8 files changed, 62 insertions, 11 deletions
diff --git a/tools/build/Build b/tools/build/Build
index 63a6c34c0c88..76d1a4960973 100644
--- a/tools/build/Build
+++ b/tools/build/Build
@@ -1 +1,3 @@
+hostprogs := fixdep
+
 fixdep-y := fixdep.o
diff --git a/tools/build/Build.include b/tools/build/Build.include
index 4d000bc959b4..1dcb95e76f70 100644
--- a/tools/build/Build.include
+++ b/tools/build/Build.include
@@ -90,3 +90,9 @@ if_changed = $(if $(strip $(any-prereq) $(arg-check)),             \
 # - per object C flags
 # - BUILD_STR macro to allow '-D"$(variable)"' constructs
 c_flags = -Wp,-MD,$(depfile),-MT,$@ $(CFLAGS) -D"BUILD_STR(s)=\#s" $(CFLAGS_$(basetarget).o) $(CFLAGS_$(obj))
+cxx_flags = -Wp,-MD,$(depfile),-MT,$@ $(CXXFLAGS) -D"BUILD_STR(s)=\#s" $(CXXFLAGS_$(basetarget).o) $(CXXFLAGS_$(obj))
+
+###
+## HOSTCC C flags
+
+host_c_flags = -Wp,-MD,$(depfile),-MT,$@ $(CHOSTFLAGS) -D"BUILD_STR(s)=\#s" $(CHOSTFLAGS_$(basetarget).o) $(CHOSTFLAGS_$(obj))
diff --git a/tools/build/Makefile b/tools/build/Makefile
index 0d5a0e3a8fa9..8332959fbca4 100644
--- a/tools/build/Makefile
+++ b/tools/build/Makefile
@@ -14,6 +14,12 @@ endef
 $(call allow-override,CC,$(CROSS_COMPILE)gcc)
 $(call allow-override,LD,$(CROSS_COMPILE)ld)
 
+HOSTCC ?= gcc
+HOSTLD ?= ld
+HOSTAR ?= ar
+
+export HOSTCC HOSTLD HOSTAR
+
 ifeq ($(V),1)
   Q =
 else
@@ -36,7 +42,7 @@ $(OUTPUT)fixdep-in.o: FORCE
 	$(Q)$(MAKE) $(build)=fixdep
 
 $(OUTPUT)fixdep: $(OUTPUT)fixdep-in.o
-	$(QUIET_LINK)$(CC) $(LDFLAGS) -o $@ $<
+	$(QUIET_LINK)$(HOSTCC) $(LDFLAGS) -o $@ $<
 
 FORCE:
 
diff --git a/tools/build/Makefile.build b/tools/build/Makefile.build
index 27f3583193e6..99c0ccd2f176 100644
--- a/tools/build/Makefile.build
+++ b/tools/build/Makefile.build
@@ -58,6 +58,12 @@ quiet_cmd_mkdir = MKDIR    $(dir $@)
 quiet_cmd_cc_o_c = CC       $@
       cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
 
+quiet_cmd_host_cc_o_c = HOSTCC   $@
+      cmd_host_cc_o_c = $(HOSTCC) $(host_c_flags) -c -o $@ $<
+
+quiet_cmd_cxx_o_c = CXX      $@
+      cmd_cxx_o_c = $(CXX) $(cxx_flags) -c -o $@ $<
+
 quiet_cmd_cpp_i_c = CPP      $@
       cmd_cpp_i_c = $(CC) $(c_flags) -E -o $@ $<
 
@@ -70,16 +76,28 @@ quiet_cmd_gen = GEN      $@
 # If there's nothing to link, create empty $@ object.
 quiet_cmd_ld_multi = LD       $@
       cmd_ld_multi = $(if $(strip $(obj-y)),\
-		       $(LD) -r -o $@  $(filter $(obj-y),$^),rm -f $@; $(AR) rcs $@)
+                     $(LD) -r -o $@  $(filter $(obj-y),$^),rm -f $@; $(AR) rcs $@)
+
+quiet_cmd_host_ld_multi = HOSTLD   $@
+      cmd_host_ld_multi = $(if $(strip $(obj-y)),\
+                          $(HOSTLD) -r -o $@  $(filter $(obj-y),$^),rm -f $@; $(HOSTAR) rcs $@)
+
+ifneq ($(filter $(obj),$(hostprogs)),)
+  host = host_
+endif
 
 # Build rules
 $(OUTPUT)%.o: %.c FORCE
 	$(call rule_mkdir)
-	$(call if_changed_dep,cc_o_c)
+	$(call if_changed_dep,$(host)cc_o_c)
+
+$(OUTPUT)%.o: %.cpp FORCE
+	$(call rule_mkdir)
+	$(call if_changed_dep,cxx_o_c)
 
 $(OUTPUT)%.o: %.S FORCE
 	$(call rule_mkdir)
-	$(call if_changed_dep,cc_o_c)
+	$(call if_changed_dep,$(host)cc_o_c)
 
 $(OUTPUT)%.i: %.c FORCE
 	$(call rule_mkdir)
@@ -119,7 +137,7 @@ $(sort $(subdir-obj-y)): $(subdir-y) ;
 
 $(in-target): $(obj-y) FORCE
 	$(call rule_mkdir)
-	$(call if_changed,ld_multi)
+	$(call if_changed,$(host)ld_multi)
 
 __build: $(in-target)
 	@:
diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
index a120c6b755a9..ae52e029dd22 100644
--- a/tools/build/Makefile.feature
+++ b/tools/build/Makefile.feature
@@ -7,7 +7,7 @@ endif
 
 feature_check = $(eval $(feature_check_code))
 define feature_check_code
-  feature-$(1) := $(shell $(MAKE) OUTPUT=$(OUTPUT_FEATURES) CFLAGS="$(EXTRA_CFLAGS) $(FEATURE_CHECK_CFLAGS-$(1))" LDFLAGS="$(LDFLAGS) $(FEATURE_CHECK_LDFLAGS-$(1))" -C $(feature_dir) $(OUTPUT_FEATURES)test-$1.bin >/dev/null 2>/dev/null && echo 1 || echo 0)
+  feature-$(1) := $(shell $(MAKE) OUTPUT=$(OUTPUT_FEATURES) CFLAGS="$(EXTRA_CFLAGS) $(FEATURE_CHECK_CFLAGS-$(1))" CXXFLAGS="$(EXTRA_CXXFLAGS) $(FEATURE_CHECK_CXXFLAGS-$(1))" LDFLAGS="$(LDFLAGS) $(FEATURE_CHECK_LDFLAGS-$(1))" -C $(feature_dir) $(OUTPUT_FEATURES)test-$1.bin >/dev/null 2>/dev/null && echo 1 || echo 0)
 endef
 
 feature_set = $(eval $(feature_set_code))
diff --git a/tools/build/Makefile.include b/tools/build/Makefile.include
index be630bed66d2..ad22e4e7bc59 100644
--- a/tools/build/Makefile.include
+++ b/tools/build/Makefile.include
@@ -1,10 +1,6 @@
 build := -f $(srctree)/tools/build/Makefile.build dir=. obj
 
-ifdef CROSS_COMPILE
-fixdep:
-else
 fixdep:
 	$(Q)$(MAKE) -C $(srctree)/tools/build CFLAGS= LDFLAGS= $(OUTPUT)fixdep
-endif
 
 .PHONY: fixdep
diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index a0b29a311816..ac9c477a2a48 100644
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -46,11 +46,13 @@ FILES=					\
 	test-lzma.bin			\
 	test-bpf.bin			\
 	test-get_cpuid.bin		\
-	test-sdt.bin
+	test-sdt.bin			\
+	test-cxx.bin
 
 FILES := $(addprefix $(OUTPUT),$(FILES))
 
 CC := $(CROSS_COMPILE)gcc -MD
+CXX := $(CROSS_COMPILE)g++ -MD
 PKG_CONFIG := $(CROSS_COMPILE)pkg-config
 
 all: $(FILES)
@@ -58,6 +60,9 @@ all: $(FILES)
 __BUILD = $(CC) $(CFLAGS) -Wall -Werror -o $@ $(patsubst %.bin,%.c,$(@F)) $(LDFLAGS)
   BUILD = $(__BUILD) > $(@:.bin=.make.output) 2>&1
 
+__BUILDXX = $(CXX) $(CXXFLAGS) -Wall -Werror -o $@ $(patsubst %.bin,%.cpp,$(@F)) $(LDFLAGS)
+  BUILDXX = $(__BUILDXX) > $(@:.bin=.make.output) 2>&1
+
 ###############################
 
 $(OUTPUT)test-all.bin:
@@ -217,6 +222,9 @@ $(OUTPUT)test-bpf.bin:
 $(OUTPUT)test-sdt.bin:
 	$(BUILD)
 
+$(OUTPUT)test-cxx.bin:
+	$(BUILDXX) -std=gnu++11
+
 -include $(OUTPUT)*.d
 
 ###############################
diff --git a/tools/build/feature/test-cxx.cpp b/tools/build/feature/test-cxx.cpp
new file mode 100644
index 000000000000..b1dee9a31d6c
--- /dev/null
+++ b/tools/build/feature/test-cxx.cpp
@@ -0,0 +1,15 @@
+#include <iostream>
+#include <memory>
+
+static void print_str(std::string s)
+{
+	std::cout << s << std::endl;
+}
+
+int main()
+{
+	std::string s("Hello World!");
+	print_str(std::move(s));
+	std::cout << "|" << s << "|" << std::endl;
+	return 0;
+}