From 026982244c45177fc251c4d670d4463d7cb879d6 Mon Sep 17 00:00:00 2001
From: BevapDin <Tho_Ki@gmx.de>
Date: Tue, 31 Dec 2019 02:00:47 +0100
Subject: [PATCH 1/2] Fix building with ccache.

When building with ccache enabled, it removes the comments before passing them to the compiler. So the `/* fallthrough */` comment that prevents certain warnings is removed as well.

Adding the `-C` switch prevents that removal and the comments remains and the warning from the compiler does not appear.
---
 Makefile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 5de0d18afdd6a..fbe226cfb1243 100644
--- a/Makefile
+++ b/Makefile
@@ -209,7 +209,7 @@ ifdef CLANG
     LDFLAGS += -stdlib=libc++
   endif
   ifdef CCACHE
-    CXX = CCACHE_CPP2=1 ccache $(CROSS)$(CLANGCMD)
+    CXX = CCACHE_CPP2=1 ccache $(CROSS)$(CLANGCMD) -C
     LD  = CCACHE_CPP2=1 ccache $(CROSS)$(CLANGCMD)
   else
     CXX = $(CROSS)$(CLANGCMD)
@@ -227,7 +227,7 @@ else
   # Appears that the default value of $LD is unsuitable on most systems
   OS_LINKER := $(CXX)
   ifdef CCACHE
-    CXX = ccache $(CROSS)$(OS_COMPILER)
+    CXX = ccache $(CROSS)$(OS_COMPILER) -C
     LD  = ccache $(CROSS)$(OS_LINKER)
   else
     CXX = $(CROSS)$(OS_COMPILER)

From 44c66e86c1c72eb7f1dd6a3cd173f1ba6087d896 Mon Sep 17 00:00:00 2001
From: BevapDin <Tho_Ki@gmx.de>
Date: Tue, 31 Dec 2019 02:22:51 +0100
Subject: [PATCH 2/2] Fix exporting comments through ccache in a different way:

This instructs ccache directly. The former version relied on gcc to interpret the "-C" flag, but clang apparently does not understand it.
---
 Makefile | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index fbe226cfb1243..a99c7e495562e 100644
--- a/Makefile
+++ b/Makefile
@@ -101,6 +101,9 @@ DEBUGSYMS = -g
 #OTHERS = -O3
 #DEFINES = -DNDEBUG
 
+# Tells ccache to keep comments, as they can be meaningful to the compiler (as to suppress warnings).
+export CCACHE_COMMENTS=1
+
 # Disable debug. Comment this out to get logging.
 #DEFINES = -DENABLE_LOGGING
 
@@ -209,7 +212,7 @@ ifdef CLANG
     LDFLAGS += -stdlib=libc++
   endif
   ifdef CCACHE
-    CXX = CCACHE_CPP2=1 ccache $(CROSS)$(CLANGCMD) -C
+    CXX = CCACHE_CPP2=1 ccache $(CROSS)$(CLANGCMD)
     LD  = CCACHE_CPP2=1 ccache $(CROSS)$(CLANGCMD)
   else
     CXX = $(CROSS)$(CLANGCMD)
@@ -227,7 +230,7 @@ else
   # Appears that the default value of $LD is unsuitable on most systems
   OS_LINKER := $(CXX)
   ifdef CCACHE
-    CXX = ccache $(CROSS)$(OS_COMPILER) -C
+    CXX = ccache $(CROSS)$(OS_COMPILER)
     LD  = ccache $(CROSS)$(OS_LINKER)
   else
     CXX = $(CROSS)$(OS_COMPILER)