Fix compilation on Fedora 34 (GCC 11.1.1)

Compiling quick-lint-js on Fedora 34 fails with the following error:

    ../vendor/googletest/googletest/src/gtest-death-test.cc: In function 'bool testing::internal::StackGrowsDown()':
    ../vendor/googletest/googletest/src/gtest-death-test.cc:1301:24: error: 'dummy' may be used uninitialized [-Werror=maybe-uninitialized]
     1301 |   StackLowerThanAddress(&dummy, &result);
          |   ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
    ../vendor/googletest/googletest/src/gtest-death-test.cc:1290:13: note: by argument 1 of type 'const void*' to 'void testing::internal::StackLowerThanAddress(const void*, bool*)' declared here
     1290 | static void StackLowerThanAddress(const void* ptr, bool* result) {
          |             ^~~~~~~~~~~~~~~~~~~~~
    ../vendor/googletest/googletest/src/gtest-death-test.cc:1299:7: note: 'dummy' declared here
     1299 |   int dummy;
          |       ^~~~~

Turn this error into a warning by disabling -Werror.

Author: strager

.github/workflows/build-and-test-dev.yml

@@ -19,6 +19,7 @@ jobs:
           - {docker_container: "centos:centos8", name: "CentOS 8", install_dependencies_script: "dnf --enablerepo=powertools install -y cmake gcc-c++ ninja-build", extra_environment: ""}
           - {docker_container: "debian:buster", name: "Debian 10 Buster", install_dependencies_script: "apt-get update && apt-get install -y cmake g++ ninja-build", extra_environment: ""}
           - {docker_container: "fedora:32", name: "Fedora 32", install_dependencies_script: "dnf install -y cmake gcc-c++ ninja-build", extra_environment: ""}
+          - {docker_container: "fedora:34", name: "Fedora 34", install_dependencies_script: "dnf install -y cmake gcc-c++ ninja-build", extra_environment: ""}
           - {docker_container: "ubuntu:18.04", name: "Ubuntu 18.04 LTS Bionic", install_dependencies_script: "apt-get update && apt-get install -y cmake g++-8 ninja-build", extra_environment: "CC=gcc-8 CXX=g++-8"}
           - {docker_container: "ubuntu:20.04", name: "Ubuntu 20.04 LTS Focal", install_dependencies_script: "apt-get update && apt-get install -y cmake g++ ninja-build", extra_environment: ""}
     runs-on: ubuntu-latest

vendor/README.txt

@@ -52,6 +52,7 @@ applications, and Google Mock, its companion mocking framework.
 The following patches have been manually applied:
 
 * googletest-result-of.patch
+* googletest-werror.patch
 
 Copyright: Copyright 2008, Google Inc.
 Download URL: https://github.com/google/googletest/archive/release-1.10.0.tar.gz

vendor/googletest-werror.patch

@@ -0,0 +1,35 @@
+googletest adds the -Werror compiler flag, which breaks compilation with newer
+compiler versions. Remove the flag to work around the following diagnostic from
+GCC 11.1.1 on Fedora 34:
+
+    ../vendor/googletest/googletest/src/gtest-death-test.cc: In function 'bool testing::internal::StackGrowsDown()':
+    ../vendor/googletest/googletest/src/gtest-death-test.cc:1301:24: error: 'dummy' may be used uninitialized [-Werror=maybe-uninitialized]
+     1301 |   StackLowerThanAddress(&dummy, &result);
+          |   ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
+    ../vendor/googletest/googletest/src/gtest-death-test.cc:1290:13: note: by argument 1 of type 'const void*' to 'void testing::internal::StackLowerThanAddress(const void*, bool*)' declared here
+     1290 | static void StackLowerThanAddress(const void* ptr, bool* result) {
+          |             ^~~~~~~~~~~~~~~~~~~~~
+    ../vendor/googletest/googletest/src/gtest-death-test.cc:1299:7: note: 'dummy' declared here
+     1299 |   int dummy;
+          |       ^~~~~
+
+diff --git a/vendor/googletest/googletest/cmake/internal_utils.cmake b/vendor/googletest/googletest/cmake/internal_utils.cmake
+index 2f70f0b0..36cbecb1 100644
+--- a/googletest/cmake/internal_utils.cmake
++++ b/googletest/cmake/internal_utils.cmake
+@@ -82,13 +82,13 @@ macro(config_compiler_and_linker)
+     # http://stackoverflow.com/questions/3232669 explains the issue.
+     set(cxx_base_flags "${cxx_base_flags} -wd4702")
+   elseif (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+-    set(cxx_base_flags "-Wall -Wshadow -Werror -Wconversion")
++    set(cxx_base_flags "-Wall -Wshadow -Wconversion")
+     set(cxx_exception_flags "-fexceptions")
+     set(cxx_no_exception_flags "-fno-exceptions")
+     set(cxx_strict_flags "-W -Wpointer-arith -Wreturn-type -Wcast-qual -Wwrite-strings -Wswitch -Wunused-parameter -Wcast-align -Wchar-subscripts -Winline -Wredundant-decls")
+     set(cxx_no_rtti_flags "-fno-rtti")
+   elseif (CMAKE_COMPILER_IS_GNUCXX)
+-    set(cxx_base_flags "-Wall -Wshadow -Werror")
++    set(cxx_base_flags "-Wall -Wshadow")
+     if(NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 7.0.0)
+       set(cxx_base_flags "${cxx_base_flags} -Wno-error=dangling-else")
+     endif()

vendor/googletest/googletest/cmake/internal_utils.cmake

@@ -82,13 +82,13 @@ macro(config_compiler_and_linker)
     # http://stackoverflow.com/questions/3232669 explains the issue.
     set(cxx_base_flags "${cxx_base_flags} -wd4702")
   elseif (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
-    set(cxx_base_flags "-Wall -Wshadow -Werror -Wconversion")
+    set(cxx_base_flags "-Wall -Wshadow -Wconversion")
     set(cxx_exception_flags "-fexceptions")
     set(cxx_no_exception_flags "-fno-exceptions")
     set(cxx_strict_flags "-W -Wpointer-arith -Wreturn-type -Wcast-qual -Wwrite-strings -Wswitch -Wunused-parameter -Wcast-align -Wchar-subscripts -Winline -Wredundant-decls")
     set(cxx_no_rtti_flags "-fno-rtti")
   elseif (CMAKE_COMPILER_IS_GNUCXX)
-    set(cxx_base_flags "-Wall -Wshadow -Werror")
+    set(cxx_base_flags "-Wall -Wshadow")
     if(NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 7.0.0)
       set(cxx_base_flags "${cxx_base_flags} -Wno-error=dangling-else")
     endif()