!43 支持使用内置clang工具链

Merge pull request !43 from Caoruihong/ohos_clang

build/BUILD.gn

@@ -50,7 +50,7 @@ if (!defined(board_configed_sysroot) || board_configed_sysroot == "") {
         arch_cflags = string_join(" ", target_arch_cflags)
         command = "make TOPDIR=$ohos_root_path SYSROOTDIR=$sysroot_path TARGETS=$targets -f $makefile"
         command += " ARCH=$arch TARGET=$target_triple ARCH_CFLAGS=\"$arch_cflags\""
-        command += " BUILD_DEBUG=false BUILD_ALL_MULTILIB=false"
+        command += " BUILD_DEBUG=false BUILD_ALL_MULTILIB=false CLANG=$ohos_current_cc_command"
 
         # copy standard libraries libc.so and libc++.so to lib out dir
         libcpp = "\$($ohos_current_cxx_command --target=$target_triple --sysroot=$sysroot_path $arch_cflags -print-file-name=libc++.so)"

build/Makefile

@@ -29,8 +29,9 @@
 
 ARCH = arm
 TARGET = $(ARCH)-liteos
-CROSS_COMPILE = llvm-
-CC = clang --target=$(TARGET) $(ARCH_CFLAGS)
+CLANG ?= clang
+CROSS_COMPILE = $(CLANG:%clang=%)llvm-
+CC = $(CLANG) --target=$(TARGET) $(ARCH_CFLAGS)
 MULTILIB = $(patsubst $(shell $(CC) -print-file-name=)%/,%,$(dir $(shell $(CC) -print-libgcc-file-name)))
 MUSLBUILDDIR = build_$(ARCH)$(subst $(eval) ,,$(patsubst -%,_%,$(sort $(ARCH_CFLAGS))))
 HIDE = @