Enable color output from gcc and clang

Force gcc and clang to always output color diagnostics.  Ninja will
strip the ANSI color codes if it is not running in a terminal.

Bug: 24273983
Change-Id: Ic9252549bfacf3bbb3f4b9d20f63010fc24ac21d

core/clang/config.mk

@@ -47,6 +47,11 @@ CLANG_CONFIG_EXTRA_CFLAGS += \
 CLANG_CONFIG_EXTRA_CPPFLAGS += \
   -Wno-inconsistent-missing-override
 
+# Force clang to always output color diagnostics.  Ninja will strip the ANSI
+# color codes if it is not running in a terminal.
+CLANG_CONFIG_EXTRA_CFLAGS += \
+  -fcolor-diagnostics
+
 CLANG_CONFIG_UNKNOWN_CFLAGS := \
   -finline-functions \
   -finline-limit=64 \
@@ -70,7 +75,8 @@ CLANG_CONFIG_UNKNOWN_CFLAGS := \
   -Wno-unused-but-set-variable \
   -Wno-unused-local-typedefs \
   -Wunused-but-set-parameter \
-  -Wunused-but-set-variable
+  -Wunused-but-set-variable \
+  -fdiagnostics-color
 
 # Clang flags for all host rules
 CLANG_CONFIG_HOST_EXTRA_ASFLAGS :=

core/config.mk

@@ -120,6 +120,10 @@ hide := $(if $(SHOW_COMMANDS),,@)
 COMMON_GLOBAL_CFLAGS:= -DANDROID -fmessage-length=0 -W -Wall -Wno-unused -Winit-self -Wpointer-arith
 COMMON_RELEASE_CFLAGS:= -DNDEBUG -UDEBUG
 
+# Force gcc to always output color diagnostics.  Ninja will strip the ANSI
+# color codes if it is not running in a terminal.
+COMMON_GLOBAL_CFLAGS += -fdiagnostics-color
+
 COMMON_GLOBAL_CPPFLAGS:= -Wsign-promo
 COMMON_RELEASE_CPPFLAGS:=