From 55de2a914c5b9f2af02a32f90d6dad909d6d0599 Mon Sep 17 00:00:00 2001
From: Brentley Jones <github@brentleyjones.com>
Date: Mon, 19 Aug 2024 14:42:56 -0500
Subject: [PATCH] Filter environment variables when building with Bazel

In order for Xcode builds to work with custom environment variables you need to use `xcodeproj.bazel_env`. This just takes the extra step of filtering out all other environment variables, ensuring more analysis cache hits. You can already do this in your own `tools/bazel`, but now people can get the benefit regardless.

This change is needed for shared outputs bases to be performant.

Signed-off-by: Brentley Jones <github@brentleyjones.com>
---
 xcodeproj/internal/templates/bazel_build.sh | 17 ++++++++++++++++-
 xcodeproj/internal/templates/runner.sh      | 17 ++++++++++++++++-
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/xcodeproj/internal/templates/bazel_build.sh b/xcodeproj/internal/templates/bazel_build.sh
index 6fc791abf0..3b1d062b5e 100755
--- a/xcodeproj/internal/templates/bazel_build.sh
+++ b/xcodeproj/internal/templates/bazel_build.sh
@@ -68,8 +68,23 @@ if [[ -s "$BAZEL_INTEGRATION_DIR/xcodeproj_extra_flags.bazelrc" ]]; then
 fi
 readonly bazelrcs
 
+readonly allowed_vars=(
+  "BUILD_WORKSPACE_DIRECTORY"
+  "DEVELOPER_DIR"
+  "HOME"
+  "TERM"
+  "USER"
+)
+passthrough_env=()
+for var in "${allowed_vars[@]}"; do
+  if [[ -n "${!var:-}" ]]; then
+    passthrough_env+=("$var=${!var}")
+  fi
+done
+
 readonly bazel_cmd=(
-  env
+  env -i
+  "${passthrough_env[@]}"
 %bazel_env%
   "%bazel_path%"
 
diff --git a/xcodeproj/internal/templates/runner.sh b/xcodeproj/internal/templates/runner.sh
index bee862b9d2..bc1dc35ada 100644
--- a/xcodeproj/internal/templates/runner.sh
+++ b/xcodeproj/internal/templates/runner.sh
@@ -178,8 +178,23 @@ common:rules_xcodeproj --repo_env=USE_CLANG_CL=%xcode_version%
 common:rules_xcodeproj --repo_env=XCODE_VERSION=%xcode_version%
 EOF
 
+readonly allowed_vars=(
+  "BUILD_WORKSPACE_DIRECTORY"
+  "HOME"
+  "TERM"
+  "USER"
+)
+passthrough_env=()
+for var in "${allowed_vars[@]}"; do
+  if [[ -n "${!var:-}" ]]; then
+    passthrough_env+=("$var=${!var}")
+  fi
+done
+
 bazel_cmd=(
-  env
+  env -i
+  "DEVELOPER_DIR=$developer_dir"
+  "${passthrough_env[@]}"
   "${envs[@]}"
   "$bazel_path"