message: Makefile.rules: Upstream SDKROOT handling code for Darwin.
diff: @@ -166,6 +166,17 @@ ifeq "$(CC)" "cc"
  endif
  endif
  +#----------------------------------------------------------------------
  +# Handle SDKROOT on Darwin
  +#----------------------------------------------------------------------
  +
  +ifeq "$(OS)" "Darwin"
  + ifeq "$(SDKROOT)" ""
  + # We haven't otherwise set the SDKROOT, so set it now to macosx
  + SDKROOT := $(shell xcrun --sdk macosx --show-sdk-path)
  + endif
  +endif
  +
  #----------------------------------------------------------------------
  # ARCHFLAG is the flag used to tell the compiler which architecture
  # to compile for. The default is the flag that clang accepts.
  @@ -248,6 +259,13 @@ endif
  DEBUG_INFO_FLAG ?= -g
  CFLAGS ?= $(DEBUG_INFO_FLAG) -O0 -fno-builtin
  +
  +ifeq "$(OS)" "Darwin"
  + ifneq "$(SDKROOT)" ""
  + CFLAGS += -isysroot "$(SDKROOT)"
  + endif
  +endif
  +
  ifeq "$(OS)" "Darwin"
  CFLAGS += $(ARCHFLAG) $(ARCH) $(FRAMEWORK_INCLUDES) -I$(LLDB_BASE_DIR)include
  else
  