From d24feacae0ad9f8a896a494e43a4ecd0b2262175 Mon Sep 17 00:00:00 2001
From: Jason Rhinelander <jason@imaginary.ca>
Date: Wed, 10 Jun 2020 13:34:02 -0300
Subject: [PATCH] Modernize how we set up ccache

CMAKE_<LANG>_COMPILER_LAUNCHER was added around cmake 3.4 and, usefully,
can be enabled/disabled via cmake invocation flags (unlike the older
RULE_LAUNCH_COMPILE property).
---
 CMakeLists.txt | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9e3c3d25a..9182dada0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,7 +5,12 @@ set(CMAKE_OSX_DEPLOYMENT_TARGET 10.13 CACHE STRING "macOS deployment target (App
 
 find_program(CCACHE_PROGRAM ccache)
 if(CCACHE_PROGRAM)
-  set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE "${CCACHE_PROGRAM}")
+  foreach(lang C CXX)
+    if(NOT DEFINED CMAKE_${lang}_COMPILER_LAUNCHER AND NOT CMAKE_${lang}_COMPILER MATCHES ".*/ccache")
+      message(STATUS "Enabling ccache for ${lang}")
+      set(CMAKE_${lang}_COMPILER_LAUNCHER ${CCACHE_PROGRAM} CACHE STRING "")
+    endif()
+  endforeach()
 endif()
 
 set(PROJECT_NAME lokinet)