configure: initial support for CXX, CXXFLAGS variables

Use CXX rather than assuming g++ to invoke the compiler. Also introduce
separate CXXFLAGS, as certain CFLAGS we enable by default cause warnings
with g++.

Change-Id: Ia2f40ef27c93e45c971d070cc58bdcde9da2ac7c

build/make/Makefile

@@ -66,6 +66,7 @@ endif
 BUILD_ROOT?=.
 VPATH=$(SRC_PATH_BARE)
 CFLAGS+=-I$(BUILD_PFX)$(BUILD_ROOT) -I$(SRC_PATH)
+CXXFLAGS+=-I$(BUILD_PFX)$(BUILD_ROOT) -I$(SRC_PATH)
 ASFLAGS+=-I$(BUILD_PFX)$(BUILD_ROOT)/ -I$(SRC_PATH)/
 DIST_DIR?=dist
 HOSTCC?=gcc
@@ -111,11 +112,11 @@ $(BUILD_PFX)%.c.o: %.c
 $(BUILD_PFX)%.cc.d: %.cc
 	$(if $(quiet),@echo "    [DEP] $@")
 	$(qexec)mkdir -p $(dir $@)
-	$(qexec)g++ $(INTERNAL_CFLAGS) $(CFLAGS) -M $< | $(fmt_deps) > $@
+	$(qexec)$(CXX) $(INTERNAL_CFLAGS) $(CXXFLAGS) -M $< | $(fmt_deps) > $@
 
 $(BUILD_PFX)%.cc.o: %.cc
 	$(if $(quiet),@echo "    [CXX] $@")
-	$(qexec)g++ $(INTERNAL_CFLAGS) $(CFLAGS) -c -o $@ $<
+	$(qexec)$(CXX) $(INTERNAL_CFLAGS) $(CXXFLAGS) -c -o $@ $<
 
 $(BUILD_PFX)%.asm.d: %.asm
 	$(if $(quiet),@echo "    [DEP] $@")
@@ -213,7 +214,7 @@ define linkerxx_template
 $(1): $(filter-out -%,$(2))
 $(1):
 	$(if $(quiet),@echo    "    [LD] $$@")
-	$(qexec)g++ $$(strip $$(INTERNAL_LDFLAGS) $$(LDFLAGS) -o $$@ $(2) $(3) $$(extralibs))
+	$(qexec)$$(CXX) $$(strip $$(INTERNAL_LDFLAGS) $$(LDFLAGS) -o $$@ $(2) $(3) $$(extralibs))
 endef
 # make-3.80 has a bug with expanding large input strings to the eval function,
 # which was triggered in some cases by the following component of

build/make/configure.sh

@@ -166,6 +166,17 @@ is_in(){
 
 add_cflags() {
     CFLAGS="${CFLAGS} $@"
+    CXXFLAGS="${CXXFLAGS} $@"
+}
+
+
+add_cflags_only() {
+    CFLAGS="${CFLAGS} $@"
+}
+
+
+add_cxxflags_only() {
+    CXXFLAGS="${CXXFLAGS} $@"
 }
 
 
@@ -277,6 +288,13 @@ check_cc() {
     check_cmd ${CC} ${CFLAGS} "$@" -c -o ${TMP_O} ${TMP_C}
 }
 
+check_cxx() {
+    log check_cxx "$@"
+    cat >${TMP_C}
+    log_file ${TMP_C}
+    check_cmd ${CXX} ${CXXFLAGS} "$@" -c -o ${TMP_O} ${TMP_C}
+}
+
 check_cpp() {
     log check_cpp "$@"
     cat > ${TMP_C}
@@ -310,8 +328,25 @@ int x;
 EOF
 }
 
+check_cxxflags() {
+    log check_cxxflags "$@"
+
+    # Catch CFLAGS that trigger CXX warnings
+    case "$CXX" in
+      *g++*) check_cxx -Werror "$@" <<EOF
+int x;
+EOF
+      ;;
+      *) check_cxx "$@" <<EOF
+int x;
+EOF
+      ;;
+    esac
+}
+
 check_add_cflags() {
-    check_cflags "$@" && add_cflags "$@"
+    check_cxxflags "$@" && add_cxxflags_only "$@"
+    check_cflags "$@" && add_cflags_only "$@"
 }
 
 check_add_asflags() {
@@ -367,7 +402,9 @@ true
 
 write_common_target_config_mk() {
     local CC=${CC}
+    local CXX=${CXX}
     enabled ccache && CC="ccache ${CC}"
+    enabled ccache && CXX="ccache ${CXX}"
     print_webm_license $1 "##" ""
 
     cat >> $1 << EOF
@@ -379,6 +416,7 @@ TOOLCHAIN=${toolchain}
 ASM_CONVERSION=${asm_conversion_cmd:-${source_path}/build/make/ads2gas.pl}
 
 CC=${CC}
+CXX=${CXX}
 AR=${AR}
 LD=${LD}
 AS=${AS}
@@ -386,6 +424,7 @@ STRIP=${STRIP}
 NM=${NM}
 
 CFLAGS  = ${CFLAGS}
+CXXFLAGS  = ${CXXFLAGS}
 ARFLAGS = -rus\$(if \$(quiet),c,v)
 LDFLAGS = ${LDFLAGS}
 ASFLAGS = ${ASFLAGS}
@@ -538,6 +577,7 @@ post_process_cmdline() {
 
 setup_gnu_toolchain() {
         CC=${CC:-${CROSS}gcc}
+        CXX=${CXX:-${CROSS}g++}
         AR=${AR:-${CROSS}ar}
         LD=${LD:-${CROSS}${link_with_cc:-ld}}
         AS=${AS:-${CROSS}as}
@@ -792,6 +832,7 @@ process_common_toolchain() {
                                -name "arm-linux-androideabi-gcc*" -print -quit`
             TOOLCHAIN_PATH=${COMPILER_LOCATION%/*}/arm-linux-androideabi-
             CC=${TOOLCHAIN_PATH}gcc
+            CXX=${TOOLCHAIN_PATH}g++
             AR=${TOOLCHAIN_PATH}ar
             LD=${TOOLCHAIN_PATH}gcc
             AS=${TOOLCHAIN_PATH}as
@@ -827,6 +868,7 @@ process_common_toolchain() {
                 SDK_PATH=${sdk_path}
             fi
             TOOLCHAIN_PATH=${SDK_PATH}/usr/bin
+            CXX=${TOOLCHAIN_PATH}/g++
             CC=${TOOLCHAIN_PATH}/gcc
             AR=${TOOLCHAIN_PATH}/ar
             LD=${TOOLCHAIN_PATH}/arm-apple-darwin10-llvm-gcc-4.2
@@ -938,6 +980,7 @@ process_common_toolchain() {
                 ;;
             solaris*)
                 CC=${CC:-${CROSS}gcc}
+                CXX=${CXX:-${CROSS}g++}
                 LD=${LD:-${CROSS}gcc}
                 CROSS=${CROSS:-g}
                 ;;

libs.mk

@@ -397,8 +397,8 @@ else
 include $(SRC_PATH_BARE)/third_party/googletest/gtest.mk
 GTEST_SRCS := $(addprefix third_party/googletest/src/,$(call enabled,GTEST_SRCS))
 GTEST_OBJS=$(call objs,$(GTEST_SRCS))
-$(GTEST_OBJS) $(GTEST_OBJS:.o=.d): CFLAGS += -I$(SRC_PATH_BARE)/third_party/googletest/src
-$(GTEST_OBJS) $(GTEST_OBJS:.o=.d): CFLAGS += -I$(SRC_PATH_BARE)/third_party/googletest/src/include
+$(GTEST_OBJS) $(GTEST_OBJS:.o=.d): CXXFLAGS += -I$(SRC_PATH_BARE)/third_party/googletest/src
+$(GTEST_OBJS) $(GTEST_OBJS:.o=.d): CXXFLAGS += -I$(SRC_PATH_BARE)/third_party/googletest/src/include
 OBJS-$(BUILD_LIBVPX) += $(GTEST_OBJS)
 LIBS-$(BUILD_LIBVPX) += $(BUILD_PFX)libgtest.a $(BUILD_PFX)libgtest_g.a
 $(BUILD_PFX)libgtest_g.a: $(GTEST_OBJS)