From 2e82a2d7bf380eb3e83a20ab506e7546f96a4e01 Mon Sep 17 00:00:00 2001
From: Adam Cozzette <acozzette@google.com>
Date: Fri, 11 Oct 2024 09:33:21 -0700
Subject: [PATCH] Reduce our reliance on COPTS variable for compiler flags

It's somewhat tedious to explicitly set this option on all of our C++ targets,
so I think ideally we should rely primarily on bazelrc files for setting
compiler flags. I tried to completely remove `COPTS`, but unfortunately that
did not work out--we have so many `-Wsign-compare` warnings that I think we
need to keep suppressing them for now or else we will get a lot of complaints.

However, I was able to get to the point where `-Wno-sign-compare` is the only
flag we need in `COPTS` for non-Windows builds. I explicitly set `-DHAVE_ZLIB`
on just the two targets that need it, and removed `-Wno-nonnull` since we are
already compliant with that warning. I moved `-Woverloaded-virtual` to our
bazelrc files so that CI will enforce that we remain compliant with that.

PiperOrigin-RevId: 684863987
---
 build_defs/cpp_opts.bzl            |  3 ---
 ci/Linux.bazelrc                   |  1 +
 ci/macOS.bazelrc                   |  3 ++-
 src/google/protobuf/io/BUILD.bazel | 10 ++++++++--
 4 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/build_defs/cpp_opts.bzl b/build_defs/cpp_opts.bzl
index d8646d1681..f46b7dcc0a 100644
--- a/build_defs/cpp_opts.bzl
+++ b/build_defs/cpp_opts.bzl
@@ -17,10 +17,7 @@ COPTS = select({
         "/wd4996",  # The compiler encountered a deprecated declaration.
     ],
     "//conditions:default": [
-        "-DHAVE_ZLIB",
-        "-Woverloaded-virtual",
         "-Wno-sign-compare",
-        "-Wno-nonnull",
     ],
 })
 
diff --git a/ci/Linux.bazelrc b/ci/Linux.bazelrc
index b4ec98f8c7..3cdf40d218 100644
--- a/ci/Linux.bazelrc
+++ b/ci/Linux.bazelrc
@@ -1,4 +1,5 @@
 import common.bazelrc
 
 build --cxxopt=-std=c++14 --host_cxxopt=-std=c++14
+build --cxxopt="-Woverloaded-virtual"
 build --copt="-Werror" --copt="-Wno-sign-compare" --copt="-Wno-sign-conversion" --copt="-Wno-error=sign-conversion" --copt="-Wno-deprecated-declarations"
diff --git a/ci/macOS.bazelrc b/ci/macOS.bazelrc
index e426b59f57..e91f62639a 100644
--- a/ci/macOS.bazelrc
+++ b/ci/macOS.bazelrc
@@ -1,6 +1,7 @@
 import common.bazelrc
 
 build --cxxopt=-std=c++14 --host_cxxopt=-std=c++14
+build --cxxopt="-Woverloaded-virtual"
 build --copt="-Werror" --copt="-Wno-sign-compare" --copt="-Wno-sign-conversion" --copt="-Wno-error=sign-conversion" --copt="-Wno-deprecated-declarations"
 common --repo_env=BAZEL_NO_APPLE_CPP_TOOLCHAIN=1
-common --xcode_version_config=@com_google_protobuf//.github:host_xcodes
\ No newline at end of file
+common --xcode_version_config=@com_google_protobuf//.github:host_xcodes
diff --git a/src/google/protobuf/io/BUILD.bazel b/src/google/protobuf/io/BUILD.bazel
index 27c4444801..eb865df566 100644
--- a/src/google/protobuf/io/BUILD.bazel
+++ b/src/google/protobuf/io/BUILD.bazel
@@ -150,7 +150,10 @@ cc_library(
     name = "gzip_stream",
     srcs = ["gzip_stream.cc"],
     hdrs = ["gzip_stream.h"],
-    copts = COPTS,
+    copts = COPTS + select({
+        "//build_defs:config_msvc": [],
+        "//conditions:default": ["-DHAVE_ZLIB"],
+    }),
     strip_include_prefix = "/src",
     deps = [
         ":io",
@@ -192,7 +195,10 @@ cc_test(
         "tokenizer_unittest.cc",
         "zero_copy_stream_unittest.cc",
     ],
-    copts = COPTS,
+    copts = COPTS + select({
+        "//build_defs:config_msvc": [],
+        "//conditions:default": ["-DHAVE_ZLIB"],
+    }),
     deps = [
         ":gzip_stream",
         ":io",