From ed3d48040b1ea680a1569cef13d2fd24fe0acb0a Mon Sep 17 00:00:00 2001
From: Mikhail Novosyolov <m.novosyolov@rosalinux.ru>
Date: Mon, 27 Jul 2020 16:53:12 +0300
Subject: [PATCH] Add ccache switch, useful for local rebuilds

---
 kernel.spec | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/kernel.spec b/kernel.spec
index 2692d3f..ae7c481 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -85,6 +85,8 @@
 %bcond_with binary_extra_modules
 %endif
 
+%bcond_with ccache
+
 # Kernel flavour
 %if %{with nickel}
 %define flavour		nickel
@@ -175,11 +177,13 @@
 %define debug_package 		%{nil}
 %endif
 
-%if %(if [ -z "$CC" ] ; then echo 0; else echo 1; fi)
-%define kmake %make CC="$CC"
+# http://nickdesaulniers.github.io/blog/2018/06/02/speeding-up-linux-kernel-builds-with-ccache/
+%if %{with ccache}
+%define kmake KBUILD_BUILD_TIMESTAMP='' %make CC='ccache gcc'
 %else
-%define kmake %make
+%define kmake %make CC='gcc'
 %endif
+
 # there are places where parallel make don't work
 %define smake make
 
@@ -338,6 +342,10 @@ BuildRequires: kernel-source-virtualbox
 BuildRequires: kernel-source-virtualbox-vboxadditions
 %endif
 
+%if %{with ccache}
+BuildRequires: ccache
+%endif
+
 # might be useful too:
 Recommends:		microcode