From 095a29a4a05b193a9900d36f338ba2abb4b90a91 Mon Sep 17 00:00:00 2001
From: Dan Crosby <dan@danielcrosby.net>
Date: Fri, 26 Jun 2026 07:28:26 -0700
Subject: [PATCH] Centralize Shardok C++ standard settings (#8197)

---
 .bazelrc                            |  1 +
 scripts/check_shardok_clang_tidy.sh |  3 ++-
 scripts/run-clang-tidy.sh           |  3 ++-
 scripts/shardok_cpp_config.sh       |  5 +++++
 tools/copts.bzl                     | 12 +++++++++++-
 5 files changed, 21 insertions(+), 3 deletions(-)
 create mode 100644 scripts/shardok_cpp_config.sh

diff --git a/.bazelrc b/.bazelrc
index ce416fa8a5..7aecde2e7f 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -14,6 +14,7 @@ common --worker_sandboxing
 common --local_test_jobs=64
 common --jobs=64
 
+# Keep these C++ standard flags in sync with tools/copts.bzl and scripts/shardok_cpp_config.sh.
 common --cxxopt="--std=c++23"
 common --cxxopt="-Wno-deprecated-non-prototype"
 common --per_file_copt=src/test/cpp/.*@-Wno-character-conversion
diff --git a/scripts/check_shardok_clang_tidy.sh b/scripts/check_shardok_clang_tidy.sh
index b61069495b..60bfb55682 100755
--- a/scripts/check_shardok_clang_tidy.sh
+++ b/scripts/check_shardok_clang_tidy.sh
@@ -7,6 +7,7 @@
 set -euo pipefail
 
 repo_root="$(git rev-parse --show-toplevel)"
+source "$repo_root/scripts/shardok_cpp_config.sh"
 
 files=(
     "src/main/cpp/net/eagle0/shardok/library/ActionCost.hpp"
@@ -15,7 +16,7 @@ files=(
 
 compiler_args=(
     "-I$repo_root"
-    "-std=c++23"
+    "$SHARDOK_CXX_STANDARD_ARG"
 )
 
 if command -v xcrun >/dev/null 2>&1; then
diff --git a/scripts/run-clang-tidy.sh b/scripts/run-clang-tidy.sh
index fb1bbab509..932cd1131a 100755
--- a/scripts/run-clang-tidy.sh
+++ b/scripts/run-clang-tidy.sh
@@ -10,13 +10,14 @@ set -e
 export PATH="/opt/homebrew/bin:/usr/local/bin:$PATH"
 
 repo_root="$(git rev-parse --show-toplevel)"
+source "$repo_root/scripts/shardok_cpp_config.sh"
 
 if [ "$#" -eq 0 ]; then
     echo "Usage: scripts/run-clang-tidy.sh [clang-tidy args] <files> [-- <compiler args>]"
     echo ""
     echo "Examples:"
     echo "  scripts/run-clang-tidy.sh --verify-config"
-    echo "  scripts/run-clang-tidy.sh src/main/cpp/net/eagle0/shardok/library/CombatDamage.hpp -- -I$repo_root -std=c++23"
+    echo "  scripts/run-clang-tidy.sh src/main/cpp/net/eagle0/shardok/library/CombatDamage.hpp -- -I$repo_root $SHARDOK_CXX_STANDARD_ARG"
     exit 2
 fi
 
diff --git a/scripts/shardok_cpp_config.sh b/scripts/shardok_cpp_config.sh
new file mode 100644
index 0000000000..2e589a7df9
--- /dev/null
+++ b/scripts/shardok_cpp_config.sh
@@ -0,0 +1,5 @@
+#!/bin/bash
+# Shared C++ settings for shell scripts that invoke Shardok tooling outside Bazel.
+
+SHARDOK_CXX_STANDARD="c++23"
+SHARDOK_CXX_STANDARD_ARG="-std=${SHARDOK_CXX_STANDARD}"
diff --git a/tools/copts.bzl b/tools/copts.bzl
index 633183fd1a..46826d7435 100644
--- a/tools/copts.bzl
+++ b/tools/copts.bzl
@@ -1,4 +1,14 @@
 # Suppress -Wdeprecated-copy-with-dtor after -Wdeprecated due to protobuf 32.x warning
-COPTS = ["--std=c++23", "-Werror", "-Wall", "-Wextra", "-Wdeprecated", "-Wno-deprecated-copy-with-dtor"]
+CXX_STANDARD = "c++23"
+CXX_STANDARD_COPT = "--std=" + CXX_STANDARD
+
+COPTS = [
+    CXX_STANDARD_COPT,
+    "-Werror",
+    "-Wall",
+    "-Wextra",
+    "-Wdeprecated",
+    "-Wno-deprecated-copy-with-dtor",
+]
 
 TEST_COPTS = COPTS + ["-Iexternal/gtest/include"]