format: add checks for type alias

tools/code_format/check_format.py

@@ -168,8 +168,56 @@
   "extensions/filters/network/common",
   "extensions/filters/network/common/redis",
 }
+
+NON_TYPE_ALIAS_ALLOWED_TYPES = {
+  "void",
+  "bool",
+  "short",
+  "short int",
+  "signed short",
+  "signed short int",
+  "unsigned short",
+  "unsigned short int",
+  "int",
+  "signed",
+  "signed int",
+  "unsigned",
+  "unsigned int",
+  "long",
+  "long int",
+  "signed long",
+  "signed long int",
+  "unsigned long",
+  "unsigned long int",
+  "long long",
+  "long long int",
+  "signed long long",
+  "signed long long int",
+  "unsigned long long",
+  "unsigned long long int",
+  "int8_t",
+  "int16_t",
+  "int32_t",
+  "int64_t",
+  "uint8_t",
+  "uint16_t",
+  "uint32_t",
+  "uint64_t",
+  "signed char",
+  "unsigned char",
+  "char",
+  "wchar_t",
+  "char16_t",
+  "char32_t",
+  "std::string",
+  "float",
+  "double",
+  "long double",  
+}
 # yapf: enable
 
+NON_TYPE_ALIAS_ALLOWED_TYPE = re.compile(fr"(.*\[\]$|^std::vector<.*|{'|'.join(NON_TYPE_ALIAS_ALLOWED_TYPES)}$)")
+
 
 # Map a line transformation function across each line of a file,
 # writing the result lines as requested.
@@ -352,6 +400,9 @@ def whitelistedForUnpackTo(file_path):
       "./source/common/protobuf/utility.cc", "./source/common/protobuf/utility.h"
   ]
 
+def whitelistedForNonTypeAlias(name):
+  return NON_TYPE_ALIAS_ALLOWED_TYPE.match(name)
+
 
 def findSubstringAndReturnError(pattern, file_path, error_message):
   text = readFile(file_path)
@@ -696,6 +747,17 @@ def checkSourceLine(line, file_path, reportError):
         reportError("Don't call grpc_init() or grpc_shutdown() directly, instantiate " +
                     "Grpc::GoogleGrpcContext. See #8282")
 
+  if not re.search("using .* = .*;", line):
+    smart_ptr_m = re.finditer("std::(unique_ptr|shared_ptr)<(.*?)>", line)
+    for m in smart_ptr_m:
+      if not whitelistedForNonTypeAlias(m.group(2)):
+        reportError(f"Use type alias for '{m.group(2)}' instead. See STYLE.md")
+
+    optional_m = re.finditer("absl::optional<std::reference_wrapper<(.*?)>>", line)
+    for m in optional_m:
+      if not whitelistedForNonTypeAlias(m.group(1)):
+        reportError(f"Use type alias for '{m.group(1)}' instead. See STYLE.md")
+
 
 def checkBuildLine(line, file_path, reportError):
   if "@bazel_tools" in line and not (isSkylarkFile(file_path) or file_path.startswith("./bazel/") or

tools/code_format/check_format_test_helper.py

@@ -216,6 +216,11 @@ def runChecks():
       "grpc_shutdown.cc",
       "Don't call grpc_init() or grpc_shutdown() directly, instantiate Grpc::GoogleGrpcContext. " +
       "See #8282")
+  errors += checkUnfixableError("non_type_alias_smart_ptr.cc",
+                                "Use type alias for 'Network::Connection' instead. See STYLE.md")
+  errors += checkUnfixableError(
+      "non_type_alias_optional.cc",
+      "Use type alias for 'ConnectionHandlerImpl::ActiveTcpListener' instead. See STYLE.md")
   errors += checkUnfixableError("clang_format_double_off.cc", "clang-format nested off")
   errors += checkUnfixableError("clang_format_trailing_off.cc", "clang-format remains off")
   errors += checkUnfixableError("clang_format_double_on.cc", "clang-format nested on")
@@ -271,6 +276,8 @@ def runChecks():
   errors += checkFileExpectingOK("real_time_source_override.cc")
   errors += checkFileExpectingOK("time_system_wait_for.cc")
   errors += checkFileExpectingOK("clang_format_off.cc")
+  errors += checkFileExpectingOK("using_type_alias.cc")
+  errors += checkFileExpectingOK("non_type_alias_allowed_type.cc")
   return errors
 
 

tools/testdata/check_format/cpp_std.cc

@@ -4,7 +4,7 @@
 
 namespace Envoy {
 
-std::unique_ptr<int> to_be_fix = absl::make_unique<int>(0);
+auto to_be_fix = absl::make_unique<int>(0);
 
 // Awesome stuff goes here.
 

tools/testdata/check_format/cpp_std.cc.gold

@@ -4,7 +4,7 @@
 
 namespace Envoy {
 
-std::unique_ptr<int> to_be_fix = std::make_unique<int>(0);
+auto to_be_fix = std::make_unique<int>(0);
 
 // Awesome stuff goes here.
 

tools/testdata/check_format/non_type_alias_allowed_type.cc

@@ -0,0 +1,11 @@
+#include <memory>
+#include <string>
+#include <vector>
+
+namespace Envoy {
+
+void a(std::unique_ptr<int>, std::shared_ptr<std::string>,
+       absl::optional<std::reference_wrapper<char[]>>,
+       absl::optional<std::reference_wrapper<std::vector<int>>>) {}
+
+} // namespace Envoy

tools/testdata/check_format/non_type_alias_optional.cc

@@ -0,0 +1,11 @@
+#include <memory>
+
+#include "server/connection_handler_impl.h"
+
+namespace Envoy {
+
+absl::optional<std::reference_wrapper<ConnectionHandlerImpl::ActiveTcpListener>> a() {
+  return nullptr;
+}
+
+} // namespace Envoy

tools/testdata/check_format/non_type_alias_smart_ptr.cc

@@ -0,0 +1,9 @@
+#include <memory>
+
+#include "envoy/network/connection.h"
+
+namespace Envoy {
+
+std::unique_ptr<Network::Connection> a() { return nullptr; }
+
+} // namespace Envoy

tools/testdata/check_format/using_type_alias.cc

@@ -0,0 +1,14 @@
+#include <memory>
+
+namespace Envoy {
+namespace Network {
+class Connection;
+
+using ConnectionPtr = std::unique_ptr<Connection>;
+
+class A {
+  using ConnectionSharedPtr = std::shared_ptr<Connection>;
+  using ConnectionOptRef = absl::optional<std::reference_wrapper<Connection>>;
+};
+} // namespace Network
+} // namespace Envoy