From 814a7c3a219c74fde3e8dbec8a948091e7cad408 Mon Sep 17 00:00:00 2001
From: Martine Lenders <m.lenders@fu-berlin.de>
Date: Tue, 7 Aug 2018 16:22:49 +0200
Subject: [PATCH] Makefile.include: add output for unsupported toolchains

Assuming `TOOLCHAIN_SUPPORTED` is provided by the board and
`TOOLCHAIN_BLACKLIST` by a module or `pkg`, this outputs the fact that
a toolchain is not supported or blacklisted in a similar manner as
(un-)supported features and boards are.
---
 Makefile.include | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/Makefile.include b/Makefile.include
index 137ad480bc..a03d563252 100644
--- a/Makefile.include
+++ b/Makefile.include
@@ -245,6 +245,9 @@ include $(RIOTBOARD)/$(BOARD)/Makefile.include
 INCLUDES += -I$(RIOTCPU)/$(CPU)/include
 include $(RIOTCPU)/$(CPU)/Makefile.include
 
+# Assume GCC/GNU as supported toolchain if CPU's Makefile.include doesn't
+# provide this macro
+TOOLCHAINS_SUPPORTED ?= gnu
 # Import all toolchain settings
 include $(RIOTMAKE)/toolchain/$(TOOLCHAIN).inc.mk
 
@@ -592,6 +595,20 @@ ifneq (, $(filter all, $(if $(MAKECMDGOALS), $(MAKECMDGOALS), all)))
     endif
   endif
 
+  #  test if toolchain is supported.
+  ifeq (,$(filter $(TOOLCHAIN),$(TOOLCHAINS_SUPPORTED)))
+    $(shell $(COLOR_ECHO) "$(COLOR_RED)The selected TOOLCHAIN=$(TOOLCHAIN) is not supported.$(COLOR_RESET)\nSupported toolchains: $(TOOLCHAINS_SUPPORTED)" 1>&2)
+    EXPECT_ERRORS := 1
+  endif
+
+  # If there is a blacklist, then test if the board is blacklisted.
+  ifneq (,$(TOOLCHAINS_BLACKLIST))
+    ifneq (,$(filter $(TOOLCHAIN),$(TOOLCHAINS_BLACKLIST)))
+      $(shell $(COLOR_ECHO) "$(COLOR_RED)The selected TOOLCHAIN=$(TOOLCHAIN) is blacklisted:$(COLOR_RESET) $(TOOLCHAINS_BLACKLIST)" 1>&2)
+      EXPECT_ERRORS := 1
+    endif
+  endif
+
   ifneq (, $(EXPECT_CONFLICT))
     $(shell $(COLOR_ECHO) "\n$(COLOR_YELLOW)EXPECT undesired behaviour!$(COLOR_RESET)" 1>&2)
   endif