From ffba4032560f7c2e12329950ebd47041ffaaebf1 Mon Sep 17 00:00:00 2001
From: Jan Lindemann <jan@janware.com>
Date: Thu, 3 Mar 2016 13:21:47 +0000
Subject: [PATCH] defs.mk.in: Add support for redefining CC and CPP from the
 environment

.. most notably to clang and clang++, respectively

Signed-off-by: Jan Lindemann <jan@janware.com>
---
 make/defs.mk | 28 ++++++++++++++++++++++------
 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/make/defs.mk b/make/defs.mk
index 039041e7..347f8911 100644
--- a/make/defs.mk
+++ b/make/defs.mk
@@ -235,6 +235,8 @@ ifeq ($(TARGET),mingw)
  endif
 GCC                   ?= $(CROSS_TOOL_BIN_PREFIX)gcc
 GPP                   ?= $(CROSS_TOOL_BIN_PREFIX)g++
+CLANG                 ?= $(CROSS_TOOL_BIN_PREFIX)clang
+CLANGPP               ?= $(CROSS_TOOL_BIN_PREFIX)clang++
 STRIP                 ?= $(CROSS_TOOL_BIN_PREFIX)strip
 RANLIB                ?= $(CROSS_TOOL_BIN_PREFIX)ranlib
 AR                    ?= $(CROSS_TOOL_BIN_PREFIX)ar
@@ -246,6 +248,8 @@ LD                     = $(GPP)
 else
 GCC                   ?= gcc
 GPP                   ?= g++
+CLANG                 ?= clang
+CLANGPP               ?= clang++
 STRIP                 ?= strip
 LD                     = $(GPP)
 RANLIB                ?= ranlib
@@ -761,8 +765,10 @@ ifeq ($(USE_GFILTER),true)
 	endif
 endif
 
+ifeq "$(origin CC)" "default"
 CC                     = $(GCC)
 CPP                    = $(GPP)
+endif
 
 PROJECTLIB_LDFLAGS  += -L$(TOPDIR)/lib
 
@@ -895,15 +901,25 @@ ifeq ($(USE_COMPILER_DEBUG_OPTS),true)
 	BUILD_LDFLAGS     += -gdwarf-2 -g3 -ggdb
 endif
 
+ifeq ($(CC),$(GCC))
+	GCC_NO_OPT_FLAGS = \
+		-fno-inline-functions-called-once \
+		-fno-tree-loop-optimize \
+		-fno-early-inlining
+else
+  ifeq ($(CC),$(CLANG))
+	BUILD_CFLAGS      += -Werror
+	BUILD_CPPFLAGS    += -Werror
+  endif
+endif
+
 ifeq ($(USE_COMPILER_OPTIMIZATION_OPTS),true)
 	BUILD_CFLAGS      += -funroll-loops -O2
 	BUILD_CPPFLAGS    += -funroll-loops -O2
 else
 	NO_OPT_FLAGS = \
 		-O0 -g -fno-inline -fno-omit-frame-pointer -fno-builtin -fno-optimize-sibling-calls \
-		-fno-inline-functions-called-once \
-		-fno-tree-loop-optimize \
-		-fno-early-inlining
+		$(GCC_NO_OPT_FLAGS)
 
 #		-fconserve-stack
 
@@ -915,10 +931,10 @@ else
 		-fno-inline \
 		-finline-limit=0 \
 		-fkeep-inline-functions \
-		-fno-inline-functions-called-once \
 		-fno-inline-functions \
-		-fno-early-inlining
-	BUILD_CFLAGS+= $(NO_OPT_FLAGS)
+		$(GCC_NO_OPT_FLAGS)
+
+	BUILD_CFLAGS      += $(NO_OPT_FLAGS)
 	BUILD_CPPFLAGS    += $(NO_OPT_FLAGS)
 	BUILD_LDFLAGS     += $(NO_OPT_FLAGS)
 endif