From eb36f3e038ff334b54cd4ba8f140ccaf3a1357a4 Mon Sep 17 00:00:00 2001
From: Per Lundberg <perlun@gmail.com>
Date: Wed, 9 Dec 2020 22:58:37 +0200
Subject: [PATCH] Fixes to make the --fatal_warnings flag work with current
 master

---
 .../compiler/command_line_interface.cc        |  4 ++++
 .../command_line_interface_unittest.cc        | 22 ++++++++++++++-----
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/src/google/protobuf/compiler/command_line_interface.cc b/src/google/protobuf/compiler/command_line_interface.cc
index 7b66f01103e3..b0b2963d2dcd 100644
--- a/src/google/protobuf/compiler/command_line_interface.cc
+++ b/src/google/protobuf/compiler/command_line_interface.cc
@@ -2054,6 +2054,10 @@ Parse PROTO_FILES and generate output based on the options given:
   --error_format=FORMAT       Set the format in which to print errors.
                               FORMAT may be 'gcc' (the default) or 'msvs'
                               (Microsoft Visual Studio format).
+  --fatal_warnings            Make warnings be fatal (similar to -Werr in
+                              gcc). This flag will make protoc return
+                              with a non-zero exit code if any warnings
+                              are generated.
   --print_free_field_numbers  Print the free field numbers of the messages
                               defined in the given proto files. Groups share
                               the same field number space with the parent
diff --git a/src/google/protobuf/compiler/command_line_interface_unittest.cc b/src/google/protobuf/compiler/command_line_interface_unittest.cc
index a0e79874adfb..effab542f5b5 100644
--- a/src/google/protobuf/compiler/command_line_interface_unittest.cc
+++ b/src/google/protobuf/compiler/command_line_interface_unittest.cc
@@ -160,6 +160,11 @@ class CommandLineInterfaceTest : public testing::Test {
   void ExpectCapturedStdoutSubstringWithZeroReturnCode(
       const std::string& expected_substring);
 
+  // Checks that Run() returned zero and the stderr contains the given
+  // substring.
+  void ExpectCapturedStderrSubstringWithZeroReturnCode(
+      const std::string& expected_substring);
+
 #if defined(_WIN32) && !defined(__CYGWIN__)
   // Returns true if ExpectErrorSubstring(expected_substring) would pass, but
   // does not fail otherwise.
@@ -522,6 +527,13 @@ void CommandLineInterfaceTest::ExpectCapturedStdoutSubstringWithZeroReturnCode(
                       captured_stdout_);
 }
 
+void CommandLineInterfaceTest::ExpectCapturedStderrSubstringWithZeroReturnCode(
+    const std::string& expected_substring) {
+  EXPECT_EQ(0, return_code_);
+  EXPECT_PRED_FORMAT2(testing::IsSubstring, expected_substring,
+                      error_text_);
+}
+
 void CommandLineInterfaceTest::ExpectFileContent(const std::string& filename,
                                                  const std::string& content) {
   std::string path = temp_directory_ + "/" + filename;
@@ -2310,7 +2322,7 @@ TEST_F(CommandLineInterfaceTest, MsvsFormatErrors) {
 }
 
 TEST_F(CommandLineInterfaceTest, InvalidErrorFormat) {
-  // Test --error_format=msvs
+  // Test implicit (default) --error_format
 
   CreateTempFile("foo.proto",
                  "syntax = \"proto2\";\n"
@@ -2318,7 +2330,7 @@ TEST_F(CommandLineInterfaceTest, InvalidErrorFormat) {
 
   Run("protocol_compiler --test_out=$tmpdir --proto_path=$tmpdir foo.proto");
 
-  ExpectErrorText("Unknown error format: invalid\n");
+  ExpectErrorText("foo.proto:2:1: Expected top-level statement (e.g. \"message\").\n");
 }
 
 TEST_F(CommandLineInterfaceTest, Warnings) {
@@ -2333,13 +2345,13 @@ TEST_F(CommandLineInterfaceTest, Warnings) {
   Run("protocol_compiler --test_out=$tmpdir "
     "--proto_path=$tmpdir foo.proto");
   ExpectReturnCode(0);
-  ExpectErrorSubstringWithZeroReturnCode(
-    "foo.proto: warning: Import bar.proto but not used.");
+  ExpectCapturedStderrSubstringWithZeroReturnCode(
+    "foo.proto:2:1: warning: Import bar.proto is unused.");
 
   Run("protocol_compiler --test_out=$tmpdir --fatal_warnings "
     "--proto_path=$tmpdir foo.proto");
   ExpectErrorSubstring(
-    "foo.proto: warning: Import bar.proto but not used.");
+    "foo.proto:2:1: warning: Import bar.proto is unused.");
 }
 
 // -------------------------------------------------------------------