clang-tidy pass on executable_semantics (#963)

executable_semantics/ast/ast_node.h

@@ -81,7 +81,7 @@ namespace llvm {
 template <typename To>
 struct cast_convert_val<To, const Carbon::AstNode*, const Carbon::AstNode*> {
   using ResultType = typename cast_retty<To, const Carbon::AstNode*>::ret_type;
-  static ResultType doit(const Carbon::AstNode* node) {
+  static auto doit(const Carbon::AstNode* node) -> ResultType {
     return dynamic_cast<ResultType>(node);
   }
 };
@@ -89,7 +89,7 @@ struct cast_convert_val<To, const Carbon::AstNode*, const Carbon::AstNode*> {
 template <typename To>
 struct cast_convert_val<To, Carbon::AstNode*, Carbon::AstNode*> {
   using ResultType = typename cast_retty<To, Carbon::AstNode*>::ret_type;
-  static ResultType doit(Carbon::AstNode* node) {
+  static auto doit(Carbon::AstNode* node) -> ResultType {
     return dynamic_cast<ResultType>(node);
   }
 };
@@ -97,7 +97,7 @@ struct cast_convert_val<To, Carbon::AstNode*, Carbon::AstNode*> {
 template <typename To>
 struct cast_convert_val<To, const Carbon::AstNode, const Carbon::AstNode> {
   using ResultType = typename cast_retty<To, const Carbon::AstNode>::ret_type;
-  static ResultType doit(const Carbon::AstNode& node) {
+  static auto doit(const Carbon::AstNode& node) -> ResultType {
     return dynamic_cast<ResultType>(node);
   }
 };
@@ -105,7 +105,7 @@ struct cast_convert_val<To, const Carbon::AstNode, const Carbon::AstNode> {
 template <typename To>
 struct cast_convert_val<To, Carbon::AstNode, Carbon::AstNode> {
   using ResultType = typename cast_retty<To, Carbon::AstNode>::ret_type;
-  static ResultType doit(Carbon::AstNode& node) {
+  static auto doit(Carbon::AstNode& node) -> ResultType {
     return dynamic_cast<ResultType>(node);
   }
 };

executable_semantics/ast/ast_test_matchers_internal.cpp

@@ -7,8 +7,7 @@
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/raw_ostream.h"
 
-namespace Carbon {
-namespace TestingInternal {
+namespace Carbon::TestingInternal {
 
 AstNodeMatcherBase::~AstNodeMatcherBase() = default;
 
@@ -210,5 +209,4 @@ void MatchesUnimplementedExpressionMatcher::DescribeToImpl(std::ostream* out,
   children_matcher_.DescribeTo(out);
 }
 
-}  // namespace TestingInternal
-}  // namespace Carbon
+}  // namespace Carbon::TestingInternal

executable_semantics/ast/ast_test_matchers_internal.h

@@ -19,8 +19,7 @@
 #include "executable_semantics/ast/statement.h"
 #include "llvm/Support/Casting.h"
 
-namespace Carbon {
-namespace TestingInternal {
+namespace Carbon::TestingInternal {
 
 // Abstract GoogleMock matcher which matches AstNodes, and is agnostic to
 // whether they are passed by pointer or reference. Derived classes specify what
@@ -28,6 +27,7 @@ namespace TestingInternal {
 // MatchAndExplainImpl.
 class AstNodeMatcherBase {
  public:
+  // NOLINTNEXTLINE(readability-identifier-naming)
   using is_gtest_matcher = void;
 
   virtual ~AstNodeMatcherBase();
@@ -202,6 +202,7 @@ class MatchesUnimplementedExpressionMatcher : public AstNodeMatcherBase {
 // Matches an `AST`.
 class ASTDeclarationsMatcher {
  public:
+  // NOLINTNEXTLINE(readability-identifier-naming)
   using is_gtest_matcher = void;
 
   // Constructs a matcher which matches an `AST` whose `declarations` member
@@ -231,7 +232,6 @@ class ASTDeclarationsMatcher {
   ::testing::Matcher<std::vector<Nonnull<Declaration*>>> declarations_matcher_;
 };
 
-}  // namespace TestingInternal
-}  // namespace Carbon
+}  // namespace Carbon::TestingInternal
 
 #endif  // EXECUTABLE_SEMANTICS_AST_AST_TEST_MATCHERS_INTERNAL_H_

executable_semantics/ast/declaration.h

@@ -107,7 +107,7 @@ struct GenericBinding : public virtual AstNode, public NamedEntity {
 class ReturnTerm {
  public:
   ReturnTerm(const ReturnTerm&) = default;
-  ReturnTerm& operator=(const ReturnTerm&) = default;
+  auto operator=(const ReturnTerm&) -> ReturnTerm& = default;
 
   // Represents an omitted return term at `source_loc`.
   static auto Omitted(SourceLocation source_loc) -> ReturnTerm {

executable_semantics/ast/statement.h

@@ -5,6 +5,7 @@
 #ifndef EXECUTABLE_SEMANTICS_AST_STATEMENT_H_
 #define EXECUTABLE_SEMANTICS_AST_STATEMENT_H_
 
+#include <utility>
 #include <vector>
 
 #include "common/ostream.h"
@@ -45,7 +46,8 @@ class Statement : public virtual AstNode {
 class Block : public Statement {
  public:
   Block(SourceLocation source_loc, std::vector<Nonnull<Statement*>> statements)
-      : AstNode(AstNodeKind::Block, source_loc), statements_(statements) {}
+      : AstNode(AstNodeKind::Block, source_loc),
+        statements_(std::move(statements)) {}
 
   static auto classof(const AstNode* node) -> bool {
     return InheritsFromBlock(node->kind());

executable_semantics/ast/static_scope.h

@@ -18,7 +18,7 @@ namespace Carbon {
 
 class NamedEntity : public virtual AstNode {
  public:
-  virtual ~NamedEntity() = 0;
+  ~NamedEntity() override = 0;
 
   NamedEntity() = default;