From aaaf67f9c39aaa22e642f6d1ff6b957cef8e162a Mon Sep 17 00:00:00 2001
From: Daniel Agar <daniel@agar.ca>
Date: Sat, 30 Jun 2018 14:35:58 -0400
Subject: [PATCH] cmake don't automatically enable ccache if already enabled

---
 CMakeLists.txt | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index adb3fe8ce1..fecbb749ed 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -231,7 +231,18 @@ endforeach()
 option(CCACHE "Use ccache if available" ON)
 find_program(CCACHE_PROGRAM ccache)
 if (CCACHE AND CCACHE_PROGRAM AND NOT DEFINED ENV{CCACHE_DISABLE})
-	set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE "${CCACHE_PROGRAM}")
+
+	get_filename_component(ccache_real_path ${CCACHE_PROGRAM} REALPATH)
+	get_filename_component(cxx_real_path ${CMAKE_CXX_COMPILER} REALPATH)
+	get_filename_component(cxx_abs_path ${CMAKE_CXX_COMPILER} ABSOLUTE)
+
+	if ("${ccache_real_path}" STREQUAL "${cxx_real_path}")
+		message(STATUS "ccache enabled via symlink (${cxx_abs_path} -> ${cxx_real_path})")
+	else()
+		message(STATUS "ccache enabled (export CCACHE_DISABLE=1 to disable)")
+		set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE "${CCACHE_PROGRAM}")
+	endif()
+
 endif()
 
 #=============================================================================