Fix ccache never being invoked on iOS builds

packages/react-native/package.json

@@ -117,8 +117,6 @@
     "scripts/setup-apple-spm.js",
     "scripts/spm",
     "scripts/xcode/asset-catalog.sh",
-    "scripts/xcode/ccache-clang.sh",
-    "scripts/xcode/ccache-clang++.sh",
     "scripts/xcode/ccache.conf",
     "scripts/xcode/with-environment.sh",
     "sdks/.hermesv1version",

packages/react-native/scripts/cocoapods/__tests__/utils-test.rb

@@ -1155,6 +1155,36 @@ def test_add_ndebug_flag_to_pods_in_release
         assert_equal("$(inherited) -DNDEBUG", custom_release_config2.build_settings["OTHER_CPLUSPLUSFLAGS"])
         assert_equal("$(inherited) -DNDEBUG", custom_release_config3.build_settings["OTHER_CPLUSPLUSFLAGS"])
     end
+
+    # ================================ #
+    # Test - ccache launcher script    #
+    # ================================ #
+
+    def test_ccacheLauncherScript_embedsResolvedCcachePath
+        # Act
+        script = ReactNativePodsUtils.ccache_launcher_script("clang", "/opt/homebrew/bin/ccache", "/app/rn/scripts/xcode/ccache.conf")
+
+        # Assert
+        assert_equal('exec "/opt/homebrew/bin/ccache" clang "$@"', script.lines.last.chomp)
+    end
+
+    def test_ccacheLauncherScript_embedsResolvedConfigPath
+        # Act
+        script = ReactNativePodsUtils.ccache_launcher_script("clang", "/opt/homebrew/bin/ccache", "/app/rn/scripts/xcode/ccache.conf")
+
+        # Assert
+        assert(script.include?("REACT_NATIVE_CCACHE_CONFIGPATH=/app/rn/scripts/xcode/ccache.conf"))
+        assert(script.include?('${CCACHE_CONFIGPATH:-$REACT_NATIVE_CCACHE_CONFIGPATH}'))
+    end
+
+    def test_ccacheLauncherScript_forCpp_execsClangpp
+        # Act
+        script = ReactNativePodsUtils.ccache_launcher_script("clang++", "/usr/local/bin/ccache", "/tmp/ccache.conf")
+
+        # Assert
+        assert_equal('exec "/usr/local/bin/ccache" clang++ "$@"', script.lines.last.chomp)
+    end
+
 end
 
 # ===== #

packages/react-native/scripts/cocoapods/utils.rb

@@ -156,6 +156,39 @@ def self.set_build_setting(installer, build_setting:, value:, config_name: nil)
         end
     end
 
+    # Generated rather than shipped: a compiler launcher gets none of Xcode's
+    # environment, so both paths have to be baked in at install time.
+    def self.ccache_launcher_script(compiler, ccache_path, config_path)
+        <<~SH
+            #!/bin/sh
+            # Copyright (c) Meta Platforms, Inc. and affiliates.
+            #
+            # This source code is licensed under the MIT license found in the
+            # LICENSE file in the root directory of this source tree.
+
+            # Generated by pod install. Edit react_native_pods.rb, not this file.
+
+            REACT_NATIVE_CCACHE_CONFIGPATH=#{config_path}
+            # Provide our config file if none is already provided
+            export CCACHE_CONFIGPATH="${CCACHE_CONFIGPATH:-$REACT_NATIVE_CCACHE_CONFIGPATH}"
+
+            exec "#{ccache_path}" #{compiler} "$@"
+        SH
+    end
+
+    def self.generate_ccache_launchers(installer, react_native_path, ccache_path)
+        pods_root = installer.sandbox.root.to_s
+        config_path = File.expand_path(
+            File.join(react_native_path, 'scripts', 'xcode', 'ccache.conf'),
+            Pod::Config.instance.installation_root.to_s
+        )
+        { 'ccache-clang.sh' => 'clang', 'ccache-clang++.sh' => 'clang++' }.each do |name, compiler|
+            path = File.join(pods_root, name)
+            File.write(path, self.ccache_launcher_script(compiler, ccache_path, config_path))
+            File.chmod(0755, path)
+        end
+    end
+
     def self.set_ccache_compiler_and_linker_build_settings(installer, react_native_path, ccache_enabled)
         projects = self.extract_projects(installer)
 
@@ -169,8 +202,8 @@ def self.set_ccache_compiler_and_linker_build_settings(installer, react_native_p
         end
 
         # Using scripts wrapping the ccache executable, to allow injection of configurations
-        ccache_clang_sh = File.join("$(REACT_NATIVE_PATH)", 'scripts', 'xcode', 'ccache-clang.sh')
-        ccache_clangpp_sh = File.join("$(REACT_NATIVE_PATH)", 'scripts', 'xcode', 'ccache-clang++.sh')
+        ccache_clang_sh = File.join("$(PODS_ROOT)", 'ccache-clang.sh')
+        ccache_clangpp_sh = File.join("$(PODS_ROOT)", 'ccache-clang++.sh')
 
         if ccache_available and ccache_enabled
             Pod::UI.puts("#{message_prefix}: Setting CC, LD, CXX & LDPLUSPLUS build settings")
@@ -182,11 +215,12 @@ def self.set_ccache_compiler_and_linker_build_settings(installer, react_native_p
                     config.build_settings["LD"] = ccache_clang_sh
                     config.build_settings["CXX"] = ccache_clangpp_sh
                     config.build_settings["LDPLUSPLUS"] = ccache_clangpp_sh
-                    config.build_settings["CCACHE_BINARY"] = ccache_path
                 end
 
                 project.save()
             end
+
+            self.generate_ccache_launchers(installer, react_native_path, ccache_path)
         elsif ccache_available and !ccache_enabled
             Pod::UI.puts("#{message_prefix}: Pass ':ccache_enabled => true' to 'react_native_post_install' in your Podfile or set environment variable 'USE_CCACHE=1' to increase the speed of subsequent builds")
         elsif !ccache_available and ccache_enabled