     node+3,
+// CHECK:STDOUT:     node+4,
+// CHECK:STDOUT:     node+5,
+// CHECK:STDOUT:     node+6,
+// CHECK:STDOUT:     node+7,
+// CHECK:STDOUT:     node+8,
+// CHECK:STDOUT:     node+9,
+// CHECK:STDOUT:     node+10,
+// CHECK:STDOUT:     node+11,
+// CHECK:STDOUT:     node+12,
+// CHECK:STDOUT:     node+13,
+// CHECK:STDOUT:     node+14,
+// CHECK:STDOUT:     node+15,
+// CHECK:STDOUT:     node+16,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+0,
+// CHECK:STDOUT:     node+1,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+8,
+// CHECK:STDOUT:     node+10,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT: ]
+
+var a: (i32, i32) = (12, 6);
+// CHECK:STDERR: fail_non_int_indexing.carbon:[[@LINE+3]]:19: Type cannot be determined at compile time.
+// CHECK:STDERR: var b: i32 = a[2.6];
+// CHECK:STDERR:                   ^
+var b: i32 = a[2.6];

toolchain/semantics/testdata/index/fail_non_tuple_access.carbon

@@ -0,0 +1,48 @@
+// 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
+//
+// AUTOUPDATE
+// CHECK:STDOUT: cross_reference_irs_size: 1
+// CHECK:STDOUT: functions: [
+// CHECK:STDOUT:   {name: str0, param_refs: block0, body: {block2}}},
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: integer_literals: [
+// CHECK:STDOUT:   0,
+// CHECK:STDOUT:   1,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: real_literals: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: strings: [
+// CHECK:STDOUT:   Main,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: types: [
+// CHECK:STDOUT:   nodeIntegerType,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: type_blocks: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: nodes: [
+// CHECK:STDOUT:   {kind: FunctionDeclaration, arg0: function0},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int0, type: type0},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int1, type: type0},
+// CHECK:STDOUT:   {kind: Return},
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: node_blocks: [
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+0,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+1,
+// CHECK:STDOUT:     node+2,
+// CHECK:STDOUT:     node+3,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT: ]
+
+fn Main() {
+  // CHECK:STDERR: fail_non_tuple_access.carbon:[[@LINE+3]]:6: Invalid index expression.
+  // CHECK:STDERR:   0[1];
+  // CHECK:STDERR:      ^
+  0[1];
+}

toolchain/semantics/testdata/index/fail_out_of_bound_access.carbon

@@ -0,0 +1,90 @@
+// 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
+//
+// AUTOUPDATE
+// CHECK:STDOUT: cross_reference_irs_size: 1
+// CHECK:STDOUT: functions: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: integer_literals: [
+// CHECK:STDOUT:   12,
+// CHECK:STDOUT:   6,
+// CHECK:STDOUT:   2,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: real_literals: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: strings: [
+// CHECK:STDOUT:   a,
+// CHECK:STDOUT:   b,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: types: [
+// CHECK:STDOUT:   node+2,
+// CHECK:STDOUT:   nodeIntegerType,
+// CHECK:STDOUT:   node+4,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: type_blocks: [
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     typeTypeType,
+// CHECK:STDOUT:     typeTypeType,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     type1,
+// CHECK:STDOUT:     type1,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: nodes: [
+// CHECK:STDOUT:   {kind: StubReference, arg0: nodeIntegerType, type: typeTypeType},
+// CHECK:STDOUT:   {kind: StubReference, arg0: nodeIntegerType, type: typeTypeType},
+// CHECK:STDOUT:   {kind: TupleType, arg0: typeBlock0, type: typeTypeType},
+// CHECK:STDOUT:   {kind: TupleValue, arg0: block2, type: type0},
+// CHECK:STDOUT:   {kind: TupleType, arg0: typeBlock1, type: typeTypeType},
+// CHECK:STDOUT:   {kind: VarStorage, type: type2},
+// CHECK:STDOUT:   {kind: BindName, arg0: str0, arg1: node+5, type: type2},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int0, type: type1},
+// CHECK:STDOUT:   {kind: StubReference, arg0: node+7, type: type1},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int1, type: type1},
+// CHECK:STDOUT:   {kind: StubReference, arg0: node+9, type: type1},
+// CHECK:STDOUT:   {kind: TupleValue, arg0: block3, type: type2},
+// CHECK:STDOUT:   {kind: Assign, arg0: node+5, arg1: node+11},
+// CHECK:STDOUT:   {kind: VarStorage, type: type1},
+// CHECK:STDOUT:   {kind: BindName, arg0: str1, arg1: node+13, type: type1},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int2, type: type1},
+// CHECK:STDOUT:   {kind: Assign, arg0: node+13, arg1: nodeError},
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: node_blocks: [
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+0,
+// CHECK:STDOUT:     node+1,
+// CHECK:STDOUT:     node+2,
+// CHECK:STDOUT:     node+3,
+// CHECK:STDOUT:     node+4,
+// CHECK:STDOUT:     node+5,
+// CHECK:STDOUT:     node+6,
+// CHECK:STDOUT:     node+7,
+// CHECK:STDOUT:     node+8,
+// CHECK:STDOUT:     node+9,
+// CHECK:STDOUT:     node+10,
+// CHECK:STDOUT:     node+11,
+// CHECK:STDOUT:     node+12,
+// CHECK:STDOUT:     node+13,
+// CHECK:STDOUT:     node+14,
+// CHECK:STDOUT:     node+15,
+// CHECK:STDOUT:     node+16,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+0,
+// CHECK:STDOUT:     node+1,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+8,
+// CHECK:STDOUT:     node+10,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT: ]
+
+var a: (i32, i32) = (12, 6);
+// CHECK:STDERR: fail_out_of_bound_access.carbon:[[@LINE+3]]:17: Index `2` is past the end of `(i32, i32) as type`.
+// CHECK:STDERR: var b: i32 = a[2];
+// CHECK:STDERR:                 ^
+var b: i32 = a[2];

toolchain/semantics/testdata/index/return_value_access.carbon

@@ -0,0 +1,85 @@
+// 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
+//
+// AUTOUPDATE
+// CHECK:STDOUT: cross_reference_irs_size: 1
+// CHECK:STDOUT: functions: [
+// CHECK:STDOUT:   {name: str0, param_refs: block0, return_type: type2, body: {block3}}},
+// CHECK:STDOUT:   {name: str1, param_refs: block0, return_type: type1, body: {block5}}},
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: integer_literals: [
+// CHECK:STDOUT:   0,
+// CHECK:STDOUT:   0,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: real_literals: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: strings: [
+// CHECK:STDOUT:   F,
+// CHECK:STDOUT:   Run,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: types: [
+// CHECK:STDOUT:   node+1,
+// CHECK:STDOUT:   nodeIntegerType,
+// CHECK:STDOUT:   node+3,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: type_blocks: [
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     typeTypeType,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     type1,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: nodes: [
+// CHECK:STDOUT:   {kind: StubReference, arg0: nodeIntegerType, type: typeTypeType},
+// CHECK:STDOUT:   {kind: TupleType, arg0: typeBlock0, type: typeTypeType},
+// CHECK:STDOUT:   {kind: TupleValue, arg0: block2, type: type0},
+// CHECK:STDOUT:   {kind: TupleType, arg0: typeBlock1, type: typeTypeType},
+// CHECK:STDOUT:   {kind: FunctionDeclaration, arg0: function0},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int0, type: type1},
+// CHECK:STDOUT:   {kind: StubReference, arg0: node+5, type: type1},
+// CHECK:STDOUT:   {kind: TupleValue, arg0: block4, type: type2},
+// CHECK:STDOUT:   {kind: ReturnExpression, arg0: node+7},
+// CHECK:STDOUT:   {kind: FunctionDeclaration, arg0: function1},
+// CHECK:STDOUT:   {kind: Call, arg0: block0, arg1: function0, type: type2},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int1, type: type1},
+// CHECK:STDOUT:   {kind: Index, arg0: node+10, arg1: node+11, type: type1},
+// CHECK:STDOUT:   {kind: ReturnExpression, arg0: node+12},
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: node_blocks: [
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+0,
+// CHECK:STDOUT:     node+1,
+// CHECK:STDOUT:     node+2,
+// CHECK:STDOUT:     node+3,
+// CHECK:STDOUT:     node+4,
+// CHECK:STDOUT:     node+9,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+0,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+5,
+// CHECK:STDOUT:     node+6,
+// CHECK:STDOUT:     node+7,
+// CHECK:STDOUT:     node+8,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+6,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+10,
+// CHECK:STDOUT:     node+11,
+// CHECK:STDOUT:     node+12,
+// CHECK:STDOUT:     node+13,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT: ]
+
+fn F() -> (i32,) { return (0,); }
+
+fn Run() -> i32 {
+  return F()[0];
+}