From 1652e5ae2497eb031fb0a4650ddca38f3f9c7234 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Joakim=20Nohlg=C3=A5rd?= <joakim.nohlgard@eistec.se>
Date: Sun, 12 Aug 2018 08:53:43 +0200
Subject: [PATCH 1/3] sht1x: Fix Wimplicit-fallthrough warning

---
 drivers/sht1x/sht1x_saul.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/sht1x/sht1x_saul.c b/drivers/sht1x/sht1x_saul.c
index 7c0abd9255..50c52eea90 100644
--- a/drivers/sht1x/sht1x_saul.c
+++ b/drivers/sht1x/sht1x_saul.c
@@ -41,6 +41,7 @@ static int read(const sht1x_dev_t *dev, int16_t *temp, int16_t *hum)
                 continue;
             case -ECANCELED:
                 puts("[sht1x] Measurement times out");
+                /* falls through */
             default:
                 /* Other failure, cannot recover so giving up */
                 return -1;

From 9e5dd332cf166025aacaf958c10f1b03f64d7154 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Joakim=20Nohlg=C3=A5rd?= <joakim.nohlgard@eistec.se>
Date: Sun, 12 Aug 2018 00:26:52 +0200
Subject: [PATCH 2/3] Makefile.include: Set CCACHE_CPP2 to fix false warnings

---
 Makefile.include | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Makefile.include b/Makefile.include
index 137ad480bc..aa34309140 100644
--- a/Makefile.include
+++ b/Makefile.include
@@ -248,6 +248,16 @@ include $(RIOTCPU)/$(CPU)/Makefile.include
 # Import all toolchain settings
 include $(RIOTMAKE)/toolchain/$(TOOLCHAIN).inc.mk
 
+# Tell ccache to pass the original file to the compiler, instead of passing the
+# preprocessed code. Without this setting, the compilation will fail with
+# -Wimplicit-fallthrough warnings even when the fall through case is properly
+# commented because the preprocessor has stripped the comments from the code.
+# This also fixes some other false warnings when compiling with LLVM/Clang.
+# The environment variable only affects builds with ccache (e.g. on CI/Murdock).
+# Non cached builds are not affected in any way.
+# For more information, see http://petereisentraut.blogspot.com/2011/09/ccache-and-clang-part-2.html
+export CCACHE_CPP2=yes
+
 # get number of interfaces straight before resolving dependencies
 GNRC_NETIF_NUMOF ?= 1
 

From dda55731ff59169addb919982ef5646fc373d541 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Joakim=20Nohlg=C3=A5rd?= <joakim.nohlgard@eistec.se>
Date: Fri, 15 Jun 2018 01:11:26 +0200
Subject: [PATCH 3/3] Makefile.include: Remove -Wno-implicit-fallthrough

---
 Makefile.include | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/Makefile.include b/Makefile.include
index aa34309140..35edb0c0e9 100644
--- a/Makefile.include
+++ b/Makefile.include
@@ -141,10 +141,6 @@ ifeq ($(WPEDANTIC),1)
   CFLAGS += -Wpedantic
 endif
 
-# remove this once codebase is adapted
-CFLAGS += -Wno-implicit-fallthrough
-CXXFLAGS += -Wno-implicit-fallthrough
-
 ifneq (10,$(if $(RIOT_VERSION),1,0)$(if $(__RIOTBUILD_FLAG),1,0))
 
 # Provide a shallow sanity check. You cannot call `make` in a module directory.