Add new removal error field to feature support error message

src/google/protobuf/compiler/command_line_interface_unittest.cc

@@ -1762,8 +1762,9 @@ TEST_F(CommandLineInterfaceTest, Plugin_DeprecatedFeature) {
   Run("protocol_compiler --test_out=$tmpdir "
       "--proto_path=$tmpdir foo.proto");
   ExpectWarningSubstring(
-      "foo.proto:4:5: warning: Feature pb.TestFeatures.removed_feature has "
-      "been deprecated in edition 2023: Custom feature deprecation warning\n");
+      "foo.proto:4:5: warning: pb.TestFeatures.removed_feature has "
+      "been deprecated in edition 2023: Custom feature "
+      "deprecation warning\n");
 }
 
 TEST_F(CommandLineInterfaceTest, Plugin_TransitiveDeprecatedFeature) {
@@ -2031,8 +2032,8 @@ TEST_F(CommandLineInterfaceTest, GeneratorFeatureLifetimeError) {
   Run("protocol_compiler --experimental_editions --proto_path=$tmpdir "
       "--test_out=$tmpdir foo.proto");
   ExpectErrorSubstring(
-      "foo.proto:6:13: Feature pb.TestFeatures.removed_feature has been "
-      "removed in edition 2024");
+      "foo.proto:6:13: pb.TestFeatures.removed_feature has been "
+      "removed in edition 2024:");
 }
 
 TEST_F(CommandLineInterfaceTest, PluginFeatureLifetimeError) {
@@ -2064,8 +2065,8 @@ TEST_F(CommandLineInterfaceTest, PluginFeatureLifetimeError) {
       "foo.proto --plugin=prefix-gen-fake_plugin=",
       plugin_path));
   ExpectErrorSubstring(
-      "foo.proto:6:13: Feature pb.TestFeatures.future_feature wasn't "
-      "introduced until edition 2024");
+      "foo.proto:6:13: pb.TestFeatures.future_feature wasn't introduced "
+      "until edition 2024 and can't be used in edition 2023");
 }
 
 TEST_F(CommandLineInterfaceTest, GeneratorNoEditionsSupport) {

src/google/protobuf/compiler/cpp/generator_unittest.cc

@@ -100,8 +100,8 @@ TEST_F(CppGeneratorTest, LegacyClosedEnum) {
       "protocol_compiler --proto_path=$tmpdir --cpp_out=$tmpdir foo.proto");
 
   ExpectWarningSubstring(
-      "foo.proto:9:16: warning: Feature pb.CppFeatures.legacy_closed_enum has "
-      "been deprecated in edition 2023");
+      "foo.proto:9:16: warning: pb.CppFeatures.legacy_closed_enum has "
+      "been deprecated in edition 2023:");
 }
 
 TEST_F(CppGeneratorTest, LegacyClosedEnumInherited) {
@@ -123,7 +123,7 @@ TEST_F(CppGeneratorTest, LegacyClosedEnumInherited) {
       "protocol_compiler --proto_path=$tmpdir --cpp_out=$tmpdir foo.proto");
 
   ExpectWarningSubstring(
-      "foo.proto: warning: Feature pb.CppFeatures.legacy_closed_enum has "
+      "foo.proto: warning: pb.CppFeatures.legacy_closed_enum has "
       "been deprecated in edition 2023");
 }
 

src/google/protobuf/compiler/java/generator_unittest.cc

@@ -354,7 +354,7 @@ BBB = 1;
       "--experimental_editions");
 
   ExpectErrorSubstring(
-      "foo.proto:6:6: Feature pb.JavaFeatures.large_enum wasn't introduced "
+      "foo.proto:6:6: pb.JavaFeatures.large_enum wasn't introduced "
       "until edition 2024 and can't be used in edition 2023");
 }
 

src/google/protobuf/descriptor_unittest.cc

@@ -12200,7 +12200,7 @@ TEST_F(FeaturesTest, DeprecatedFeature) {
           }
         }
       )pb",
-      "foo.proto: foo.proto: NAME: Feature "
+      "foo.proto: foo.proto: NAME: "
       "pb.TestFeatures.removed_feature has been deprecated in edition 2023: "
       "Custom feature deprecation warning\n");
   const FileDescriptor* file = pool_.FindFileByName("foo.proto");
@@ -12287,9 +12287,9 @@ TEST_F(FeaturesTest, RemovedFeature) {
           }
         }
       )pb",
-      "foo.proto: foo.proto: NAME: Feature "
-      "pb.TestFeatures.removed_feature has been removed in edition 2024 and "
-      "can't be used in edition 2024\n");
+      "foo.proto: foo.proto: NAME: "
+      "pb.TestFeatures.removed_feature has been removed in edition 2024: "
+      "Custom feature removal error\n");
 }
 
 TEST_F(FeaturesTest, RemovedFeatureDefault) {
@@ -12319,9 +12319,9 @@ TEST_F(FeaturesTest, FutureFeature) {
           }
         }
       )pb",
-      "foo.proto: foo.proto: NAME: Feature "
-      "pb.TestFeatures.future_feature wasn't introduced until edition 2024 and "
-      "can't be used in edition 2023\n");
+      "foo.proto: foo.proto: NAME: "
+      "pb.TestFeatures.future_feature wasn't introduced until edition "
+      "2024 and can't be used in edition 2023\n");
 }
 
 TEST_F(FeaturesTest, FutureFeatureDefault) {
@@ -14121,10 +14121,11 @@ TEST_F(DatabaseBackedPoolTest, FeatureLifetimeError) {
   DescriptorPool pool(&database_, &error_collector);
 
   EXPECT_TRUE(pool.FindMessageTypeByName("FooFeatures") == nullptr);
-  EXPECT_EQ(error_collector.text_,
-            "features.proto: FooFeatures: NAME: Feature "
-            "pb.TestFeatures.future_feature wasn't introduced until edition "
-            "2024 and can't be used in edition 2023\n");
+  EXPECT_EQ(
+      error_collector.text_,
+      "features.proto: FooFeatures: NAME: "
+      "pb.TestFeatures.future_feature wasn't introduced until edition 2024 "
+      "and can't be used in edition 2023\n");
 }
 
 TEST_F(DatabaseBackedPoolTest, FeatureLifetimeErrorUnknownDependencies) {
@@ -14193,9 +14194,9 @@ TEST_F(DatabaseBackedPoolTest, FeatureLifetimeErrorUnknownDependencies) {
   error_collector.text_.clear();
   ASSERT_EQ(pool.FindExtensionByName("foo_extension"), nullptr);
   EXPECT_EQ(error_collector.text_,
-            "option.proto: foo_extension: NAME: Feature "
-            "pb.TestFeatures.legacy_feature has been removed in edition 2023 "
-            "and can't be used in edition 2023\n");
+            "option.proto: foo_extension: NAME: "
+            "pb.TestFeatures.legacy_feature has been removed in edition 2023: "
+            "Custom feature removal error\n");
 }
 
 TEST_F(DatabaseBackedPoolTest, DoesntRetryDbUnnecessarily) {

src/google/protobuf/feature_resolver.cc

@@ -26,6 +26,7 @@
 #include "absl/strings/str_join.h"
 #include "absl/strings/str_split.h"
 #include "absl/strings/string_view.h"
+#include "absl/strings/substitute.h"
 #include "absl/types/span.h"
 #include "google/protobuf/cpp_features.pb.h"
 #include "google/protobuf/descriptor.h"
@@ -364,26 +365,36 @@ absl::Status ValidateMergedFeatures(const FeatureSet& features) {
 
 void ValidateSingleFeatureLifetimes(
     Edition edition, absl::string_view full_name,
-    const FieldOptions::FeatureSupport& support,
+    const FieldOptions::FeatureSupport& feature_support,
     FeatureResolver::ValidationResults& results) {
   // Skip fields that don't have feature support specified.
-  if (&support == &FieldOptions::FeatureSupport::default_instance()) return;
-
-  if (edition < support.edition_introduced()) {
-    results.errors.emplace_back(
-        absl::StrCat("Feature ", full_name, " wasn't introduced until edition ",
-                     support.edition_introduced(),
-                     " and can't be used in edition ", edition));
-  }
-  if (support.has_edition_removed() && edition >= support.edition_removed()) {
-    results.errors.emplace_back(absl::StrCat(
-        "Feature ", full_name, " has been removed in edition ",
-        support.edition_removed(), " and can't be used in edition ", edition));
-  } else if (support.has_edition_deprecated() &&
-             edition >= support.edition_deprecated()) {
-    results.warnings.emplace_back(absl::StrCat(
-        "Feature ", full_name, " has been deprecated in edition ",
-        support.edition_deprecated(), ": ", support.deprecation_warning()));
+  if (&feature_support == &FieldOptions::FeatureSupport::default_instance())
+    return;
+  // safe guarding new features that aren't available yet
+  if (edition < feature_support.edition_introduced()) {
+    std::string error_message = absl::Substitute(
+        "$0 wasn't introduced until edition $1 and can't be used in "
+        "edition $2",
+        full_name, feature_support.edition_introduced(), edition);
+    results.errors.emplace_back(std::move(error_message));
+  }
+  if (feature_support.has_edition_removed() &&
+      edition >= feature_support.edition_removed()) {
+    std::string error_message = absl::Substitute(
+        "$0 has been removed in edition $1$2", full_name,
+        feature_support.edition_removed(),
+        (feature_support.has_removal_error())
+            ? absl::StrCat(": ", feature_support.removal_error())
+            : "");
+    results.errors.emplace_back(std::move(error_message));
+  } else if (feature_support.has_edition_deprecated() &&
+             edition >= feature_support.edition_deprecated()) {
+    std::string error_message = absl::Substitute(
+        "$0 has been deprecated in edition "
+        "$1: $2",
+        full_name, feature_support.edition_deprecated(),
+        feature_support.deprecation_warning());
+    results.warnings.emplace_back(std::move(error_message));
   }
 }
 

src/google/protobuf/feature_resolver_test.cc

@@ -634,7 +634,21 @@ TEST(FeatureResolverLifetimesTest, RemovedFeature) {
                                                            features, nullptr);
   EXPECT_THAT(results.errors,
               ElementsAre(AllOf(HasSubstr("pb.TestFeatures.removed_feature"),
-                                HasSubstr("removed in edition 2024"))));
+                                HasSubstr("removed in edition 2024:"),
+                                HasSubstr("Custom feature removal error"))));
+  EXPECT_THAT(results.warnings, IsEmpty());
+}
+
+TEST(FeatureResolverLifetimesTest, RemovedFeatureWithNoRemovalError) {
+  FeatureSet features = ParseTextOrDie(R"pb(
+    [pb.test] { same_edition_removed_feature: VALUE1 }
+  )pb");
+  auto results = FeatureResolver::ValidateFeatureLifetimes(EDITION_2023,
+                                                           features, nullptr);
+  EXPECT_THAT(results.errors,
+              ElementsAre(AllOf(
+                  HasSubstr("pb.TestFeatures.same_edition_removed_feature"),
+                  HasSubstr("removed in edition 2023"), Not(HasSubstr(":")))));
   EXPECT_THAT(results.warnings, IsEmpty());
 }
 
@@ -644,9 +658,11 @@ TEST(FeatureResolverLifetimesTest, NotIntroduced) {
   )pb");
   auto results = FeatureResolver::ValidateFeatureLifetimes(EDITION_2023,
                                                            features, nullptr);
-  EXPECT_THAT(results.errors,
-              ElementsAre(AllOf(HasSubstr("pb.TestFeatures.future_feature"),
-                                HasSubstr("introduced until edition 2024"))));
+  EXPECT_THAT(
+      results.errors,
+      ElementsAre(AllOf(HasSubstr("pb.TestFeatures.future_feature"),
+                        HasSubstr("wasn't introduced until edition 2024"),
+                        HasSubstr("can't be used in edition 2023"))));
   EXPECT_THAT(results.warnings, IsEmpty());
 }
 
@@ -730,7 +746,8 @@ TEST(FeatureResolverLifetimesTest, ValueSupportBeforeIntroduced) {
   EXPECT_THAT(results.errors,
               ElementsAre(AllOf(
                   HasSubstr("pb.VALUE_LIFETIME_FUTURE"),
-                  HasSubstr("introduced until edition 99997_TEST_ONLY"))));
+                  HasSubstr("wasn't introduced until edition 99997_TEST_ONLY"),
+                  HasSubstr("can't be used in edition 2023"))));
   EXPECT_THAT(results.warnings, IsEmpty());
 }
 
@@ -740,10 +757,10 @@ TEST(FeatureResolverLifetimesTest, ValueSupportAfterRemoved) {
   )pb");
   auto results = FeatureResolver::ValidateFeatureLifetimes(
       EDITION_99997_TEST_ONLY, features, nullptr);
-  EXPECT_THAT(
-      results.errors,
-      ElementsAre(AllOf(HasSubstr("pb.VALUE_LIFETIME_REMOVED"),
-                        HasSubstr("removed in edition 99997_TEST_ONLY"))));
+  EXPECT_THAT(results.errors,
+              ElementsAre(AllOf(HasSubstr("pb.VALUE_LIFETIME_REMOVED"),
+                                HasSubstr("removed in edition 99997_TEST_ONLY"),
+                                HasSubstr("Custom feature removal error"))));
   EXPECT_THAT(results.warnings, IsEmpty());
 }
 

src/google/protobuf/unittest_features.proto

@@ -66,6 +66,7 @@ enum ValueLifetimeFeature {
   VALUE_LIFETIME_REMOVED = 6 [feature_support = {
     edition_deprecated: EDITION_2023
     edition_removed: EDITION_99997_TEST_ONLY
+    removal_error: "Custom feature removal error"
   }];
 }
 
@@ -190,12 +191,24 @@ message TestFeatures {
       edition_deprecated: EDITION_2023
       deprecation_warning: "Custom feature deprecation warning"
       edition_removed: EDITION_2024
+      removal_error: "Custom feature removal error"
     },
     edition_defaults = { edition: EDITION_LEGACY, value: "VALUE1" },
     edition_defaults = { edition: EDITION_2023, value: "VALUE2" },
     edition_defaults = { edition: EDITION_2024, value: "VALUE3" }
   ];
 
+  EnumFeature same_edition_removed_feature = 21 [
+    retention = RETENTION_RUNTIME,
+    targets = TARGET_TYPE_FILE,
+    targets = TARGET_TYPE_FIELD,
+    feature_support = {
+      edition_introduced: EDITION_2023
+      edition_removed: EDITION_2023
+    },
+    edition_defaults = { edition: EDITION_LEGACY, value: "VALUE1" }
+  ];
+
   EnumFeature future_feature = 18 [
     retention = RETENTION_RUNTIME,
     targets = TARGET_TYPE_FILE,
@@ -212,6 +225,7 @@ message TestFeatures {
     feature_support = {
       edition_introduced: EDITION_PROTO3
       edition_removed: EDITION_2023
+      removal_error: "Custom feature removal error"
     },
     edition_defaults = { edition: EDITION_LEGACY, value: "VALUE1" },
     edition_defaults = { edition: EDITION_2023, value: "VALUE2" }
@@ -225,6 +239,7 @@ message TestFeatures {
       edition_deprecated: EDITION_99998_TEST_ONLY
       deprecation_warning: "Custom feature deprecation warning"
       edition_removed: EDITION_99999_TEST_ONLY
+      removal_error: "Custom feature removal error"
     },
     edition_defaults = {
       edition: EDITION_LEGACY,